Time of grazing effects on stream channel stability instream sediment loads
by Thomas Martin Pogacnik
A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in
Range Science
Montana State University
© Copyright by Thomas Martin Pogacnik (1985)
Abstract:
A study was conducted during the 1981 and 1982 summer grazing seasons to determine the effects of
time of livestock grazing on stream channel stability and suspended sediment concentrations for
Cottonwood Creek, a small watershed located on the Red Bluff Research Ranch in southwest Montana.
Eight pastures were grazed in succession for 14 days each from June 14 through October 4, with a
ninth pasture remaining ungrazed as a control. Stream channel stability, soil moisture, stream flow, and
suspended sediment concentrations were monitored during each grazing period. Stream channel
alterations were found to be significantly greater during the early grazing periods (June 14 - August 9),
with Iate-season channel alterations (August 9 -October 14) being not different from the ungrazed
control (P < 0.01). Periods of peak channel alterations were associated with high vegetation utilization
rates and were correlated to high soil moisture (r^2 = 0.84). Alterations associated with the winter
monitoring periods were 10 to 800 percent greater than alterations directly attributable to livestock
grazing and may be an indirect repercussion of summer livestock activity. No direct relationship
between peak concentrations of suspended sediment and cattle activity was discernible. Peak sediment
concentrations occurred during periods of high rainfall and appear to be a function of erosion from
streambanks altered during the previous season’s grazing. Sediment concentrations were generally
higher downstream of areas exhibiting the greatest streambank instability. TIME OF GRAZING EFFECTS ON STREAM CHANNEL
STABILITY INSTREAM SEDIMENT LOADS
by
Thomas M artin Pogacnik
A t h e s i s su b m itted i n p a r t i a l f u l f i l l m e n t
of th e re q u ire m e n ts f o r th e degree
of
Master of S c ie n ce
in
Range S cience
MONTANA STATE UNIVERSITY
Bozeman, Montana
August 1985
/V-378
c.^
ii
APPROVAL
o f a t h e s i s su b m itted by
Thomas M artin Pogacnik
This t h e s i s has been re a d by each member of th e t h e s i s com m ittee
and h a s b e en fo u n d to be s a t i s f a c t o r y r e g a r d i n g c o n t e n t , E n g l i s h
usage, fo rm a t, c i t a t i o n s , b i b l i o g r a p h i c s t y l e , and c o n s is te n c y and i s
ready f o r su b m iss io n to the C ollege o f G raduate S tu d ie s .
Date
Approved f o r th e Major Department
\
Date
.......
Head, Major Department
Approved f o r the C ollege o f Graduate S tu d i e s
F
Date
- 2
G r a d u a te Dean
ill
STATEMENT OF PERMISSION TO USE
'
In
p re se n tin g
th is
th e sis
in
p a rtia l
f u l f i l l m e n t of th e
r e q u i r e m e n t s f o r a m a s t e r ’s d e g r e e a t M ontana S t a t e U n i v e r s i t y ,
I
a g r e e t h a t t h e L i b r a r y s h a l l make i t a v a i l a b l e t o b o r r o w e r s u n d e r
r u l e s of th e L ib ra ry .
B r i e f q u o t a t i o n s from t h i s t h e s i s a r e a llo w a b le
w ith o u t s p e c i a l p e rm is s io n , provided t h a t a c c u r a t e acknowledgement o f
so u rc e i s made.
P e rm iss io n f o r e x te n s iv e q u o t a t i o n from or r e p r o d u c tio n of t h i s
t h e s i s may be g ra n te d by my m ajor p r o f e s s o r , o r i n h i s ab sen ce, by the
D ir e c to r o f L i b r a r i e s when, i n t h e o p in io n o f e i t h e r , th e proposed use
of th e m a t e r i a l i s f o r s c h o l a r l y purposes.
m a te ria l
Any copying or use of th e
i n t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l n o t be a l l o w e d
w ith o u t my w r i t t e n p e rm is sio n .
iv
TABLE OF CONTENTS
Page
LIST OF TABLES ...................................................................................
LIST OF FIGURES.......................................
v
vi
ABSTRACT.......................................................................................................................v i i i
INTRODUCTION...................................
I
LITERATURE REVIEW. . ................................. .... ..................................................... '
4.
SITE DESCRIPTION . ...........................................
Cottonwood Creek....................................................
S o i l s ........................................................................... , .........................................
C l i m a t e ............................................................................... ..................................
V e g e ta tio n ...................... .... . . . ......................................................... .... .
Study S i t e . . . . . . . . .
..........................
C a t t l e . ...........................................
METHODS...........................................
14
14
17
18
20
21
23
24
Stream Channel S t a b i l i t y ...............................................................................
Stream Flow D i s c h a r g e .......................................
Suspended Sedim ent............................................................................................
S o il .M oisture ..............................
V e g e ta tio n U t i l i z a t i o n . .....................
24
28
Bi
35
36
RESULTS................................................................... ............................................... .
38
Stream Channel S t a b i l i t y . . .......................................................................
S o il M oisture . . ........................................................................................ .
Stream Flow D i s c h a r g e .......................................
Suspended Sedim ent. . . ...............................................................................
V e g e ta tio n U t i l i z a t i o n .....................................................................
38
44
46
49
53
DISCUSSION............................... ’...................................... ..
SUMMARY.
.................................... ..................................................... . . . . .
57
65
LITERATURE CITED................................... • • .................................. ....
68
APPENDICES....................................;................................. ....
!
Appendix A - V e g e ta tio n Types Common t o th e Cottonwood
Creek Study S i t e .....................................................................
Appendix B - D e s c r ip tio n of Computer Program......................................
77
78
81
V
LIST OF TABLES
Table
1
Page
D i r e c t i o n o f change e x h ib ite d by stream channel c r o s s s e c t i o n s d u rin g th e 1981 and 1982 g r a z in g seaso n s and
t h e t o t a l change from pre-1981 to p o s t - 1982.
I n c r e a s e s i n channel a re d e s ig n a te d by (+) and
d e c r e a s e s i n channel a r e d e s ig n a te d by ( - ) ......................
45
Appendix Table
2
V e g e ta tio n ty p e s common t o t h e Cottonwood Creek
stu d y s i t e based on c r i t e r i a e s t a b l i s h e d by the
Montana Rural. Areas Development Committee (1982),
w ith m o d i f i c a t i o n t o in c lu d e a d ja c e n t upland
v e g e t a t i q n t y p e s ...................... ........................................................
79
vi
LIST OF FIGURES
F ig u re
1
2
3
4
5
6
7
8a
8b
9
TO
11
12
13
Page
View of th e Cottonwood. Creek D rainage Taken From th e
C en ter o f th e Study S i t e Looking South. ....................................
-14
Montana A g r i c u l t u r a l Experiment S t a t i o n ' s Red B l u f f
Research Ranch i n Southw estern Montana Showing
L o c a tio n o f Study S i t e . .......................................................................
15
The Topography o f Cottonwood Creek i s C h a r a c te riz e d
by Moderate to S te e p Slopes ...............................................................
16
View o f Cottonwood Creek I n d i c a t i n g th e L o catio n o f Three
S o i l P i t s and T h eir R esp e ctiv e S o i l C l a s s i f i c a t i o n . . . .
19
View of P a s tu re 5 Showing Upland and R ip a ria n Community
T y p e s ....................... ...................................... ................................................
22
D iag ram atic View o f P a s tu re Layout and Grazing Schedule
Used During th e 1981 and 1982 G razing Seasons . . . . . .
22
Channel Measurements Were Taken Using a H o r iz o n ta lly
S tr e t c h e d Meter Tape and V e r t i c a l l y Held Meter S t i c k . . .
26
Measurements Were Taken t o th e N e are st C entim eter Along
th e H o riz o n ta l P lane and a t Ten C entim eter I n t e r v a l s
Across t h e V e r t i c a l Plane ......................................................................
27
The T r a n s e c t 's C r o s s - S e c tio n a l Area i s R epresented by th e
Shaded P o r tio n o f th e I l l u s t r a t i o n . ............................................
27
D iag ram atic S k e tc h es o f Each T r a n s e c t B efore and A f te r
Grazing Were Produced Using t h e Channel Measurement
D ata. ..................................................... ............................................... .... .
29
D ia g ra m atic I l l u s t r a t i o n o f P a s tu r e Layout I n d i c a t i n g
With Black Squares th e L o c a tio n o f Water Sampling
S t a t i o n s ; Each U n it i s 0 .5 H e c ta re . . . . . . ' ...........................
30
P a r s h a l l Flumes and S tev en s Type - F Continuous
R ecorders Were Used t o Measure Stream Flow. . . . . . . .
30
D iag ram atic Views o f Water Sampling S t a t i o n I n d i c a t i n g
th e L o c a tio n o f Suspended Sediment Samplers . .......................
33
M odified C o l l e c t i o n / S e t t l i n g B o t t l e s C ontaining I n ta k e
and Exhaust P o r ts t o Allow f o r Continuous Water Flow. . .
34
v ii
LIST OF FIGURES - Continued
F ig u r e s
14
'
15
16
17
18
19
20
21
22
23
24
page
N eutron Probe Access Tubes Were P o s itio n e d i n th e Upland
and Along t h e Stream banks. S o il M o istu re Measurements
Were Taken a t 15, 30, 45, 6 0 , 75, and 90 C en tim eter
...............................
Depths. ...........................^
36
Change i n Stream Channel Area (cm2 ) Observed D uring th e
1981 and 1982 Grazing S e a s o n s ............................................................
39
Change i n Stream Channel Area (cm2 ) Observed Follow ing
th e W inter o f 1981-1982 .........................................................................
41
T o ta l Change i n Stream Channel Area (cm2 ) Observed From
th e S p rin g o f 1.981 U n til th e F a l l o f 1982 . . . . . . . .
43
. Streambank S o il M oisture ($) Recorded During th e 1981 and
1982 Grazing Seasons Using a T r o x le r Neutron Probe. . . .
47
Water Volume Recorded f o r Cottonwood Creek During th e 1981
and 1982Grazing Seasons (m^/day) .........................................................
48
Suspended Sediment C o n c e n tra tio n s (g/m^) C o lle c te d
D uring t h e 1981 Grazing Season Using a Modified S in g le
S tag e Sediment Sampler. The Shaded P o r tio n of th e
F ig u re R e p re s e n ts t h e L o c a tio n o f th e C a t t l e i n
R e la tio n to th e Sampling S t a t i o n s ..................■.............................
50
Suspended Sediment C o n c e n tra tio n s (g/m^) C o lle c te d
During th e 1982 G razing Season Using a Modified S in g le
S tage Sediment Sampler. The Shaded P o r tio n o f th e
F ig u re R ep re s e n ts th e L o c a tio n o f th e C a t t l e i n
R e l a tio n t o th e Sampling S t a t i o n s . . . . . ...........................
51
Suspended Organic M a tte r (g) C o lle c te d During th e
1982 Grazing Season Using a M odified S in g le Stage
Sediment Sampler. The Shaded P o r tio n o f th e F ig u re
R ep rese n ts t h e L o c a tio n o f th e C a t t l e i n R e la tio n
to th e Sampling S t a t i o n s . ..................................................................
54
P e rc e n t U t i l i z a t i o n o f Upland and R ip a ria n V e g e ta tio n
Determined Using th e Cage Comparison Method ...........................
55
Time (Hours) Spent by C a t t l e Group i n Upland and
R ip a ria n H a b ita t Types During th e 1982 Grazing
Season (Marlow 19 8 3 ). Dates Along t h e H o riz o n ta l
Axis a r e Synonymous w ith G razing P e r i o d s . ...................... .... .
59
v iii
ABSTRACT
A s t u d y was c o n d u c te d d u r i n g t h e 1981 and 1982 summer g r a z i n g
s e a s o n s t o d e t e r m i n e t h e e f f e c t s o f t i m e o f l i v e s t o c k g r a z i n g on
s t r e a m c h a n n e l s t a b i l i t y and s u s p e n d e d s e d im e n t c o n c e n tr a tio n s f o r
Cottonwood Creek, a s m a ll w a te rsh e d l o c a t e d on th e Red B l u f f Research
Ranch i n s o u th w e st Montana.
E ig h t p a s t u r e s w ere grazed i n s u c c e s s io n
f o r 14 days each from Ju n e 14 through O ctober 4, w ith a n in th p a s tu r e
re m a in in g ungrazed a s a c o n tr o l.
S tr e a m c h a n n e l s t a b i l i t y , s o i l
m o i s t u r e , s t r e a m f l o w , and s u s p e n d e d s e d i m e n t c o n c e n t r a t i o n s w e re
m o n ito red d u rin g each g r a z in g p e rio d . Stream channel a l t e r a t i o n s were
fo u n d t o be s i g n i f i c a n t l y g r e a t e r d u r i n g t h e e a r l y g r a z i n g p e r i o d s
(June 14 - August 9)» w ith I a t e - s e a s o n channel a l t e r a t i o n s (August 9 O ctober 14) b ein g not d i f f e r e n t from th e ungrazed c o n t r o l (P < 0.01).
P e r i o d s o f p e a k c h a n n e l a l t e r a t i o n s w e r e a s s o c i a t e d w i t h h ig h
v e g e t a t i o n u t i l i z a t i o n r a t e s and were c o r r e l a t e d to high s o i l m o is tu re
(r
= 0 .8 4 ).
A lte r a tio n s a s s o c ia te d w ith th e w in te r m o n ito rin g
p e r i o d s w e r e 10 t o 800 p e r c e n t g r e a t e r t h a n a l t e r a t i o n s d i r e c t l y
a t t r i b u t a b l e to l i v e s t o c k g r a z in g and may be an i n d i r e c t r e p e r c u s s io n
o f sum m er l i v e s t o c k a c t i v i t y . No d i r e c t r e l a t i o n s h i p b e tw e e n peak
c o n c e n t r a t i o n s o f s u s p e n d e d s e d i m e n t and c a t t l e a c t i v i t y was
d isc e rn ib le .
Peak sedim ent c o n c e n tr a tio n s o c cu rred d u rin g p e rio d s of
h ig h r a i n f a l l and a p p ea r to be a f u n c t i o n o f e ro s io n from stream banks
a l t e r e d d u rin g th e p re v io u s season’s g ra z in g . Sediment c o n c e n tr a tio n s
w e re g e n e r a l l y h i g h e r d o w n s tre a m o f a r e a s e x h i b i t i n g t h e g r e a t e s t
stream bank i n s t a b i l i t y .
I
INTRODUCTION
R ip a ria n a r e a s a re p ro d u c tiv e , y e t v e ry f r a g i l e eco sy stem s which
serve as a fo c a l
p o in t
o f m anagem ent f o r
th e e n t i r e w a te rsh e d .
A lth o u g h t h e r i p a r i a n z o n e may o c c u p y o n ly a b o u t two p e r c e n t o f a
w a te rs h e d ’s a r e a (Buckhouse nda), i t i s i n th e s e com m unities t h a t u s e r
i n t e r e s t i s d i s p r o p o r t i o n a t e l y h ig h .
M an a g e rs o f v i r t u a l l y e v e r y
n a t u r a l re s o u rc e d i s c i p l i n e fo cu s t h e i r a t t e n t i o n on th e u t i l i z a t i o n
of r i p a r i a n a r e a s , which o f t e n r e s u l t s i n many u s e r groups competing
fo r
a lim ite d
o b je c tiv e s,
reso u rce.
The m u l t i t u d e
and v a l u e s e x p r e s s e d
of in te r e s ts ,
by t h e v a r i o u s
m anagem ent
g r o u p s m akes a
c o n f l i c t over r i p a r i a n a r e a s i n e v i t a b l e .
One such c o n f l i c t co n cern s th e e f f e c t s g ra z in g l i v e s t o c k e x e r t on
r i p a r i a n eco sy stem s.
The m anagement g o a ls
e s t a b l i s h e d by w i l d l i f e
and f i s h e r i e s b i o l o g i s t s t o m a in ta in th e i n t e g r i t y of r i p a r i a n h a b i t a t
f o r t e r r e s t r i a l and a q u a t i c o r g a n i s m s a r e o c c a s i o n a l l y i n c o n f l i c t
w ith th e management g o a ls o f l i v e s t o c k p ro d u c e rs,
who a r e m a rk e tin g
h e r b a g e t h r o u g h a r u m i n a n t a n i m a l and l o o k t o r i p a r i a n a r e a s a s a
h ig h ly p ro d u c tiv e
s o u r c e o f f o r a g e , w a t e r , s h a d e , and p r o t e c t i o n
th roughout th e g r a z in g season.
In r e c e n t y e a r s ,
numerous s t u d i e s have equated l i v e s t o c k g ra z in g
w i t h d e c l i n i n g r i p a r i a n e c o s y s te m s t a b i l i t y .
A lth o u g h many o t h e r
a c t i v i t i e s c a n r e s u l t i n a s much o r m ore d e g r a d a t i o n o f r i p a r i a n
h a b i t a t (B usby 1979. C l a i r e and S t o r c h i n p r e s s ) , i t i s l i v e s t o c k
g ra z in g ,
because of i t s high v i s i b i l i t y ,
i
which has been im p l i c a t e d a s
2
th e p r i n c i p l e fo rc e c o n tr ib u tin g to th e d e s ta b iliz a tio n of rip a ria n
areas
(B usby 19 7 9 ).
Damage t r a c e a b l e t o l i v e s t o c k g r a z i n g o c c u r s w hen im p r o p e r
management p r a c t i c e s a llo w l i v e s t o c k to c o n c e n tr a te i n r i p a r i a n a r e a s
f o r e x t e n d e d p e r i o d s o f t i m e (Armour 1 9 7 7 ).
g e n e r a l l y o c c u r a s d e s t a b i l i z e d stream b an k s,
The r e s u l t i n g i m p a c t s
a l t e r e d s tre a m ch an n els,
in c r e a s e d suspended s ed im en t lo a d in g , and e x c e s s iv e v e g e t a t i o n removal
(Behnke and R aleig h 1978; P l a t t s 1981a).
The im p a c ts l i v e s t o c k e x e r t
on r i p a r i a n a r e a s may be obvious im m e d ia te ly ,
a s denuded v e g e t a t i o n
and c o l l a p s e d s t r e a m b a n k s , o r t h e dam age may o c c u r a s s u b t l e a n n u a l
a l t e r a t i o n s which can ta k e many y e a r s t o d e t e c t ( P l a t t s 1981a).
N a t u r a l r e s o u r c e m a n a g e rs a r e b e i n g p r e s s u r e d t o r e d u c e t h e
im p a c ts l i v e s t o c k i n f l i c t on r i p a r i a n sy ste m s, y e t a l a c k o f re s e a rc h
p e r t a i n i n g to a l t e r n a t i v e g r a z in g p r a c t i c e s i n r i p a r i a n a r e a s l i m i t s
t h e m an ag em en t o p t i o n s a v a i l a b l e .
Many s t u d i e s have su g g ested t h a t
th e only management a l t e r n a t i v e , which i s c o m p atib le w i t h m a in ta in in g
th e i n t e g r i t y o f r i p a r i a n h a b i t a t , i s t o e x clu d e or r e s t r i c t l i v e s t o c k
u s e i n t h e s e a r e a s (Ames 1977, B ehnke 1979» D a v is 1982, and P l a t t s
1978).
However, th e r e s t r i c t i o n o r e l i m i n a t i o n o f l i v e s t o c k a c c e s s to
r i p a r i a n a r e a s may be u n d e s ir a b le f o r th e l i v e s t o c k p ro d u c e r a s th e se
a r e a s may c o n s t i t u t e th e prim ary fo ra g e base of a p a s t u r e and produce
th e only d e s i r a b l e fo r a g e d u rin g l a t e summer g ra z in g p e rio d s .
A num ber o f s t u d i e s e x a m i n i n g
r i p a r i a n c o m m u n itie s
t h e i m p a c t l i v e s t o c k e x e r t on
h a v e b een c o n d u c te d i n r e c e n t y e a r s . Much o f
t h i s r e s e a r c h has c e n te re d on a t t e m p t i n g t o e s t a b l i s h to w hat degree
liv e sto c k
g ra z in g
im p a c ts
rip a ria n
areas
and
e v a lu a tin g
th e
3
e f f e c t i v e n e s s o f v a r io u s g ra z in g methods t o reduce l i v e s t o c k im p a c ts
in th e se a re a s.
Much o f t h e r e s e a r c h
t o d a t e h a s b e en b a s e d on
!
s u b j e c t i v e d a ta ,
little
which may in c lu d e only one year's, o b s e r v a tio n s w ith
c o n sid e ra tio n
p a ra m e te rs o r to
g iv e n
to
s t a t i s t i c a l d esig n .
f a i l e d to c o n s id e r s to c k in g r a t e s ,
use
in
a n a ly sis
th e
of
d a ta .
m easurem ent
of q u a n tifia b le
Many tim e s th e s e s t u d i e s have
d u r a t i o n o f g ra z in g ,
T h is r e s u l t s
in
or season of
a la c k o f p e rtin e n t
i n f o r m a t i o n on w h ic h m anagem ent d e c i s i o n s c o u ld be made.
I t i s in
r e g a r d t o t h i s f a c t t h a t t h e need f o r m ore a c c u r a t e and p r e c i s e
r e s e a r c h becomes e v id e n t.
In re sp o n se t o t h e need f o r r e s e a r c h concerned w ith m in im izin g
l i v e s t o c k g r a z in g im p a c ts on r i p a r i a n com m unities,
a f i v e - y e a r study
i s bein g conducted by th e Montana A g r i c u l t u r a l Experim ent S t a t i o n i n
c o n ju n c tio n w ith Montana S t a t e U n iv e r s ity to d e te rm in e t h e e f f e c t s of
tim e of g r a z in g on a s e r i e s o f r i p a r i a n ecosystem c h a r a c t e r i s t i c s .
A
p o r ti o n of t h i s study i s to d i s c e r n t h a t p e rio d or p e rio d s d u rin g the
g r a z in g sea so n (June 15 - October 4) when li v e s t o c k - i n d u c e d stream bank
and channel i n s t a b i l i t y and suspended sed im en t lo a d in g a r e minimized.
The p r i n c i p l e o b j e c t i v e s o f t h i s s tu d y were: I) to d e te rm in e what
tim e d u rin g th e g r a z in g seaso n stream b an k s w ere most s u s c e p t i b l e to
c a ttle
g ra z in g im p a c ts,
and 2 ) t o , d e t e r m i n e
if
f lu c tu a tio n s in
s u s p e n d e d s e d i m e n t l e v e l s o c c u r e d d u r i n g p e r i o d s when c a t t l e w e re
present
4
LITERATURE REVIEW
The c o m b in e d i n f l u e n c e s o f g e o lo g y ,
geomorphology, v e g e t a t i o n ,
c lim a te ,
s o il stru c tu re ,
and w a te r r u n o f f o f te n r e s u l t i n u n s ta b le
r i p a r i a n sy ste m s, even i n a s t a t e u n a lte r e d by human a c t i v i t y (Meehan
and
P la tts
1978).
m a rg in a lly
sta b le
When e x c e s s i v e
sy ste m s th ro u g h
m anagem ent p r a c t i c e s ,
s tre ss
is
im p ro p e rly
e x e rte d
o n 'th e s e
c o n tro lle d
la n d
s e v e r e damage u s u a l l y r e s u l t s (Meehan and
P l a t t s 1978).
I t h a s b e e n s u g g e s t e d t h a t one o f t h e m o st d e s t r u c t i v e f o r c e s
i n f l u e n c i n g r i p a r i a n e co sy stem s i s lo n g -te rm o v e rg ra z in g by l i v e s t o c k
( Behnke 1977, D a v is 1982, L e o p o ld 1975).
Townsend and S m ith (1977)
and Cope (1979) have r e p o r t e d t h a t l i v e s t o c k g r a z in g d e g ra d es r i p a r i a n
h a b i t a t and s u b s e q u e n t l y r e d u c e s t h e p r o d u c t i v i t y o f t h e s e a r e a s .
Mismanagement o f l i v e s t o c k cart r e s u l t i n a n im a ls b e in g c o n c e n tra te d i n
rip a ria n areas,
f o u r m a jo r
th u s i n f l i c t i n g some d e g re e of damage on each of th e
c o m p o n e n ts
of a r ip a r ia n
e co sy stem :
I)
stre a m sid e
v e g e t a t i o n , 2 ) stre a m channel morphology, 3 ) stream bank s t a b i l i t y , and
4) w a te r q u a l i t y (Behnke and R aleig h 1978, C l a i r e and S to r c h i n p re s s ,
Marcuson 1977, P l a t t s 1979, P l a t t s 1981a).
Streambank
v e g e t a t i o n m a in ta in s th e i n t e g r i t y o f r i p a r i a n a r e a s
by s t a b i l i z i n g stream b an k s (Meehan,
Swanson and S e d e ll 1977, Winegar
1977), r e d u c i n g e r o s i o n (W h ite and B r y n i l d s o n I 967), r e d u c i n g w a t e r
t e m p e r a t u r e s by s h a d i n g s t r e a m s
(A rm our 1977, B ow ers e t a l . 1979,
P l a t t s 1 9 7 8 ), and a s a s o u r c e o f o r g a n i c d e t r i t u s and t e r r e s t r i a l
5
' i n s e c t s w h i c h s e r v e i n t h e f o o d c h a i n o f r i p a r i a n s y s t e m s (Cum m ins
1974,
Meehan, Swanson and S e d e l l 1977).
T h e re e x i s t s an a b u n d a n c e o f l i t e r a t u r e r e g a r d i n g t h e e f f e c t s
l i v e s t o c k e x e r t on r i p a r i a n v e g e t a t i o n (Ames 1977, B o l d t , U re sk and
Severson 1978, Bryant e t a l . 1972, Buckhouse nda, C l a i r e and S to rch i n
p r e s s , C ro u ch 1979, D a v is 1977, E vens and K re b s 1977, H ayes 1978,
Knoph and Cannon I 9 82, M eyers 1981, Pond 1961, R oath 1 9 8 0 , R oath and
K ru e g e r 1982, S m ith n d a , T u i n s t r a 1967, V o g le r 1978, W in e g a r I 977).
T h ese
stu d ie s
have
re p o rte d
th a t
liv e sto c k
u n d e s ira b le changes in p la n t s u c c e s s io n ,
g ra z in g
re su lts
in
co m m u n ity p r o d u c t i v i t y ,
s p e c i e s c o m p o s i t i o n , r e p r o d u c t i o n , and d i v e r s i t y a s s o c i a t e d w i t h
rip a ria n a re as.
The e f f e c t s o f l i v e s t o c k g r a z i n g on r i p a r i a n v e g e t a t i o n can
g e n e r a l l y be te r m e d a s n e g a t i v e (B u c k h o u se n d a ). As e a r l y a s 1946,
l i v e s t o c k w e r e r e p o r t e d t o c o n c e n t r a t e i n r i p a r i a n c o m m u n i t i e s and
u t i l i z e th e v e g e t a t i o n more i n t e n s i v e l y th a n i n a d ja c e n t h a b i t a t ty p es
(Reid and P ic k fo rd 1946).
The im p a c ts o f e x c e s s iv e herbage removal i n
rip a ria n
c a te g o riz e d
areas
u tiliz a tio n
of
can
be
herbaceous
v e g e ta tio n
by v e g e t a t i o n
stru c tu re :
and u t i l i z a t i o n
of
woody
v e g e t a t i o n (Buckhouse n d a ).
The p rim ary e f f e c t o f e x c e s s iv e l i v e s t o c k g ra z in g on herbaceous
v e g e ta tio n i s
th e re p la c e m e n t of n a tiv e
b u n c h g r a s s e s by i n v a d e r
g r a s s e s and f o r b s (Dobson 1973, Evenden and Kauffman 1980, flayes 1978,
Volland 1978).
G razing h as been r e p o r te d t o i n c r e a s e
th e number o f
u n d e s i r a b l e s p e c i e s fo u n d i n r i p a r i a n a r e a s (E v e r d e n and K auffm an
19 8 0 ) by o p e n i n g up t h e v e g e t a t i o n and c r e a t i n g n i c h e s i n w h ic h
6
r u d e r a l s p e c i e s inay become e s t a b l i s h e d (Dobson 1 973, Hayes 1978).
In f o rm a tio n re g a r d in g p r o d u c t i v i t y of stre am s id e v e g e ta tio n ,
in flu en c ed
by g r a z i n g i s
c o n flic tin g
( B uckhouse n d a ).
as
Numerous
s t u d i e s h a v e r e p o r t e d d e c r e a s e s i n p r o d u c t i v i t y due t o l i v e s t o c k
g r a z i n g (D u ff 1979, G u n d e rso n 1968, M cClean, N ic h o ls o n and Ryswyk
1973, M arcu so n 1977, Pond 1961).
H ow ever, R o ath (1 9 8 0 ) and V o lla n d
( 1978) found l i v e s t o c k g r a z in g had no s i g n i f i c a n t
a f f e c t on biomass
p ro d u c tio n and Kauffman e t a l . ( i n p r e s s ) observed g r e a t e r p ro d u c tio n
i n grazed com m unities o v er s i m i l a r ungrazed a re a s .
The e f f e c t s
of h e rb iv o ry
on s h r u b and
tre e
p r o d u c t i o n and
r e p r o d u c t i o n i s a c r i t i c a l im p a c t t o r i p a r i a n eco sy stem s (Buckhouse
nda). Marcuson (1977) found shrub p ro d u c tio n to be 13 tim e s g r e a t e r i n
an ungrazed a r e a th a n i n a s e v e r e ly grazed a re a . C a ro th e rs (1977) and
G l i n s k i (1 9 7 7 ) r e p o r t t h a t e x c e s s i v e g r a z i n g p r e s s u r e p r e v e n t s t h e
e s ta b lis h m e n t o f s e e d lin g s o r s u c k e rs r e s u l t i n g i n com m unities which
are
e v e n - a g e d and n o n - r e p r o d u c i n g .
V o g le r (1978) fo u n d l i g h t
b r o w s i n g may s t i m u l a t e s p r o u t i n g o f r i p a r i a n woody s p e c i e s , y e t ,
p e r s i s t e n t l i v e s t o c k u s e c a n r e s u l t i n t h e e l i m i n a t i o n o f woody
s p e c i e s (Crouch 1979).
S e a so n o f u s e a p p e a r s t o h a v e an a f f e c t on t h e
r i p a r i a n v e g e t a t i o n t o w ith s ta n d g r a z in g p re s su re .
a b ility
of
C l a i r e and S to rc h
( i n p re s s ) and Roath (1980) i n Oregon have shown I a t e - s e a s o n g ra z in g
h as l i t t l e im p a c t on e i t h e r h erb aceo u s o r woody r i p a r i a n v e g e ta tio n ,
w h ile Myers (1981) concluded t h a t l i v e s t o c k use of r i p a r i a n h a b i t a t i n
t h e s p r i n g i s more c o n d u c iv e t o s h r u b s u r v i v a l t h a n d u r i n g t h e "h o t
p e rio d " o f l a t e summer.
7
P erhaps th e g r e a t e s t im p a c t o f e x c e s s iv e l i v e s t o c k g ra z in g in
r i p a r i a n com m unities i s th e su b sequent
d e s t a b i l i z a t i o n o f stream b an k s
f o ll o w i n g v e g e t a t i o n rem oval. The f i r s t s ig n o f r i p a r i a n damage, as a
r e s u l t o f l i v e s t o c k a c t i v i t y , w i l l o c cu r a s r e d u c tio n s i n v e g e t a t i v e
c o v e r and a s u b s e q u e n t i n c r e a s e i n
s t r e a m bank and s t r e a m c h a n n e l
i n s t a b i l i t y ( P l a t t s 1981 a, S k o l y i n 1967).
Hayes
(1978)
and
W in e g a r
(1977)
a ll
S t u d i e s by B e r r y (1978)
in d ic a te
th a t
a c c e le ra te d
stream bank u n d e r c u ttin g o c c u rs a f t e r e x c e s s iv e v e g e t a t i o n rem oval by
liv e sto c k .
P l a t t s (19 8 1 b ) r e p o r t e d l e s s s t a b l e s t r e a m b a n k s when
u tiliz a tio n ra te s
o f 25 p e r c e n t
w ere 65 p e rc e n t or g r e a t e r , w h ile u t i l i z a t i o n r a t e s
o r l e s s r e s u l t e d i n l i t t l e o r no s t r e a m b a n k damage.
S i m i l a r r e s u l t s were p re s e n te d by Hayes (1978), who r e p o r t e d in c re a s e d
stream bank i n s t a b i l i t y a f t e r v e g e t a t i o n u t i l i z a t i o n r a t e s exceeded 60
p e rc e n t.
C ooper
(1 9 7 9 )
sta te s
th a t
in d ep en d en t o f anim al numbers though and
s tr e a m b a n k
dam age
may
be
t h a t i t does n o t ta k e f u l l
u t i l i z a t i o n o f stre am b a n k v e g e t a t i o n t o s e r i o u s l y dam age s e n s i t i v e
banks.
The im p a c t o f l i v e s t o c k g ra z in g on s tre a m channel morphology and
stream bank s t a b i l i t y v a r i e s depending upon th e n a tu re o f th e stream
b ein g s tu d ie d (Buckhouse nda).
I t h a s been su g g ested t h a t stream bank
s u s c e p t i b i l i t y t o l i v e s t o c k im p a c t may be d eterm in ed by s o i l s t r u c t u r e
and bank ro c k c o n te n t (Behnke and R aleig h 1978, Cooper 1979» Gunderson
1968, M arcu so n 1977, P l a t t s 1979).
C o o p er (1979) s t a t e s t h a t ban k s
c o n ta i n in g a h ig h e r p e rc e n ta g e of ro ck s i g n i f i c a n t l y impede u n g u la te
damage. Stream banks w i t h low p e rc e n ta g e s o f bank ro ck a s w e ll a s s o i l s
8
w i t h sandy t e x t u r e s a r e r e p o r t e d t o be' h i g h l y s u s c e p t i b l e t o t r a m p l i n g
damage (USDI 1978).
Numerous s t u d i e s have r e p o r te d t h e e f f e c t s o f l i v e s t o c k tr a m p lin g ,
on s o i l co m p ac tio n .a n d s o i l d is tu r b a n c e (A ld e r f e r and Robinson 1979» ,
B r y a n t e t a l . 1972, O rr I 9 6 0 , R a u z i and H anson
R o ath ( 1980) s t a t e s
1966, R oath 1980).
t h a t t h e g r e a t e s t i m p a c t l i v e s t o c k e x e r t on
r i p a r i a n a r e a s i s t r a m p l i n g damage and h e n o t e s t h a t t h e am ount o f
i m p a c t a p p e a r s t o be d e p e n d e n t upon s o i l m o i s t u r e .
C ooper (1979)
s p e c u l a t e d t h a t m o i s t u r e f r o z e n i n s t r e a m b a n k s may s u p p l y t h e s o i l
w ith s u f f i c i e n t s u p p o rt t o w ith s ta n d
heavy w eight.
L iv e s to c k g r a z in g h as been shown t o a l t e r stre am channel shape,
r e s u l t i n g i n c h a n n e l s w h ic h a re ' t y p i c a l l y w i d e r and s h a l l o w e r t h a n
com parable a r e a s no t b eing grazed (Armour 1977, Duff 1979, Gunderson
1968, K a u ffm a n e t a l . i n p r e s s , M arcu so n I 977, W h ite and B r y n i l d s o n
1967).
A stre am channel r e c e i v i n g heavy g ra z in g p r e s s u r e from sheep
w as r e p o r t e d by P l a t t s (19 8 1 b ) t o be f o u r t i m e s a s w id e a s an a r e a
r e c e i v i n g l i g h t g ra z in g .
Kauffman e t a l .
( i n p re s s ) found a r i p a r i a n
s y s te m g r a z e d u n d e r a s t o c k i n g r a t e o f 2.5 ha/AUM l o s t o v e r t h r e e
tim e s a s much
stre am bank a s an ungrazed c o n tr o l area.
However, th e s e f i n d i n g s c o n f l i c t w ith th o s e r e p o r te d by Buckhouse
e t a l.
(1 9 8 1 ) , Hayes (1 9 7 8 ) , and R o ath (1 9 8 0 ).
fe w e r changes i n stre am b a n k shape
Hayes (1978) fo u n d
w i t h i n p a s t u r e s b e i n g g r a z e d by
c a t t l e t h a n i n p a s t u r e s w h ic h r e c e i v e no g r a z i n g . B oth B uckhouse
S k o l v i n and K n ig h t (1 9 8 1 ) and R o a th (1 9 8 0 ) r e p o r t i n s i g n i f i c a n t
s t r e a m b a n k a l t e r a t i o n s f o l l o w i n g l i v e s t o c k g r a z i n g i n O regon. They
su rm iz e
t h a t t h e n a t u r a l l y o c c u r r i n g i m p a c t s o f w a t e r f lo w (R o a th
9
1980) and i c e damage (Buckhouse e t a l .
1981) r e s u l t e d i n more channel
a l t e r a t i o n s th a n were c o n tr ib u te d by c a t t l e .
it
is
Buckhouse (1980) s t a t e s
a c c e p t e d t h a t l i v e s t o c k do i m p a c t s t r e a m b a n k s ,
but i t
is .
im p o r ta n t t o q u a n t i f y how much of th e damage i s i n e x c e s s o f n a t u r a l l y
o c c u r r i n g changes.
T ra m p le d s t r e a m b a n k s h a v e b e e n r e p o r t e d t o i n c r e a s e o v e r l a n d
w a te r and sed im en t flo w , r e s u l t i n g i n h ig h e r suspended sed im en t l e v e l s
i n s tr e a m s (Armour 1977, Johnson e t a l . 1978). Rosgen (1975) r e p o r t s a
good
c o rre la tio n
b e tw e e n
suspended sed im en t l e v e l s .
a ssu m p tio n t h a t a g iv e n
stre am b a n k
sta b ility ,
w a ter
flo w
and
R osgen1s r e l a t i o n s h i p i s b a s e d on t h e
w a te r d is c h a rg e can t r a n s p o r t a s e t amount of
sedim ent i n su sp e n sio n and t h e a v a i l a b i l i t y of sedim ent i s dependent
upon stream bank s t a b i l i t y .
a l s o in c r e a s e
As bank damage i n c r e a s e s , sed im en t l e v e l s
(Cooper 1979).
In c re a s e d l e v e l s o f suspended sed im en t i n t h e w a te r column have
been i d e n t i f i e d a s th e most damaging im p a c t l i v e s t o c k have on stream
p ro d u c tiv ity
(Armour 1977, P u f f 1979).
Berry (1978) and Cordone and
K e lley (1961) found t h a t suspended sed im en t d e c r e a s e s a s tr e a m 's t o t a l
o rg a n ism
p ro d u c tiv ity .
N u m e ro u s s t u d i e s h a v e i n d i c a t e d t h a t
o v e rg ra z in g by l i v e s t o c k may r e s u l t i n i n c r e a s e d s u s p e n d e d s e d i m e n t
l e v e l s and in c r e a s e d l e v e l s o f sedim ent i n t h e stream bed, r e s u l t i n g i n
red u ced f i s h biomass p ro d u c tio n and lo w e re d salm onoid numbers w i t h i n
th e f i s h p o p u la tio n (Armour 1977, Behnke and R aleigh 1978, Bowers e t
a l . I 979, C l a i r e and S t o r e d i n p r e s s , C ordone and K e l l e y 1961, D u ff
1979, Gunderson 1968, Marcuson 1977).
10
T h e re i s g e n e r a l a g r e e m e n t among a q u a t i c b i o l o g i s t s t h a t t h e
i n t r o d u c t i o n of p a r t i c u l a t e m a t t e r i n t o a body o f w a te r can r e s u l t i n
adverse e c o l o g i c a l consequences (C a irn s 1968).
There i s ,
however, ,a
l a c k of agreem en t a s to th e amount of suspended sed im en t which can be
a s s i m i l a t e d b e fo re th r e s h o ld v a lu e s f o r a q u a t i c o rg a n ism s a r e reached
(C a irn s 1968, and Hoak 1957).
McKee and Wolf (1963) s t a t e t h a t w a te r
c o n t a i n i n g s u s p e n d e d s e d i m e n t l e v e l s o f 80 mg/ 1 i s n o t h a r m f u l t o
a q u a ti c o rg a n ism s.
P e t e r s (1 9 6 2 ) r e p o r t e d t h a t l e v e l s o f 200 mg/1
w e r e fo u n d t o i n f l i c t 75% m o r t a l i t y f o r i n c u b a t i n g em b ry o ra in b o w
tro u t
( Salm o
g a i r d n e r i ).
H erbert
and
M e rk in s
(1 9 6 1 )
re p o rte d
suspended sed im en t c o n c e n tr a tio n s o f 30 ppm ( p a r t s p er m i l l i o n ) having
no a d v e rs e e f f e c t on a q u a ti c o rg an ism s y e t l e v e l s o f 270 ppm r e s u l t e d
in a
50 p e rc e n t d e ath r a t e among t h e salm onoids b eing m onitored.
In
c o n t r a s t , a s t u d y by B e n o i t , C a i r n s and R e im e r ( i n p r e s s ) r e p o r t e d
y o ung s a lm o n c o u ld t o l e r a t e o v e r 120 h o u r s i n a s much
c o u ld be k e p t i n s u s p e n s i o n by v i g o r o u s a e r a t i o n .
s e d im e n t a s
R e p o r te d l e t h a l
l e v e l s o f s u s p e n d e d s e d i m e n t f o r s a l m o n o i d s r a n g e fro m 75 ppm t o
270,000 ppm (W allen 1951).
A lth o u g h a q u a t i c o r g a n i s m s can s u r v i v e i n w a t e r w i t h i n a w id e
r a n g e o f s u s p e n d e d s e d i m e n t l e v e l s ( C a i r n s 1968), i t i s t h e l o s s o f
s p a w n in g a r e a s and f o o d w h ic h may be m o st d e t r i m e n t a l
,s u rv iv a l
(C a irn s
196 8 ).
C airn s
(1 9 6 8 )
n o te d
to t h e i r
th a t, in v e rte b ra te
o r g a n is m p r o d u c t i o n i s s u b s t a n t i a l l y lo w e r i n san d a n d s i l t th a n i n
r u b b le and g ra v e l.
When in o rg a n ic , s e d im e n ts cover r u b b le and g ra v e l,
f i s h food and spaw ning a r e a s a r e d e stro y e d .
11
L iv esto c k
have
b e en i m p l i c a t e d
as th e
p rin c ip le
source
of
in c r e a s e d sed im en t l e v e l s i n s tre a m s (Cooper 197,9» Busby 1979» P l a t t s
1978, W in eg a r I 97 7 ).
Y et, s t u d i e s by G ary, J o h n s o n and Ponce (1983)
a n d J o h n s o n e t a l . ( 1978) h a v e i n d i c a t e d l i t t l e c o r r e l a t i o n b e tw e e n
liv e sto ck a c tiv ity
i n r i p a r i a n a r e a s and t h e l a r g e c o n c e n tr a tio n s o f
suspended sed im en t re c o rd e d i n the stre am they w ere m o n ito rin g . Both
s t u d i e s c o n c lu d e d t h a t , a l t h o u g h l i v e s t o c k a c t i v i t y d i d r e s u l t i n a
s l i g h t i n c r e a s e i n suspended se d im e n t l e v e l s ,
th e
a m o u n ts w e re
i n s i g n i f i c a n t r e l a t i v e t o n a t u r a l l y o c c u r r i n g c o n c e n tr a tio n s .
Peak
sed im en t c o n c e n t r a t i o n s w ere r e c o rd e d d u rin g p e r io d s of h ig h w a te r
flow i n both th e g ra z ed and ungrazed re a c h e s o f th e stre am (Johnson e t
a l.
1 9 7 8 ),
and
th e y
fe lt
it
w as
apparent
th a t
th e se
h ig h
c o n c e n tr a tio n s o r i g i n a t e d up stream of th e study s i t e w ith th e c a t t l e
c o n t r i b u t i n g i n s i g n i f i c a n t amounts of a d d i t i o n a l sedim ent.
R e c o g n i z i n g and u n d e r s t a n d i n g t h e i m p a c t s l i v e s t o c k e x e r t on
s t r e a m s id e s i s a p r e r e q u i s i t e t o f o r m u l a t i n g r i p a r i a n management p la n s
( C l a i r e and S t o r c h i n p r e s s ) .
O f te n , w h a t i s fo u n d t o be good r a n g e
management i s not good r i p a r i a n management ( P l a t t s 1979).
Methods f o r
im proving r i p a r i a n zone management t o red u ce l i v e s t o c k damage in c lu d e :
e x c lu s io n o f l i v e s t o c k , a l t e r n a t i v e g r a z i n g m e th o d s , c h a n g e s i n th e
c la ss of liv e s to c k ,
and m a n a g in g r i p a r i a n a r e a s a s
sp e c ia l-u se
p a s tu r e s (Buckhouse n d a ).
S e v e r a l s t u d i e s , r e p o r t e d by B uckhouse e t a l . (1 9 8 1 ) e v a l u a t e d
v a r io u s g r a z in g methods f o r t h e i r c o m p a t a b ili ty w ith th e o b j e c t i v e s of
both l i v e s t o c k and w i l d l i f e m anagers o f r i p a r i a n a r e a s .
Some g ra z in g
methods have shown p o t e n t i a l f o r p r e s e r v i n g r i p a r i a n w i l d l i f e h a b i t a t ,
12
w ith r e s t - r o t a t i o n a c h ie v in g t h e most s u c c e s s
(Davis 1982, C la ir e and
S t o r c h i n p r e s s , H ayes 1978, K im b a ll and S a v a g e 1977$
D raw backs
of
re s t-ro ta tio n
and o t h e r
i n c r e a s e d t r a i l i n g a lo n g f e n c e l i n e s ,
Swan 1979).
g r a z i n g m e th o d s
in c lu d e s ,
c o n c e n tra tio n of liv e s to c k in
r i p a r i a n a r e a s , in c r e a s e d t r a m p lin g damage, and s tre a m bank i n s t a b i l i t y
(Ames 1977, and Meehan and P l a t t s 1978). No w id e ly -u s e d g r a z in g method
has been observed t o be c o m p a tib le w ith th e o b j e c t i v e s o f a l l r i p a r i a n
eco sy stem s u s e r groups (Ames 1977$ and Meehan and P l a t t s 1978).
T o tal e x c lu s io n o f l i v e s t o c k from r i p a r i a n a r e a s ,
a s recommended
by Ames (1977)$ Dahlen (1978), Davis (1982) and P l a t t s (1978), has met
w i t h m a r g i n a l b e n e f i t s (V o lla n d 1978).
A lth o u g h some s u c c e s s i n
r e s t o r i n g dam aged r i p a r i a n a r e a s h a s b e e n a c h i e v e d
by e x c l u d i n g
l i v e s t o c k (Behnke 1979$ D a v is 1977)$ V o lla n d (1978) r e p o r t s t h a t a
r i p a r i a n a r e a e x c l u d e d fr o m l i v e s t o c k g r a z i n g f o r e l e v e n y e a r s w as
fo u n d t o p ro d u c e l e s s v e g e t a t i v e b i o m a s s t h a n an a r e a b e i n g g r a z e d .
A lso ,
p o litic s,
fu n d in g ,
personnel c o n s tr a in ts ,
and c o n f l i c t i n g
re s o u rc e demands make l i v e s t o c k e x c lu s io n an u n a c c e p ta b le a l t e r n a t i v e
f o r r e s o u r c e managers (Davis 1982).
F e n c in g
p a stu re s
may
rip a ria n
be a
areas
se p a ra te ly
su ccessfu l
in to
m u ltip le -u se
m anagem ent (K au ffm an e t a l . , i n p r e s s ) .
sp e c ia l
s y s te m
managem ent
of
rip a ria n
S t u d i e s by J o h n s o n ( 1965)$
K auffm an (1 9 8 2 ) , Pond (1 9 6 1 ), and R o a th (1980) a l l r e p o r t e d r e d u c e d
l i v e s t o c k damage t o r i p a r i a n a r e a s w hen g r a z e d l a t e i n t h e s e a s o n .
Cooper (1979) s u g g e s ts t h a t l a t e f a l l
g r a z in g may have been conducive
t o re d u c in g stream b an k damage on r i p a r i a n a r e a s i n Wyoming.
F u r th e r
s tu d y i s n e c e s s a r y r e l a t i n g t o t h e e f f e c t s o f t i m e o f g r a z i n g on
13
I
r i p a r i a n e co sy stem s i n e s t a b l i s h i n g p ro p e r r i p a r i a n g r a z in g p r a c t i c e s
( P l a t t s 1981b).
14
SITE DESCRIPTION
This study was i n i t i a t e d i n 1981 on the n o rth f o r k o f Cottonwood
C re ek ,
a trib u ta ry
of
th e
M adison R i v e r
in
s o u th w e st
M ontana.
Cottonwood Creek i s l o c a t e d i n th e f o o t h i l l s of th e Madison Mountain
Range and d r a i n s a s m a l l w a t e r s h e d o f a p p r o x i m a t e l y 1360 h e c t a r e s
(F ig u re
F ig u re I .
I).
The C o tto n w o o d w a t e r s h e d i s
situ a te d
16 k i l o m e t e r s
View of th e Cottonwood Creek Drainage Taken From
the C enter of th e Study S i t e Looking South.
s o u th e a s t o f N o rris ,
Montana on t h e Montana A g r i c u l t u r a l Experiment
S t a t i o n 's Red B lu f f R esearch Ranch (F ig u re
2).
Cottonwood Creek
Cottonwood Creek i s a p p ro x im a te ly 4 km i n le n g th and flo w s
n o r t h e a s t w h e re i t j o i n s t h e M ad iso n R i v e r i n B e a r t r a p Canyon.
15
F ig u re 2.
M o n ta n a A g r i c u l t u r a l E x p e r i m e n t S t a t i o n ' s Red B l u f f
Research Ranch i n S o u th w e stern Montana showing L o c a tio n of
Study S i t e .
MONTANA
16
Topography o f th e w a tersh e d i s c h a r a c t e r i z e d by m oderate to s te e p
s l o p e s , ( F i g u r e 3) w i t h e l e v a t i o n s r a n g i n g from 2000 m e t e r s a t
t h e h e a d w a t e r s p r i n g t o 1400 m e t e r s w h e re t h e c r e e k f l o w s i n t o
th e Madison River. The c re ek i s bordered on th e south by a s te e p
r id g e w ith s lo p e s o f 30 to 50 p e rc e n t and on the n o rth by r o l l i n g
h i l l s w i t h 15 t o 30 p e r c e n t s l o p e s .
At i t s s o u r c e , C o tto n w o o d
Creek i s s i t u a t e d i n r o l l i n g t e r r a i n w ith a w ide r i p a r i a n zone.
The r i p a r i a n a r e a becom es c o n s i d e r a b l y n a r r o w e r a s t h e c r e e k
flo w s to w ard s i t s co n flu e n ce w ith th e Madison River.
Cottonwood
Creek i s s u e s from a l a r g e p e re n n ia l s p r in g w ith numerous
s m a ll,
p e r e n n i a l and i n t e r m i t t e n t s p r i n g s f e e d i n g l a t e r a l l y i n t o th e
channel a lo n g i t s e n t i r e le n g th .
The s o u th f o r k o f C o tto n w o o d
C reek m e r g e s w i t h t h e n o r t h f o r k o f C o tto n w o o d C reek a p p r o x i ­
m ately I km upstream of i t s co n flu en ce w ith th e Madison River.
F ig u re 3.
The Topography of Cottonwood Creek i s C h a r a c te riz e d
by Moderate t o S teep Slopes.
17
Stream morphology of Cottonwood Creek i s h ig h ly v a r i a b l e over i t s
e n t i r e le n g th .
th e I n i t i a l
The c re e k flo w s over a r e l a t i v e l y l e v e l g r a d i e n t f o r
1.5 km below t h e h e a d w a t e r s p r i n g w i t h t h e g r a d i e n t
becoming g r a d u a lly s t e e p e r over th e re m a in in g 2.5 km.
A l e v e l p o r tio n
o f th e c re ek a p p ro x im a te ly I km downstream from th e h e ad w a te r s p rin g
w as c h o s e n f o r t h e s t u d y s i t e .
The c r e e k f l o w s a l o n g a 13 p e r c e n t
g r a d ie n t th ro u g h o u t th e study area.
The stre am bottom w i t h i n t h e study s i t e has a s u b s t r a t e o f f i n e
g ra v e l c o v e rin g the c e n te r channel and sand and s i l t alo n g th e w a te r
column - stre am bank i n t e r f a c e .
S p a tte r e d s e c t i o n s o f th e stream a re
covered w ith d e p o s i t s of sm all r u b b le and c o arse g ra v e l.
Stream flow
d is c h a rg e a s m easured a t th e downstream end o f th e study a re a , v a r i e s
c o n sid e ra b ly w ith in season.
J u n e t o 0.01
Flow v a l u e s r a n g e fr o m 0.03 m ^ /s e c i n
m ^ /s e c i n S e p te m b e r .
t h r o u g h o u t th e s t u d y s i t e .
C h an n el w i d t h and d e p th v a r y
Maximum c h a n n e l w i d t h b e tw e e n b an k s i s
a p p r o x i m a t e l y 8 m e t e r s w i t h a maximum d e p th o f a p p r o x i m a t e l y 1.6
m e te rs from the bank edge to stream bottom.
th e channel i s
The n a rro w e s t s e c t i o n o f
1.1 m e t e r s and s h a l l o w e s t s e c t i o n i s 0.21 m e t e r s .
C o tto n w o o d C re e k i s p r e d o m i n a n t l y r i f f l e s , w i t h p o o l s b e i n g l e s s
p re v a le n t.
The p r i m a r y s o u r c e o f d e b r i s w i t h i n t h e c r e e k c h a n n e l
r e s u l t s fr o m f a l l e n t r e e s and b r a n c h e s .
The b a n k s a r e p r i m a r i l y
form ed o f deep sandy-loam s o i l w ith l i t t l e or no bank rock.
S o ils
S o i l s o f t h e C o tto n w o o d C re e k d r a i n a g e a r e f o r m e d fro m h a r d ,
c o a r s e - g r a in e d m etam orphic rock.
a
co m p lic ate d
su ite
of
The m etamorphic ro c k i s composed o f
rock ty p e s.
These i n c l u d e
g ra n ite
and
18
am phibole g n e is s ,
a n d M ontagne
am p h o b o lite,
1980).
sandy-loam s o i l s ,
sc h ist,
q u a rtz ite ,
The m e ta m O rp h ic r o c k w e a t h e r s i n t o c o a r s e ,
which a r e w e l l - d r a i n e d and s u s c e p t i b l e t o e r o s io n
problems (V eseth and Montagne 1980).
The study s i t e i s com prised of
s o i l s developed from colluvium and a llu v iu m .
th e stu d y s i t e
and m a rb le (Veseth
( F i g u r e 4).
Three s o i l s a r e found on
The n o r t h and s o u t h f a c i n g s l o p e s a r e
composed o f co llu v iu m d e p o s its .
The n o rth f a c i n g s lo p e s a r e com prised
o f l o a m y - s k e l e t a l , m ix ed T y p ic C r y o r t h e n t s , w h i l e t h e s o u t h - f a c i n g
e x p o su res a r e a lo a m y - s k e l e t a l ,
mixed Typic C ry o b o ro ll.
r i p a r i a n z o n e i s a f i n e - l o a m y , m ix ed A rg ic C r y o b o r o l l .
ta b le
in
th e
rip a ria n
zone
v a rie s
fro m
a few
The a l l u v i a l
The w a t e r
c e n tim e te rs
to
a p p ro x im a te ly one m e te r below th e s o i l s u r f a c e .
S tr e a m b a n k s o i l t e x t u r e s v a r y a l o n g t h e l e n g t h o f t h e s t r e a m .
The predom inant s o i l t e x t u r e i s sandy-1 oam, w ith some a r e a s o f loamysand and loam.
C lim ate
A N a tio n a l Oceanographic and A tm ospheric A d m in is tr a tio n w e ath e r
re p o rtin g
s ta tio n i s lo c a te d a t
t h e Red B l u f f R e s e a r c h
S ta tio n
h e a d q u a r te r s .
The Red B l u f f a r e a h a s a f r o s t - f r e e p e r i o d l a s t i n g 75 t o 100
days.
During th e 1982 g r a z in g season, te m p e ra tu re s ranged from a h ig h
o f 31 °C t o a low o f - 3 °C.
The study s i t e r e c e i v e s betw een 400 mm and
510 mm o f p r e c i p i t a t i o n a n n u a l l y , i n c l u d i n g 1 ,200 mm o f snow.
The
snow c o l l e c t s i n l a r g e d r i f t s on t h e n o rth s lo p e s o f th e d ra in a g e and
p e rsists
u n til
e a rly
May.
Up t o
40
percen t
of
th e
annual
p r e c i p i t a t i o n f a l l s d u rin g t h e months o f May and June w h i l e th e p e rio d
19
F ig u r e 4 .
View of Cottonwood Creek I n d i c a t i n g th e L o c a tio n o f Three
S o il P i t s and T h e ir R e s p e c tiv e S o il C l a s s i f i c a t i o n .
F ine-lo am y , mixed
Arole C ryoboroll
20'
of minimum m o is tu r e a cc u m u la tio n o c c u r s from November u n t i l February
(NOAA 1982).
V e g e ta tio n
V e g e ta tio n a lo n g Cottonwood Creek i s h ig h ly v a r i a b l e .
c r i t e r i a e s t a b l i s h e d by C l a i r e and S to r c h ( in p r e s s ) ,
v e g e t a t i o n z o n e s b o r d e r C o tto n w o o d C re e k .
Based on
th r e e d i f f e r e n t
At t h e h e a d w a t e r s ,
a
s a g e b r u s h /g r a s s la n d zone b o rd e rs the c re e k channel, w h i l e w i t h i n th e
s t u d y a r e a , an a s p e r i / g r a s s / f o r b v e g e t a t i o n z o n e f o r m s tt i e d o m in a n t
rip a ria n
c o m p o n en t.
The l o w e r r e a c h e s o f C o tto n w o o d C re ek a r e
bord ered by a mixed b r o a d le a f s h r u b /c o n if e r o u s t r e e zone.
Using t h e
p r e d o m i n a n t s p e c i e s o f v e g e t a t i o n , s e v e r a l v e g e t a t i v e t y p e s can be
d e s c r i b e d w i t h i n t h e a s p e n / g r a s s / f o r b v e g e t a t i v e z o n e f o u n d on t h e
s t u d y s i t e (M o n tan a S t a t e R u r a l A re a s D e v e lo p m e n t C o m m itte e 1982)
(A p p e n d ix A).
How ever, f o r t h e p u r p o s e s o f t h i s s t u d y , v e g e t a t i o n t y p e s a re .
c o l l e c t i v e l y r e f e r r e d t o a s e i t h e r u p l a n d o r r i p a r i a n c o m m u n itie s .
The r i p a r i a n community i s com prised o f th e aspen,
a s p e n /w illo w ,
bog,
meadow and stre am bank v e g e t a t i o n ty p e s w h ile the upland community i s
com posed o f u p l a n d / g r a s s l a n d , s a g e b r u s h and a s p e n p a r k v e g e t a t i o n
ty p e s .
The r i p a r i a n com m unities a r e dom inated by Canada b lu e g r a s s (£oa
c o m n r e s s a L.).
n r a t e n s e L .),
re d to p
( A g r o s t i s s t o l o n i f e r a L.),
T im o th y ( Phleum
sm o o th brom e (Bromus i n e r m i s L e y s s . ) ,
beaked sedge
( C a re x r o s t r a t a S t o k e s ) . S p r e n g e l ’ s s e d g e ( C arex s p r e n g e l i i Dewey),
w h ite c lo v e r ( T r if o li u m re o e n s L.) w ith an o v e r s to r y o f q u ak in g aspen
( PoduI us
t r e m u l o i d e s M ich x .), w i l l o w ( S a l i x spp. L.),
chokecherry
21
( P r u n u s v l r g i n i a n a L . ) , and swamp g o o s e b e r r y ( R ib e s l a c u s t r e ( P e r s . )
P o ir.).
The upland com m unities a r e composed o f Canada b lu e g r a s s ,
n e e d le g ra s s ( S tio a v i r i d u l a T rin .),
g reen ,
n e e d l e a n d t h r e a d ( S t i p a c o m ata
T r i n. & R u p r .) , w e s t e r n w h e a t g r a s s (A g ro p y ro n s m i t h i i Rydb.), and
Idaho fe s c u e fF e s tu c a id a h o e n s is Elmer) w ith s c a t t e r e d dense s ta n d s of
m o u n t a i n b i g s a g e b r u s h ( A r t e m i s i a t r i d e n t a t a subsp. vaseyana (Rydb.)
)
B e e tle ) i n t e r s p e r s e d w i t h woods ro s e (Rosa w oods!! Lind L.) and Rocky
Mountain j u n i p e r ( J u n ip e r u s scopulorum Sarg.).
B o th t h e u p la n d and r i p a r i a n c o m m u n i t i e s h av e p o p u l a t i o n s o f
s e v e r a l in tr o d u c e d s p e c ie s .
o f f i c i n a l e L.),
These in c lu d e :
houndstongue (Cvnaglossum
s p o t t e d knapw eed ( C e n t a u r e a m a c u l o s a Lam .),
ta ll
l a r k s p u r ( D e lp h in iu m o c c i d e n t a l e W a ts .), Canada t h i s t l e ( C i r i c i u m
av arense (L.) Scop.),
and c h e a t g r a s s brome (Bromus te o to ru m L.).
Study S i t e
The Cottonwood Creek stu d y s i t e was s e l e c t e d f o r i t s u n if o r m ity
of v e g e ta tio n ,
s o ils,
s l o p e and s t r e a m m o rp h o lo g y .
N in e 0.5 ha
p a s t u r e s w e r e c o n s t r u c t e d on t h e s i t e t o p r o v i d e e i g h t p a s t u r e s f o r
g r a z in g t r e a t m e n t s and one p a s tu r e f o r an ungrazed c o n tr o l.
t h e p a s t u r e s c o n ta i n s a p p ro x im a te ly
u p la n d
c o m m u n itie s
(F ig u re
5).
Each of
equal p ro p o r tio n s o f r i p a r i a n and
The
p a stu re s
are
num bered
c o n s e c u t i v e l y one t h r o u g h n i n e , ■b e g in n in g w ith th e p a s t u r e f u r t h e s t
downstream.
P a s t u r e s one th r o u g h e i g h t r e c e i v e annual, f o u r te e n -d a y g ra z in g
tre a tm e n ts.
G r a z i n g i s i n i t i a t e d i n p a s t u r e one d u r i n g t h e sec o n d
w eek o f J u n e e a c h y e a r ( F i g u r e 6 ).
Upon c o m p l e t i o n o f a g r a z i n g
22
F ig u r e 5 .
View o f P a s t u r e 5 Show ing U pland and R i p a r i a n Community
Types.
F ig u re 6 .
D i a g r a m a t i c View o f P a s t u r e L a y o u t and G r a z i n g S c h e d u le
Used During th e 1981 and 1982 G razing Seasons.
GRAZING SCHEDULE
1 : JUNE 14 - JUNE 28
2 : JUNE 28 - JULY 12
3 : JULY 12 - JULY 26
4 : JULY 26 - AUGUST 9
5 : AUGUST 9 - AUGUST 23
6 : AUGUST 23 - SEPTEMBER 6
7 : SEPTEMBER 6 - SEPTEMBER 20
8 : SEPTEMBER 20 - OCTOBER 4
9 : UNGRAZED
23
p e r i o d , t h e c a t t l e w e r e moved t o t h e a d j o i n i n g u p s t r e a m p a s t u r e t o
avoid confounding o f w a t e r q u a l i t y d a t a w ith p re v io u s a c t i v i t y .
p a stu re
w as g r a z e d
d u rin g th e
sam e p e r i o d a n n u a l l y
Each
to m o n ito r
c u m u la tiv e y e a r l y e f f e c t s .
C a ttle
F o u r y e a r l i n g h e i f e r s w e re u s e d t o p r o v i d e a m o d e r a t e s t o c k i n g
ra te .
Spayed H e r e f o r d - A n g u s - T a r e n t a i s e c r o s s h e i f e r s w e i g h i n g an
a v e r a g e 232 k i l o g r a m s w e r e u s e d d u r i n g t h e 1981 s e a s o n and H e r e f o r d
h e i f e r s a v e r a g i n g 194 k i l o g r a m s w e re u s e d d u r i n g t h e 1982 s e a s o n .
B oth g r o u p s o r i g i n a t e d fro m t h e M ontana S t a t e U n i v e r s i t y , Bozeman
L iv e s to c k C enter and s p e n t t h e i r f i r s t y e a r i n p a s t u r e s and f e e d l o t s
a t th e c e n te r.
The h e i f e r s had no p r e v i o u s e x p e r i e n c e g r a z i n g o p e n
ra n g e la n d o r r i p a r i a n communities.
I t should be noted t h a t th e Cottonwood Creek s tu d y s i t e was once
p a r t of th e Cottonwood g r a z in g u n i t f o r th e Red B lu f f R esearch Ranch.
T his d ra in a g e
r e c e i v e s y e a r l y heavy g r a z i n g u s e fro m c a t t l e , s h e e p
and o c c a s i o n a l l y h o r s e s .
I n t h e p a s t , g r a z i n g h a s o c c u r r e d o n ly
d u rin g t h e summer and autumn w ith no use re c o rd e d d u r in g t h e w in te r .
The s i t e was a f f l i c t e d w i t h v a r i o u s l e v e l s o f l i v e s t o c k im p a c ts p r i o r
to th e i n i t i a t i o n o f t h i s study.
24
METHODS
Stream Channel S t a b i l i t y
S tr e a m b a n k s t a b i l i t y
was m o n i t o r e d a t f o r t y - f i v e p e r m a n e n t 1
t r a n s e c t s l o c a t e d a l o n g th e c r e e k c h a n n e l a s i t f l o w s th r o u g h t h e
study s i t e .
F iv e t r a n s e c t s ,
w ere l o c a t e d i n each
p o s itio n e d p e r p e n d ic u la r to t h e channel,
p a stu re .
The
c o n s e c u tiv e ly one th rough f o r t y - f i v e ,
tra n se c ts
w ere
num bered
b e g in n in g i n t h e downstream end
of p a s tu r e one and t e r m i n a t i n g i n th e u pstream end of p a s tu r e nine.
T ransect
lo c a tio n s
w ith in each
p o s i t i o n i n g th e f i r s t t r a n s e c t
p a s tu r e w ere d e te rm in e d
by
a t a randomly s e l e c t e d d i s t a n c e of one
t o f i v e m e te rs from th e downstream c r o s s - f e n c e .
The re m a in in g f o u r
t r a n s e c t s w ere ev en ly d i s t r i b u t e d a t t e n - m e t e r i n t e r v a l s a lo n g th e
r e m a i n d e r o f t h e c r e e k w i t h i n t h a t p a s t Urei
The c h a n n e l a r e a had
r e c e i v e d h e av y l i v e s t o c k u s e p r i o r t o t h e i n i t i a t i o n o f t h i s s t u d y ,
and
much o f t h e s t r e a m b a n k s w e r e a l r e a d y a t v a r i o u s l e v e l s o f
in s ta b ility .
A re a s s h o w in g e x c e s s i v e p r e - s t u d y l i v e s t o c k - r e l a t e d
i m p a c t s w e r e a v o i d e d when p o s i t i o n i n g t h e c h a n n e l t r a n s e c t s .
In
s i t u a t i o n s w h e re a t r a n s e c t l i n e w o u ld h a v e i n t e r s e c t e d a s e v e r e l y
damaged stre a m bank, th e t r a n s e c t was r e p o s i t i o n e d im m e d ia te ly upstream
of th e
dam aged a r e a .
T r a n s e c ts w ere
a lso
not
p la ce d
s u b j e c t i v e l y d e t e r m i n e d t o be i n a c c e s s i b l e t o c a t t l e .
in
areas
T herefore,
dense s ta n d s o f w illo w and swamp g o o seb e rry w ere avoided.
The e n d p o in ts o f each t r a n s e c t w ere perm anently marked w ith s t e e l ,
o r wooden pegs p o s itio n e d above th e h ig h w a te r mark a t a minimum o f 0.5
m e te rs from th e stream bank edge.
L o c a tin g th e t r a n s e c t e n d p o in ts 0.5
25
m fro m t h e bank ed g e w as done t o p r e v e n t t h e i r l o s s t o s tr e a m b a n k
s l o u g h i n g and t o e n s u r e t h e e n t i r e c h a n n e l , w h ic h may be s u b j e c t to
c a t t l e im p a c ts , i s b is e c te d by th e t r a n s e c t l i n e .
The l e n g t h o f e ac h t r a n s e c t l i n e v a r i e d
morphology of th e channel.
d e p e n d i n g upon t h e
P o r tio n s o f th e creek w ith s te e p banks and
a n a rro w c h a n n e l w e re c h a r a c t e r i z e d by s h o r t e r t r a n s e c t s ,
w h ile
s e c t i o n s o f th e channel which w ere d is h -s h a p e d g e n e r a l l y r e s u l t e d i n
lo n g e r t r a n s e c t l i n e s .
Each t r a n s e c t was measured a lo n g two a x e s:
v e rtic a l.
I) h o r i z o n t a l and 2)
A n y lo n m e t e r t a p e w as s t r e t c h e d and l e v e l e d b e tw e e n th e
tw o p e r m a n e n t t r a n s e c t e n d p o i n t s t a k e s t o r e p r e s e n t t h e h o r i z o n t a l
a x is.
The h e i g h t s o f t h e m e t e r t a p e on t h e e n d p o i n t s t a k e s w e re
recorded
and
th en
used
in
fu tu re
c o n s is te n c y betw een measurem ents.
tra n se c t
re a d in g s
to
ensure
A m e te r s t i c k h e ld p e rp e n d ic u la r to
th e nylon m e te r tap e was used t o p ro v id e a s c a l e f o r th e v e r t i c a l a x is
( F i g u r e 7).
The h o r i z o n t a l m e te r t a p e w as u s e d a s a b a s e l i n e fro m w h ic h
v e r t i c a l m easurem ents a r e made t o th e stre am channel.
Measurements of
th e stre am channel w ere ta k en a t ten-cm i n t e r v a l s a lo n g t h e b a s e lin e
ta p e .
The d i s t a n c e b e tw e e n t h e b a s e l i n e t a p e and t h e c h a n n e l w as
re c o rd e d t o th e n e a r e s t c e n ti m e te r (F ig u re 8a).
The shaded p o r ti o n o f
F ig u re 8b r e p r e s e n te d the c r o s s - s e c t i o n a l a re a of t h a t p o r ti o n of th e
c re e k .
M e a s u re m e n t o f t h e w a t e r d e p th w as c o n d u c te d by r e c o r d i n g t h e
v e r t i c a l d i s t a n c e b e tw e e n t h e b a s e l i n e t a p e and t h e w a t e r s u r f a c e ,
26
f o l l o w e d by a m e a s u re m e n t o f t h e d i s t a n c e fro m t h e t o p o f t h e w a t e r
column to the streambed.
F ig u re 7 .
Channel Measurements Were Taken Using a H o r iz o n ta lly
S tr e t c h e d Meter Tape and V e r t i c a l l y Held Meter S tic k .
Changes i n stream channel s t a b i l i t y were re c o rd ed f o ll o w i n g th r e e
m o n i t o r i n g p e r i o d s : I) t h e 1981 g r a z i n g s e a s o n , 2) t h e 1982 g r a z i n g
season,
and 3) th e w i n t e r of 1981-1982.
Each t r a n s e c t was measured i n s p r in g tim e b e fo re th e f i r s t g ra z in g
perio d .
T r a n s e c ts w i t h i n a p a s tu r e r e c e i v i n g a g ra z in g tr e a tm e n t were
rem easured
im m e d ia te ly
upon
c o m p le tio n
of
th e
g ra z in g
p e rio d .
T r a n s e c t s l o c a t e d w i t h i n t h e c o n t r o l p a s t u r e w e re m e a s u r e d i n t h e
sp rin g p rio r
to th e f i r s t
g ra z in g
p e r i o d and i n
th e f a l l
a fte r
27
F ig u re 8a.
Measurements Were Taken t o th e N earest C en tim eter Along
t h e H o r i z o n t a l P la n e and a t Ten C e n t i m e t e r I n t e r v a l s
Across th e V e r t i c a l Plane.
STREAM CHANNEL C R O S S - S E C T I O N
MEASUREMENT
F ig u re 8b.
The T r a n s e c t ' s C r o s s - S e c t i o n a l Area i s R e p r e s e n t e d by
th e Shaded P o r tio n o f th e I l l u s t r a t i o n .
STREAM CHANNEL C R O S S - S E C T I O N AREA
28
co m p le tio n o f th e l a s t g r a z in g p e rio d .
A r e p r e s e n t a t i o n o f th e stream
c h a n n e l c o n f i g u r a t i o n b e f o r e and a f t e r e a c h g r a z i n g t r e a t m e n t w as
d e r iv e d from th e t r a n s e c t m easurem ents,
a llo w in g a d e te r m in a tio n of
r e l a t i v e a m o u n ts o f c h a n n e l a l t e r a t i o n s w h ic h o c c u r r e d d u r i n g t h e
g r a z i n g p e rio d .
Changes i n t h e stre am channel which o c cu rred d u r in g t h e w i n t e r
between th e 1981 and 1982 f i e l d se a so n s were d eterm in ed by comparing
th e channel c o n fig u ra tio n s a f t e r
c o m p l e t i o n o f t h e 1981 g r a z i n g .
t r e a t m e n t s and th e p r e - g r a z in g m easurem ents of th e 1982 season.
Stream Flow Discharge
F i v e w a t e r s a m p l i n g p o i n t s , d e s i g n a t e d A, B, C, D and E w e re
lo c a te d
im m e d ia te ly
d o w n s tre a m
r e s p e c t i v e l y ( F i g u r e 10).
of
p a stu re s
I,
3,
5,
7 and
9,
W ater f lo w and s u s p e n d e d s e d i m e n t w e re
m o n ito red a t each of th e s e s t a t i o n s .
Water s ta g e was measured c o n tin u o u s ly u s in g S tev en s Type-F Level
R e c o r d e r s m o u n te d on P a r s h a l l f l u m e s
P a r s h a l l flu m es w ere used i n th e study.
( F i g u r e 11).
Two s i z e s o f
Flumes w ith t h r e e - i n c h t h r o a t
w i d t h s , h a v i n g a c a p a c i t y o f one c u b i c f o o t p e r s e c o n d , w e re u s e d a t
s t a t i o n s B, C, D and E, w h i l e a s i x - i n c h f lu m e w i t h t h r e e c u b i c f e e t
p e r s e c o n d c a p a c i t y w a s l o c a t e d a t s t a t i o n A.
The l a r g e r flu m e a t
s t a t i o n ' A w as r e q u i r e d t o a c c o m o d a te p e ak flo w l e v e l s e n c o u n t e r e d
d u rin g s p r i n g ru n o ff.
The Stev en s r e c o r d e r s m easure w a te r s ta g e on a co n tin u o u s b a sis .
Recorder s t r i p c h a r t s w ere r e p la c e d e v ery 14 days i n c o n ju n c tio n w ith
c o m p le tio n o f a g r a z in g p e r io d and t h e subsequent movement o f c a t t l e
F ig u re 9•
D ia g ra m atic Sk etch es o f Each T ran sect B efore and A fte r Grazing Were
Produced Using the Channel Measurement Data.
RI PARI AN G R A Z I N G S T U D Y
COTTONWOOD CREEK
RED BLUF F , M O N T A N A
T R A N S E C T 19
ro
vo
30
F ig u re 10.
D ia g ra m a tic I l l u s t r a t i o n o f P a s tu re Layout I n d i c a t i n g With
B la c k S q u a r e s t h e L o c a t i o n o f W a te r S a m p lin g S t a t i o n s .
Each u n i t i s 0 .5 h e c ta r e .
PARSHALL FLUME AND SUSPENDED SEDIMENT COLLECTOR
LOCATIONS
F ig u re 11.
P a r s h a ll Flumes and S te v e n s Type - F Continuous R ecorders
Were Used t o Measure Stream Flow.
BI
t o an a d j o i n i n g p a s t u r e .
S tre a m f lo w d i s c h a r g e w as m o n i t o r e d fro m
mid-May u n t i l m id-O ctober o f each f i e l d season.
Water flow c h a r t s w ere analy zed u s in g a com puterized d i g i t i z e r to
d e te rm in e average s ta g e d u rin g a c o l l e c t i o n period.
The a v erag e w a te r
depth in f o r m a t io n was used t o d e te rm in e t o t a l c u b ic m e te r s o f w a te r
p a s s in g th ro u g h a s t a t i o n d u rin g th e c o l l e c t i o n p e r io d f o ll o w i n g
p r o c e d u r e s o u t l i n e d i n t h e S t e v e n s W a te r R e s o u r c e s D a ta Handbook
(1975).
The i n f o r m a t i o n was th e n c o n v e rte d t o be e x p re s s e d a s w a te r
d is c h a r g e i n c u b ic m e te r s p er second.
T h i s w as done t o p r e s e n t t h e
d a ta i n a fo rm at c o m p a tib le w ith o th e r p u b lish e d
w a te r q u a lity
s t u d i e s r e p o r t i n g suspended sed im en t c o n c e n tr a tio n s .
Suspended Sediment
I n t h i s s t u d y , s u s p e n d e d s e d i m e n t c o n c e n t r a t i o n s w e r e s a m p le d
u s in g m o d ifie d s i n g l e s ta g e suspended sed im en t sam p ler (Inter-A gency
Committee on Water R esources 1983). The m o d ified u n i t i s desig n ed to
s a m p le c o n t i n u o u s l y a p o r t i o n o f t h e w a t e r colum n. A c c u ra c y o f t h e
s a m p l e r w as d e t e r m i n e d by d i v e r t i n g a n d c a p t u r i n g t h e t o t a l w a t e r
column and e v a lu a tin g th e t o t a l grams of sedim ent p er u n i t volume of
w a t e r . T h i s w a s c o m p ared t o a c o l l e c t i o n made by t h e s a m p l e r u n i t s .
This p ro c e d u re was r e p e a te d f o u r tim e s.
R e s u lts i n d i c a t e c o n s id e ra b le acc u ra cy of th e sam p lin g u n its .
Average t o t a l c o n c e n tr a tio n s of sed im en t from th e e n t i r e w a te r column
w e re
33.0
m g/1,
w h ile
c o n c e n tr a tio n o f 32.0 mg/1.
th e
sam p ler
u n its
c o lle c te d
an a v erag e
No d i f f e r e n c e was noted betw een th e t o t a l
c o l l e c t i o n and sa m p le r c o l l e c t i o n u s in g an A n a ly sis o f V ariance t e s t
(P2 .01).
32
Suspended sed im en t s a m p le rs w ere l o c a t e d a t each w a te r sam pling
statio n .
U.S- U-59
The sa m p le rs used i n t h i s stu d y w ere
m o d ified s i n g l e - s t a g e ,
suspended sed im en t sam pler (In ter-A g en cy Committee on Water
R e s o u r c e s I 963).
A b a t t e r y of fo u r sed im en t c o l l e c t i o n s i s lo c a te d
w ith each P a r s h a l l flu m e (F ig u re 12).
The s a m p le rs c o n s i s t e d o f a 500 ml s e t t l i n g b o t t l e f i t t e d w ith a
ru b b e r s to p p e r and two tu b e s which serv ed a s i n t a k e and e x h au st p o r ts
( F i g u r e 13).
An i n t a k e p o r t w as c o n n e c t e d by p l a s t i c t u b i n g ; t o a
c o l l e c t i o n p o in t p o s itio n e d w i t h i n th e d iv e r g in g o u t l e t s e c t i o n of th e
P a r s h a l l flume.
As w a te r flow ed th ro u g h th e tu b in g i n t o t h e b o t t l e ,
suspended sed im en t s e t t l e d o u t i n th e b o t t l e and s e d i m e n t - f r e e w a te r
e x ite d th ro u g h th e e x h au st p o rt.
T h i s d e s i g n a l l o w e d w a t e r t o flo w
through th e system p e r m i t t i n g co n tin u o u s sampling.
The s a m p le rs w ere
a b l e t o c o l l e c t sedim ent i n th e s i z e ran g e o f 63 ym to 500 ym i n s iz e .
P a r t i c l e s i z e s s m a l le r th an 63 Pm w i l l no t s e t t l e o u t o f s u sp e n sio n i n
t h e s e t t l i n g b o t t l e s and p a r t i c l e s l a r g e r th a n 500 -pan w i l l g e n e r a lly
not be c a r r i e d i n s u sp e n sio n i n a c re e k w i t h low flo w s (EPA 1979).
33
F ig u r e 12.
D i a g r a m a t i c V iew s o f W a te r S a m p lin g S t a t i o n I n d i c a t i n g
L o c a tio n o f Suspended Sediment Samplers.
STEVENS RECORDER
SETTLI NG B OT T L E S
I O
FLOW
o z
PARSHALL FLUME
SIDE VIEW
SETTLI NG BOTTLES
FLOW
C OL L E CT I ON POI NTS
TOP VIEW
34
F ig u re 13.
M odified C o l l e c t i o n / S e t t l i n g B o t t l e s C o n tain in g In ta k e and
Exhaust P o r ts t o Allow f o r Continuous Water Flow.
EXHAUST PORT
INTAKE PORT
5 0 0 ml
The c o l l e c t i o n p o i n t s , p o s i t i o n e d w i t h i n t h e d i v e r g i n g o u t l e t
s e c t i o n of th e P a r s h a ll flum e, were a s e r i e s o f 0.64-cm d ia m e te r copper
tu b e s s e t a t fo u r h e ig h ts .
The c o l l e c t i o n p o i n t s w e r e n u m b ered one
through f o u r and were p o s itio n e d i n a v e r t i c a l a r r a y a t s e t d is ta n c e s
from th e flum e bottom.
12.5 cm,
P o in t I was 23 cm from th e bottom , p o in t 2 i s
p o i n t 3 i s 7.5 cm and p o i n t 4 i s 2.5 cm a b o v e t h e flu m e
bottom.
S u s p e n d e d s e d i m e n t was c o l l e c t e d c o n t i n u o u s l y fro m e a r l y June
u n t i l m id-O ctober.
S e t t l i n g b o t t l e s from a l l f i v e sam p lin g s t a t i o n s
w ere r e p la c e d every f o u r te e n days upon co m p le tio n of a g r a z in g p e rio d .
35
The sed im en t sam ples c o l l e c t e d d u rin g each g ra z in g p e rio d were
d r ie d f o r 24 h o u rs a t 50°C.
The d r ie d m a t e r i a l was weighed then ashed
f o r 12 h o u r s a t 500°C i n a m u f f l e f u r n a c e , a f t e r w h ic h t h e m a t e r i a l
was rew eighed to d e te rm in e th e amount o f m in e ra l and o rg a n ic m a tte r i n
each sample.
To p r e s e n t s e d i m e n t d a t a on a g r a m - p e r - c u b i c - m e t e r - o f - w a t e r b a s i s , i t w as n e c e s s a r y t o d e t e r m i n e w h a t p r o p o r t i o n o f t h e w a t e r
column i s a c t u a l l y sampled.
This v a lu e was th e n used t o i n t e r p o l a t e
th e t o t a l amount of suspended sedim ent b ein g tr a n s p o r te d by th e w a te r
column d u rin g t h e fo u r te e n -d a y c o l l e c t i o n period.
A com puter program
w as w r i t t e n , u n d e r t h e g u id a n c e o f Dr. J o h n E. T a y l o r (1 9 8 3 ) o f t h e
Department o f Animal & Range S c ie n ce s,
Montana S t a t e U n iv e r s ity ,
to
c a l c u l a t e s e d i m e n t t r a n s p o r t fro m t h e t o t a l w a t e r flo w c o l l e c t e d
d u rin g a sam p lin g p e rio d
(A p p en d ix B).
The p ro g ram
c a lc u la te d
s e d i m e n t t r a n s p o r t by i n p u t t i n g a v e r a g e s t a g e h e i g h t , t o t a l w a t e r
flo w , and t o t a l grams o f sedim ent c o l l e c t e d d u rin g a sam p lin g period.
S o il M oisture
S o il m o is tu re was measured u s in g a T ro x le r n e u tro n probe.
Access
t u b e s w e re l o c a t e d i n p a s t u r e s 2 , 4 , 6 , 8 and 9 a l o n g t r a n s e c t l i n e s
s e t p e rp e n d ic u la r to t h e stream channel.
f o u r a c c e s s tu b e s.
Each t r a n s e c t l i n e c o n ta in s
Two tu b e s were p o s itio n e d i n the u p la n d s and two
o t h e r s on e i t h e r s id e of th e stream bank f o r each t r a n s e c t l i n e (Figure
14).
S o i l m o i s t u r e w as r e c o r d e d a t d e p t h s o f 15 cm, 30 cm, 45 cm, 60
cm, 75 cm and 90 cm.
High w a te r t a b l e s i n c e r t a i n l o c a t i o n s r e s u l t e d
i n some t u b e s n o t b e i n g m e a s u re d a t a l l s i x d e p t h s d u r i n g t h e f i e l d
season.
36
F i g u r e Vi.
Neutron Probe Access Tubes Were P o s i t i o n e d i n t h e Upland
a n d A lo n g t h e S t r e a m b a n k s . S o i l M o i s t u r e M e a s u r e m e n t s
Were T ak e n a t 15, 3 0 , 4 5 , 6 0 , 7 5 , and 90 C e n t i m e t e r
Depths.
MEASURED
DEPTHS
N E U T R O N PROBE
15 c m
A C C E S S TUBE L O C A T I O N S
30
45
60
75
80
UPLAND
STREAMBANK
UPLAND
M e a s u r e m e n t o f s o i l m o i s t u r e w a s i n i t i a t e d i n e a r l y - J u n e and
c o n t i n u e d t h r o u g h o u t th e g r a z i n g s e a s o n a t
coincide
w ith
com pletion of
fourteen-day
each g r a z i n g p e r io d .
i n t e r v a l s to
The l a s t
soil
m o i s t u r e r e a d i n g was co nd uc te d f o u r t e e n d ays a f t e r c o m p l e t i o n of t h e
l a s t grazing treatm ent.
S o il m o i s t u r e was re c o rd e d a t a l l
a c c e s s t u b e s on each s a m p l i n g d a t e .
tw enty
Access t u b e s were n o t e s t a b l i s h e d
f o r p a s t u r e 9 u n t i l t h e 1982 f i e l d seas on .
N eutron
outlined
probe
data
was
analyzed
using
standard
procedures
by T a y l o r (1972).
V egetation U t i l i z a t i o n
The a m o u n t o f h e r b a g e r e m o v e d f r o m a p a s t u r e d u r i n g a g r a z i n g
t r e a t m e n t w a s e s t i m a t e d a t t h e end o f t h a t g r a z i n g p e r i o d u s i n g t h e
cage co m p a r is o n method f o l l o w i n g p r o c e d u r e s d e s c r i b e d by Brown (1954).
U t i l i z a t i o n w as d e t e r m i n e d a t s i t e s r a n d o m l y s e l e c t e d w i t h i n t h e
3.7
v a rio u s v e g e t a t i o n ty p e s found i n a p a s tu r e .
The s i t e s w ere p r o te c te d
f o r sam p lin g w ith tw e lv e I m x 2 m x I m g ra z in g u t i l i z a t i o n cages.
The number of cages p la ce d i n each v e g e t a t i o n type w ere s u b j e c t i v e l y
d e t e r m i n e d b a s e d on t h e s i z e o f t h a t ty p e .
S a m p lin g c o n s i s t e d o f
c l i p p i n g v e g e t a t i o n ( t o a h e i g h t o f one cm.) w i t h i n a 0.25 s q u a r e
m e te r p l o t fram e beneath th e u t i l i z a t i o n cage,
A com plim entary p l o t
w as c l i p p e d w i t h i n one t o tw o m e t e r s o u t s i d e t h e u t i l i z a t i o n cag e.
The v e g e t a t i o n was s e p a ra te d by s p e c ie s and d r ie d t o a c o n s ta n t w eig h t
to e x p re s s p ro d u c tio n e s t i m a t e s on an oven-dry b a s is .
The p e r c e n t o f v e g e t a t i o n u t i l i z e d d u r i n g a g r a z i n g p e r i o d w as
d e term in e d by th e r e l a t i o n :
% u tiliz a tio n =
w here
P e q u a ls
th e
o v en-dry
P -G
P
x 100%
w e ig h t
of v e g e ta tio n
c lip p e d
fro m
p r o t e c t e d p l o t s and G i s t h e o v e n - d r y w e i g h t o f v e g e t a t i o n c l i p p e d
fro m g r a z e d p l o t s .
The p e r c e n t u t i l i z a t i o n f o r e ach s p e c i e s was
d e term in e d and then compiled by v e g e t a t i o n type.
d iffe re n t
v e g e ta tio n
ty p e s
community c l a s s i f i c a t i o n s .
w as
p o o le d
in to
U t i l i z a t i o n of the
u p la n d
or
rip a ria n
38
RESULTS
I n t h e f o l l o w i n g s e c t i o n s , p a s t u r e n u m b ers and g r a z i n g p e r i o d
n u m b e rs a r e
used
s y n o n y m o u sly
to ! f a c i l i t a t e
g ra p h ic s
and
d a ta
p re sen ta tio n .
Stream Channel S t a b i l i t y
Changes i n stream channel a r e a w ere found t o be e i t h e r p o s i t i v e
or n e g a tiv e v a lu e s.
P o s i t i v e v a lu e s c o rre sp o n d e d to an i n c r e a s e i n
channel a re a, w h ile n e g a tiv e v a lu e s re p re s e n te d a d e c re a se in area.
I n c o m p i l i n g t o t a l c h a n g e s i n c u r r e d by a s t r e a m
m o n i t o r i n g p e r i o d , a b s o l u t e v a l u e s w e r e u sed .
s e c tio n d u rin g a
T h is p r o c e d u r e w as
i n s t i t u t e d t o e l i m i n a t e th e c o u n te r a c tin g e f f e c t s of summing n e g ativ e
and p o s i t i v e v a lu e s , which could r e s u l t i n an u n d e r e s tim a tio n o f t o t a l
stre am channel a l t e r a t i o n s .
T o ta l stre am channel a l t e r a t i o n s d e riv e d f o r each p a s t u r e d u rin g
a r e s p e c t i v e m o n ito rin g p e rio d a r e i l l u s t r a t e d i n F ig u r e s 15, 16, and
17.
P a s tu re numbers a r e r e p r e s e n te d on t h e h o r i z o n t a l a x i s and stream
channel changes i n sq u are c e n t i m e t e r s a r e d i s p l a y e d on t h e v e r t i c a l
a x is.
S tr e a m c h a n n e l a l t e r a t i o n s w h ic h o c c u r r e d d u r i n g t h e I 981 and
1I 982 g r a z i n g s e a s o n m o n i t o r i n g p e r i o d s a r e p r e s e n t e d i n F ig u r e ; 15.
D u r in g b o th
th e
1981
and
1982 g r a z i n g
seasons,
stre a m
channel
a l t e r a t i o n s w e re s i g n i f i c a n t l y g r e a t e r (P < 0 .01) d u r i n g t h e f i r s t
h a l f o f t h e g r a z i n g s e a s o n (Ju n e 14 - A ugust 9) t h a n d u r i n g t h e l a s t
h a l f o f t h e s e a s o n (A u g u st 9 - O c to b e r 4).
P a s t u r e 2 ( J u n e 28 - J u l y
12) e x h i b i t e d t h e g r e a t e s t l e v e l o f r e l a t i v e ch an g e d u r i n g b o th t h e
39
C H A N G E in C H A N N E L A R E A ( c m 2 )
F i g u r e 15.
Change i n S t r e a m C h a n n e l A r e a (cm2 ) O b s e r v e d D u r i n g t h e
1981 and 1982 G r a z in g Seasons.
P<0.0 1
198 I
1982
PASTURE
40
1981 and 1982 g r a z in g s e a s o n s and was s i g n i f i c a n t l y d i f f e r e n t from a l l
o th e r p a s t u r e s .
P a s t u r e 8 ( S e p te m b e r 20 - O c to b e r 4) r e p r e s e n t e d t h e g r a z i n g
p e rio d showing th e l e a s t amount of stream channel a l t e r a t i o n .
s ig n ific a n tly
a lte ra tio n s
in
d iffe re n t
p a stu re
fro m
p a stu re s
I th r o u g h 4 ,
8 w ere a p p ro x im a te ly
equal
yet
to
I t was
channel
(1 9 8 1 ) o r
s l i g h t l y lo w e r ( 1982) t h a n t h e c h a n n e l a l t e r a t i o n s r e c o r d e d i n t h e
ungrazed c o n t r o l p a s tu r e 9.
The r e l a t i v e am ount o f s t r e a m
channel a l t e r a t i o n s ex p ressed
w i t h i n e ach p a s t u r e a p p e a r s t o be c o n s i s t e n t fro m y e a r t o y e a r .
Channel a l t e r a t i o n s from 1981 were not s i g n i f i c a n t l y d i f f e r e n t from
th o s e re c o rd e d f o r the same p a s tu r e d u rin g th e 1982 g r a z in g season.
The
1981
and
1982
stre a m
channel
a lte ra tio n
d a ta
w ere
c o l l e c t i v e l y a n a l y z e d u s i n g a l i n e a r r e g r e s s i o n to d e t e r m i n e i f a
t r e n d i n channel a l t e r a t i o n s e x i s t s .
C a lc u la tio n s produced a n e g a tiv e
s lo p e :
Y = -0.41 X +74.96
i n d i c a t i n g a d e c r e a s i n g t r e n d i n c h a n n e l a l t e r a t i o n s fr o m e a r l y t o
l a t e i n th e season.
F ig u re
16 r e p r e s e n t s
th e
stre a m
channel
a l t e r a t i o n s , w h ich
o c c u rre d d u rin g th e w i n t e r o f 1981-1982 m o n ito r in g p e rio d .
R e la tiv e
changes i n channel a re a w ere g r e a t e s t i n p a s tu r e s I and 2 and lo w e st
i n p a s t u r e s 8 and 9.
However,
th e r e was no s i g n i f i c a n t d i f f e r e n c e i n
channel a l t e r a t i o n s among t h e p a s tu re s .
41
CHANGE IN CHANNEL AREA ( c m 2 )
F i g u r e 16.
Change i n S tre am Channel Area (cm2 ) Observed F o l l o w i n g t h e
W i n t e r o f 1981-1982.
P<0.01
42
L i n e a r r e g r e s s i o n a n a l y s e s o f w i n t e r d a t a p ro d u c e d a n e g a t i v e
slo p e :
Y = -0 .6 6 X +77.94
i n d i c a t i n g a d e c l i n e i n damage from e a r l y to l a t e grazed p a s tu r e s .
C h an n el a l t e r a t i o n s r e c o r d e d d u r i n g t h e w i n t e r o f 1981-1982
m o n ito r in g p e rio d w ere found to be ,10 t o 800 p e rc e n t g r e a t e r than th e
stream channel changes, re c o rd e d d u rin g t h e g ra z in g s e a so n s o f 1981 and
1982.
The t o t a l stre am channel changes which o c cu rred d u rin g t h e twoy e a r s t u d y w e re d e t e r m i n e d by c o m p a r in g t h e c h a n n e l a r e a s r e c o r d e d
b e f o r e t h e I 981 g r a z i n g s e a s o n t o t h e c h a n n e l a r e a s r e c o r d e d a t t h e
end of th e 1982 g r a z in g season.
17.
These r e s u l t s a re p re s e n te d i n F ig u re
The g r a p h show s t h a t t h e d e g r e e o f s t r e a m c h a n n e l a l t e r a t i o n s
g r a d u a lly d e c r e a s e s a s th e season p r o g r e s s e s i n a p a t t e r n s i m i l a r to
t h e y e a r l y g ra z in g seaso n changes.
P a s tu r e 2 a g a in showed t h e g r e a t e s t l e v e l s o f channel a l t e r a t i o n s
and was s i g n i f i c a n t l y d i f f e r e n t from a l l th e o th e r p a s tu r e s .
P a s tu re s
7 and 8 both i n d i c a t e d l e s s channel a l t e r a t i o n s th a n d id t h e ungrazed
c o n tro l
p a stu re ,
9.
A lin e a r re g re ssio n
te st
of t o t a l
channel
a l t e r a t i o n s produces t h e e q u a tio n :
Y = - I .56 X +137.30
i n d i c a t i n g a d e c r e a s in g tre n d i n changes of channel a r e a from p a s tu r e
I through p a s tu r e 9.
As p r e v io u s ly m entioned,
changes i n channel a re a a r e denoted by
p o s i t i v e or n e g a tiv e v a lu e s i n d i c a t i n g e i t h e r an in c r e a s e or d e c re a se
in channel area.
A n a l y s i s o f t h e d i r e c t i o n o f c h an g e show s l i t t l e
43
T o t a l Change i n S t r e a m C h a n n e l A rea (cm2 ) O b s e r v e d From
t h e S p r i n g o f 1981 U n t i l th e F a l l o f 1982.
CHANGE IN CHANNEL AREA ( c m 2)
F i g u r e 17.
P CO. OI
P AS T URE
44
c o n s i s t e n c y b e tw e e n t h e 1981 and 1982 g r a z i n g p e r i o d s ( T a b le I ) .
C o m p a ris o n o f t h e two g r a z i n g
seasons re v e a ls
th a t 9 tra n s e c ts
i n c r e a s e d i n a r e a and 9 t r a n s e c t s d e c r e a s e d i n a r e a d u r i n g b o th
g ra z in g seasons.
area
one y e a r
in c o n siste n c y
tra n se c ts.
Y et, d u r i n g b o th y e a r s , 27 t r a n s e c t s i n c r e a s e d i n
and d e c r e a s e d
in
th e
ty p e
of
in
area
changes
th e
b e in g
o th e r
re v e a lin g
recorded
at
an
th ese
C h an n el a l t e r a t i o n s w h ic h o c cu rred d u rin g t h e w i n t e r of
19 81- 1982 show 32 t r a n s e c t s i n c r e a s i n g i n a r e a and 13 t r a n s e c t s
d e c r e a s i n g i n a re a .
There was no s i m i l a r i t y between w hich t r a n s e c t s
in c r e a s e d i n a r e a and which d ecrea se d when comparing th e 1981 and 1982
g ra z in g p e r io d s t o t h e o v e r - w in te r a l t e r a t i o n s .
T o ta l stre am channel a l t e r a t i o n s over th e tw o -y ear, stu d y show 34
t r a n s e c t s i n c r e a s e d i n a r e a w h ile only 11 d e c re a se d i n a r e a .
T ran sect
9, l o c a t e d i n p a s tu r e 2, e x h i b i t e d th e g r e a t e s t degree of i n c r e a s e i n
c h a n n e l a r e a (144.39 crn^), and t r a n s e c t 19. i n p a s t u r e 4 showed t h e
g r e a t e s t d e c r e a s e (24.54 cm2 ).
T r a n s e c t s 4 th r o u g h 6 and 30 th r o u g h
33 a p p e a r t o be tw o a r e a s o f d e p o s i t i o n w i t h i n t h e s t r e a m c h a n n e l.
These d e p o s i t i o n a r e a s c o n t a i n tw o t h i r d s o f t h e t r a n s e c t s w h ic h
c o n s i s t e n t l y d e c re a se d i n a re a .
S o il M oisture
S o il m o is tu re d a ta w ere analy zed f o r th e to p 45 cm of s o i l .
This
d e p t h w as s e l e c t e d due t o i t s g r e a t e r , p o t e n t i a l s u s c e p t i b i l i t y t o
l i v e s t o c k im p a c ts and because s o i l m o is tu r e v a r i e s l i t t l e below 45 cm
(Papendick,
Cochran and Woody 1971).
The average s o i l m o is tu re of th e
t o p 45 cm o f s o i l f o r a l l s t r e a m b a n k a c c e s s t u b e s i s p r e s e n t e d i n
Tabl e I .
D ir e c tio n o f change e x h ib ite d by stream channel c r o s s - s e c t i o n s d u rin g t h e 1981 and 1982
g ra z in g seasons and the t o t a l change from pre-1981 to p o st-1982.
I n c r e a s e s in channel a r e
d e s ig n a te d by (+) and d e c r e a s e s i n channel a r e d e sig n a te d by ( - ) .
Pasture
Transect
1
I
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
2
3
4
5
G r az in g Season
1981
1982
+
+
+
+
+
+
+
+
+
+
-
-
-
-
—
+
-
—
+
+
-
+
+
-
+
+
+
+
-
+
+
Pre-1981
to
Post-1 982
+
+
+
+
+
+
+
Pasture
Transect
6
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
7
8
m
m
—
+
+
+
—
+
+
+
+
+
+
+
—
+
+
+
+
_
+
+
+
+
+
+
+
9 C ontrol
G r a z in g Season
1981
1982
+
+
Pre-1981
to
P o s t - 198?
+
+
+
+
+
+
+
+
+
+
—
4r
Vl
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
46
F i g u r e 18.
S o i l m o i s t u r e w as s a m p le d a t t h e end o f e ac h g r a z i n g
p e rio d and p re s e n te d h e re a s p a s tu r e numbers.
During both th e 1981 and 1982 sea so n s,
s o i l m o is tu re v a lu e s w ere
found to be h i g h e s t i n th e e a r l y g r a z in g p e rio d s fo llo w e d by a ra p id
d e c re a se th rough g ra z in g p e rio d s I and 2 and a g ra d u a l d e c re a se u n t i l
p e rio d s 6 (1982) and 7 (1981) when f a l l
p r e c i p i t a t i o n in c r e a s e d s o i l
and m o is tu r e l e v e l s .
O v e r a l l s o i l m o i s t u r e l e v e l s w e r e h i g h e r i n I 982 t h a n i n 1981.
T h is i s e s p e c i a l l y e v i d e n t d u r i n g t h e f a l l s o i l m o i s t u r e r e c h a r g e
p e rio d .
F a l l re c h a rg e o c c u rre d e a r l i e r and was o f a g r e a t e r magnitude
t h a n i n I 981.
Stream Flow Discharge
F i g u r e 19 r e p r e s e n t s w a t e r f lo w d a t a from' I 981 and 1982 a s t h e
av erag e flow from a l l f i v e sam p lin g s t a t i o n s a t the end of a g ra z in g
p erio d .
Flow d a ta a r e p re s e n te d on a m^/day b a s is .
During b o th 1981 and 1982,
T th ro u g h
TO,
th u s
e n d in g
peak flow o c c u rre d a p p ro x im a te ly June
a p p ro x im a te ly
i n i t i a t i o n of any g r a z in g tr e a tm e n ts .
d u rin g th e f i r s t
fo u r
days
th e
Flow l e v e l s r a p i d l y decreased
f o u r g r a z i n g p e r i o d s and s t a b i l i z e d
re m a in d e r of th e g ra z in g season.
b efo re
d u rin g th e
L i t t l e f a l l r e c h a r g e w as n o te d .
Flow l e v e l s d u r i n g ,1982 w e re g e n e r a l l y g r e a t e r t h a n d u r i n g t h e 1981
seaso n
47
Streambank S o il M o istu re ($) Recorded During th e 1981 and
1982 G razing Seasons Using a T ro x le r Neutron Probe.
S T R E A MB A N K SOI L MO I S T U R E ( %)
F ig u r e 18.
I 982
198 1
PASTURE
48
F ig u re 19.
Water Volume Recorded f o r Cottonwood Creek D uring th e 1981
and 1982 G razing Seasons (m^/day).
198 1
1982
PASTURE
49
Suspended Sediment
Suspended sed im en t d a ta a r e p re s e n te d i n F ig u re s 20 and 21.
The
g r a p h s p r e s e n t t h e am o u n t o f s u s p e n d e d s e d i m e n t c o l l e c t e d d u r i n g a
g ra z in g p e r io d a t each sam p lin g s t a t i o n .
S a m p lin g s t a t i o n s a r e
d e s i g n a t e d A, B, C, D and E on t h e r i g h t - h a n d a x i s o f t h e g ra p h .
The
fo reg ro u n d a x i s r e p r e s e n t s t h e p a s tu r e number or g r a z in g p e r io d d u rin g
which sed im en t was c o l l e c t e d .
The v e r t i c a l a x i s d i s p l a y s th e amount
o f s e d i m e n t c o l l e c t e d d u r i n g e a c h g r a z i n g p e r i o d i n g/m ^ o f w a t e r
flow.
The shaded p o r t i o n s o f each graph r e p r e s e n t th e l o c a t i o n o f th e
c a ttle
d u rin g
th a t
g ra z in g
p e r i o d ■a n d h e l p
to
id e n tify
w h ic h
c o l l e c t i o n s t a t i o n i s d o w n s tre a m o f t h a t l o c a t i o n (e .g . c o l l e c t i o n
s t a t i o n A i s downstream of p a s tu r e s I and 2,
c o lle ctio n s ta tio n E i s
downstream of th e ungrazed p a s tu r e , 9« and r e p r e s e n t s t h e co n tro l).,
For th e 1981 g r a z in g season (F ig u re 20),
peak suspended sedim ent
f lo w w as f o u n d t o o c c u r d u r i n g t h e s e c o n d g r a z i n g p e r i o d a t e ach o f
th e f iv e
sa m p lin g s t a t i o n s .
S e d im e n t l e v e l s
sh a rp ly
decreased
f o ll o w i n g t h e peak lo a d in g p e rio d a t s t a t i o n s B through E. ' Sediment
c o n c e n t r a t i o n s th en s t a b i l i z e d
d u rin g t h e f o u r t h g r a z in g p e rio d and
rem ained c o n s ta n t th ro u g h o u t th e re m a in d e r o f th e g r a z in g season.
A
g r a d u a l d e c r e a s e i n s e d i m e n t c o n c e n t r a t i o n s was n o t e d a t s t a t i o n A
f o ll o w i n g t h e peak lo a d in g p e rio d , and c o n tin u e d u n t i l th e te r m i n a t i o n
of th e g r a z in g season.
S ta tio n
B reco rd ed
th e h ig h e s t
c o n c e n tra tio n
of
suspended
s e d i m e n t a t p e ak s e d i m e n t flo w d u r i n g t h e sec o n d g r a z i n g p e r i o d .
D u rin g t h e s e c o n d a n d t h i r d g r a z i n g p e r i o d s ,
s ta tio n B c o lle cte d
50
F i g u r e 20.
Suspended S e d im e n t C o n c e n t r a t i o n s (g/m^) C o l l e c t e d During
t h e 1981 G r a z i n g S e a s o n U s i n g a M o d i f i e d S i n g l e S t a g e
Sedim ent Sam pler.
The S h a d e d P o r t i o n o f t h e F i g u r e
R e p re se n ts th e L o ca tio n of the C a t tle in R e la tio n to the
S am p li ng S t a t i o n s .
SEDIMENT g /m
198 I
<9
f
51
F ig u re 21.
Suspended S ed im en t C o n c e n t r a t i o n s (g/m^) C o l l e c t e d During
t h e 1982 G r a z i n g S e a s o n U s i n g a M o d i f i e d S i n g l e S t a g e
Sedim ent Sam pler.
The S h a d e d P o r t i o n o f t h e F i g u r e
R e p re s e n ts th e L o c a tio n of the C a t t l e in R e la tio n to the
S am pl in g S t a t i o n s .
SEDIMENT
g/m
1982
52
g r e a t e r a m o u n ts o f s e d i m e n t t h a n any o t h e r s t a t i o n (P < 0 ,0 1 ).
No
o t h e r ■s i g n i f i c a n t d i f f e r e n c e s were noted between th e sam p lin g s t a t i o n s
d u rin g any o th e r g r a z in g p e rio d .
Also, sed im en t c o n c e n tr a tio n s d u rin g
th e f i r s t th r e e g r a z in g p e rio d s w ere found to be s i g n i f i c a n t l y g r e a t e r
t h a n t h e l a s t f i v e g r a z i n g p e r i o d s ' f o r s t a t i o n s B t h r o u g h E and f o r
g r a z in g p e rio d s 7 and 8 f o r s t a t i o n A.
The 1982 suspended sed im en t d a ta d i s p l a y s t r e n d s s i m i l a r to th o se
e x p r e s s e d i n 1981 ( F i g u r e 21).
Peak s e d i m e n t c o n c e n t r a t i o n s w e re
r e c o r d e d d u r i n g t h e s e c o n d g r a z i n g p e r i o d f o r a l l sam p lin g s t a t i o n s
e x c e p t E, w h e re p e ak s e d i m e n t l o a d i n g o c c u r r e d d u r i n g t h e f i r s t
g ra z in g p e rio d .
A r a p i d d e c r e a s e i n s e d i m e n t c o n c e n t r a t i o n s w as
reco rd ed f o llo w in g
c o n c e n tra tio n s
th e
peak
s ta b iliz e d
c o n c e n tra tio n
d u rin g th e
fo u rth
p e rio d .
S e d im e n t
g r a z i n g p e r i o d and
rem ained c o n s ta n t th ro u g h o u t th e re m a in d e r o f the g r a z in g season.
As w i t h
1981,
c o n c e n tra tio n s
sta tio n
d u rin g
th e
B reco rd ed
second
th e
g ra z in g
h ig h e st
se d im e n t
p e rio d .
S e d im e n t
c o n c e n tr a tio n s f o r s t a t i o n B were s i g n i f i c a n t l y g r e a t e r th a n th e o th e r
sta tio n s.
No o t h e r
sig n ific a n t
d i f f e r e n c e s w e re n o te d
b e tw e e n
s t a t i o n s d u r i n g t h e r e m a i n i n g g r a z i n g p e rio d s ex cep t t h a t suspended
s e d i m e n t c o n c e n t r a t i o n s d u r i n g t h e f i r s t two g r a z i n g p e r i o d s w e re
s i g n i f i c a n t l y g r e a t e r th a n th e l a s t s i x g r a z in g p e r io d s a t a l l f i v e
sam p lin g s t a t i o n s .
No in c r e a s e i n suspended sed im en t c o n c e n tr a tio n s was observed due
to th e p re s e n c e of c a t t l e .
I n m o st c a s e s , a g e n e r a l r e d u c t i o n i n
c o l l e c t e d suspended sed im en t was re c o rd e d i n 1981 d u r in g a l l g ra z in g
p e r i o d ’s and i n 1982 d u r i n g g r a z i n g p e r i o d s 3 t h r o u g h 8.
An i n c r e a s e
53
i n suspended sed im en t c o n c e n tr a tio n s was observed downstream of th e
c a t t l e a t s t a t i o n A d u rin g g r a z in g p e rio d s I and 2, however, t h i s same
in c r e a s e was a l s o noted u pstream of th e c a t t l e a t s t a t i o n s B, C, D and
E d u rin g th e same p erio d .
F i g u r e 22 r e p r e s e n t s t h e g ra m s o f s u s p e n d e d o r g a n i c m a t t e r
c o l l e c t e d a t each sam p lin g s t a t i o n d u rin g th e 8 g r a z in g p e rio d s from
t h e I 982 g r a z i n g s e a s o n .
No d a t a a r e a v a i l a b l e f o r 1981.
A lth o u g h
o rg a n ic m a t t e r l e v e l s were g r e a t e s t d u rin g th e e a r ly g r a z in g p e rio d s ,
I through 3 ,
t h e r e w as no s i g n i f i c a n t d i f f e r e n c e b e tw e e n e a r l y and
l a t e p e rio d s.
S a m p lin g s t a t i o n s A, B, C and D r e c o r d e d p e a k o r g a n i c
m a te r ia l lo a d in g d u rin g th e t h i r d g ra z in g p e rio d , w h ile
sta tio n E
re c o rd e d i t s peak l e v e l s d u rin g th e second g ra z in g p e rio d .
Subsequent
peaks w ere observed a t s t a t i o n s A, C, D and E a t v a r io u s tim e s d u rin g
th e g r a z in g season.
No i n c r e a s e i n o rg a n ic m a t t e r l o a d in g was e v id e n t
due to c a t t l e a c t i v i t y upstream of any r e c o r d in g s t a t i o n .
V e g e ta tio n U t i l i z a t i o n
During t h e 1981 g r a z in g sea so n u t i l i z a t i o n r a t e s i n t h e r i p a r i a n
I
a r e a were c o n s i s t e n t l y h ig h e r th an i n the upland com m unities (Figure
I
2 3 ).
U t i l i z a t i o n r a t e s i n t h e r i p a r i a n c o m m u n i t i e s a v e r a g e d 59
p e rc e n t w ith a high o f 71 p e rc e n t d u rin g g r a z in g p erio d 2 and a low o f
49 p e r c e n t d u r i n g p e r i o d 5.
U pland c o m m u n i t i e s a v e r a g e d 46 p e r c e n t
u t i l i z a t i o n over th e g r a z in g season w ith
a high o f 73 p e rc e n t d u rin g
g ra z in g p e rio d 7 and a low o f 27 p e r c e n t d u rin g p e rio d 4.
54
O R G ANI C M A T T E R ( g)
F i g u r e 22.
S u s p e n d e d O r g a n i c M a t t e r ( g ) C o l l e c t e d D u r i n g t h e 1982
G razin g Season Using a M odified S in g le S ta g e Sedim ent
Sampler.
The Shaded P o r t i o n o f t h e F i g u r e R e p r e s e n t s t h e
L o c a tio n of th e C a t t l e i n R e la tio n to th e Sam pling
Stations.
1982
55
P e r c e n t U t i l i z a t i o n o f U pland and R i p a r i a n V e g e t a t i o n
Determined Using the Cage Comparison Method.
P E R C E N T UTILIZATION
P E R C E N T UTILIZATION
F ig u re 23.
PASTURE
56
U t i l i z a t i o n r a t e s d u rin g th e 1982 season show r i p a r i a n u t i l i z a ­
tio n h ig h e r in
e a rly
season
(p a s tu re s 2,
3 and 4) w h i l e
u p la n d
u t i l i z a t i o n r a t e s w ere h ig h e r d u rin g t h e l a t t e r ( p a s t u r e s 5» 6 and 7).
R ip a ria n u t i l i z a t i o n r a t e s averaged 52 p e rc e n t w ith a high o f 74
p e r c e n t d u r i n g g r a z i n g p e r i o d 3 and a low o f 42 p e r c e n t d u r i n g 4.
U p lan d c o m m u n i t i e s a v e r a g e d 54 p e r c e n t w i t h a h ig h o f 74 p e r c e n t
d u rin g g r a z in g p e rio d 7 and a low o f 35 d u r in g p e rio d 4. .
D u rin g b o th t h e 1981 and 1982 s e a s o n s , p e ak u t i l i z a t i o n i n t h e
u p l a n d c o m m u n i t i e s o c c u r r e d d u r i n g g r a z i n g p e r i o d 7,
w h i l e p eak
r i p a r i a n u t i l i z a t i o n o c c u r r e d d u r i n g g r a z i n g p e r i o d 2 i n 1981 and
p e rio d 3 i n 1982.
The p e rio d o f lo w e s t u t i l i z a t i o n f o r both y e a r s f o r
upland com m unities was d u rin g p e rio d 4, w h ile f o r r i p a r i a n com m unities
i t o c c u rre d i n g ra z in g p e r io d 5 i n 1981 and p e rio d 4 i n 1982.
both sea so n s,
During
u t i l i z a t i o n r a t e s i n th e s p r in g w ere h ig h f o r r i p a r i a n
and upland com m unities dro p p in g t o a low d u rin g m id -se a so n and th e n
i n c r e a s i n g a g a in d u rin g l a t e season.
57
DISCUSSION
Time o f g r a z i n g w as fo u n d t o be f u n d a m e n t a l i n e v a l u a t i n g t h e
e f f e c t s o f li v e s t o c k - i n d u c e d stream bank i n s t a b i l i t y a lo n g Cottonwood
Creek..
A l t e r a t i o n s of stre am banks a t t r i b u t a b l e t o l i v e s t o c k g ra z in g
w ere found t o be g r e a t e s t d u rin g e a r l y g ra z in g p e rio d s (p e rio d s I to
4) and s i g n i f i c a n t l y l e s s i n t h e l a t t e r p e r i o d s ( p e r i o d s 5 t o 8) (P <
0 .0 1 ).
The s e c o n d g r a z i n g p e r i o d i n l a t e J u n e and e a r l y J u l y was
found t o have s i g n i f i c a n t l y g r e a t e r s t r e a m bank a l t e r a t i o n s t h a n any
o t h e r g r a z i n g p e r i o d d u r i n g b o th y e a r s o f m o n i t o r i n g .
A lte ra tio n s
w ere observed to be c o n s i s t e n t from one y e a r t o the n e x t,
in d ic a tin g
th e banks w ere r e c e i v i n g a p p ro x im a te ly th e s a m e .im p a c ts each season.
Streambank a l t e r a t i o n s d u rin g th e l a t t e r p a r t of th e seaso n were n o t
s ig n ific a n tly
d i f f e r e n t t h a n t h o s e d i s p l a y e d w i t h i n t h e u n g ra z e d
co n tro l.
Q u a l i t a t i v e o b s e r v a tio n s i n d i c a t e c o n s id e ra b ly more exposed banks
and hoof damage d u rin g th e e a r l y p e rio d s , e s p e c i a l l y a t c re ek c r o s s in g
l o c a t i o n s , and a t p o in ts where th e c a t t l e e n te r e d t h e c re ek channel to
g r a z e on s t r e a m b a n k v e g e t a t i o n .
V e g e t a t i o n u t i l i z a t i o n s t u d i e s by
P l a t t s (1982) and Hayes (1978) i n d i c a t e t h a t d e c r e a s e d s t r e a m b a n k
s ta b ility
is .lik e ly
e x c e ssiv e .
to
re su lt
when
u tiliz a tio n
le v e ls
become
P l a t t s (1982) r e p o r t e d t h a t stream bank a l t e r a t i o n s w ere
probable' when r i p a r i a n v e g e t a t i o n u t i l i z a t i o n exceeds 65 p e r c e n t w ith
Hayes (1978) r e p o r t i n g s i m i l a r f i n d i n g s o f damage o c c u r r in g above 60
p e rc e n t use.
U t i l i z a t i o n o f r i p a r i a n v e g e t a t i o n on t h e C ottonw ood
s tu d y s i t e averaged 62 and 63 percent, f o r 1981 and 1982 r e s p e c t i v e l y
58
d u r i n g t h e f i r s t h a l f o f t h e g r a z i n g s e a s o n and 55 and 52 p e r c e n t
d u rin g the second h a l f of th e season.
The p e rio d s o f g r e a t e s t stre am bank a l t e r a t i o n s c o in c id e w ith high
u tiliz a tio n ra te s su p p o rtin g
P la tts'
(1 9 8 2 ) and H ay est
(I 97 8)
c o n c l u s i o n s t h a t h ig h u t i l i z a t i o n i s a good i n d i c a t o r o f d e c r e a s e d
stream bank s t a b i l i t y .
This concept d id n o t hold t r u e i n 1981 d u rin g
g ra z in g p e r io d 7, however, when r i p a r i a n v e g e t a t i o n u t i l i z a t i o n l e v e l s
exceeded 70 p e r c e n t and stre am bank a l t e r a t i o n s w ere m in im al, fo llo w e d
i n 1982 by u t i l i z a t i o n l e v e l s o f 55 p e rc e n t and a marked in c r e a s e i n
a lte ra tio n s.
u tiliz a tio n
C ooper (1 9 7 9 ) and D u ff (1 9 7 9 ) b o th n o t e d t h a t h eavy
was n o t n e c e s sa ry to im p a r t damage
upon t h e stream banks
t h a t t h e am ount o f a n i m a l a c t i v i t y and t h e s e n s i t i v i t y o f t h e banks
w ere a more c r i t i c a l f a c t o r .
A c a ttle
b e h av io r
stu d y
c o n d u c te d
by Marlow
(1983) on t h e
C o tto n w o o d C re ek s t u d y s i t e r e v e a l s t h a t t h e c a t t l e a r e s p e n d i n g
s i g n i f i c a n t l y l e s s tim e i n t h e r i p a r i a n com m unities d u rin g t h e f i r s t
h a l f of th e g r a z in g season th a n th e l a s t (F ig u re 24).
No c o r r e l a t i o n
between t h e amount of tim e c a t t l e spend i n t h e r i p a r i a n com m unities
and s t r e a m ban k a l t e r a t i o n s w as d i s c e r n i b l e ( r ^ = 0 .0 4 ).
The c a t t l e
w e re h a v i n g a s i g n i f i c a n t l y g r e a t e r i m p a c t on t h e s t r e a m b a n k s and
doing i t i n a s h o r t e r p e rio d of tim e d u rin g th e e a r ly g r a z in g p e rio d s ,
w h ile h a v in g l i t t l e
la tte r
g ra z in g
im p a c t over a lo n g p e r io d o f tim e d u rin g th e
p e rio d s.
T h is l e a d s
to
th e
in fe re n c e
th a t
th e
stream banks may be more v u l n e r a b le to l i v e s t o c k im p a c ts i n t h e e a r ly
p a r t of the g r a z in g season.
59
F ig u r e 24.
Time (Hours) Spent by C a t t l e Group i n Upland and R ip a ria n
H a b i t a t Types D u rin g t h e 1982 G r a z i n g S e a so n (Marlow
I 983). D a te s A long t h e H o r i z o n t a l A xis a r e Synonymous
With G razing Periods.
••
••
DATE
The d i r e c t i o n of stre am bank changes (in c re a s e d a r e a due to s o i l
l o s s or d e crea se d a re a due to s o i l g a in ) was h ig h ly v a r i a b l e between
m o n ito rin g p e rio d s.
c a t t l e b eh av io r.
T h is v a r i a b i l i t y
may a g a i n be a t t r i b u t e d t o
D u rin g e a c h g r a z i n g s e a s o n a d i f f e r e n t g ro u p of
h e i f e r s w e re u s e d .
Q u a l i t a t i v e o b s e r v a t i o n s r e v e a l t h a t t h e two
groups used d i f f e r e n t c re ek c r o s s in g p o in ts which r e s u l t e d in c e r t a i n
t r a n s e c t s r e c e i v i n g more tr a m p lin g damage w h ile o t h e r s downstream of
such a r e a s r e c e iv e d
d e b r i s and s e d i m e n t a c c u m u l a t i o n s .
The
60
c o n s i s t e n c y o f im p a c t s h o u ld be n o te d th o u g h .
tra n s e c ts
A lth o u g h d i f f e r i n g
d i s p l a y e d a l t e r a t i o n s one y e a r t o th e n e x t ,
a l t e r a t i o n s , w i t h i n each p a s t u r e
th e t o t a l
rem ained c o n s i s t e n t d u rin g th e two
years.
R oath
(1 9 8 0 )
sta te s
th e
g re a te st
im p act
liv e sto c k
h a v e on
r i p a r i a n a r e a s may be tr a m p lin g damage and t h a t wet s o i l , i s th e most
s u s c e p t i b l e to l i v e s t o c k im p a c ts.
The p e rio d s o f g r e a t e s t stream bank
a l t e r a t i o n s w ere found to be c l o s e l y c o r r e l a t e d t o high s o i l m o is tu re
l e v e l s ( r 2 = 0.82) d u r in g f r o s t - f r e e g r a z in g p e rio d s .
S o il m o is tu re
was found to be h i g h e s t e a r l y i n the seaso n and g r a d u a lly d e crea se d t o
th e lo w e s t l e v e l s i n e a r l y September. Stream bank a l t e r a t i o n s w ere a ls o
h i g h e s t e a r l y i n th e seaso n fo llo w e d by a g ra d u a l d e c re a s e throughout
th e re m a in d e r of th e season.
As t h e stream bank d r i e d ,
be l e s s s u s c e p t i b l e t o tr a m p lin g damage.
i t appeared t o
During th e 1981 season, th e
dry stream banks showed l i t t l e im p act due t o t h e c a t t l e , y e t, in c re a s e d
s t r e a m b a n k a l t e r a t i o n s w e re n o te d w i t h i n p a s t u r e 7 d u r i n g t h e I 982
season a f t e r an e a r l y f a l l snow storm in c r e a s e d s o i l m o is tu re l e v e l s .
This i n c r e a s e and damage l a s t e d only one g r a z in g p erio d .
. The c o r r e l a t i o n betw een s o i l m o is tu re and stream b an k a l t e r a t i o n s
dropped ( r 2 = 0.63) a f t e r m id - S e p te m b e r d u r i n g b o th g r a z i n g s e a s o n s .
D u rin g t h e l a s t tw o g r a z i n g p e r i o d s , s o i l m o i s t u r e i n c r e a s e d w h i l e
stream bank a l t e r a t i o n s d e c re a se d even though s o i l m o is tu r e was being
r e c h a r g e d by f a l l p r e c i p i t a t i o n e v e n t s .
D u rin g b o th I 981 and 1982,
e a r l y f a l l snowstorm s and average d a i l y a i r te m p e ra tu re s below 2° C.
may have combined t o f r e e z e th e re c h a rg e m o is tu r e i n t h e upper l a y e r
of s o i l ,
th u s a c t i n g to
cem ent th e
banks in
p la ce .
The f r o z e n
61
stre am banka may th e n have been s tr o n g enough to su p p o rt th e w e ig h t of
the c a t t l e and not succumb to tr a m p lin g damage.
re p o rte d
by Cooper (1 9 7 9 ) ,
S i m i l a r f i n d i n g s w ere
who. n o t e d r e d u c e d s t r e a m b a h k damage
a s s o c i a t e d w i t h l i v e s t o c k g r a z in g l a t e i n th e f a l l and w i n t e r a f t e r
t h e s t r e a m b a n k s had become f r o z e n .
K au ffm an (1982) a l s o r e p o r t e d
reduced s o i l d is tu r b a n c e d u rin g l a t e f a l l g ra z in g .
Although d i r e c t l i v e s t o c k im p a c ts t o stream bank s t a b i l i t y may be
reduced d u rin g
th e f a l l and w in te r ,
i t was o v e r - w in te r a l t e r a t i o n s
which w ere found t o be g r e a t e r th an li v e s t o c k - i n d u c e d damage.
Over­
w i n t e r a l t e r a t i o n s w ere 10 t o 800 p e rc e n t g r e a t e r th a n th e a l t e r a t i o n s
reco rd ed a lo n g th e same t r a n s e c t s d u rin g t h e g ra z in g season.
r e s u l t s w ere re p o r te d by Buckhouse (1980) and Hayes (1978).
S im ila r
Buckhouse
(1980) r e p o r t e d g r e a t e r s t r e a m bank a l t e r a t i o n s o c c u r r in g d u rin g t h e
w i n t e r t h a n d u r i n g th e g r a z i n g s e a s o n and c o n c lu d e d t h a t i c e f l o e s ,
high w a te r ,
and channel physiognomy were c r i t i c a l f a c t o r s in v o lv e d i n
th e e ro s io n p ro c e ss.
Hayes (1 9 7 8 ) a l s o fo u n d w i n t e r / s p r i n g c h a n n e l
a l t e r a t i o n s t o be i n e x c e s s o f a l t e r a t i o n s a t t r i b u t a b l e t o c a t t l e
g r a z in g im p a c ts d u rin g th e g r a z in g season.
Cottonwood Creek c h a r a c t e r i s t i c a l l y has deep snow d r i f t s l i n i n g
the channel le n g th over th e w i n t e r and i n t o l a t e May.
The w eig h t of
snow and i c e may a c t t o lo o s e n t h e s o i l and cause stre am bank slum ping
on a r e a s im p a c t e d by l i v e s t o c k d u r i n g t h e p r e v i o u s y e a r ’s g r a z i n g .
The d e g r e e o f l i v e s t o c k
i m p a c t d u r i n g t h e g r a z i n g s e a s o n c o u ld
i n f l u e n c e t h e am ount o f o v e r - w i n t e r dam age.
p e rio d s
occu rred
i n w h ic h t h e g r e a t e s t
The f i r s t two g r a z i n g
d e g re e of stre am b a n k a l t e r a t i o n s
d u r i n g t h e g r a z i n g s e a s o n a l s o had t h e g r e a t e s t am ount o f
62
o v e r - w i n t e r c h an g e .
The r e m a i n i n g 7 p a s t u r e s a l l had s t a t i s t i c a l l y
s i m i l a r l e v e l s of a l t e r a t i o n s d u rin g th e w i n t e r p e rio d alth o u g h they
w ere s i g n i f i c a n t l y g r e a t e r
g ra z in g season.
th a n t h e im p a c ts re c o rd e d d u rin g th e
H ow ever, o v e r - w i n t e r a l t e r a t i o n s i n t h e u n g r a z e d
c o n t r o l p a s t u r e a ls o averaged 655 p e rc e n t g r e a t e r th a n t h e a l t e r a t i o n s
re c o rd e d d u rin g th e g ra z in g season.
T h is i n d i c a t e d t h a t n a t u r a l l y
o c c u r r i n g f a c t o r s may h av e a s s i g n i f i c a n t an i m p a c t on i n d u c i n g
stream bank i n s t a b i l i t y and e v e n t u a l l y i n c r e a s e d s u s p e n d e d s e d i m e n t
lo a d in g a s does l i v e s t o c k im p a c ts.
Rosgen (1975) r e p o r t s t h a t suspended sed im en t c o n c e n tr a tio n s a r e
c o r r e l a t e d t o s t r e a m b a n k s t a b i l i t y and w a t e r f lo w .
become l e s s s t a b l e ,
As s t r e a m b a n k s
more sedim ent w i l l be c o n tr ib u te d t o t h e stream
flow and i n c r e a s i n g volumes o f w a te r can t r a n s p o r t a g r e a t e r volume of
sedim ent.
of
Johnson e t a l .
suspended
sed im en t
(1978) a l s o s t a t e t h a t h ig h c o n c e n tr a tio n s
are
g e n e ra lly
an
in d ic a tio n
of
e ro sio n
a s s o c i a t e d w ith some d eg ree of im pact.
C a t t l e p resence appeared t o have no e f f e c t on t h e p e rio d o f peak
s e d i m e n t c o n c e n t r a t i o n s a s p eak s u s p e n d e d s e d i m e n t c o n c e n t r a t i o n s
o c c u r re d a t a l l r e c o r d in g s t a t i o n s d u rin g th e second g r a z in g p e rio d
d u rin g b o th m o n ito r in g s e a so n s r e g a r d l e s s of c a t t l e p re se n c e .
same h e ld t r u e f o r suspended o rg a n ic m a tte r .
The
Peak suspended sedim ent
c o n c e n t r a t i o n s o f 24.04 g/m ^ i n 1981 t o 25.25 g/m^ i n 1982 w e r e . w e l l
below t h e c r i t i c a l l e v e l of 80 g/m^ r e p o r te d by McKee and Wolf (1963)
to be d e t r i m e n t a l t o a q u a ti c organism s.
The p a t t e r n o f p e a k s u s p e n d e d s e d i m e n t c o n c e n t r a t i o n s l a s t i n g
o n ly f o r a p p r o x i m a t e l y tw o w e ek s i m m e d i a t e l y f o l l o w e d by a r a p i d
63
d e c re a s e and s t a b i l i z a t i o n w ith low c o n c e n tr a tio n s i s c o n s i s t e n t w ith
i
f i n d i n g s by Gary e t a l .
(1983), who found s i m i l a r peak c o n c e n tr a tio n
- s t a b i l i z a t i o n p a t t e r n s on a s m a ll w a te rsh e d i n t h e Colorado Front
R ange.
In
th e ir
o b se rv a tio n s,
th e y
n o te d
m axim um
c o n c e n tr a tio n s o c c u rre d d u rin g peak stre am flow p e rio d s .
stu d y ,
m axim um
a p p ro x im a te ly
suspended
14 to 21
se d im e n t
se d im e n t
Yet, i n t h i s
c o n c e n tra tio n s
o ccu rred
days a f t e r th e peak w a te r flow p erio d .
The peak suspended sedim ent c o n c e n tr a tio n p erio d (June 28 - J u l y
12) c o i n c i d e s w i t h
th e p e rio d o f h e a v ie s t p r e c i p i t a t i o n f o r th e
Cottonwood Creek d ra in a g e.
The Cottonwood Creek d ra in a g e r e c e i v e s an
a v e r a g e o f 450 mm p e r y e a r w i t h 110 mm, o r 24 p e r c e n t o f t h e y e a r l y
average o c c u r r in g d u rin g l a t e June and e a r l y J u ly .
The l a r g e volumes
of w a te r o r i g i n a t i n g from c o n v e c tio n a l th u n d e rs to rm s may a c t to . wash
lo o sen e d s o i l
a l o n g dam aged s t r e a m b a n k s i n t o
th e w a te r
colum n.
A lth o u g h t h e r e w as no o b s e r v a b l e i n c r e a s e i n s u s p e n d e d s e d i m e n t
c o n c e n t r a t i o n s due t o c a t t l e a c t i v i t y a s th e y w e r e moved u p s tr e a m
th ro u g h th e p a s tu r e s ,
t h e r e may have been an i n d i r e c t i n c r e a s e d u rin g
th e f o l l o w i n g s p r in g a s s o c i a t e d w ith t h e i r r e s i d u a l im p a c ts.
Suspended sed im en t c o n c e n tr a tio n s w ere found t o be g r e a t e r below
p a s t u r e s t h a t had c o n s id e ra b le stream bank a l t e r a t i o n s .
Peak sedim ent
c o n c e n tr a tio n s w ere found a t c o l l e c t i o n s t a t i o n s A and B, which w ere
downstream of th e p a s tu r e s grazed e a r l y i n the season and which showed
th e
g re a te st
a lte ra tio n s.
The c a t t l e
a c tiv ity
of
a lte rin g
th e
stre am banks may be coupled w ith th e d e s t a b i l i z i n g f o r c e s of i c e and
snow d u rin g t h e w i n t e r to lo o s e n t h e exposed banks and may provide a
so u rce of sed im en t to be f lu s h e d i n t o th e w a te r column.
64
I t a p p e a rs t h a t p e rio d s o f peak suspended sed im en t c o n c e n tr a tio n s
may be m a g n ifie d by l i v e s t o c k a c t i v i t y on Cottonwood Creek d u rin g th e
p re v io u s g r a z in g season.
65
SUMMARY
L i v e s to c k .g r a z in g can a f f e c t a l l components o f a r i p a r i a n system.
The i n f l u e n c e o f l i v e s t o c k on r i p a r i a n a r e a s d e p e n d s on n u m e ro u s
fa c to rs,
in c lu d in g th e tim e of g ra z in g .
was t o a s c e r t a i n what tim e
The o b j e c t i v e o f t h i s study
d u rin g th e g r a z in g season stream b an k s a r e
most s u s c e p t i b l e to l i v e s t o c k - g e n e r a t e d im p a c ts and w h e th er i n c r e a s e s
i n suspended sedim ent c o n c e n t r a t i o n s o c c u r d u r i n g p e r i o d s o f c a t t l e
a c tiv ity .
Q u a n t i t a t i v e m e a s u r e m e n ts o f s t r e a m c h a n n e l a r e a , s o i l
m o istu re ,
stre a m
flo w ,
suspended
sed im en t
c o n c e n tra tio n s,
and
v e g e t a t i o n u t i l i z a t i o n w e r e made d u r i n g e a c h f o u r t e e n - d a y g r a z i n g
p e rio d .
E a rly - s e a s o n g ra z in g induced im m ed iate stream bank a l t e r a t i o n s a s
w e ll a s i n c r e a s e d suspended sedim ent c o n c e n tr a tio n s which o c c u rre d the
f o llo w in g y e a r.
Stream channel a l t e r a t i o n s w ere found t o be g r e a t e s t
d u rin g th e e a r l y g r a z in g p e r io d s and w ere a s s o c i a t e d w ith r i p a r i a n
v e g e t a t i o n u t i l i z a t i o n r a t e s ex ceed in g 60 p e rc e n t.
P a s tu r e s r e c e i v i n g
l e s s than 60 p e rc e n t use showed f a r l e s s stream bank i n s t a b i l i t y .
S o il
m o is tu re was c l o s e l y c o r r e l a t e d w ith stre am channel a l t e r a t i o n s (r^ =
0 .8 4 ) d u r i n g f r o s t - f r e e g r a z i n g p e r i o d s .
T h is c o r r e l a t i o n w as l e s s
e v id e n t (r^. = 0.63) a f t e r mid-Septem ber when t h e stream banks began t o
freeze.
F rozen
s t r e a m b a n k s may be a b l e t o w i t h s t a n d l i v e s t o c k
a c t i v i t y w ith v ery l i t t l e damage.
W ith in p a s t u r e s and between y e a r s , th e tr e n d o f change i n channel
a l t e r a t i o n s w as i n c o n s i s t e n t fro m one y e a r t o t h e n e x t and may be a
r e s u lt of d iff e r e n t
c r o s s i n g p o i n t p r e f e r e n c e s d i s p l a y e d by t h e
66
d i f f e r e n t h e i f e r groups used d u rin g t h e two y e a r s o f study.
Behavior
o b s e r v a t i o n s ' of th e c a t t l e used i n t h i s s tu d y (Marlow 1983) i n d i c a t e
t h e a n im a ls a r e spending l e s s tim e i n r i p a r i a n a r e a s d u rin g t h e e a r ly
g ra z in g seaso n w h ile i n f l i c t i n g a g r e a t e r im p act on th e stream banks.
T h is le n d s t o th e i n f e r e n c e t h a t th e stream b an k s a r e more s u s c e p t i b l e
to c a t t l e damage e a r l y i n th e g r a z in g season.
Although d i r e c t im p a c ts o f c a t t l e w e re g r e a t e r d u rin g t h e e a r ly
g r a z in g p e rio d s ,
o v e r a l l channel a l t e r a t i o n s w ere 10 t o 800 p e rc e n t
g r e a t e r d u rin g t h e w i n t e r m o n ito rin g p e r io d th a n d u rin g t h e g ra z in g
season.
T h i s i n c r e a s e i n dam age may h a v e b een due t o i c e and snow
c o l l a p s i n g s t r e a m b an k s a l r e a d y a l t e r e d by c a t t l e t h e summer b efo re.
C a t tle - in d u c e d a l t e r a t i o n s ,
in te n sifie d
by snow and i c e damage,
may
p r o v i d e t h e so u rce, o f h ig h s u s p e n d e d s ed im en t c o n c e n tr a tio n s i n th e
l a t e s p rin g .
S i m i l a r i n c r e a s e s i n a l t e r a t i o n s were d is p la y e d
w ith in
t h e c o n t r o l p a s t u r e , i n d i c a t i n g e n v i r o n m e n t a l f a c t o r s may h ave a s
s i g n i f i c a n t a r o l e i n im p a c tin g stream b an k s a s do l i v e s t o c k .
Peak s u s p e n d e d s e d i m e n t c o n c e n t r a t i o n s w e r e g r e a t e s t a t a l l
sam p lin g s t a t i o n s d u rin g th e second g r a z in g p erio d (June 28 - J u l y 12)
r e g a r d l e s s o f c a t t l e p resen ce.
The h i g h e s t c o n c e n tr a tio n s o c c u rre d 14
t o 21 d a y s a f t e r p e ak s t r e a m flo w d i s c h a r g e i n t h e c r e e k and i n
c o n ju n c tio n w ith p e rio d s o f heavy r a i n f a l l *
Peak suspended sed im en t
lo a d in g may be a f u n c t i o n of o v e rla n d sed im en t t r a v e l from stream banks
a l t e r e d by c a t t l e g r a z i n g t h e s e a s o n b e f o r e and dam aged by i c e and
snow d u r i n g t h e w i n t e r .
The g r e a t e s t s e d i m e n t c o n c e n t r a t i o n s w e re
g e n e r a l l y downstream of th e p a s t u r e s t h a t have th e g r e a t e s t stre am bank
in s ta b ility .
67
The sam p lin g te c h n iq u e used t o e s t i m a t e stream channel a l t e r a t i o n
a p p e a rs a c c u r a t e and r e p e a t a b l e .
Although tim e-consum ing, th e method
pro v id ed a r e l i a b l e r e p r e s e n t a t i o n o f channel movement.
The m o d ified
s i n g l e - s t a g e sedim ent sam ples a ls o proved to be a c c u r a te and r e l i a b l e
i n e s t i m a t i n g sed im en t c o n c e n tr a tio n w i t h i n th e w a te r column.
A major
drawback of th e sam p ler was c lo g g in g w ith i c e d u rin g th e l a t t e r p a r t
o f th e season.
L a t e —s e a s o n g r a z i n g . m a y be a l e s s d a m a g in g a l t e r n a t i v e th a n
g r a z in g a t o th e r tim e s i n r i p a r i a n a r e a s deemed c r i t i c a l t o f i s h e r i e s
o r i n a r e a s w i t h s e n s i t i v e s t r e a m b an k s o r a r e a s a l r e a d y e x h i b i t i n g
l i v e s t o c k damage. This could re d u c e l i v e s t o c k - g e n e r a t e d im p a c ts t o the
environm ent, w h ile s t i l l p e r m i t t i n g u t i l i z a t i o n o f th e r i p a r i a n fo ra g e
base.
P r o p e r g r a z i n g m anagem erit, u s i n g m o d e r a te s t o c k i n g r a t e s ,
s a l t i n g away fro m t h e r i p a r i a n z o n e ,
and h e r d i n g t h e a n i m a l s t o
p r e v e n t a r e a s o f o v e r g r a z i n g , i s a n e c e s s a r y p a r t o f any r i p a r i a n
g r a z i n g pl^n.
More i n t e n s i v e r e s e a r c h i s r e q u i r e d c o n ce rn in g t h e c o r r e l a t i o n o f
th e
p h y sic a l
liv e sto c k
a lte ra tio n
of
rip a ria n
a re a s w ith
g r a z i n g u n d e r p r o p e r m a n ag e m e n t.
th e
e ffe cts
Too o f t e n ,
of
rip a ria n
s t u d i e s have e v a lu a te d im p r o p e r .g r a z in g p r a c t i c e s r e s u l t i n g i n an
in d ic tm e n t o f l i v e s t o c k ' g ra z in g
in f o r m a tio n a s to
in te ra c tio n .
i n g e n e r a l, y e t p ro v id e d l i t t l e
th e e c o lo g i c a l
p r in c ip le s in v o lv e d in
th e
An a d e q u a t e u n d e r s t a n d i n g o f th e e c o lo g i c a l p ro c e ss e s
and p ro p e r l i v e s t o c k management i n r i p a r i a n a r e a s i s e s s e n t i a l i f we
are
to
fu lly
reso u rces.
o p tim iz e
th e
m u ltip le
use
of
rip a ria n
e c o s y s te m
68
LITERATURE CITED .
69,
LITERATURE CITED
A l d e r f e r , R. B. and R. R. R o b in so n . 1979» R u n o ff fro m p a s t u r e s . i n
r e l a t i o n t o g r a z in g i n t e n s i t y and s o i l compaction. J. Amer. Soc.
Agro n. 3 9 ( 1 0 ) :9 4 8 - 9 5 8 1,
Ames, C. R.
1977.
W i l d l i f e c o n f l i c t s i n r i p a r i a n m a n a g e m e n t:
g ra z in g .
%n:
R.R. J o h n s o n and D.A. J o n e s ( t e c h , c o o r d .) .
I m p o r t a n c e , P r e s e r v a t i o n and Management of R ip a ria n H a b ita t : A
Symposium.
U.S. D ep t. Agr. F o r. S e rv . Gen. Tech. Rep. RM-43.
Rocky Mt. F o r. and Range Exp. S ta . F o r t C o l l i n s , CO. pp. 4 9 -5 1 .
Armour, C. L. 1977. E f f e c t s of d e t e r i o r a t e d range s tr e a m s on t r o u t .
U.S.D.I. B u reau o f Land M anagem ent. B o is e , ID. 7 pp.
Behnke, R. J. 1977. F is h fa u n a l changes a s s o c i a t e d w i t h la n d use and
w a te r developm ent.
G r e a t - P la i ns-Rocky MT. Geol. J. 6(2): 133-136,
B ehnke, R.J. 1979. V a lu e s and p r o t e c t i o n o f r i p a r i a n e c o s y s t e m s .
I n : M i t i g a t i o n Symposium: A N a tio n a l Workshop on M i t i g a t i n g Laws
o f F i s h and W i l d l i f e H a b i t a t s . U.S. D ept. Agr. F o r. S e rv . Gen.
Tech. Rep. RM-65. pp. 1 6 4 -1 6 6 .
Behnke, Rt J . , and R. F. R a l e ig h .
1978. G r a z in g and t h e r i p a r i a n
z o n e : i m p a c t and m anagem ent p e r s p e c t i v e s . J j i : R.R. J o h n s o n and
J.F. McCormick ( t e c h , c o o r d . ) .
S t r a t e g i e s f o r P r o t e c t i o n and
Management of F lo o d p la in W etlands and O ther R ip a ria n Ecosystems.
U.S. D ept. Agr. F o r. S e rv . Gen. Tech. Rep. WO-12. W a s h in g to n ,
D.C. pp. 2 6 3 -2 6 7 .
B e n o i t , R. J . , J. C a i r n s , J r . , and W. C. R eim er.
(in p ress).
A
li m n o l o g i c a l r e c o n n a i s s a n c e o f a n im p o u n d m e n t r e c e i v i n g h eav y
m e t a l s , w i t h s p e c i a l e m p h a s is on d i a t o m s and f i s h . %n: P ro c.
Symp. on R e s e rv o ir F is h e ry Resources. Amer. F ish . Soc.
B e r r y , C. R. I 978. Im p a c t o f s a g e b r u s h m anagem ent on r i p a r i a n and
s t r e a m h a b i t a t . UT. Coop. F i s h e r i e s U n i t , UT. S t . U n iv ., Logan,
UT. 18 p.
B o l d t , C. E., D. W. U re sk , and K. E. S e v e rs o n .
1978.
R ip a ria n
woodlands i n je o p ard y on n o r th e r n high p la in s . J ji: R.R. Johnson
and D.A. J o n e s ( t e c h , c o o r d . ) . S t r a t e g i e s f o r P r o t e c t i o n and
Management of F lo o d p la in W etlands and O ther R ip a ria n Ecosystems.
U.S. D ep t. Agr. F o r. S e rv . Gen. Tech. Rep. WO-12. W a s h in g to n ,
D.C. p p .1 8 4 -1 8 9 .
70
B o w ers, W., B. H o sfo r d , A. O ak ley , and C, Bond.
1979.
W ild life
h a b i t a t s i n managed ra n g e la n d s - The G re at B asin o f S o u th e a s te rn
Oregon - N a t i v e T r o u t.
U.S. D ept. Agr. F o r. S e r v . Gen. Tech.
Rep. PNW-84. Pac NW F o r. a n d Range Exp. S t a . L aG ran d e, OR. 16
p.
Brown, D.
1954. M eth o d s o f S u r v e y i n g and M e a s u r in g V e g e t a t i o n .
Commonwealth Agr. Bureau. Farnham Royal Bucks, England.
B r y a n t , H. T., R. E. B l a s e r , and J . R. P e t e r s o n .
1972. E f f e c t o f
tr a m p lin g by c a t t l e on b lu e g r a s s y i e l d and s o i l com paction of a
m ead o w v ille loam.
Agron. . J. 64(3);331-334.
Buckhouse, J. C„ nda. L iv e s to c k g r a z in g e f f e c t s i n r i p a r i a n zones o f
th e w e s te r n U n ited S t a t e s . Unpubl. 29 p.
■
B u ck h o u se , J. C. 1980. W a t e r q u a l i t y a n d i t s r e l a t i o n s h i p t o r a n g e
liv e sto ck .
Paper p re s e n te d a t 1980 summer m e etin g s o f American
S o c ie ty of A g r i c u l t u r a l Engineers. San Antonio, TX. 4 p.
B u c k h o u se , J. C., J. M. S k o l v i n , and R. W. K n ig h t. 1981. S tr e a m b a n k
e r o s i o n and u n g u l a t e g r a z i n g r e l a t i o n s h i p s .
J . Range Manage.
3 4 (4 ):3 3 9 -3 4 0 .
Busby. F. E.
1979.
R i p a r i a n and s t r e a m e c o s y s t e m s , l i v e s t o c k
g r a z i n g , and m u l t i p l e - u s e m a n ag e m e n t. JLq.: O.B. Cope (e d .).
P ro ceed in g s o f th e Forum-Grazing and Ri p a r i a n / S t r earn Ecosystems.
Trout U n lim ite d . Denver, CO. pp. 6-13.
C airn s, J ., J r .
1968. Suspended s o l i d s stan d a rd s' f o r th e p r o t e c t i o n
o f a q u a t i c organism s.
Purdue Univ. Eng. B u ll.
129(1): 16-27.
C a ro th e rs, S. W. 1977. Im portance, p r e s e r v a tio n , cind management o f
r i p a r i a n h a b i t a t s : an overview . I n : R.R. Johnson and D.A. Jo n es
(te c h , c o o rd .).
I m p o r t a n c e , P r e s e r v a t i o n , and M anagement o f
R i p a r i a n H a b i t a t s : A Symposium. U.S. Dept. Agr. F o r. S e rv . Gen.
Tech. Rep. RM-43.
Rocky Mt. F o r. and Range Exp. S ta .
F ort
C o l l i n s , CO. pp. 2 -4 .
C l a i r e , E. and R. S t o r c h .
(in p ress).
S t r e a m s i d e m anagem ent and
l i v e s t o c k g r a z i n g : an o b j e c t i v e l o o k a t th e s i t u a t i o n . JLn.: J.
Menke (ed.).
Symposium on L iv e s to c k I n t e r a c t i o n s w ith W i ld lif e ,
F i s h and T h e i r E n v i r o n m e n ts . S p a r k s , NV. May 1977. U.S. D ept.
' Agr. F o r. S e rv . Pac. SW F o r. and Range Exp. S ta . B e r k l e y , CA.
C e i l i n g s , B. J .
Bozeman, MT.
1982.
P erso n al
c o m m u n ic a tio n .
, MT.
S t.
Univ.
71
C o o p er, .J. L. I 979. A t e c h n i q u e f o r e v a l u a t i n g and p r e d i c t i n g t h e
im p act o f g r a z in g on sm a ll stream ch an n els.
Paper p re s e n te d a t
32nd Annual M eeting o f th e S o c ie ty f o r Range Management. Casper,
WY. Feb. 1 2 -1 5 , 1979. 13 p.
Cope, 0. B., ed. 1 979.
stream eco sy stem s.
P r o c e e d i n g s , fo ru m - g r a z i n g and r i p a r i a n /
Trout U n lim ite d In c ., W ashington, D.C. 94 p.
C o rd o n e , A. J . , and D. E. K e l l e y . 1961. The i n f l u e n c e o f i n o r g a n i c
s e d i m e n t on t h e a q u a t i c l i f e o f s t r e a m s .
CA. F i s h and Game.
4 7 (2 ):1 8 9 -2 2 8 .
Crouch. G. L. 1979. Long-term changes i n cottonwoods on a grazed and
an u n g r a z e d p l a i n s b o t t o m l a n d i n n o r t h e a s t e r n C o lo ra d o . U. S.
D ept. ,Agr. F o r. S e rv . Res. Note RM-370. Rocky Mt. F o r. and Range
Exp. S t a . F o r t C o l l i n s , CO
4 p.
Cummins, K. W. I 974. S t r u c t u r e and f u n c t i o n o f s t r e a m e c o s y s te m .
B io sc ie n c e . 2 4 ( 11) :6 3 1 -6 4 1 .
Dahlen, E. A. 1978. The Mahogany. Creek w a tersh e d - w ith and w ith o u t
g r a z i n g . I n : O.B. Cope (e d .). P ro c . o f th e Forum - G r a z i n g and
Ri p a r i a n / S t r earn E c o s y s te m s .
T r o u t U n lim ited . Denver, CO. pp.
31-34.
Davis, G. A. 1977. Management a l t e r n a t i v e s f o r th e r i p a r i a n h a b i t a t
i n th e s o u th w e s t.
In :
R.R. J o h n s o n and D.A. J o n e s ( t e c h ,
c o o r d . ) . I m p o r t a n c e , P r e s e r v a t i o n and M anagement o f R i p a r i a n
H a b i t a t . U.S. D ept. Agr. F o r. S e rv . Gen. Tech. Rep. RM-43. pp.
59-76.
Davis, J. W. 1982. L iv e s to c k vs. r i p a r i a n h a b i t a t management - th e r e
a r e s o l u t i o n s . J n : J.M. Peck and P.D. D alke ( e d .). W i l d l i f e L iv e s to c k R e l a tio n s h ip Symposium: P ro ceed in g s 10.
Univ. of ID.
F o r e s t, W i l d l i f e and Range Exp. S ta. Moscow, ID pp. 175-185.
Dobson, A. T. 1973. Changes i n t h e s t r u c t u r e of a r i p a r i a n community
a s th e r e s u l t of g ra z in g .
P ro c . New Z e a la n d E c o l. Soc. Vol.
2 0 (1 ) :5 8 - 6 4 .
Duff, D. A.
1979.
R i p a r i a n h a b i t a t , r e c o v e r y on B ig C re e k , Rich
C o b n ty , U ta h - A sum m ary o f 8 y e a r s o f s t u d y .
I n : O.B. Cope
( e d .) . P r o c e e d i n g s o f t h e fo ru m - G r a z in g and Ri p a r i a n / S t r earn
Ecosystems. T rout U n lim ited . Denver, CO. pp. 91-92.
Environm ental P r o t e c t i o n Agency. ■1979. Methods f o r c h em ical a n a l y s i s
o f w a t e r and w a s t e s . Method 1 6 0 -5 , S e t t l e a b l e M a t t e r . S t o r e t
No. 500 8 6 . U.S. Env. P r o t e c t i o n Agency. C i n c i n n a t i , OH.
72
E v an s, K. E., and R„ R. K re b s. 1977. A vian u s e o f l i v e s t o c k w a t e r i n g
p o n d s i n w e s t e r n S o u th D a k o ta. U.S. D ept. Agr. F o r, S e rv . Gen.
Tech. Rep. RM-35.
Rocky Mt. F o r. and Range Exp. S ta .
F ort
C o l l i n s , CO. 11 p.
E v en d en , A., and J . B. K auffm an. 1980. A p r e l i m i n a r y i n v e s t i g a t i o n
of two r i p a r i a n e co sy stem s exclu d ed from g r a z in g i n th e Ochoco
Mountains o f c e n t r a l Oregon. Unpubl. 14 p.
Gary, H. L., S. R. J o h n s o n , and S. L. P once.
1983.
C a ttle g ra z in g
im pact on s u r f a c e w a te r q u a l i t y i n a Colorado F ro n t Range stream .
J. S o il and Water Conserv. 38(2),:124-128.
G l i n s k i . R. L. 1977. R e g e n e r a t i o n and d i s t r i b u t i o n o f s y c a m o re and
cottonwood t r e e s a lo n g S o n o ita Creek, S anta Cruz County, Arizona.
Z n:
R.R. J o h n s o n and D.A. J o n e s ( t e c h , c o o r d . ) .
Im p o rtan c e ,
P r e s e r v a t io n , and Management o f R ip a ria n H a b ita t : A symposium.
U.S. D ept. Agr. F o r. S e rv , Gen. Tech. Rep. RM-43. Rocky Mt. F o r.
a n d Range Exp. S t a . F o r t C o l l i n s , CO. pp. 1 1 6 -123.
Gunderson, D. R. 1968. F lo o d p la in use r e l a t e d t o stre am morphology
and f i s h p o p u la tio n s .
J. W ild l. Manage. 32(3):507-5l4.
H ayes, F. A. 1978. S tr e a m b a n k s t a b i l i t y and meadow c o n d i t i o n i n
r e l a t i o n t o l i v e s t o c k g r a z i n g i n m o u n t a i n meadows o f c e n t r a l
Id a h o . M.S. T h e s i s . Univ. o f ID. Moscow, ID. 91 p.
H e r b e r t , D. W. M. and J. C. M erk en s. 1961. The e f f e c t o f s u s p e n d e d
m i n e r a l s o l i d s on t h e s u r v i v a l o f t r o u t .
A ir and W a te r P o l l .
V o l. 5, pp. 4 6 -5 5 .
Hoak, R.' D.
1957.
E f f e c t s o f suspended m a tte r i n w a s te w a te r.
Papers f o u r t h O n ta rio In d u s t. Waste Conf., 1957.
pp. 45-49.
I n t e r - A g e n c y C o m m itte e on W a te r R e s o u r c e s . 1963. M e a su re m e n t and
a n a l y s i s of se d im e n t lo a d s in s tre a m s .
R e p o r t No. 14.
D e t e r m i n a t i o n o f f l u v i a l s e d i m e n t d is c h a rg e . U.S. Gov. P r i n t i n g
O ffice.
Washington, D.C. pp. 118-121.
J o h n s o n , W. M.
1965.
R o t a t i o n , r e s t - r o t a t i o n , and s e a s o n - l o n g
g r a z i n g on a m o u n ta in r a n g e i n Wyoming. UUS. D ep t. Agr. For.
S e r v . Res. P a p e r RM-14. Rocky Mt. F o r. and Range Exp. S ta . F o r t
C o l l i n s , CO. 14 p.
.
J o h n s o n , S. R., H. L. G ary, and S. L. Ponce.
1978.
Range c a t t l e
im p a c ts on s tre a m w a t e r i n th e Colorado F ro n t Range.
U.S. Dept.
Agr. F o r. S e rv . Res. N ote RM-359. 8 p.
K a u ffm a n , J. B.
1982,
S y n ec o lo g ic al e f f e c t s of c a t t l e g ra z in g
r i p a r i a n e c o s y s t e m s . M.S. T h e s i s . OR. S t. U n iv ., C o r v a l l i s , OR.
283 P.
73
K a u ffm a n , J. B., W. C. K r u e g e r , and M. V avra, ( i n p r e s s ) . I m p a c t s o f
c a t t l e g r a z i n g a s t r e a m bank i n n o r t h e a s t e r n O regon. J. Range
Manage.
K i m b a l l , J . , and F. Sav ag e. 1977. Diamond F o rk a q u a t i c and r a n g e
h a b i t a t im p ro v e m e n ts.
U.S. D e p t . A g r. F o r . S e r v . P a p e r .
I n te r m o u n ta in Region. Ogden, UT. 19 p.
Knoph, F. L., a n d R. W. Cannon. 1982. S t r u c t u r a l r e s i l i e n c e o f a
w illo w r i p a r i a n community t o changes i n g r a z in g p r a c t i c e s . J n :
J.M. P e c k a n d P.D. D a l k e ( e d . ) .
W ild lif e - L iv e sto c k
R e l a t i o n s h i p s S y m p o siu m : P r o c e e d i n g s 10. Univ. o f ID. F o r e s t ,
W i l d l i f e and Range Exp. S ta. Moscow, ID. pp. 198-207.
L e o p o ld , S.
1975.
R e s e a r c h n e e d s o f an e c o s y s t e m . J n :
W ik in g
(e d .).
P r o c e e d i n g s o f t h e W ild T r o u t M anagem ent Symposium.
T rout U n lim ite d . Denver. CO. pp. 96-98.
M arcu so n , P. E. 1977. The e f f e c t s o f c a t t l e g r a z i n g on brow n t r o u t
i n Rock Creek, Montana. MT. Dept. F ish and Game, F ish Div. Spec.
Rep. P ro j . No. F - 20—R—21, I I —a.
26 p.
M arlow , C. B. 1983. C a t t l e b e h a v i o r i n a f o o t h i l l s r i p a r i a n zo n e.
P a p e r p r e s e n t e d a t t h e 3 6 th A nnual M e e tin g o f t h e S o c i e t y f o r
Range Management. Albuquerque, NM, (Feb. 14-18, 1983).
McKee, J. E., and H. W. W o lf, e d s .
1963. W a te r q u a l i t y c r i t e r i a .
C a l i f o r n i a S t a t e W a t e r R e s o u r . C o n t r o l B o a r d , P u b l . 3 -A
( r e v is e d ) .
Sacram ento, CA. 548 p.
McLean, A., H. H. N i c h o l s o n , and A. L. Van Ryswyk.
1963. Growth
p r o d u c t i v i t y and chem ical c o m p o sitio n of a s u b a lp i n e meadow i n
i n t e r i o r B r i t i s h Columbia. J. Range Manage. 16(5):235-240.
Meehan, W. R., and W. S. P l a t t s .
1978. L i v e s t o c k g r a z i n g and t h e
a q u a t i c environm ent.
J. S o il and W ater Con. 33(6):274-278.
Meehan, W. R., F. J. Sw anson, and J . R. S e d e l l . 1977. I n f l u e n c e s o f
r i p a r i a n v e g e t a t i o n on a q u a t i c e c o s y s t e m s w i t h p a r t i c u l a r
r e f e r e n c e t o s a lm o n o id f i s h e s and t h e i r fo o d s u p p l y . J n : R.R.
Johnson, and D.A. Jones (tech, coord.).
Im portance, P r e s e r v a tio n ,
and Management o f R ip a ria n H a b ita t : A Symposium. U.S. Dept. Agr..
F o r. S e rv . Gen. Tech. Rep. RM-43. Rocky Mt, F o r. and Range Exp.
S t a . F o r t C o l l i n s , CO. pp. 1 3 7 -1 4 5 .
Montana S t a t e Rural Areas Development Committee.
1982. A taxonomic
c l a s s i f i c a t i o n s y s te m f o r M ontana r i p a r i a n v e g e t a t i o n t y p e s .
Montana Rural Areas Development Committee. Bozeman, MT. 13 p.
74
M o r r i s , M. J . I 973. E s t i m a t i n g u n d e r s t o r y p l a n t c o v e r w i t h r a t e d
m ic ro p lo ts.
U. S. D ept. Agr. F o r. S e rv . Res. P a p e r RM-104.
Rocky Mt. F o r. and Range Exp. S ta . F o r t C o l l i n s , CO. 12 p.
M yers, L. H. 1981. G r a z i n g m an ag em en t v s . r i p a r i a n m a n ag em en t i n
so u th w est Montana. Paper p re s e n te d a t th e 34th Annual Meeting o f
t h e S o c i e t y f o r Range M anagem ent. T u l s a , OK. Feb. 9 - 1 3 , 1981.
14 p.
N a tio n a l Oceanic and A tm ospheric A d m in is tra tio n .
Data - Montana.
85 (4).
O rr1
1982.
C lim a to lo g ic
H. K.
I9 6 0 .
S o i l p o r o s i t y and b u l k d e n s i t y on g r a z e d and
p r o te c te d Kentucky b lu e g r a s s ra n g e i n th e B lack H i l l s .
J. Range
Manage. 13(2):80-86.
P a p e n d ic k , R, I . , V. C. C o ch ran , and W. M. Woody. 1971. S o i l w a t e r
p o t e n t i a l and w a te r c o n te n t p r o f i l e s w ith wheat un d er low s p r in g
and summer r a i n f a l l .
Agron. J. 63:731-734.
P e t e r s , J. C. 1962. The e f f e c t s o f s t r e a m s e d i m e n t a t i o n on t r o u t
embryo s u r v i v a l . J q: B io lo g ic a l Problems i n W ater P o l l u t i o n T hird Sem inar, U.S. P u b lic H e alth Serv. C in c in n a ti , OH.
P l a t t s , W. S. 1978. L i v e s t o c k i n t e r a c t i o n s w i t h f i s h and a q u a t i c
e n v i r o n m e n t s : p r o b le m s i n e v a l u a t i o n . T r a n s . 4 3 rd . N. Am. and
N at. R eso u r. Conf. pp. 4 9 8 -5 0 4 .
P l a t t s , W. S. 1979. L iv e s to c k g r a z in g and r i p a r i a n / s t r e a m eco sy stem s
- an o v e r v i e w . Jr*: O.B. Cope ( e d . ) . P r o c e e d i n g s o f t h e Forum G r a z i n g and R i p a r i a n / S t r earn E c o s y s te m s .
T rout U n lim ite d ,
D e n v er, CO. pp. 3 9 - 4 5 .
P l a t t s , W. S. 1981 a. In f lu e n c e of f o r e s t and ra n g e la n d management on
anadr.om ous f i s h h a b i t a t i n w e s t e r n N o rth A m e ric a . E f f e c t s o f
l i v e s t o c k g ra z in g .
U.S. D ept. Agr. F o r. S e rv . Gen. Tech. Rep.
PNW-124. I n t e r m o u n t a i n F o r. and Range Exp. S t a . B o i s e , ID. 25
P.
P l a t t s , W. S. 1981b. E f f e c t s o f sheep g r a z in g on a r i p a r i a n - stream
e n v iro n m e n t.
U.S. D ept. Agr. F o r. S e rv . Res. N o te .
INT-307.
I n t e r m o u n t a i n F o r. and Range Exp. S ta . B o is e , ID. 6 p.
P l a t t s , W. S. 1982. Sheep and c a t t l e g ra z in g s t r a t e g i e s on r i p a r i a n
- stre am environm ents. J q : W i l d l i f e - L iv e s to c k R e l a tio n s h ip s
Sym posium : P r o c e e d i n g s 10. U niv. o f ID. F o r e s t , W i l d l i f e and
Range Exp. S ta . Moscow, ID. pp. 2 5 1 -2 7 0 .
Pond, F. W. 1961. E f f e c t s o f t h r e e i n t e n s i t i e s o f c l i p p i n g on t h e
d e n s i t y and p r o d u c t i o n o f meadow v e g e t a t i o n . «J. Range Manage.
1 4 (0 :3 4 -3 7 .
75
R auzi . F., and C. L. Hanson.
1966.
a f f e c t e d by i n t e n s i t y o f g r a z i n g .
356.
W ater i n t a k e and r u n o f f a s
J f Range Manage. 1 9 (6 ) :3 5 1 -
Reid, E. H., and G. D. P ic k f o r d. 1946. Judging m ountain meadow range
c o n d i t i o n i n e a s t e r n O regon and e a s t e r n W a s h in g to n . U.S. Dept.
Agr. G iro . No. 748. 38 p.
R o ath , L. R. 1980. C a t t l e g r a z i n g h a b i t s and m o v e m e n ts r e l a t e d t o
r i p a r i a n h a b i t a t s and f o r e s t e d ra n g e s w ith i n f e r e n c e to a c u te
b o v in e d i e t a r y p u lm o n a ry emphysema. PhD. D is s . OR S t a t e Univ.
C o r v a l l i s , OR. 134 p.
R o a th . L. R., and W. C. K ru e g e r . 1982. C a t t l e g r a z i n g i n f l u e n c e on a
m ountain r i p a r i a n zone. J. Range Manage. 35;( 1)100-104.
R osgen, D. 1975. P r e l i m i n a r y r e p o r t - p r o c e d u r e s f o r q u a n t i f y i n g
s e d i m e n t p r o d u c t i o n . U.S.. D ep t. Agr. F o r. S e rv . S a n d p o i n t , ID.
S k o lv in , J. 1967. F l u c t u a t i o n s i n fo r a g e q u a l i t y on summer range i n
t h e B lu e M o u n ta in s . U.S. D ep t. Agr. F o r. S e rv . PNW-RES. Pap. 44.
20 p.
S m ith , B. H. nda.
R i p a r i a n w i l l o w m an ag e m e n t: i t s p r o b le m s and
p o t e n t i a l s w i t h i n th e scope o f m u l t i p l e use on p u b l i c ra n g e lan d s,
(u n p u b lish ed p a p e r).
USDI Bureau o f Land Manage., Rock S p rin g s,
WY. 11 p.
S t e v e n s W a te r R e s o u r c e s D ata Ward Book. 1975.
S tev en s, Inc. Beaverton* OR. pp. 109-130.
2nd Ed.
L e u p o ld and
Swan, B. 1979. R i p a r i a n h a b i t a t - t h e c a t t l e m a n ’ s v i e w p o i n t . I n :
O.B. Cope ( e d . ) .
P r o c e e d i n g s o f t h e F o ru m - G r a z i n g a n d
Ri p a r i a n / S t r earn E c o s y s te m s .
T r o u t U n lim ited . Denver, CO. pp.
4-6.
Taylor. J. E.
MT.
1983.
P e rso n a l communication,
MT. St. Univ.
Bozeman,
T a y l o r . S. A. 1972. P h y s i c a l E d a p h o lo g y . Ed. G.L. A s h c r o f t .
Freeman and Company. San F r a n s c is c o , CA. pp. 254-255.
W.'H.
Tow nsend, J. E., and P. J . S m ith .
1977.
P ro c. o f a s e m i n a r on
im p ro v in g f i s h and w i l d l i f e b e n e f i t s i n ra n g e management.
U.S.
D ep t. I n t . F i s h and W i l d l . S e r v . P ro g .
W a s h i n g t o n , D.C.
FWS/0BS-77/1. 118 p.
T u i n s t r a , K. E.
1967.
V e g e t a t i o n o f t h e f l o o d p l a i n s and f i r s t
t e r r a c e s o f Rock C re ek n e a r Red L odge, M ontana. PhD. D is s . MT.
,
S t . Univ. Bozeman, MT. 110 p.
76
U nited S t a t e s Department o f th e I n t e r i o r , Bureau o f Land Management.
1978.
Sandy G r a z i n g E n v i r o n m e n t a l I m p a c t S t a t e m e n t .
Rock
S p r i n g s , WY. 348 ,p.
V e s e t h 1 R., a n d 'C. M ontagne.
1980. G e o lo g ic P a r e n t M a t e r i a l s o f
M ontana S o i l s .
MT. Agr. Exp. S t a . B u l l . 721.
MT. S t . Univ.
Bozeman, MT. 117 p.
V o g l e r 1 J . P.
1978.
E f f e c t s o f g r a z i n g , c l e a r i n g , and s t r e a m
c h a n n e l i z a t i o n on r i p a r i a n and a s s o c i a t e d v e g e t a t i o n o f G u th rie
C o u n ty , Iow a. M.S. T h e s i s . I A. S t. Univ. Ames, IA. 79 p. (
V olland, L. A. 1978. Trends i n s ta n d in g crop and s p e c ie s c o m p o sitio n
o f a r e s t e d K e n tu ck y b l u e g r a s s meadow o v e r a n 11- y e a r p e r i o d .
JLn:
D.N. R y d e r ( e d . ) . P r o c . 1 s t I n t e r n a t i o n a l R a n g e l a n d
Congress.
Denver. CO. pp. 525-529«
W a ll e n ,
I. E.
1951.
The d i r e c t a f f e c t o f t u r b i d i t y on f i s h e s .
B u l l . OK. Agr. Mech. C o ll. 4 8 ( 2 ) : 1>27.
W h ite , R. J . , and 0. M. B r y n i l d s o n . I 967« G u i d e l i n e s f o r m an ag em en t
o f t r o u t s t r e a m h a b i t a t i n W is c o n s in . D ept. N at. Re s o u r . Div.
Cons. Tech. B u l l . No. 39« M ad iso n , WI . 65 p.
Wine g a r . H. H. 1977« Camp C re ek c h a n n e l f e n c i n g p l a n t , w i l d l i f e ,
s o i l and w a te r re sp o n se . Rangemans J. , 4(1): 10-12.
APPENDICES
78
Appendix A
V e g e ta tio n Types Common t o th e Cottonwood Creek Study S i t e
79
A ppendix A
Table 2.
V e g e ta tio n ty p e s common t o th e Cottonwood Creek study s i t e
b a s e d on c r i t e r i a e s t a b l i s h e d by t h e M ontana R u ra l A re as
Development Committee (1982), w i t h m o d i f i c a t i o n t o in c lu d e
a d ja c e n t upland v e g e t a t i o n ty p e s.
RAD
C la ssific a tio n
V e g e ta tio n
Type
R ip a ria n
Predominant S p e c ies
I A4
Aspen
Po p u Ius tremuloides miehx.
Poa comoressa L.
Bromus in e rm is L eyss.
Phleum o r a t e n s i s L.
T rifo lln m re o e n s L.
Taraxlcum o f f i c i n a l e Weber
Ribes l a c u s t r e ( P e r s . ) P o ir .
I I A 1/99
Aspen/Willow
Pooulus tre m u lo id e s
S a l l x spp. L.
Poa comoressa
A e r o s tis s t o l o n i f e r a L.
Carex r o s t r a t e a Stokes
Carex s o r e n e e l i i Dewey
Junous b a l t i c u s W i l l [ .
Rlbes l a c u s t r e
Prunus v l r e l n l a n u s L.
III E
Bog
Carex r o s t r a t a
Carex s o r e n e e l i i
A e r o s tis s t o l o n i f e r a
Juncus b a l t i c u s
Ribes l a c u s t r e
IV A
Meadow
Bromus in e rm is
Phleum o r a t e n s i s
Poa comoressa
A e r o s tis s t o l o n i f e r a
Carex r o s t r a t a
Juncus b a l t i c u s
A c h ille a m l l l l f o l i u m L.
C irsium a v a re n s e ( L . ) Scop.
Ill B I
Streambank
Poa comoressa
A e r o s t is s t o l o n i f e r a
Bromus in e rm is
Carex r o s t r a t a
Carex s o r e n e e l i i
Juncus b a l t i c u s
L ln a re a v u l e a r i s H i l l
80
Table 2 (C ontinued)
RAD
C la ssific a tio n
V e g e ta tio n
Tvoe
Upland
Predominant S p e c ies
VAI
Upla n d /G ra ssla n d
Poa comoressa
Poa s a n d b e r g li Vasey
Poa o r a t e n s i s L.
S ti o a comata T r i n. & Rupr.
S ti o a v i r i g u l a T r i n.
Agroovron s m ith ! ! Rydb.
A g r o o v r o n s o ic a t u m (P u r s h )
S c r i bn. & Smith
F e s tu c a id a h o e n s is Elmer
Bromus teotorum L.
A c h ille a m i l l i f o l i u m
V B I
Up lan d /S ag eb ru sh
A rte m isia t r l d e n t a t a v a r.
vaseyana (R ydb.) B e e tle
Rosa woods i i L in d . L.
Bromus tecto ru m
Poa comoressa
S ti o a comata
A c h ille a m i l l i f o l i u m
I A 4/99
Aspen Park
Pooulus tre m u lo id e s
Poa comoressa
Bromus in e rm is
Geranium v is c o s ls sim u m F.&M.
Taraxicum o f f i c i n a l e
Appendix B
D e s c r ip tio n of Computer Program
82
A ppendix B
D e s c r ip tio n o f computer program d e s i g n e d t o d e t e r m i n e s u s p e n d e d
s ed im en t lo a d s f o r each sam p lin g p e r io d based on av erag e w a te r depth,
t o t a l w a t e r flow and t o t a l sedim ent c o l l e c t e d (T ay lo r 1983). Computer
i s a T ex as I n s t r u m e n t s TI - 58 h a n d - h e l d c a l c u l a t o r m o u n ted on a
p rin to u t c rib .
The program c o n s i s t s o f f o u r s t e p s :
1.
I n i t i a l i z e t h e c o m p u te r t o e r a s e e x i s t i n g m a t e r i a l and p r e p a r e
u n i t t o work program.
2.
E n t e r a v e r a g e w a t e r d e p th ( s t a g e h e i g h t ) d u r i n g t h e c o l l e c t i o n
p e rio d .
P rogram c a l c u l a t e s t h e a r e a o f w a t e r f l o w i n g th r o u g h
flu m e and a d j u s t s f o r th e number o f c o l l e c t i o n tu b e s which would
be f i l l i n g .
3.
E n t e r t o t a l w a t e r f lo w r e c o r d e d d u r i n g t h e c o l l e c t i o n p e r i o d .
P ro g ram m e a s u r e s t h e l e n g t h o f t h e
w a t e r co lu m n t o g i v e a
v o lu m e tr ic v a lu e t o w a te r f lo w in g i n t o t h e c o l l e c t i o n tube.
4.
E n te r t o t a l sedim ent c o l l e c t e d d u r in g c o l l e c t i o n p e rio d .
Program
c a l c u l a t e s t h e grams o f sedim ent p er c u b ic m e te r of w a te r d u rin g
th e c o l l e c t i o n p erio d .
'S
83
A ppendix B - C o n tin u ed
Step
000 76 LBL
001 10 ©
002 47 CMS
003 25 CLR
004 58 FIX
005 09 09
006 91 R/S
007 76 LBL
008 11 W
009 99 PRT
010 65 X
011 07 7
012 93 •
013 06 6
014 02 2
015 95 =
016 55
017 01 I
018 00 0
019 00 0
020 00 0
021 00 0
022 95 =
023 42 STD
024 01 01
025 91 R/S
026 76 LBL
ZR*
027 12
028 99 PRT
029 55
030 43 RCL
031 01 01
032 95 =
033 42 STD
034 02 02
035 91 R/S
036 76 LBL
/p\
037 13 ©
—
— i
In itia liz e
—
E n ter av erage w a te r depth
—
-
— 2
Determine w a te r a re a
E nter t o t a l w a te r flow
— 3
Determine w a te r volume
E n te r t o t a l sedim ent c o l l e c t e d
84
A ppendix B - C o n tin u ed
Step
038 99 PRT
039 42 STD
040 03 03
041 43 RCL
042 02 02
043 65 X
044 01 I
045 93
046 09 9
047 06 6
048 03 3
049 52 EE
050 05 5
051 94 + / 052 95 =
053 22 INV
054 52 EE
055 55
056 43 RCL
057 03 03
058 95 =
059 35 1/x
060 99 PRT
061 98 ADV
062 91 R/S
063 00 0
064 00 0
065 00 0
066 00 0
4
C a lc u la te sedim ent - g / m ^ / c o l l e c t i o n p eriod
MONTANA STATE UNIVERSITY LIBRARIES
I III I I I IIiIIII
CM
CD
3 17
1001 5201 4
3378
P7k