MONITORING INVASIVE SPECIES
IN A SEMI-DESERT SAGEBRUSH
SHRUBLAND POST-WILDFIRE
REHABILITATION SEEDING
Megan M. Taylor1, Ann L. Hild2, Nancy L. Shaw3, Erin K. Denney4, and
Matthew R. Fisk4
1M.S. Student and 2Professor, Department of Ecosystem Science & Management,
University of Wyoming, Laramie, WY
3Research Botanist and 4Biological Science Technicians, USFS Rocky Mountain
Research Station, Boise, ID
OVERVIEW AND PROJECT
JUSTIFICATION
• Fire is a significant agent of disturbance in the
semi-arid shrublands of the Great Basin
(Bainbridge 2007)
• Long recovery periods of sagebrush communities
can allow non-native species to invade
(Ziegenhagen & Miller 2009)
• Post-fire reseeding is intended to reduce weed
reentry and return ecosystem function
• Little detailed information on mechanisms of exotic
return in wildfire rehabilitation projects
OBJECTIVES
• Compare Rangeland Drill and Minimum-Till Drill
seeded treatments for exotic presence
• Document the temporal presence of exotic annuals
following rehabilitation seeding
• Assess the relative biomass of native seeded
species versus exotic annuals
SCOOBY FIRE SITE
LOCATION
• Wildcat Hills, 20 miles southwest
of Snowville, UT
• August 2008 wildfire burned
380 acres of native
sagebrush
Adapted from U.S.
Department of the
Interior (2008)
Map: Amarina Wuenschel
Great Salt Lake Area (MLRA 028A)
028AY215UT, Semi-desert gravelly loam, Wyoming big sagebrush
• Elevation of 1440 m (4725 ft)
• Mean annual precipitation
20 – 30 cm (8 – 12 in)
• Mean annual air temperature
7 – 10 C (45 – 50 F)
• Frost-free period ranges from
116 to 151 days
• Soils
• Xeric Haplocalcids
(cobbly loam)
• Xeric Torriorthents
(gravelly coarse sand)
• Sandy loams and loamy sands
• Native plant community
• Artemisia tridentata ssp.
wyomingensis
(Wyoming big sagebrush)
• Achnatherum hymenoides
• (Indian ricegrass)
• Pseudoroegneria spicata
(Bluebunch wheatgrass)
NRCS (2011) and Soil Survey Staff (2011)
Photo: Johnson T, Corbeil M, Tews A (2009)
SCOOBY FIRE
PRECIPITATION
*
140
120
11 Year Average
80
Drill
seeding
60
Biomass
and soil
collection
Biomass
collection
40
20
2008
2009
2010
2011
JUL
JUN
MAY
APR
MAR
FEB
JAN
DEC
NOV
OCT
SEP
AUG
JUL
JUN
MAY
APR
MAR
FEB
JAN
DEC
NOV
OCT
SEP
AUG
JUL
JUN
MAY
APR
MAR
FEB
JAN
DEC
NOV
OCT
0
SEP
Precipitation (mm)
100
Photos: N. Shaw, E. Denney, & M. Fisk, USFS-RMRS
Standard
Rangeland
Drill
Drill seeded
November
2008
Minimum-Till
Drill
SCOOBY FIRE TREATMENT
APPLICATION
5 blocks → 13 treatments → 5 transects per plot
We sampled 4 blocks → 13 treatments → 2 transects per plot
SCOOBY FIRE TREATMENT
APPLICATION
Drill
No Drill
Drill Seed
Broadcast Seed (Sagebrush Rate)
Code
No Seed
No Seed
C
No Seed
No Seed
M (0)
Drill
Drill (std)*
M (std)
Minimum-Till
Drill
Drill (5x)
M (5x)
(Broadcast seed covered
with impactor unit)
Drill
Drill (10x)
M (10x)
Drill
Hand broadcast, fall (5x)
Drill
Hand broadcast, winter (5x)
No Seed
No Seed
R (0)
Drill
Drill (std)
R (std)
Rangeland
Drill
Drill (5x)
R (5x)
(Broadcast seed covered
with chain)
Drill
Drill (10x)
R (10x)
Drill
Hand broadcast, fall (5x)
Drill
Hand broadcast, winter (5x)
* Standard, 5x and 10x refer to A. tridentata ssp. wyomingensis seeding rate
M+BC (5x)
M+wBC (5x)
R+BC (5x)
R+wBC (5x)
Seeding Rate (PLS m-2)
Scooby Seed Mix Species
Standard
5x
10x
Artemisia tridentata wyomingensis (Wyoming big sagebrush)
52
234
495
Ericameria nauseosa (rubber rabbitbrush)
86
86
86
100
100
100
Poa secunda Mt. Home Germplasm (Sandberg bluegrass)
91
91
91
Penstemon cyaneus (blue penstemon)
76
76
76
405
587
848
‘Rimrock’ Achnatherum hymenoides (Indian ricegrass)
51
51
51
Sphaeralcea munroana (Munro’s globemallow)
93
93
93
Pseudoroegneria spicata Anatone Germplasm (bluebunch
wheatgrass)
67
67
67
Elymus elymoides Toe Jam Creek Germplasm (squirreltail)
47
47
47
Eriogonum umbellatum (sulphur-flower buckwheat)
11
11
11
269
269
269
674
856
1117
Broadcast mix
Achillea millefolium Eagle Germplasm (common yarrow)
Total Broadcast
Drill mix
Total Drill
Total Drill + Broadcast
MATERIALS AND METHODS
Biomass Collection
• Randomly placed four 0.25 m2 quadrats in each
•
•
•
treatment
Native grass (volunteer and seeded) clipped as a
group
Volunteer forbs clipped
as a group
Seeded forbs and exotic
annuals clipped
separately by species
0.25m2 quadrat
MATERIALS AND METHODS
Soil Sampling for Microbial Community Analysis
• Native grass (Poa secunda)
•
•
•
•
•
microsites
Exotic grass (Bromus tectorum)
microsites
C, R(0), M(0), R(5x), and M(5x)
treatments
5 replicates from each treatment
Soil texture, pH, and EC samples
adjacent to PLFA samples
0-5 cm sampling depth
Poa secunda microsite
R(std)
Control
2011
M(std)
TOTAL BIOMASS
2010
2011
BIOMASS BY PLANT
GROUP
2010
2011
BIOMASS BY PLANT
GROUP
SEEDED FORBS
Biomass (% of total)
14
A
12
AB
10
Broadcast Forbs
AB
8
6
Drill Seeded Forbs
AB
B
4
B
2
B
B
B
0
Rangeland R+wBC (5x)
Drill
R+BC (5x)
R (0)
Control
M (0)
M+BC (5x) M+wBC (5x) Minimum-Till
Drill
Biomass (% of total)
A. millefolium
14
12
10
8
6
4
2
0
A
AB
AB
AB
B
B
B
Rangeland R+wBC (5x)
Drill
R+BC (5x)
R (0)
B
Control
Treatment
B
M (0)
M+BC (5x) M+wBC (5x) Minimum-Till
Drill
BIOMASS BY PLANT
GROUP
Exotic Annuals
90
A
Biomass (% of total)
80
A
A
70
60
50
40
30
20
10
B
B
0
Rangeland Drill
R (0)
Control
Treatment
M (0)
Minimum-Till Drill
EXOTIC ANNUALS
2010
2011
BIOMASS RESULTS
• Total biomass
• Exotic annuals and volunteer forbs greatest
in unseeded controls
• Broadcast forbs greatest in Minimum-Till
seeded treatments
• Exotic annuals S. kali and H. glomeratus
greater in 2010, B. tectorum dominated in
2011
SOIL MICROBES
6
µg Fatty Acid/g soil
5
4
Gram + Bacteria
Gram - Bacteria
3
AM Fungi
General Fungi
2
Protozoans
1
0
Brte
Pose
Brte
Pose
R(5x)
R(5x)
R(0)
R(0)
Brte
Pose
Brte
Pose
Brte
Pose
C
C
M(0)
Microsite by Treatment
M(0)
M(5x)
M(5x)
SOIL MICROBIAL
COMMUNITY RESULTS
•
•
•
•
Preliminary results
100 samples analyzed
190 more to extract
No obvious trends yet…
CONCLUSIONS
• Few drill differences three years after
seeding
• More broadcast forbs with the Minimum-Till
Drill
• Tradeoff between seeding and
recruitment of volunteer forbs
• Native seeding does minimize relative
biomass of annual exotics
FUTURE CONSIDERATIONS
• PLFA analysis may reveal differences in soil
microbial communities beneath broadcast,
drilled, and exotic grass
• Soil microbial communities may differ between
drills
• Impacts of drill differences and seeding rate may
become more apparent as size and density of
seeded species increases
QUESTIONS?
Plant Biomass (g/m2)
Year
2010
2011
Treatment
Native
Grass
Seeded
Forbs
Volunteer
Forbs
Exotic
Annuals
S. kali
H. glomeratus
B. tectorum
Total
Biomass
Rangeland
Drill
153.56
14.18
5.55
8.53
3.21
3.95
1.37
181.82
R (0)
0.39
0.00
52.90
98.29
63.23
23.79
11.27
151.57
Control
0.00
0.00
25.64
96.28
29.30
28.37
38.61
121.92
M (0)
0.00
0.00
47.61
110.51
60.41
22.93
27.17
158.11
MinimumTill Drill
172.48
19.01
5.33
11.95
2.13
9.44
0.38
208.76
Rangeland
Drill
212.99
9.46
16.01
11.13
0.002
0.00
11.12
249.59
R (0)
1.78
0.00
42.07
76.15
0.46
0.003
75.69
119.99
Control
5.96
0.00
28.74
97.78
0.01
0.00
97.77
132.48
M (0)
1.94
0.00
20.43
72.21
0.10
0.00
72.11
94.58
193.52
15.26
8.71
8.96
0.00
0.05
8.91
226.45
MinimumTill Drill
Plant Biomass (lb/acre)
Year
2010
2011
Treatment
Native
Grass
Seeded
Forbs
Volunteer
Forbs
Exotic
Annuals
S. kali
Rangeland
Drill
1369.74
126.52
49.52
76.09
28.66
35.19
12.23
1621.83
R (0)
3.43
0.00
471.82
876.70
563.97
212.21
100.53
1352.00
Control
0.00
0.00
228.71
858.84
261.38
253.04
344.42
1087.53
M (0)
0.00
0.00
424.64
985.75
538.86
204.51
242.38
1410.34
MinimumTill Drill
1538.49
169.53
47.57
106.57
19.01
84.16
3.39
1862.14
Rangeland
Drill
1899.90
84.39
142.83
99.25
0.02
0.00
99.23
2226.34
R (0)
15.90
0.00
375.22
679.21
4.06
0.02
675.13
1070.31
Control
53.19
0.00
256.38
872.18
0.07
0.00
872.11
1181.72
M (0)
17.33
0.00
182.25
644.08
0.88
0.00
643.20
843.65
1726.16
136.13
77.73
79.93
0.00
0.47
79.46
2019.93
MinimumTill Drill
H.
glomeratus
B.
tectorum
Total
Biomass
ANOVA
Total
Biomass
Native
Grass
Seeded
Forbs
Volunteer
Forbs
Exotic
Annuals
S. kali
H. glomeratus
B. tectorum
%
g/m2
Treatment
0.0057
<0.0001
<0.0001
<0.0001
<0.0001
0.0002
<0.0001
<0.0001
Year
0.0663
0.4181
0.5346
0.4188
0.1642
<0.0001
0.0002
<0.0001
Year*Treatment
0.2779
0.9503
0.9355
0.8646
0.7638
<0.0001
0.0445
<0.0001
SEEDED FORBS
BIOMASS BY PLANT
GROUP