REGENERATION AND GROWTH OF COASTAL DOUGLAS- IR
Ri c h a rd E . t1i l l er , Ri chard L . W i l l i amson ,. and Roy R . S i l en
ABSTRACT
Environmental requirements for regenerating coastal
Douglas-fir are described. The effects of forest residu s
and various residue treatments on natural regeneration and
growth are discussed; in general lack of residue treatment
favors regeneration of species more shade-tolerant than
Douglas-fir. Residues left after harvest of old-growth
stands are the most typ'ical and most costly to eliminate
especially where economics do not permit a high level of
utilization. Some of these residues have potential value
for wood products or for soil humus and nutrients essential
to soil productivity; however residues can also be fire
hazardS or obstacles to other forest management objectives.
Residues and their treatment affect the effort needed for
regenerating tending and protecting the forest--timber
yields as weE as water ' 'recreation and wildlife are
influenced. A detailed examination of conditions at each
location should routinely precede the slash treatment
decision. In most situations conservation of small branches
twigs and needles is important to site productivity
particulqrly in managing immature or easily erodible soils.
Information is presented to help the land manager assess the
conflicting values of forest residues and determine the best
treatment 'for specific site conditions.
Keywords : Pseudotsuga menziesii--site p repara t i o n , natural
regene rat i on , soi l producti vi ty , tree growth,
c l earcut t i n g , fi re effects .
INTRODUCTION
Al l orga n i c ma tter of the fo rest eventual ly fa ns to the fores t floor a s a
res ul t of natural s tand devel opment , c a tas troph i c even t s , or ma n 's a c t i v i ti es .
In commerc i al l y ma naged fore s ts , man ha rvests whatever can b e u t i l i zed.for wood
products ; the rema i n i ng materi a l i s termed fo res t res i due . Under natural c o nd i ­
ti ons , for e s t res i dues are destroyed by wi l dfi re o r gradual l y mi neral i zed o r
mod i fi ed to humus and i ncorporated i n to the mi neral so i l .
Currentl y , exces s i v e accumu l a ti ons of res i dues rema i n i ng a fter h a rves t of
old-growth s tands a re our mos t pre s s i ng res i due probl em i n t he Pac i fi c Northwe s t .
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Some of these res i dues have poten ti al va l ue for woo d pro du c ts or for so i l humu s
and nutri ents essen t i a l to soi l fert i l i ty; however , i f res i dues a re l eft
untreate d , they can a l so be fi re hazards or obs ta c l es to o ther fores t mana gement
objec t i ves . For exampl e , spec i e s compo s i t i on , a dequacy , a n d t i mi ng of natural
regenera t i on a re s tron g l y i nfl uenced by the amount and di s tr i bution o f "res i dues
or by the me thod u s e d to re duce the hazard of wi l df i re . T i mber ha rves t or
accompany i ng res i due treatment a n affect the short- term g rowth and l ong- term
pro ducti v i ty of Dougl a s - fi r fo re s ts , as wel l as wa ters h e d a n d recrea ti onal
va l ues of the fore s t . Moreover , the practi cal effects of these opera t i ons
depen d on stand a n d s i te condi t i o ns ; removal o r re di s tr i bu t i on of l ogg i ng s l a s h
a n d the orga n i c accumul a t i on overl yi ng mi neral so i l can be di s a s trous a t some
s i tes a n d of l i ttl e l ong-term s i g n i fi cance on others . The refore , for max i mum
benefi t : co s t rat i os from mana g i ng commerc i a l Dougl a s - fi r fores ts , the i nter­
rel a t i ons of i n di v i du a l ma nageme n t operations shoul d be known and coo rdi n ated
in pl anni ng and executi ng t i mber ha rves ts , res i du e tre a tme n t , a n d subsequent
regenera t i on a n d cul tural prac t i ces .
DESCRI PT ON OF FOREST TYPE , ENV I RONMENT ,
AND S I LV I CAL CHARACTER I ST I CS
Coastal Doug l a s - fir , Ps udotsuga menziesii ( Mi rb . ) Franco v ar . menzies1,'/,
( herea fter ca l l e d Dougl a s - f i r ) , i s the maj or tree spec i es i n one of the worl d' s
mo s t pro ducti ve forest type s . The coa stal vari e ty i s res t r i cted to areas wes t
o f the Coa s t Ra nge i n Bri ti s h Col umbi a , wes t o f the Casc a de Range Cres t i n
Oregon a n d Wa s h i ngton , we s t o r the S i erra Nevada Range i n northern Cal i forn i a ,
a n d wes tern Nevada . The Dou gl as - fi r type currently covers appro fj ma te l y 1 1 . 7
mi l l i on acres ( 4 . 7 mi l l i on ha ) i n wes tern Was h i ngton a n d Oregon . - I t represents
a bo u t 47 perc ent of the commerc i a l fores t l an d a n d an es t i ma te d ti mbe r vol ume of
a pproxima te l y 352 b i l l i on boa r d feet ( I nternati onal 1 / 4 - i nch rul e ) in that a rea
(Wa l l 1 969 ) .
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Fore s t Type a n d Env i ronment
Coa s ta l Dougl a s - f i r i s usual l y a s ubcl i ma x component i n the Tsuga
Zon e ( Fran k l i n a n d Dyrness 1 969 ) . Thi s zone i s c ha racter i z e d by
a moi s t , mi l d mari t i me cl i ma te wi th dry summers , al though there i s much vari a ­
t i o n from di ff,erences i n l a t i tude , e l evat i o n , a n d l ocati o n rel a t i ve to
mou n ta i n s . Al mos t pure , even-ag e d natural stands of coa s ta l Do ugl a s - f i r commonly
evo l v e d after wi l dfi res or c l earcut l oggi ng opera t i ons and s l a s h burn i ng . The
pri nc i pa l assoc i a tes of Dou gl a s - f i r are we stern heml ock (Tsuga heterophylla
( Ra f . ) Sarg.) and wes tern redc e da r (Thuja plioata Donn ) . Al though Doug l as - f i r
i s a maj o r spec i es south of the Tsuga heterophylla Zone , our di s cu s s i on wi l l be
l imi ted to the Dougl a s - f i r fo re s ts north of the di v i de between the North a n d
South Umpq ua Ri vers a n d north of the Kl a ma t h Mounta i ns i n sou thern Orego n .
heterophylla
So i l s support i n g the Dougl as -fi r type vary wi de l y i n phys i ca l a n d chemi cal
chara c ter i s ti cs res u l ti ng in vari ous amounts and rates of orga n i c ma tter
l! Persona l correspondence wi th Dona l d R. Gedney , Pac i fi c Northwe s t
Fore s t a n d Range Expe r i ment Sta t i on , Po rtl and, Oregon , December 1 973 .
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decompos ition ( Fore s t So il s Committee o f the Dougl a s - fir Reg ion 1 957 , Fra n kl in
and Dyrne s s 1 969 , Moore a n d Norris 1 974 ) . Reg iona l soil s al s o vary in suscep­
tibil ity to ero s ional a n d productivity lo sses which are l ike l y to fo l l ow severe
dis turba nce of pro tec tive vegeta t ion a n d the fores t fl oor (Swans ton a n d Dyrness
1 97 3 ) .
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Sil vical C harac teris tics a n d Micro s ite Requ irements
To regenera te and grow Dougl a s - fir effectivel y , one s houl d co ns ider its
requirements for a n d tol erances of mo is ture , tempera ture , l ig h t , a n d n u trients ,
and how these factors are a ffecte d by res idues a n d res idue trea tmen t .
C oa s ta l Doug l a s - fir is mo dera te in its soil mo is ture requ irements , to l era t­
ing neither h igh water ta bl es as do wes tern redceda r a n d red al der (A lnus rubra
Bong . ) (t1inore 1 97 1 ) , nor exces s iv e l y droughty conditio n s as do pon dero sa pine
(Pinus ponderosa L aws . ) and bl ack o a k (Quercus ke l loggiiNewbr . ) (Waring 1 969 ) .
Adequate soil mois ture is particul arly critica l for s e e d germination a n d seedl in
surviva l . The amount a n d rate o f movement o f soil mois ture to germina t ing seed
or seedl ing roots are l a rge l y determined by soil charac teris tics a n d the amount
of compet in g vegeta tion . Subsequent water u s e by the'pl a n t , however , depends on
cl ima tic s tres s and the pl an t1s response to it . I n the Dougl a s - fir reg ion ,
warm , dry s ummers create l arge evapo - transpirational s tres s ; rel a t ive to l o dge­
po l e pin e (Pinus contorta Dougl . ) and pon derosa p in e , Dougl a s - fir seedl ings show
l ess contro l of the amount o f wa ter l os t to this s tres s . For exampl e , a t a
soil wa ter ten s ion of - 1 0 a tmospheres , Dou gl a s - fir s ee dl ings con tinue to
tra nspire a bout 32 percent of max imum rates compare d with 9 percent for the
pines ( Lopus hin s ky a n d Kl o c k 1 97 4 )
Extremes in a ir a n d soil temperatures have a dverse e ffec ts o n seedl ing
survival a n d growth . High tempera tures dev el op a t the a ir- soil in terface
exposed to direct sunl ight ; s u ffic iently l ong expos ure of see dl ings to soil
su rface temperatures over 1 2 50 F may cause heat l es ibns upon the s tems of newl y
germinated s e e dl ings a n d subsequent dea th . Hence , in termittent s h a de a n d seed
be d ma teria l s whic h conduct heat away from the seed be d surface a re importa n t
in the a b il ity of ,seedl ing s to survive h igh tempera tures ( S il en 1 960) . So il
surface tempera tures a bove 1 380 F are u s ua l l y l etha l . Such temperatures are
common o n southerl y s l opes in the Oregon Cascades but a l so occur on exposed
northerl y s l opes ( S il en 1 960 , Hal l in 1 968b ) . Al though first-ye ar Dougl a s - fir
seedl ing s gra du a l l y devel op in rea s e d res is ta nce to h ig h tempera tures ( Ke ij zer
and Herma n n 1 966 ) , seedl ings escaping or surviv ing h ig h soil surface tempera tures
can die from prol onged dro ught wh ich causes morta l ity l os s es throughout the
Dougl a s - fir type ( I saac 1 938 ) .
Bel ow- freezing temperatures a re 'equa l ly hazardous to yo ung seedl ings .
Fro s t heaving o f 1 ­ to 2-year-ol d natural seedl ings a n d fres h l y pl a nted seedl ings
can be expected if temperatures drop bel ow freezing a n d the surface soil is
bare and mo is t . Fro s ts n ip s uccul ent new fol iage o f young seedl ings . On
establ is h e d trees , fo l ia ge can be inj ured with subsequent l os s of tree " growth
when very col d a ir tempera tu res occur ( Reukema 1 964b ) .
Doug l a s - fir s e e dl ing s have high req u irements fo r nu trients compared with
associa t e d con ifers (Wa l ker et a l . 1 972 ) . Yet , fertil iza t ion unde r fie l d con­
ditions genera l l y fail s to improve surv ival
o f artHic ia l ly-seede dY or p l a nted
,
U npubl is hed da ta on fil e a t Fores try Sciences Labora tory , Olympia ,
Wa s h ing ton .
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Dou g l a s - fi r (Aus t i n a n d Stra n d 1 960 , Rotha cher a n d Fran k l i n 1 964 ) , mos tly becau se
ferti l i za t i on i nc reases the growth of other vegeta t i on compe t i ng for mo i s ture .
Nu tri e n t to l erances or req u i rements probably i ncrea se wi th tree age ; for exampl e ,
l i g h t to mo derate dosages of ferti l i zer wh i c h i ncrea s e d morta l i ty of newl y
germi n a t e d see ds or young seedl i ngs a l so i nc rea s e d growth i n young po l e - s i ze
trees ( se e footnote 2 ) .
Onl y u n der very heavy s l a s h or vegeta t i ve cover i s l i g h t i ns uffi c i ent for
'sur v i val and growth of Dougl a s - fi r see dl i ng s . M i n i mum requ i rement for norma l
rowth of s e e dl i ngs under f i el d si tua t i ons i s a bou t 50 percent of fu l l sun l i g ht
(I saac 1 943 ) ; however , l i ght req u i rements of Dougl as - f i r ev i dently i ncrea s e wi th
i nc rea s i n g mo i s ture stress (Atzet and War i ng 1 970 ) . Th i s may expl a i n why
Strothma n ( [ Stro thma nn] 1 97 2 ) obs e rved that shade di d not improve s u rv i va l of
pl a nted Dou g l a s - fi r in northern Cal i fo rn i a and tha t 25-percent s ha de reduced
seedl i ng growth. There has been cons i derabl e i nves t i g a t i on of l i gh t requ i rement s
of Dou g l a s - fi r seedl i ngs i n favorabl e growt h chamber o r nursery envi ronments
( Krueger a n d Ferre l l 1 965 , Wal ker et a l . 1 972 ) ; however , extrapo l a t i on of these
res ul t s to fi el d condi t i ons i s uncerta i n . Thus , l i gh t-to-mo derate s ha di ng of
see dl i ng s by res i dues or res i dual trees p robably permi t s a deq uate l i gh t for
norma l s u rv i va l a n d growth as wel l as protects from temperature extremes .
The c a pa c i ty of mi c ros i tes for pro v i di ng Dougl a s -fi r seed a n d seedl i ngs
wi th a dequate mo i s ture , tempera ture , l i ght, and nutr i en t s is ma rke dl y a ffec te d
by forest res i dues a n d res i due treatments . Res i due trea tment di rectly affects
the amou n t a n d di s tr i bu t i o n of vari ous ki n ds of see d beds , a boveground res i due s ,
and res i du a l vegeta t i on ; subsequent pl a n t succes s i on a n d wi l dl i fe depreda t i ons
are i n di rec t l y a ffec ted.
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M i n e ra l soi l i s the bes t see d be d for regenera t i ng Doug l a s fi r from seed.
M i ne ra l s o i l surfaces a re u s ual l y cool e r wi th l es s ' extremes of tempera ture than
orga n i c ma tter seed beds (Anonymous 1 92 9 , Si l en 1 96 0 , Herma nn and Chi l cote 1 965 ,
Fowl e r 1 974 ) . N i neral soi l surfaces u s ua l l y provi de l es s compe t i t i on from
res i du a l vegeta t i o n . I n contras t , orga n i c seed be ds have i n s u l a t i ng propert i es
wh i ch de l ay the tra n s fer of hea t energy to a n d from the under l y i n g so i l , thus
ra i s i n s urface temperature dur i ng the day ( S i l en 1 96 0 ) and dep ress i ng i t a t
n i g ht (S i l en 1 960 , Fowl er 1 974 ) . Moreover , orga n i c see d beds become exc es s i ve l y
dry u n de r expos e d condi ti ons . Al though Doug l a s - f i r see d germi n a tes u n der a wi de
va r i e ty of con di t i on s ( I saac 1 943 , Tappe i ner 1 966 ) , ra te a n d percentage of
germ i na t i on a re a ffected by see d be d type ( Herma nn and C h i l co te 1 965 ) .
Seed be d surface tempe ratures a n d mo i s ture condi ti ons a re l es s c r i ti ca l for pl a n t e d seedl i ngs than for natural see dl i ngs . The thi c ke r bark of ol de r , p l a n t e d seedl i ngs i s more res i s ta n t to h i g h 'soi l surfa c e tempe ratures a n d the i r roo t s a re pl a nted deep i n to mi neral so i l where mo i s ture condi t i on s a re gen e ra l ly more favora b l e than i n the surface so i l . Under extreme condi ti ons ( steep south s l opes wi th sha l l ow so i l , for exampl e ) even pl a nte d seedl i ngs nee d protec t i on from exc e s s i ve surfa ce temperatures a n d soi l mo i s tu re s tres s . See al so E dgren a n d Ste i n ( 1 974 ) . '
The n e t e ffec t on Dougl a S - fi r regenera t i on of vegeta ti onal commun i t i e s wh i ch
deve l op on c l earc uts i s extremel y vari a bl e a n d depends l a rgely on re l a ti ve rates
of dev e l opment be tween Doug l a S - fi r see dl i ng s and compe t i n g vegeta t i on a n d the
type of vegeta t i on . For i n i ti a l surv i v a l i n mos t s i tu a t i ons , recently germi nated
Doug l a s - fi r seedl i ngs nee d s h a de ( I saac 1 943 ) ; however , mo de rate to heavy
sha di ng on s e e d be ds can i nc rease l os s e s from dampi ng -off fung i a n d c l i pp i ng by
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wh i te -footed deer mi ce ( Peromysous maniouZatus ) ( Herma nn a n d C h i l cote 1 965 ) .
Over a 6-year per i o d at h i s s tu dy s i te i n sou thwes tern Was h i ngton , I s aac ( 1 943 )
found that fi rs t-year survi val averag e d 7 , 21 , and 57 percen t , respect i ve l y ,
wi th no shade , medi um s h a de , a n d dense s h a de ( l og g i ng debr i s a n d brus h ) . Subse­
quent s urvi v a l through 5 years was a l so improv e d by s h a de , a l though h e i ght growth
was gra dua l l y re duced whe n the s h a de was prov i de d by veg eta t i on .
Vegeta t i on can prov i de too much s h a de a n d competi t i o n for mo i s tur e . For
exampl e , Hal l i n ( 1 968a ) found tha t sQi l mo i s ture at the 6- i nch ( 1 5-cm) depth
i n l a te s ummer i n a southwes tern Oregon c l earcut wa s at - 1 5 to -25 a tmospheres
ten s i on u n der 2-year-ol d herbaceous vegeta t i on compared wi th 2 to 8 a tmos p heres
where the vegeta t i on was remove d. I saac ( 1 943 ) conc l u de d tha t spec i es whi ch
occupy gro u n d a s ,wel l as crown space a re more seri ous compet i tors than those
whi c h occur i n c l umps and l eave g rowi ng space for seedl i ngs bel ow and between
these c l umps . Both I saac ( 1 943 ) a n d Dyrness ( 1 965 ) concl u de d that i nv a di ng
herbaceous s p ec i es were general l y more compe t i t i ve to Dougl a s -fi r seedl i ngs than
res i du a l shrub speci es . Bes i des modera t i ng mi c rocl i ma t e , s ome s hrub spec i es
i mprove seedl i ng s u rvi val growth by pro v i di ng mecha n i ca l protecti on aga i n s t
brows i ng ( G ra t kows k i 1 967 ) .
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Afte r i n i ti al survi val , Doug l a s - fi r nee ds to ma i nta i n a domi nant pos i ti o n
among i ts competi tors . I nvesti gati ons of s nowbrush a n d varn i s h l eaf cea no thus ,
two va r i e t i e s of Ceanothus veZutinus wh i ch are promo te d by s l a s h burn i ng , i l l us ­
trate thi s po i nt . Zav i tkov s k i e t al . ( 1 969 ) concl u de d that snowbrus h ' i s eventu­
al l y suppre s s e d by coni fers , but the per i o d of domi nance by snowbru s h probably
determi n e s spec i es compo s i t i on o ,the succeedi ng con ifer s ta n d . If s nowbrush
rema i ns domi n a n t for more than 1 5 yea rs , then only to l erant spec i es , especi al l y
heml ock , c a n s ucceed i t natural l y. Dougl a s - f i r a n d nobl e fi r ( Abies prooera
Rehd. ) , p l a n te d or na tura l , can be succes sors provi di ng they become es ta bl i s hed
a t the same t i me a s snowbrus h . Simi l a r res u l ts were reporte d i n southwe s t
Oregon for varni s ,hl eaf ceanothus ( Gra tko\'/s k i 1 967 ) . ,
FOREST RES I DU ES
I n unma naged, Dougl a s - f i r fo res ts , accumu l a t i o n of res i due typi cal l y s ta rts
a fter wi l dfi r e . As snags of the o l d, f i re- k hl l e d s ta n d brea k and fal l , rotten
wood accumU l a tes and gra dua l l y decompo s e s . As the new stand g rows through
sapl i ng , pol e , a n d 'saw-l og s tages , i t prov i des a ddi ti onal woo dy materi a l from
s uppre s s i on a n d o ther l os ses . Mos t of thi s ma ter i a l i s sapwoo d wi th l i tt l e
res i s ta nc e to decay; a n d s i nce the fo res t envi ronment i s usual l y wel l sha ded,
the fores t reaches i ts mos t res i du e- free a n d fi re res i s ta n t s tage . As the new
s'tan d reaches maturi ty , morta l i ty a n d l i ve brea kage have hi gher port i o n s of
hea rtwoo d wh i c h de cay s l owl y i n the mo i s t condi ti ons of the fores t . F i n a l l y ,
accumul ated woo d o n the fores t fl oor o f the u nma naged overma ture o r o l d- grqwth
s ta n d becomes so grea t that a catas troph i c fi re eventua l l y occurs to s tart the
cycl e anew.
In harves ti ng ol d-g rowth s ta n ds , ma n i nterrupts thi s n a tu ra l cycl e a n d s ub ­
sti tutes harv e s t fo r cata s trophi c fi re . Beca u s e of the exce s s i ve amounts of
res i dual orga n i c ma tter of the fo res t fl oor a n d tha t con ta i ne d in u nmerchanta b l e
tree crown s a n d bo l es , these harvests crea te l ocal fi re hazards ; these haza rds
iema i n unti l much of the res i due gra dua l l y decomposes , burns through n a tural or
acc i denta l ma n - caused fi re , or is purposeful l y trea ted by burn i ng or mechan i ca l
means .
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I n managed, young-g rowth Doug l a s - fi r s tands , few res i dues pers i s t because
the amount of natural res i du e is smal l and i nc l udes only a sma l l propo r t i o n of
decay-res i s tant woo d. I n termedi a te and f i na l harvests of these young - rowth
stands pro duce l es s s l a s h tha n o l d- growth harves t , because of reduced defect a n d
. fel l i ng breakag e . Thus , i nc rea s e d uti l i za ti on o f to ta l woo d pro duc t i on wi l l
he l p mi n i mi ze the fu ture r es i du e probl em .
Type s a n d Amounts of Res i due s
Naturat residue si tuati ons . - -As o n e o f the worl d's mos t pro ducti ve fo res t
types , coa s ta l Dougl a s - fi r produces l a rge quanti t i es of fores t res i dues . Average
a nnua l l i tter fal l ( needl e s and twi gs ) in youn g Doug l a s - fi r s ta n ds i s approx i ­
ma te l y 1 ton per acre ( 2 . 24 metri c . tons per ha j j l es se r amounts fal l i n thi nned
stands ( Reukema 1 964a ) . L i t ter fal l i n ol d-growth s ta n ds of s i mi l a r s i te q u a l i ty
i s a bo u t the same ; however , l a rger l i mbs , bark , and unders tor¥ hardwoo ds con­
tri bute a n a ddi ti ona l 1 ton per a c re ( 2 . 24 metri c tons per ha) per yea r (Abee
and Lavender 1 972 ) . Normal a n d c a ta s troph i c tree morta l i ty contr i bute a ddi t i ona l
amou n ts .
Wi th the mos t favora b l e so i l a n d cl ima t i c condi ti on s and 'l ea s t decay­
res i s ta n t pl ant res i dues , there i s rap i d so i l b i ol og i ca l acti v i ty and thus rap i d
decompos i ti on of l i tter fal l or i ncorporation i nto the so i l .
nl y a th i n l ayer
accumul a tes a bove the so i l . Th i s i s the
of orga n i c res i dues , the for e s t fl oor ,
so-ca l l ed "mul l " fores t fl oor type , wh i ch i s rea di l y observed i n re d a l de r a n d
fas t-growi ng Do ugl a s - fi r s ta n ds . As macrocl i ma te or mi crocl i ma t e becomes coo l er
or dri er , soi l s l es s fer t i l e, o r pl ant res i du es more res i s ta n t , so i l b i o l o g i c a l
acti v i ty i s reduced a n d i nc reas i ng amo unts of res i dues accumul a te . I n extreme
s i tua ti ons , the s o -ca l l ed "mor" or " raw humu s / I (Hoover a n d Lunt 1 952 ) form i s
observed; th i s forest h umu s type i n di ca tes an un des i rabl y l ow rate of orga n i c
ma tter a n d nutr i en t cyc l i n g . U n der these con di t i ons , an average of 70 ton s
( 1 50 metr i c tons p e r ha ) o f orga n i c ma tter and. .l , 800 poun ds of n i trogen p e r
acre ( 2 , 01 7 k g p e r ha ) acc um ul a t e d o n <iJthe forest fl oor i n n i ne o l d-g rowth s tands
i n western Was h i ngton (Gess .e l a n d Bal c i 1 963) . I n the maj o ri ty of Do ug l a s - f i r
stands , however , an in terme diate , "du ff mu l l " humus type i s presen t . Thi s type
can have q uant i t i es of orga n i c ma tter over l y i n g m i neral s o i l tha t are nearly a s
deep as i n the mor type ( Ge s s el a n d Bal c i 1 963); however , th ere i s an i nco rpora ­
ti on o f orga n i c ma tter i n the upper s o i l so that an A l hori zo n i s presen t as i n
the mul l type .
Man-retated residue si tua ti ons -Through h i s fi nal or i n termedi a te h a rvests,
cul tura l p rac ti ces , o r roa d cons truc t i o n , man peri o di ca l l y i ncreases the r a te of
orga n i c depo s i t i on . Wi th i n 1 0 to 1 2 yea rs , needl es and twi gs of Doug l a s - f i r
s l a s h u s ua l l y decompose on; o i s t s i tes , but some fol i ag e a n d much twi g ma ter i a l
rema i n o n very dry s i tes ( C h i l ds 1 93 9 ) . A study ( Wagener a n d Offo r d 1 972 ) i n
the m i xe d con i fer type o f northern Cal i forn i a over a 34-year peri o d sugges ted
tha t h i gh summer tempera tu res a n d l ow summer and fal l prec i p i t a t i o n were maj o r
factors a ffecti ng s l a s h decay organi sms . Res i due trea tment i s parti cul a r l y
i mporta n t o n an estima te d 1 00 , 000 a cres (40 , 000 ha ) o f ol d-growth coa s t a l
Doug l a s - f i r harves ted annual l y ; cons i derably l es s importa n t on a grea ter number
of acres of young g rowth . O l d- g rowth l oggi ng s l a s h often exc ee ds 1 50 tons per
.-
11 Term i n ol ogy used i n thi s paper co rresponds to that of the Soi l Sc i en ce
Soc i e ty of Ameri ca Commi t tee on Termi nol ogy ( 1 965 ) .
J-6
a cre (335 metri c to ns per ha ) , and res i dues from harvest of 80- to 1 50-year-ol d
Dougl as-fi r a re l i kely to be l ess than hal f th i s amount ( Del l and Ward 1 9 71 ) .
Al though the acreage harves ted annual l y i n ma ture young growth i s i ncrea s i ng
s teadi l y , cu tti ng i n ol d growth i s expected to con t i nue for several d ecades .
Character i s ti cs of Fores t Res i dues
Res i dues vary i n qual i ty as wel l as qua n t i ty . Type and s i ze of res i du e'
are si gni fi can t ; sma l l s i ze res i dues i n i ti al l y a re a grea ter fi re ha z a rd (Morr i s
1 9 70 ) , but they con tri bute more nutri ents to the so i l than do tree bo l es ( Moore
a nd No rr i s 1 9 74 ) :
Need l es
Branches
Bo l es
Wei g h t per acre
M i n i mum
Moderate
Max i mum
Fi re hazard :
Rate of s pread
Res i s ta nce to control
Maxi mum
M i n i mum
Moderate
Mo derate
Mi n i mum
Max i mum
Nutr i en ts per ton
Maxi mum
·t oderate
Mi n i mum
Rate of convers i on :
To mi nera l s
To humus
Maxi mum
Maxi mum
Modera te
Moderate
Mi n i mum
Mi n i mum
Need and Met hods for Res i due Treatmen t
A t p res e n t , res i dues from c iearcutti ng of ol d-growth ti mber a re the mos t
d i ffi cul t to treat in coa stal Dougl a s - fi r fores ts . The i ncreas i ng u s e o f s hel ter­
wood harve s t i ng and regenerati ng sys tems , parti cul a r ly i n sou thwes tern Oregon ,
crea tes l ower fi re'hazard a nd i n tens i ty than c l earcu tti ng becau s e s l a s h i s
spaced o u t between two or three c u ts a t l ea s t 5 years apart . Moreover , u nder
the p rotec ti ve canopy , s l a s h does not'd ry so rap i dl as i n the open ( Fahnes to c k
1 96 0) and , therefore , decays more rap i d l y (Aho 1 9 74 ). I f needed , s l a s h c a n
s ti l l b e d i sposed of by burn i ng o r o ther mea n s , al though t h e s e mea s ures a re
usual ly more cos tl y to a ppl y wi thi n a par t i a l l y cu t than i n a compl etel y cut
s tand . Use of s hel terwood sys tems probabl y wi l l i ncrea s e as young- growth fores ts
make up a h i gher propor t i o n of the total harv e s t .
Wi th al l harve s t i ng sys tems , the l a nd ma nager c a n i ni ti al l y mi n i mi ze
resi dues by fel l i ng careful ly to reduce brea kage and thus i ncrease u ti l i zati o n
of the tree bol e . Some of the u nmercha ntabl e tree bol es a r e deGayed , s h a ttered ,
or broken beyond i n tens i ve uti l i za t i on; however , i t has been e s t i ma ted that
about 50 percent of the vol ume i n unmerc hantabl e bol es meet curren t u ti l i ty l og
s ta ndards and coul d produce a bou t one-hal f the raw ma ter i a l req u i rements of
reg i onal pul p , paper , and part i cl e board i nd u s tr i es ( Howard 1 9 71 ) . I ncreased
s tumpage pri ces and i mp roved harv e s t i ng nd manufactur i ng practi ces wi l l prov i d e
add i ti on a l i ncenti ves for better u ti l i za t i on . Thus , there i s con s i derabl e
opportuni ty for i ncrea s i ng usabl e yi el ds per acre and for reduc i ng res i due and
thus cos t s of fi re protecti on .
Al though u ti l i za t i on of economi cal l y mar g i nal or subma rg i na l ·l ogs i ncrea ses
harvesti ng costs , i t reduces cos t of res i due treatment a nd s i te prepara t i on for
future s i l v i cul tural opera ti on s . I n 1 9 70 , the U . S . Fore s t Serv i ce i n the Paci f i c
J-7
No rthwe s t Reg i on began requ lr l ng that a l l l ogg i ng res i dues exc eedi ng spec i fi e d
m i n i mum s i zes be yarde d to l a n di ngs . Appra i sed s tumpage pri ces were reduced
to compensate the opera to r for the, extra l o gg i ng costs . Expec tati ons were that
some re s i dues , after be i ng yarded to l a n di ng s , m i g h t ? ave enough va l ue to pay
4'
fo r l oa di ng a n d haul i ng them to ma nufacturi ng s i tes .However, tran s porti ng
defecti v e ma ter i al td a mi l l may change the nature of the res i due di sposal
probl em . When dec ks of yarde d cul l ma ter i a l are not use d, they may be burned
o r l eft a s a conc entra ted, l ocal i zed haza rd.
Al though numerous a l terna ti ves are ava i l abl e for trea ti ng res i dues , the
manager ' s speci fi c cho i ce mu s t depend on hi s ma nagement obj ec t i ves a n d the
spe c i f i c s i te condi ti on s , e . g . , vol ume a n d a rrangement of res i due, s teepness
of sl ope , a n d s tabi l i ty of so i l . Hi s opti ons i ncl u de l ea v i ng res i due to
decompos e natura l l y or burn i ng i t bro a dc a s t , i n p i l es , or wi th mechani cal hel p
as i n pi ts wi th a bl ower o r i n a porta bl e bi n . He may l eave i t unburned but
trea t i t mecha n i ca l l y by c h i ppi ng, cru s h i ng , or buryi ng . He may wi n drow , p i l e ,
o r move i t i nto rav i nes o r oth r depres s i ons . Mo ie res tr i ct ive opti ons i ncl u de
trea ti ng wi th fi re retarda n ts or decay-promo ti ng chemi cal s or removi ng mos t
res i dues from the s i te for use or di sposal el sewhe re .
RES I DU E TREATMENT AN D DOUGLAS-F I R
S I LV I CULTURE AND MANAGEMENT
The pru de n t fores t manager cons i ders hi s ma nagement obj ecti ves , the l ocal
res i due s i tua ti on ( ex i s t i ng or pe ndi ng ) , a n d the trea tments mos t l i ke l y to hel p
obta i n these ma na geme n t obj ecti ves . Res i dues and res i du e trea tments affec t costs
a n d benefi ts of fores t ma n gemen t . I f trea tmen t i s nee de d, then what a re the
cos ts and benefi ts of vari o us opti ons at a spec i f i c l oc a t i o n ? If res i dues are
l eft u n treated, th e ma nager saves cos t and contr i butes to so i l pro ducti v i ty; to
some degree, however, the ma nager thereby i ncurs a fi re haza r d and o ther o b s ta cl es
to regenera t i on o r stand acces s . Co nversely, ' by t r: a t i ng res i dues , future fi re
pro tecti on and pos s i bl e regenera t i o n cos ts wi l l be re duced. Al though res i due
treatment reduces or a n i c ma tter and di s turbs so i l , some o f thi s can b e offs et
by other trea tments ( fo r exampl e, ferti l i zers or eros i on control ) .
Common ma nagement objec ti ves on l an ds des i gnated for woo d pro duc ti on , the
ma jor vari abl es a ffecti ng them , and a ddi t i onal sourCBS of i nforma t i on are :
A ddi t i ona l compendi um
i n forma ti on
Mana gemen t obj ec ti ves
Majo r vari a bl es
1 . Mi
n i m i ze producti on
cos ts ( per a c re a n d
per u n i t of pro ducts
removed)
Marti n and Brackebusch 1 974
1 . Res i due di sposal
Ru th 1 974 , Sei del 1 974 , E dgren
2 . Regenera t i on of
a n d Ste i n 1 974
des i red spe c i e s
3 . S ta n d acces s i b i l i ty
4 . P rotec ti on
Marti n and Brackebusch 1 974
F i re
Mi tche l l and Sartwe l l 1 974
I nsects
Nel son and Harvey 1 974
Di sease
Moore and Norri s 1 974
5 . S o i l amen dments
11 See Fores t Serv i ce Manual 51 5 0 . 3 - - 5 Suppl ement R-6 65, Apr i l 1 97 2 ,
rega r di ng YUM (yar di ng unuti 1 i ze d ma ter i a l ) .
J-8
"
'.A
Additional c omp n di um
i nfo rma t i on
Management objective s
Maj or vari a bles
2 . Mainta i n or improve
soi l pro ducti v ity
1 . Orga n ic ma tter
2. Soi l dis turbance
3. Soi l compaction
Moore a n d Norri s 1 974
Bo llen 1 974 , Aho 1 974
Rothacher a n d Lopu s h in s ky 1 974
3. t·1 aximiz e compa t ib il ity
with non t imber
pro ducts
1 . Wa ter qual ity
2 . Recreation
3. W i l dl i fe
Rothacher a n d Lopus h i n s ky 1 9 74
Wa gar 1 974
D imoc k 1 974 , Garri son and Smit h
1 9 74
Brown 1 974
Soi l i s the bas ic resource of the l an d ma nager; ma i n ta i n i ng or i mprov i ng
soi l pro duc tiv i ty should be a maj or ma na gement obj e c t iv e . Yet , harves tin g
Dougl a s - f i r t i mber a n d trea t i ng res i dues i nherentl y lea d to some l os s of s o i l
pro ducti v ity , so the l an d manager seeks to re duce the s e i mpacts by choos ing
methods wh i ch mi n i mi ze the percentage of the area a ffecte d and the degree of
dis turbance to the mineral so i l or to the vegetation a n d orga n i c l ayer pro tect ing
i t . Addit i ona ll y , he can c brrect . rem throug h soil - improv ing practices . Except
for catas trophic los s of soil mantl e , changes in fore s t soil pro ducti v ity a re
difficult to mea s u re . Thus , general princ ipl es of soil mana gement mu s t frequently
be accepte d on the ba s i s o f intuition rather than ev i dence .
By mi n imiz i n g 'dis turbance on mos t fores t soi ls , we ma in ta i n h ig h i nfiltra­
ti on rates and reduce s urfa c e runo ff and thus po tential for so i l ero s i on . A
concern for o rga n i c ma tter' l os s es a n d ero s i on i s pa r t icu larly impor ta n t on
certa in s o i ls a n d s i tua tion s , i ncl u ding : ( 1 ) soil s on s teep s l ope s ; ( 2 ) so ils
with l ow i nfi ltra t i on rat s ; ·an d ( 3 ) soi ls develo p i n g from ac idic parent ma teri­
als such a s gra n i te , rhyo lite , a n d some sediments i n contra s t to tho se from
more bas i c paren t ma teria l s such as basal t , an des i te , a n d gabbro ( Dyrnes s 1 966 ,
Swansto n a n d Dyrne s s 1 973 ) . Soil compaction is a di sturbance of partic u l ar
concern o n f in e textured soils , es pecia lly when these are wet ; conversely , com­
pac tion i s of li ttl e concern on gravelly or sandy soils .
t o re than ever before , t he res idue dec i s ion req u ires an eva lua t i on of the
compati b i li ty of trea tment opti ons with water quality , recreation , and wildl ife .
The l a n d ma nager mu s t con s i der a l l hi s ma n a gement obj ectives a n d pos s ib le tra de ·
offs . A lthough genera l gu i de l ines wil l gu ide his ' p la nn i ng , his dec is ion wil l
depend on the loc a l s itua tion . Where res idues accumu l a te to unacceptable levels ,
cho ice of tre a tment s hould a ttempt to min imize the ra t i o between tota l trea tment
costs ( inc luding s ite degrada t ion or remedia l effo rt s ) and trea tment benefi ts .
J-9
EFFECTS OF UNTREATED FOREST RESIDUES
Amount a n d di s tri but i on of fore s t res i dues a ffec t the cost of harves t i n g ,
regenerat i n g , ten di ng , a n d protect i n g the fo res t.
RES I DUES AND CONDI T I ONS FOR NATURAL REGENERAT I ON
I n c1 earcut h a rves ts of Dougl a s - fi r wi th no res i due trea tme n t after l ogg i ng ,
from 94 to 65 perce n t of the a rea may rema i n rel a t i ve l y u n di s turbed (Swa n s ton a n d
Dyrness 1 973 ) . f·1i n i ma 1 di s turbance resu l ts whe n l o w vol umes per acre a re removed
and ya rdi ng sys tems wh i ch prima r i l y l i ft l ogs ra ther than drag them a re u s e d;
e . g . , s kyl i n e , bal l oo n , o r hel i copter. If re s i dues a re l eft untrea te d a n d
i ncreased fi re hazard i s accepted·for a p er i o d o f t i me , then the cos ts of regen­
erati ng Doug l as-fi r may be substa nt i a l l y i n crea s e d or decrea s e d dependi ng on
the spec i f i c s i tu a t i on . I f natural regenera t i on is the manager ' s obj ec t i v e , then ,
the benefi ts of th i s no- treatmen t res i due dec i s i o n depend on ( 1 ) the presence and
spec i es o f a dvance regenera t i on ; ( 2 ) a n t i c i pated natura l seed fa l l ; ( 3 ) type s ;
amou nts , a n d di s tr i b u t i o n of see d bed.surfaces and mi croc l imates ; ( 4 ) types of
res i dual compet i ng vegeta t i on ; and ( 5 ) l i ke l i hood of wi l dfi re .
Untrea te d res i du e s are u s ua l l y poor seed bed ma teri al s fo r i n i t i a l s urvi va l
of Dougl a s - fi r ; the presence of exces s i ve res i dues a s deep fores t fl oor or dense
l ogg i ng s l a s h can prec l u de Dougl a s - fi r natural regenera t i on (Bever 1 954 , Lavende r
e t al . 1 956 ) . Pre s e nce of re i dues i s of l es s concern i f pl a n t e d s e e dl i ngs a re
u s e d , a l though qua n t i t i e s o r s l a s h after harves t of ol d- growth s ta n ds u s ua l l y
i nh i b i t p l a n t i ng opera t i on s ( E dg re n an d Ste i n 1 974) . I n part because o f i ts
effecti venes s i n i mp ro v i n g access i b i l i ty for pl a n t i n g a n d other s ta n d management
pract i ces , broa dc a s t s l a s h burn i ng has been a ' s tanda
. . . r d pra c t i ce i n the Do u g 1 a s ­
f i r reg i on .
",
A maj o r benefi t from s l a s h i s tha t i t provi des numerous patches of s h a de th roughou t cutover a rea s , thus moderat i ng h i gh and l ow surface temperatures (S i l en 1 96 0 , Hal l i n 1 968b, Fowl er 1 974 ) ' and redu. c i n g morta l i ty from freeze , fros t heave , heat l es i on , a n d drought.
Shru bs or l es s e r vegeta t i o n rema i n i ng a fter l og g i n m i g h t be cons i dered
forest res i dues and a fac to r in the trea tmen t dec i s i on ( J em i s o n a n d Low den 1 974 ) .
Wi th some notabl e exc ept i on s , res i dual vegeta t i on - - i n con tra s t to i nv a di ng
spec i es- - i s probably of l i ttl e consequence in s ucces s fu l l y regenera t i ng Dougl a s ­
f i r . Nontree spec i es , present i n the s ta n d before l ogg i n g , u s u a l l y dec l i ne i n
. v i gor o r i ncrease the i r a rea occupancy very s l owl y a fter l og g i ng ( Y e tke s 1 960,
Dyrness 1 965 ) . Exc e p t i o n s a re establ i s hed sal monberry (Rubus spectabi lis Purs h )
commun i t i es c ha rac ter i s t i c o f open Dougl a s - f i r and re d a l der s ta n ds of the
Coa s t Ranges a n d swor dfern ( Polystichum munitum ( Ka u l f . ) Pre s l . ) - -Oregon oxa l i s
( Oxalis oregana Nutt . ex T . & G . ) commu n i t i e s o n mo i s t s i te s i n the wes tern
Cascades . These two c o mmu n i t i e s commonl y i nc rease ra p i dl y i n v i g o r a fter ti mber
i s c l earc u t . I nv a di n g spec i es , i ncl udi ng Ceanothus s pec i e s , a r e u s u a l l y more
ser i o u s competi tors for Dougl a s - fi r seedl i ngs ( Dyrne s s 1 965 ) . Control of such
l i v i ng res i due may be neces s a ry to mi n i mi ze competi ti on and a s s ure
successfu l regenera t i on ( Gratkows k i 1 974 ) .
J-10
RES I DUES AND-SOIL PRODUCT I V ITY
Cl i ma t e a n d soi l a re maj or fa ctors of s i te produ c t i v i ty . Produ c ti v i ty of
fo res t soi l s c a n be imp roved or degrade d by ma n 's a c t i v i t i e s , espec i a l l y those
affecti ng q u a n t i ty , qual i ty , and di s tr ib u t i o n of orga n i c ma tter on or i n the
mineral so i l . S i nce fine- textured res i dues a re a p r inc i pa l source of s o i l
humus a n d many n u t r i ents needed for forest growt h , a gen eral 9u i gel i ne i s :
Mi n i m i z e the l os s of s u ch ma teri a l s from the s i te . Thi s prec auti on i s parti cu­
l arly i mporta n t on i mma ture soi l s wh i c h characteri s t i ca l l y conta i n rel a t i vely
sma l l amounts o f soi l h umus and n itrogen .
Beca u s e i n s uffi c i ent n i trogen c ha racteri s t i c a l l y l i mi ts growth of Dougl a s ­
fi r fores t s i nt t he Pac i fi c Northwes t , the l os s , accumul a t i on , a n d cycl i ng of
thi s el eme n t i n a n d between vegeta t i on , fores t fl oor , a n d so i l a re part i cu l a rly
s i gn i fi ca n t . I n forest so i l s of wes tern Wa s h i n gton a n d Oregon, the amo unt of
n i trogen i n the mi neral so i l ranges from a bout 1 , 800 to over 23 , 500 pou n ds per
a c re {2 ,000 to over 26 , 000 kg per ha } with l owe r amo un t s a s s o c i a te d wi th coarse­
textured, i mma ture,so i l s and hi g her amounts wi th fi n e - textured, res i du a l soi l s
{Gessel e t a l . 1 97 2 } . Thu , i n the a bsence of fore s t fl oor a n d vegeta t i on , al l
n i trogen of the s i te i s conta i ne d i n the so i l . As veg e ta t i on devel ops , n i tro­
gen accumu l a te s i n the forest fl oor a n d stand so that the proport i on i n the
soi l may fa l l to 50 to 80 percent of the total , wi t h l ower percentages i n
imma ture s o i l s . Al though total orga n ic ma tter pro du c t i on on coarse- textured
or'imma ture s o i l s i s rel a t i v e ly l ow , the l ow l evel of b i o l og i cal a c t iv i ty on
such soil s can res ul t i n a fas ter rate of fores t fl oor accumu l a ti on than on
deep , ma ture so i l s . Except for extremel y hot fi res , mos t s o i l n i trogen i s safe
from l os s through forest management ; however , ma n agement prac ti ces can redi s ­
tri bute so il N from spe c if ic mi cro s ites through mecha n i ca l dis tu rbance or ero s io D
or cause n i trogen t o b e l es s avai l a bl e for pl a n t u s e by degradi n g the envi ronment
for soi l mi cro-orga n i sms {Bol l en 1 9 74}.
\
Pri ma ri l y due ' to vari a t i ons i n stand age a n d decompo s i ti on rate , n i trogen
i n the overl y i n g fores t fl oor var i e s in quan ti ty a n d i n propor t i o n to the total
supp l y . In coa s tal Dougl a s - f i r fores ts , n i trogen i n the overl y i n g fore s t fl oor
general l y ranges from 90 to 1 , 800 poun ds per acre {1 00 to 2 , 000 kg per h a }
{Gess e l et a l . 1 97 2 } . F o r exampl e , i n i mma tu re , pol e - s i ze s ta n ds , 90 to 270
pou nds per a c re ( 1 00 to 300 kg per ha ) may be l ocated i n the fore s t fl oo r ; i n
ol d- growth s ta n ds , 1 , 2 5 0 to 1 ,800 pounds per acre ( 1 , 400 to 2 , 000 kg per ha ) have
been mea s ur e d i n duff-mu l l and mor humus type s (Ges s e l et al . 1 972 ) . N i trogen
i n the overl y i ng fores t fl oor is l i ke l y to be re du c e d or re di s tri buted by
res i due trea tments .
N itrogen i n the s ubor di n ate vegeta t i on and the tree stand g ra du a l l y
accumul ates , pri ma r i l y through wi thdrawa l s from the n i trogen capi ta l o f the
so i l . Al though amounts and di s tr i bu t ion of n i trogen i n ma ture and overma ture
s ta n ds of Dougl a s -fi r a re unknown {Gessel et al . 1 97 2 } , total amounts ofN i n
a l l above rou n d vegeta t i o n are probably l es s than 1 , 000 pou n ds per a cre ( 1 , 1 20
kg per ha), even i n ol d-growth Dougl a s - fi r of hi ghe s t pro du c t i v i ty . For
exampl e , Moore and No rri s ( 1 974 ) have es t i mated that 7 60 pou n ds per acre (852
kg per ha ) m i g h t be conta i ne d in tree crown s and s tems of a 400-year-o l d Dougl a s ­
fi r stand on average s i te qua l i ty . A 36-yea r-o l d Dou gl a s - f i r p l a nta t i on on a n
imma ture s o i l i n Was h i ngton showe d the fol l ow i n g di s tr i b u t i on of n i trogen
( D i ce 1 970 ) :
J-l l
mponent
Fores t
Subvege ta t i on
Fores t fl oor
So i l
Pou n ds N pe r acre
Percent of tota l
286
5
1 56
2,506
9. 7
.2
5.3
84 . 8
2,953
( 3 , 3 1 0 kg/ ha )
100.0
From da ta on n i trogen transfer a n d accumu l a t i on a t th i s s i te , Gessel et a l .
(1 972 ) have e s t i ma te d that by the time th i s stand i s 200 yea rs ol d, the soi l
wi l l con ta i n l es s than 50 perc ent of the tota l amount of N . Thus , more than 50
percent of the n i trogen cap i ta l wi l l be vul nerabl e to l o s s or redi s tr i but i on by
wi l d fi re or tree harves t a n d sub e uen t s l a s h re du c t i o n or s i te prepa r a t i o n
effo rts . I n contras t , s i tes wi th l a rger q u an t i t i e s a nd proport i on s of N i n
the so i l are l es s vu l nerable to re duct i on s i n s i te prod u c t i v i ty through natural
fi re s or ma n ' s fore s t acti v i t i es .
RES I DU ES AND MORTAL ITY LOSSES
A l though cons e rva t i on of certa i n fore s t res i dues i s des i rabl e , exc es s i ve
accumul a t i on may l ea d to morta l i ty through fi re (Mart i n a n d Brac kebusch 1 97 4 ) ,
bar k beetl es ( Johnson 1 970 , Mi tche l l a nd Sartwe l l 1 974 ) , or di sease ( Ne l son and
Harvey 1 974 ) . To the extent that morta l i ty i s unsal vaged or creates unused
openi ngs i n the s tand , it l a ds to reducti ons in us abl e yi e l ds a n d short- term
producti v i ty .
•
Res i dues from th i nn i ng ope rat i ons i n young growth s ta n ds can cons ti tu te a
f i r e ha zard for several years . The hazard gradual l y a bates a s needl es fa l l , the
sl a s h compac ts , a n d the canopy cl oses ( Fahnes Q k 1 960 ) . Wi thout trea tment ,
the se res i dues can i ncrease the i n ten s i ty of acc i dental gro u n d fi res so tha t
seri o u s damage or l os s i n the s ta n d ca n occur .
I n some case s , the amount of n i trogen ava i l a bl e to res i dua l trees may be
tempora r i ly reduced by orga n i sms decayi ng res i dues ( Cochra n 1 96 8 ) ; th i s cou l d
cause l os ses i n g rowth but , i n our opi n i on , i s unl i ke l y to cause morta l i ty i n
Dougl a s - fi r .
EFFECTS OF RESIDUE TREATMENTS
Al though recogn i z i ng the i mpos s i b i l i ty of compl etely fi reproofi ng h i s fores t ,
the l a n d ma nager frequentl y fi n ds s i tuati ons where comb i na t i ons o f factors cl ea rly
favor res i du e trea tment . By a pprop r i a te cho i ce of method of trea tmen t , however ,
he can ac h i eve opti mum bal ance between hi s obj ec t i ves --mi n i mum produ c t i o n costs ,
, ma i n tenance of so i l prod u cti v i ty , and maxi mum compati bi ii ty a n d benefi t s to water
qu a l i ty , recrea t i on , a n d wi l dl i fe .
T re a tme n t methods may be compare d by the proport i on o f the total a rea tha t
is a ffected a n d the deg ree to wh i c h : ( 1 ) orga n i c ma tter o n o r bel ow the s o i l
surface i s removed from or redi s tri buted over the treated area - -i f orga n i c ma tter
has been co nsumed by fi re , n i trogen , s u l fur , a n d pho sphoru s a re l os t from the
s i te to the a tmosphere , bu t mos t other nutr i e n t el ements i n the a s h or unconsumed
orga n i c ma tter rema i n onsi te; ( 2 ) mi neral soi l i s phys i , ca l l y d i s tu rbe d- -i . e . ,
J -1 2
!
l o osened, compa c te d , o r m i x e d wi th orga ni c ma tter; (3 ) ex i s ti ng vegeta t i o n o r
co ndi t i o ns for i nv a di ng vegeta t i o n a re affec ted- - th i s veg eta t i o n ca n be a soi l
pro tector or a potent i a l fi re hazard, but al so a po tenti a l compet i to r fo r
seedl i ngs a nd e s ta b l i s hed tree s ; ( 4 ) res i dual seedl i ngs or trees wi th i n or
surrou ndi ng the trea tme nt a rea wou l d be di rectly affec ted.
Current l y , the re i s l i ttl e di rec t ev i de nce of the effec ts of v a ri ous methods
of trea ti ng res i du e s o n so i l product i v i ty , regenera ti on, a nd growth of Dou g l a s ­
fi r . However , by k nowi ng the effec ts o f trea tme nt on env i ronment a l factors , o ne
ca n pre di ct the effects of the se cha nged factors - - a nd thus trea tme nt - -o n seedl i ng
or tree growth . For exampl e , trea tme nts wh i ch di s turb mi ne ra l s o i l o n s teep
s l opes are 1 i ke 1 Y to cause soi l eros i o n a nd thus l os s of pro ducti v i ty .
.
I t i s i mporta nt to recogni ze , however , that res i due trea tme nt i s o nl y o ne
acti v i ty i n the harves ti ng opera t i o n tha t changes fores t env i ro nment . Roa d con­
s tru c t i o n a nd ma i nte na nce i n s teep terra i n a re ma jo r a nd recurri ng causes of
soi l di s tu rba nce a nd eros i o n (Swa ns to n a nd Dyrness 1 973 , Rothacher a nd
Lopu s h i ns ky 1 974 ) ; however , a s s e s s i ng the effect of i ndi v i du a l harves ti ng
acti v i ti es i s di ffi c u l t . . Each succes s i ve ha rves ti ng acti v i ty contr i butes new
di s turba nce o r expo s u re of the mi neral so i l a nd ma s ks the effect of the prev i ous
acti vi ty . For exampl e , Dyrness ( 1 972 ) repo rted that the l i mi te d amou nt o f bare
soi l exposed after bal l oo n ya rdi ng ( 6 pe rce nt , compare d wi th that a fter
s kyl i ne a nd h i g h - l e a d yardi ng , 1 2 a nd 1 4 perce nt , respect i ve l y ) permi tte d h i m
t o i de nti fy tha t mos t of the s l i g htly di s turbed a rea resul ted from tree fel l i ng
a nd ya r di ng .
Some yardi ng o r res i due trea tme nts cause more s i te di s turbanc e tha n o thers ,
a nd the effec ts of trea tme nt a l so . vary from si te to s i te . C ri ti ca l v frr i a b l es
i ncl ude : s i ze a nd amo u nt of res i due , steepnes s a nd i rregul a r i ty of the terra i n,
a nd fragi l i ty of the so i l . Consequent l y , genera l i ti es have l i mi te d appl i ca ti o n.
For h i g h qual i ty o f , l a nd ma nageme nt , a na l ys i s a nd preEcri pti o n of trea tment a nd
equi pme nt for eac h s i te a nd resi due s i tua t i o n a re nec e s s a ry .
EFFECTS OF BROADCAST BURN I NG
Starti ng i n the l a te 1 930 ' s , s l a s h bu rni ng i n the Doug l a s - f i r type was ·;)
i nvesti gated to determi ne i ts effects o n f i re hazard, na tura l a nd pl a nte d
regenera t i o n , seco nda ry pl a nt succes s i o n , a nd on phys i cal , chemi c a l , a nd bi o l og i ­
ca l propert i e s of the so i l . Mu ch of thi s wo rk has bee n s umma r i ze d ( Ta rr a nt 1 95 6 ,
Dyrness 1 9 96 , Morri s 1 97 0 ) . The re i s general agreement tha t , i n return for
reduct i on of fi re h a zard a nd el i m i na t i o n of phys i cal barri ers to pl a nti ng a nd
some potent i a l l y compe ti ti ve vegeta t i o n , s l a s h bur ni ng Ga u s e s a ddi ti o na l bari ng
of mi nera l soi l a nd l os se s of orga ni c matter from the fore s t fl oor a nd mi neral
so i l . However , the pote nt i a l l y ha rmfu l effec ts of s l a s h burni ng on soi l pro duc­
ti v i ty were cons i dered res tr i c te d to severely burne d port i o ns wh i c h we re u s ual l y
l ess tha n 1 0 perc e nt o f the total a rea . Al l i nves t i ga tors recogni zed that better
u ti l i za t i o n s ta nda r ds i n harvesti ng ol d-growth timber a nd a grea ter proport i on
of harves ts i n you ng-g rowth t i mber woul d further re duce the nee d for o r i ntens i ty
of sl a s h burni ng .
Hazard reduction . - -Morri s ( 1 970) conc l u de d tha t broa dca s t s l a s h b urn i ng
accompl i s hes i ts p r i ma ry pu rpose of re duc i ng wi ldfi re hazard. From a n exte ns i ve
sampl i ng i n we s te r n Was h i ngton a nd Oregon, he estima te d tha t s l a s h burni ng
greatly re duces p ro babl e rate of wi l dfi re sprea d a nd resis ta nc e to co ntrol for
J-1 3
5 yea rs , a n d s i gn i ficantly reduc es rate of s p rea d for 1 5 yea rs . However , i n a reas where l uxur i ant growth of herbaceous vegeta t i on p rovi des a n annual crop of dea d fuel , burni ng offers a shorter per i od of redu c e d rate of s pread . Thu s , by burn i ng s l a s h dur i ng favorabl e wea ther and wi th a dequate personnel us i ng corre c t procedures , a 'manager can reduce da nger o f unco n tro l l e d fi res . But even dur i ng wea ther favorabl e for burn i ng , a s u dden change of wi n d or fuel mo i s ture may spread fi re beyon d the s l a s h a rea i n to surrou n di ng t i mbe r . "E i ther l eav i ng or burn i ng sl ash enta i l s r i s k ." (Morr i s 1 958 , p . 43 ) . Severity and extent of burning. - - Broa dc a s t burn i ng a fter c l ea rcutt i ng o l d- g rowth Doug l as - fi r provi des a mos ai c i n burn i n g i n tens i ty a n d i ts effects , ( tab l e 1 ) . W i th few exceptions , the porti on of the s ampl ed un i t whi ch was severe l y
burn ed ( mi n eral so i l exposed a nd changed i n co l or - - u s ua l l y to reddi s h ) , wa s
l es s than 1 0 percen t ; severe burn i ng occu rred i n sma l l , sca t tered pa tches ,
u s ua l l y whe re some l ogs r s tumps ha d produced pro l onged i ntense hea t .
L e s s i n tense fi re can expose mi n eral soi l wi thout cha n g i ng i ts col o r .
Morr i s ( 1 958 , 1 97 0 ) reported th i s mo derate burn condi t i on averaged 2 2 a n d 1 4
percent o f the a rea o n hi s pl ots i n the we s te rn C a s c a des a n d coa s ta l Oregon ,
respec t i vel y . Mo rri s (1 970 ) fou n d expose d mi neral so i l on 50 percent of l i ne
tra n s ec ts on burned pl ots , but only 22 percent ( pres uma b l y from l og g i ng ) on
nearby u nb urned pl o ts . Thus , fi re more than dou b l e d the amount of expo s e d
mi nera l soi l , mo s t of whi ch was probabl ,y i n the mo derate burn' category ( tabl e 1 ) .
Tarran t ( 1 956 ) a n d Dyrness et a l . ( 1 957) ev i den t l y found so' l i ttl e of the
mo de ra te burn cate gory in the i r re specti ve s t u dy a reas th at they di d not c l as s i fy
or reco rd i t . One l i kely expl anati on i s tha t they s a mp l e d burned c l earcuts
to det e rmi n e the extent o t vari ou s sever i ty c l a s se s for the e n t i re uni t , whereas
Morr i s rej ected c a n di da te pl o ts that were l es s than two - t h i rds bl ackened by a
s l a s h fi re ; thus , t ·10 rri s proba b l y ' overes t i ma te d sever i ty of burn i ng on the enti re
u n i t . T he re is l i ttl e ques t i on that bro a dc a s t s l a s h b u rn i ng c a n expose a ddi t i ona l
mi n era l soi l wi thout severe l y a ffecti ng i ts t;:p.l o r . I t i s u n l i kel y , for exampl e ,
whe n s l a s h wa s broadca s t burned on a s kyl i ne l ogged c l e a rc u t a n d,:rthe percent of
ba re m i n era 1 s o i l was i ncrea sed fro'm 1 2 to 5 5 ( Merserepu a n d Dyrness 1 972 ) , tha t a l l mi neral so i l was severely burned. The que s t i o n rema i n s a s to the extent to wh i ch mo derate burni ng occu rs a n d i ts effect s on s o i l a nd s u b sequ ent vegeta t i o n . L i g ht l y burned and unburned port i ons combi n e d averaged 72 to 94 percent of broa dc a s t burned un i ts (tabl e 1 ) . Wi th l i g h t burn i ng , fi re co n s umed branches , twi g s , needl e s, a n d l ogs l es s than 1 1 i nches ( 28 cm ) i n d i ameter , a n d bl ac kened or c h a rred the forest fl oor wi thout compl etely consum i n g i t . Unburned a reas i nc l u de tho se in wh i ch l ogg i ng remove d poten t i al fuel , a s in s k i d trai l s . The amount of a ddi t i o na l mi neral soi l expose d by severe a n d mo dera te bur n i ng can have prac t i cal con sequences in regenera t i o n a nd s o i l eros i on . Inves ti g a ti ons have shown tha t broadcast bur n i ng i nc rea s e s the amount of mi neral soi l over that exposed by l ogg i ng . The a d di ti onal mi neral so i l has vari e d from s l i g h t (8-1 2 percen t ) t o excessi ve ( 43 perc en t ) wh i ch res u l te d i n exposed mi n eral soi l on more than hal f of the un i t ( ta bl e 2 ) . Burning temperatuY'es and their effects . --To the general s ta tement , lithe hotter the fi re , the cl eaner the burn , " one can a dd : "an d the more des truc t i v e of so i l producti v i ty"; th i s rev i se d s ta tement s umma r i zes t h e confl i ct fac i ng the l a n d ma nager . Wi th the obj ect i ve of remo v i n g res i dues wi th mi n i ma l future J -1 4
T abl e 1 .--Extent of burn by severity c sses from broadcas t s
in oZd-growth Douglas-fir clearcuts
Loc at i on
C l e arc u ts
observ e d
Number
Weste rn Casc ades
Co as tal s t ri p , Oregon
Wes te rn C as cades
Wes tern C as cades , Oregon
Co rv al l i s waters hed
]j
s h burning
Source
Averaqe severi t y o f b roadc as t burn
Severe 1/
I
t·1o derat eY
I
Li gh tli
I
Unburned4/
- - - - - - Percent of total area - - - - - -
49
6
9
.1
10
·3
8
2
3
8
(
'(
22 55
17 Mo rri s 1 97 0 14 75
10
Mo rri s
)
47
47
Ta rrant 1 956
7.
29
62
S i l en 1 960
44
48
Dyrness et al . 1 957
1 970 -
)
.'
Severe bu rn --top l ayer o f mi n e ral soi l expo s e d an d c h anged i n col or, u s u al l y to re ddi s h .
y Mo de rate bu rn --duff an d other woo dy debri s con s ume d b u t mi neral s o i l un der as h not c h anged
i n col o r.
Li ght bu rn --du ff an d o th e r woo dy deb ris part l y burned, but not to m i n eral so i l . c....
I
-.I
01
11
Unbu rne d--m i ne ral s o i l , duff, o r othe r woo dy debris . 1/
Not fou n d o r cl ass i fi e d. Tabl e 2.--Pe
Ya rding method
ent of mineral soi l exposed after logging and
after fire by yarding method
Un its examined
Nwnber
Mineral soil e ose d
After
I ncrease
After
bJ[ fire
fire
l o ggin g
I
-
-
J
- - - Percent -
-
- -
Source
,
-
58
JJ22
Y50
28
H ig h 1 ead 3
31
39
8
H igh l ea d 4
44
56
12
Sil en 1 960 Tra c to r 3
36
48
12 Sil en 1 960 12 55
43
Mersereau a n d Dyrness 1 972 Unspec if i e d
H ig h l ea d Morris 1 958
Dyrness et a 1 . 1 957 JJ An un de res t i ma te because p l o t s e l ection avo ide d are a s without s l as h
•
s uch a s catroads .
Y An overe s t i ma te because s ampl ing was res tricted to we l l -burned pl ots .
"
An un derestimate ; i ncl u de s IIdist urb ed, unburned II b u t not IIdi s turbed ,
burne d II c a tegory .
fire h a za r d a n d a i r pol l u ti on ( Frits chen e t al . 1 970 ) , h e wi l l a ttempt to crea te
con dit ions for a rapid, hot burn. As he increa ses fire tempera ture , however , h e
inc rea s e s h i s l os s e s of fi ne-textured orga n i c ma tter a n d t h e depth a n d deg ree
to wh i c h he a ffec ts 'the mineral soil ( ta b l e 3 ) .
At l ow f i re tempera tures , vapors a n d gases fl ow from the o rga n i c ma tter ,
some o f the se ga ses conta i n hydrophobic . substances wh i c h co n dense on coo l er
surfaces wi th in the soil a n d subse g uentl y cause a n u n des i ra b l e wa ter-repel l ency
tha t l as ts a t l ea s t 5 to 1 0 yea rs ( De Bano and Ri ce 1 973 ) . S i gn i fi cant to our
particu l ar concern a bout the effects of res i due trea tme n ts on imma ture soi l s is
the obs ervation i n Wes tern Uni ted Sta tes that coars e - textured soi l s become more
wa ter-repe l l en t than s o il s of finer texture , po s s ibly because there is l es s
surface area to coat wi th hy dropho bic substa nces ( DeBano a n d Rice 1 973 ) . '
When o rga nic ma tter i s consumed by burning , pra c t ical l y a l l its content of
n i trogen ( DeBel l a n d Ral s ton 1 970) , s u l fur (Al l en 1 964 ) , a n d much pho s phorus '
(Grier 1 97 2 ) are l os t a s gases to the atmos phere . N i trogen a n d other el ements
in unco n s umed orga nic ma tter rema i n on the s ite al ong with a s h from cons ume d
J- 1 6
, I
Tabl e 3.--Effects of burning temperature on organic matter and soiZ depth at
which such temperatures Were attained
I a x i mum temperatur ell
I
Effects on orga n i c ma tter ll
So i l depth under
Heavy s l a s
I
L i ght s l a s
- Inches -
1 00- 200
212-424 Nondestructi ve di sti l l a ti on of
vo l a ti l e organi c components
200-300
424-636 Destruc t i ve di s t i l l a t i on of u p
to 8 5 percent of orga n i c ma tte r ;
sound wood does n o t i gn i te ;
bl ack a s h or cha rcoa l res i due
300
636 Igni ti on of ca rbon res i dues
450- 500
842-932 Wh i te ash res i due
2
2+
,
-
1
o
99 percent of orga n i c matter
removed if tempera tures ma i n ­
ta i ned at'500° C for
hou r
JJ Ral s ton and Hatchel l ( 1 971 ) .
Y Neal et a l . ( 1 965 ) .
orga n i c matte r . ,Preci p i tation l eaches these nutr i en ts to the soi l bel ow a n d
ca uses temporary i nc reases i n pH wh i ch can favor n i tra te pro ducti on ( t 10 0re a n d
Norri s 1 974 ) . I f vegeta ti o n i s s ti l l presen t , on l y i ns i gn i f i ca nt amo u n t s are
l eache d from the rooti ng zone ( G r i e r and Col e 1 971 , Fredri ksen 1 971 ) .
On severe l y burned port i ons ( u s u a l l y l es s than 1 0 percent of the total
area ) of cl ea rc u t u n i ts , phys i ca l , chemi cal , and b i o l ogi cal properti es of so i l
a re a dversel y affected ( I saac a n d Hopk i n s 1 937 , Tarrant 1 956 , Dyrness e t al .
1 957 , Neal et al . 1 965 ) . These changes a re l i ke l y to affec t pl a n t g rowth
a dvers e l y . Mo i s ture-ho l di ng capa c i ty i n the top few i nches of mi neral s o i l i s
re duced ( Neal et a l . 1 965 ) , wi th l os s of s ome orga n i c ma tte r , n i trogen , s ul fur ,
a n d phos p horu s , and pos s i bl e i nc rea ses i n a va i l abl e n i trogen , a s h , a n d pH .
When severe burn i ng occurs , water-s tabl e soi l aggrega tes are reduced i n number
and s i ze , presumably by l os s e s of a s soc i a ted orga n i c col l oi ds ( Dyrn e s s et a l .
1 957 ) . Cl ay and s i l t frac ti ons decrease wi th correspondi ng i ncrease i n c oarse
frac t i o n s ( Dyrness et al . 1 957 ) . Water i n t he c l ay l a tti ce s truc ture i s
eva pora ted so that expa n di ng cl ay types (mon tmor i l l on i t i c ) permanently l ose
the i r capaci ty to expan d a n d contrac t ; net effect is for cl ay aggrega te s to
a s s ume the mo i s ture character i s ti cs of s a n ds and gravel s ' ( Ral s ton and Hatchel
l
.
1 971 ) .
J- 1 7
Broadca s t Burn i n g a n d Natural Regenera t i o n
Desp i te wi de vari a t i ons i n i ts sever i ty and extent , broa dca s t burn i ng
no rma l l y affec ts 40 to 90 percent of a cl earc u t u n i t ( tabl e 1 ) . Mos t o f the
a rea i s l i ghtl y burned whe re fi re con s umes branches , -twi gs , n e e dl e s , a n d sma l l
l ogs and bl ackens the fo re s t fl oor . Burn i ng des troys or severely d ama g es a ny
a dvance regenera ti on (mo s t l y spe c i e s o ther than Doug l a s -fi r ) a n d des troys any
new seedl i ngs or see d from the mos t recent seed fal l of Dou g l a s - fi r ; burn i ng
s ubsequen tl y affects fa te of seeds fa ll i ng on the burn e d area a n d the seedl i ng s
wh i ch devel op from them.
.
Burn i ng i nfl uences subsequent a bove- and be l ow- ground mi croc l i ma te ( Fowl e r
1 974 ) affec t i ng bo th seed a n d seedl i ng s of Dougl a s - f i r di rec tl y , a s we l l a s
i nd i rec t l y through effec ts on a s so i a ted fung i , pl ants , a n d a n i ma l s . On charred
r bl ackened fores t fl oor , so i l temperatures a re i ncrea sed ( I saac 1 938 , Neal et
al . 1 96 5 ) ; thi s can i ncrea s e the amount a n d rate of see d germi n a t i o n (Herma nn
and Chi l cote 1 965 ) . Where ea rl y spring fro s ts are a probl em , earl i e r germi na ­
t i on of Dougl as-fi r and a scarc i ty of protecti ve overhead s l a s h or vegeta ti on ,
wi th con s equent freez i ng , cou l d reduce stoc k i ng . Converse l y , s toc k i ng cou l d be
improve d by earl i e r or -grea ter germi n a t i o n in areas whe re heat and dro u g h t are
maj or fac tors of seedl i ng s urv i val , be cause seedl i ngs wou l d be o l der a n d there­
fore more l i kely to tol erate env i ronmental extremes ( Ke i j zer and Herma n n 1 96 6 )
or mo re numerous s o that s uffi c i en t seedl i ngs surv i ve the greater morta l i ty
from h i g her soi l s urface temperatures characteri s ti c of burn e d seed be ds ( I s aac
1 94 9 , S i l en 1 960 ) . For exampl e , Herma nn and Chi l cote ( 1 965 ) sowed equa l numbers
of Dougl a s - f i r seeds on di fferent seed be d ma teri a l s pl a c e d on a n unburned s i l t
l oam on a south aspect i n tHe Coast Ranges of Oregon ; des p i te grea ter pos tgermi na ­
ti on l os s e s , they found s i g n- i fi cantly grea ter fi rs t-year s urv i va l on charcoal ( 3 0
percen t ) and soi l di scol ored from a hard b u r n ( 1 7 percen t ) compared wi th l i ghtly
burned so i l , l i tter , no nburned so i l , a n d sawdu s t ( 1 7 to 12 percen t ) .
I n genera l , l es s than 1 0 percen t of c l earcu ts a n d burne d u n i ts i s severel y
burned so that al l s ur face orga n i c matter , i n c l u di ng charcoa l , i s remo v e d a n d
the so i l baked t o a reddi s h c o l o r . Exi s t i ng data ( tab1e 1 ) s ug ges t tha t about
three ti mes more a rea i s mo dera tely burne d. C hanges in severe l y burned so i l may
a dvers e l y affec t Doug l a s - fi r regenera t i on , but our i nforma ti on i s l i mi te d a n d
freque n tl y confl i cti ng . Al though ex i s ti ng seed and seed l i ngs a re des t roye d,
germi nati on of s ubsequent seed i s not affected (Tarrant 1 954 ) o r may be i n crease d
i n ra te a n d amount ( Herma nn a n d Chi l co te 1 965 ) . Postgermi na ti on l os s e s to heat
damage a re genera l l y reduced whe re m i ne ral soi l i s exposed. I n g reenho u s e or
l a bo ratory tests , l os ses to damp i ng-off fu ngi i ncrease on severe l y burne d soi l ,
pres uma b l y because i ncre as es i n so i l pH promo te growth of thes e orga n i s ms
(Tarra n t 1 954 ) . I n a fie l d s t u dy , however , Herma nn a n d Chi l cote ( 1 965 ) note d
that dampi ng-off l o s se s typ i ca l l y occ u rre d whe re shade exi s ted a n d pre s uma b l y
prov i de d a mo i s t envi ronment a t the so i l surface for these fun g i ; s uc h condi tions
are u n l i kely on severel y bu rne d a reas beca use the seedl i ngs wou l d probably be
res i s ta n t by the t i me s h a de from vegeta ti on devel ope d on severely burned spots .
However , seedl i ng l osses to drought a re l i ke l y whe re severe burn i n g reduces
mo i s ture- hol di ng c a pac i ty of so i l .
Subsequent growth of s urv i v i n g see dl i n gs on severe l y burned soi l h a s been
mea s u re d at only a few l ocati on s . At two s i tes , growth of 1 - and 2-year-o l d
n atura l Dougl as-fi r seed l i ng s was no t i nh i b i te d (Tarra n t a n d Wri ght 1 955 ) ,
a l though the proportion of mycorrh i za l see dl i ngs was reduced by severe burn i ng
(Wri ght a n d Tarrant 1 95 8 ) .. The se observat i ons of young na tu ra l seedl i ng s i n
J-18
...
"
s everel y burned mi cro s i tes confl i c t wi th earl i e r , l onger term observa t i ons on ,
surv i va l and growth of pl an ted Dougl a s - fi r ( I saac a nd Hopk i ns 1 937 ) . They noted
part i cul arly l ow surv i val of seedl i ngs p l a n ted i n severe l y burned spots where
severa l l ogs had been burned togethe r . Surv i va l of repl acement seedl i ng s
i ncrea sed annual l y u p t o the fi fth year of repl acement , when prac t i ca l l y a l l
s urvi ved . However , even i n the i r 1 0th yea r , Dougl a s -fi r seedl i ngs i n heav i l y
burned soi l were no t a s v i gorous a s those g rowi ng o n l i g h tl y burned s oi l .
Baker and Phe l ps ( 1 9 6 9 ) al so reported that l -yea r-ol d Doug l a s - fi r grown o n b urned
s o i l s were a bout hal f as ta l l as those grown on u nburned s o i l s . They col l ected
undi s turbed s o i l cores from two d i fferen t so i l s a nd grew the i r seedl i ngs u n d er
con trol l ed cond i t i o n s of temperature , l i gh t , humi d i ty , and water . I n short ,
a dd i ti onal di rect ev i dence about the effects of burn i ng on Doug l a s - fi r i s needed ,
espec i a l l y on shal l ow or coars e - textured so i l s
,
"
Competing and protecting vegetation is affected . - - Second ary succes s i on a fter
cl earcutti ng prov i des a l uxuri ant devel opment of bru s h and herbaceous spec i es
whi c h surv i ve l ogg i ng or i nvade c l earcu ts . Wi th s l a s h burn i ng , however , o ther
changes can occur o n the 40 to 90 percent of the u n i t affected . Burn i ng e l i mi ­
na tes some speci es from the ori g i nal fores t and del ays expa n s i on of o thers
capa bl e of respro u t i ng . These shrubs i nc l u d e sal a l (Gaultheria shallon Purs h ) ,
Oregon grape (Berberis nervosa Purs h ) , v i ne mapl e (Acer circinatum Pursh ) , and
sal monberry (Rubus spectabilis Purs h ) ( I sa ac 1 943 ) . Morr i s ( 1 970) found that
s l a s h burn i ng u s ua l l y reduced shrub ( bru s h ) compe t i t i on for several years and i n
the coa s tal s tr i p o f Oregon red ced the preval ence of s a l monberry , a parti c u l arly
s trong compe t i tor for Dougl as-fi r seedl i ng s . However , a t some s i tes i n the
sou thern Cascade Ra nge , heat assoc i a ted wi th sl a s h burn i ng s t i mul a tes germ i na­
t i on of l ong-do rma n t s eed from sev'e'ra l s h ru b spec i e s not present i n the stand at
harves t . These i nc l uded several spec i e s of manza n i ta (Arctostaphylos s pp . ) , '
Ceanothus spp . , and s umac (Rhus spp . ) ( Gra tkowski 1 967 ) . Seed beds c rea ted by
burni ng were q u i c k l y popu l ated by herbaceou s spe c i e s wi th wi ndbl own seed , but
to tal herbaceous growth was not s i g n i f i cantly d i fferent from u n burned area s
(Horri s 1 958 , 1 97 0 ) . Moreover , second a ry succes s i on , on severel y burned spots
was del ayed by several years .
Animal damag may be increased . - - Res i du e trea tments a ffect the amo u n t and
type of b i rd and a n i ma l dama g e to Dougl a s -fi r . When res i dues a re broadca s t ,
burned , a ccess to s eed a nd seedl i ngs i s i mproved ; grea ter depredati on by b i rds
and l arg e a n i ma l s i s l i ke l y . Conce i v ab l y , burn i ng cou l d promote growth of s h ru b
and herbaceous p l a n t spec i es wh i ch prov i de more or l es s attra c t i v e a n i ma l
ha bi tats a nd a l ternate food sources to Dougl a s - f i r . Al though s hade from some
pl ants or u nburned sl a s h can a i d s u rv i v a l of seedl i ngs , s hade may i ncrease
seedl i ng damage by an i ma l s . Thus , Herman n and C h i l c o te ( 1 96 5 ) reported that
l o sses by a n i ma l s i n newl y germi nated Dougl as -fi r i ncrea sed from 1 3 perce n t o n
open seed beds t o 31 perc e n t o n l i g htl y s haded , a nd t o 5 7 percent o n heav i l y
shaded ( 2 5 percent of fu l l s unl i g h t ) seed be ds . t os t of thi s morta l,i ty wa s
caused by whi te-footed deer mi ce c l i pp i ng cotyl edons and s tems of newl y emerged
seedl i ng s . , T he comp l ex rel ations of res i due trea tments a nd a n i mal d amage are
rev i ewed by D i mo c k ( 1 974 ) .
1.
species composition and stocking percentages . - - I t i s genera l ly recog n i zed
that l ac k of burn i ng favors dom i nance of the a s soc i ates of Doug l a s - f i r , s uch
a s western heml ock , we s tern redcedar , and Pac i fi c s i l v er fi r (Abies amabilis ) .
T hese speci e s a re often present as advance regenera t i on ( Hofma nn 1 924 ; Morr i s
1 958 , 1 970 ) and survi ve wel l on nonm i neral so i l ' seed beds ( M i nore 1 97 2 ) . For
exampl e , t10rri s c ompared s tocki ng of commerc i al con i fers on 4-mi l a cre quadrat
J-19
regenera t i on of Dougl a s - fi r req u i res removal or d i s turbance of the fo rest floor .
at numero us mi c ro s i tes throughout the harves ted a rea . I f reg enera t i o n i s t h rough
pl anti ng , then the need to prov i de mi n era l soi l seed bed s is repl a c ed by a need
to remove phys i ca l obs tac l es a nd redu ce bru s h compe ti ti on . Broadc a s t burn i ng i s
one of several means for accompl i s h i ng adequate s i te prepara t i on . Wi th h i g h - l ead
yardi ng of cl e a rc u ts a nd i n tens i ve u t i l i zati on , the ma nager ' s postl ogg i ng s urvey
cou l d often show tha t no add i t i onal s i te prepa ra t i on i s nece s s a ry .
Broadca s t Burn i ng and G rowth
Growth of exi s t i n g or fu ture s tands can be a ffected by res i due trea tment .
Effect on existing stands . - - Broadcast burn i ng has been the u s ua l method for '
reduci ng the extreme fi re haz a rd that frequentl y rema i ns after cl earcut harves ts
in ol d- growth Dougl a s - f i r . T h i s prac t i ce can affect any advance regenera t i on
wi thi n the harves ted u n i t and tree s ou ts i de the u n i t . Any advance regenera t i on
rema i ni ng after l og g i n g i S , usual l y of spec i e s other than Dougl a s - f i r . Broadca s t
burni ng wi l l u s ua l l y destroy advance reg enera t i on , i n spec i e s i nfected by
dwarf mi s tl etoe , Apceuthobium spp . , or bal sam wool l y aphi d , Ade lges piceae , th i s
may be of l i ttl e consequence ( Nel son a nd Harvey 1 974 ) .
I n a prope r l y execu ted burn , s tands adj acen t to the broadcast- burned c l ear­
cut wi l l benefi t from the l owe r d r i s k of wi l dfi re . M i n i mum edge scorc h i ng and
sl opovers can be expected whe re re s i d u e ma na gement wa s a des i gn cons i de ra t i on .
More seri ous damage has res ul ted from hol dove fi re wh i ch rea ppeared days o r
weeks after s l a s h burn i ng ; i n mos t , case s , fi re- k i l l ed trees c a n b e s a l v aged . We
know of no publ i s hed data about acres of l i ve ti mbe r burned from escaped sl a s h
fi res and the res ul tant i mpacts on s tand ma nagemen t ; however , s uch da ta a re
i mportan t for eva l uati ng the true costs and benefi ts of broadca s t burn i ng to
reduce fi re ha z a rd or prepa re a s i te for regenerat i on .
,
,
Not al l Dougl a s - f i r i s harves ted by cl earcutt i ng . Thi n n i ng i s common ;
shel terwood ha rve s t i ng i s i nc reas i ng . Though not currentl y practi ced i n the
Pac i fi c Northwe s t , l i ght underburn i ng i n the future may be used i n res i dual
stand s to expo se mi neral so i l or reduce vegetati ve competi t i on for seed l i ng s .
The use of underburn i ng i n stands wi th he vy accumu l a t i ons of fore s t fl oor to
reduce fi re hazard and s t i mu l a te n u tr i e n t cycl i ng to the m i n e ral s o i l has a l so
been propo sed (Moore a nd Norri s 1974 ) . Obv i ou s l y , the poten t i a l for dama ge to
res i dual tree s can be mi n i mi zed by l ow fi re i n tens i ty . P i l i ng s l a s h , remov i ng
concentra t i ons near tree s , and burn i ng under carefu l l y pres cri bed fuel and
weather cond i t i ons that perm i t a control l ed fi re of the des i red i n tens i ty are
opti ons for the l and manager . S i nce prec a u t i onary mea sures to reduce hea t o r
fi re dama ge to res i d ual trees i ncreas e the costs o f res i due treatme n t , i nfo rma­
ti on is needed to quanti fy the vul nera bi l i ty of vari ous tree spec i e s to damag e
and to i d enti fy the degree t o wh i c h preca u t i onary mea sures mu s t b e ta ken to
avo i d dama g e .
Effects o n futupe fopest productivity . - - So i l producti v i ty i s proba bly
reduced to the extent tha t broadcast burn i ng exposes mi neral soi l a nd cons umes
fi ne-textured o rga n i c ma t te r . Unfo rtu natel y , di rec t ev i dence tha t tree g rowth
is actual ly reduced , even i n severe l y burned spots , is short term , l i mi ted ,
and confl i c ti ng . Thus , Tarrant a nd Wri g h t ( 1 95 5 ) found no d i fference i n h e i g h t
and root l ength of 1 - and 2-ye a r-ol d Dougl a s -fi r growi ng on severe l y burned a nd
unburned so i l ; the s o i l a t the two l oca ti ons stud i e d wa s nei ther s tony nor
J-21
shal l ow . Yet , I saac and Hopki ns ( 1 937 ) and Baker a nd Phel ps ( 1 969 ) observed tha t
severe burn i ng d i d red uce Dougl as-fi r seed l i n g growth for a t l ea s t 1 0 years after
pl anti n g . The soi l at the i r respe c t i v e s tudy s i tes wa s al s o n e i ther s tony nor
sha l l ow . Unfo rtunate l y , the effects of vari ous i n tens i t i e s of burn i ng on Doug 1 a s ­
fi r growth have no t ye t been mea sured o n shal l ow , s tony soi l s l ocated o n s teep
s l opes where soi l d i s tu rbance and l os s of orga n i c ma tter are mo s t l i ke l y to resul t
i n so i l produc t i v i ty and Dougl a s - fi r growth .
S l a s h burn i ng i ncre a s e s the proport i o n of exposed mi neral s o i l to an add i ­
ti ona l 8 to 4 3 perc ent over that exposed by harves t i n g acti v i ti es ( ta b l e 2 ) ,
al thoug h th i s prov i des more favorabl e seed beds or ma kes pl a n t i n g eas i er ; exposed
soi l on s l op i ng terra i n i s l i ke l y to accel erate ero s i on and reduce s o i l
producti v i ty .
The effects of s l a s h burn i ng on eros i on have been s umma r i zed by Dyrness
( 1 966 , p . 605 ) :
. . . a l though severe burn i ng may a l ter s urface so i l characteri s ti cs s uffi c i en t l y to bri ng a bou t some i ncrease i n rod i b i 1 i ty , moderate and l i g h t burn i ng often have very l i ttl e d i rect effect on soi l propert i e s . Therefore , the mo s t i mportant changes caused by f i re a re often not i n the mi nera l so i l i tse l f , but rather i n the vegeta t i on and l i tter wh i c h prq tect the so i l s u rfac e . I f es sent i a l l y a l l surfa ce fuel i s con s umed by an i nten s e f i re , expos ure of mi neral so i l wi l l often res u l t i n d ecrea s ed i nfi l tra t i on rates l a rgely due to destruc ti on of s urfa ce s truc ture by ra i ndrop i mpac t . A l i g ht su rfac e fi re , on the o ther hand , wi l l genera l l y o n l y char the l i tter , l eav i ng mos t of the mi nera l soi l at l ea s t pa rt i a l l y covered . I n ma ny i n s tances , thi s rema i n i n g - l i tter may a fford s uffi c i e n t protec t i on to ma i n ta i n soi l poros i ty , a nd , therefore , to a vo i d a l arge-sca l e i ncrease i n accel erated eros i on . To meet h i s obj ec t i ve of ma i n ta i n i ng or improv i ng s i te produc t i vi ty , the
l and ma nager s hou l d be se l ec t i ve i n ·hi s use of broadc a s t burn i ng . I n our
opi n i o n , broadcast burn i ng shou l d be avoi ded on imma ture soi l s wh i ch are
characteri s t i ca l l y s tony , coarse · textu red , or sha l l ow and in s i tua t i ons where
accel erated eros i on i s l i ke l y . When broadca s t burn i ng i s the mo s t effec t i ve
way to sec ure regenera t i o n o r reduce the danger of wi l dfi re , an even grea ter
threa t to short- or l ong- term prod uc t i v i ty-- remed i a l efforts such as drai nage
contro l , fert i l i z er , a nd see d i ng annual cover 'crops are recommended ( Ro thacher
and Lopu s h i nsKY 1 974 ) .
EFFECTS OF OTHER RES I DU E TREATMENTS
The need to mi n i mi z e r i s k of acci denta l fi res i n l og g i n g s l a s h , yet a vo i d
a i r pol l u t i on from broadcast s l a s h fi res , ha s s t i mu l a ted search for , a nd u s e of ,
a l terna t i ve method s of res i d u e d i sposal . However , the effects of a l tern a t i ve
methods on regenera t i on a nd espec i a l l y on so i l producti vi ty and growth of
Doug l a s - f i r have not been i nvestigated . Thu s , we have onl y i nd i rect ev i dence
a bout 'the effects of these a l terna ti ves to s l a s h burn i n g .
When compa red wi th broadca s t burn i n g , mo s t other res i due treatments ( p i l i ng ,
pi l i ng and burn i ng , cru s h i n g ; or chi p p i n g i n pl ace ) have l i mi ted a pp1 i c t i o n
because tractors ra ther t h a n cabl e sys tems a r e used ; thus , opera t i on s a re
genera l l y l i m i ted to s l ope s under a bout 40 pe rcent . I n add i t i on , opera ti ons
i nvol v i ng heavy mac h i n ery d n med i um-to-heavy- textured soi l s sho u l d be l i mi ted to
J-22
dry pe ri ods to avo i d s o i l compact i on ( Ste i n bren ner 1 971 ) . Add i ti onal tractor
opera t i ons after ya rd i ng increa se the amount of d i s turbance to the mi neral so i l .
For exampl e , tractor l ogg i ng wi th sl a s h p i l i n g on 1 1 sma l l c l earcuts on gentl e
s l opes l eft an a verage of onl y 5-percent und i s tu rbed soi l compared wi th 44
percent after hi gh- l ead ya rd i ng on a 3 5- percent s l ope . §! Al though add i t i ona l
d i s turbance exposes more m i neral so i l seed bed and promo tes na tural reg enera t i on
of Dougl a s - fi r . thi s d i s tu rbance c a n adverse l y affect advance reg enerat i on and
soi l produ c t i v i ty .
P i l i ng S l a s h
Use of trac tors t o p i l e res i dues c a n prov i de s uffi c i en t expos ure of m i neral
s o i l for natural regenerat i on , further red u c t i o n of bru s h compet i t i on for l i ght
and mo i s tu re , a nd good access for pl a nt i ng and other c u l tura l pra c t i c es . How­
ever , removal of res i d ues a nd red u c t i on of bru sh den s i ty reduce shade or fro s t
protect i on for seedl i ng s ; on severe s i tes , th i s cou l d b e catas troph i c u n l ess
cover is ma i n ta i n ed by other mea n s , s u c h a s s hel terwood .
.
P i l i ng s l a s h i mpl i e s a dd i t i onal so i l d i s tu rbance and l os s o f org a n i c matter
i n affected port i ons of the u n i t . I n cl ea rc u t harve s ts , l arge materi a l i s l i ke l y
to b e pi l ed , ye t m u c h fi ne l og g i n g sl a s h a n d surface soi l wi l l a l so be i nc l uded
unl ess bru s h bl ades are u sed ca refu l l y to a vo i d so i l d i s tu rbance . Ord i na r i l y ,
s l a s h p i l i ng by t rac tors s trongl y confl i c ts wi th prudent soi l ma nagement s i nce
exposure of bare soi l or compac t i on can l ead to se r i ous ero s i on and reduc t i on i n
s i te product i v i ty . Wi th except i on a l care , reasona bl e terra i n , a nd d ry s o i l
cond i ti on s , however , pi l i ng residues after l ogg i ng shou l d not g rea tl y i n crea se
the extent of exposed or compac ted so i l or l os s of orga n i c ma tter from the s i te
over tha t wi th broa dc a s t s l a s h . burn i ng .
Pi l i n g and Burn i n g Sl a s h
.
.
Burn i ng pi l ed s l a s h creates hotter fi re s wi th l es s a i r pol l u t i on than
broadca s t, burns ( Fri tschen et a l . 1 9 7 0 ) ; burn i ng the pi l ed s l a s h fur ther
i ncrea s e s acces s i b i l i ty for future c u l tura l prac t i c e s . Effects on regenera t i on
wi l l be the same a s for pi l i ng wi thout burn i ng , but the h i g h soi l temperatures
achi eved under the pi 1 es wi l l a ffect the soi 1 even more adverse ly .than under
severe l y burned spots after broadca s t burn i n g . We found no exi s t i ng d a ta on the
amount of severe l y burned area res u l t i ng from pi l e- a nd - burn opera t i ons compa red
wi th broa dc a s t burn i ng .
Mec ha n i c a l Trea tment o f S l a s h
Reduci ng the s i ze o f l og g i ng s l a s h by cru s h i n g o r c h i p p i n g a nd by l ea v i ng
s l a s h c l o s e to o r m i xed wi th the so i l can reduce fi re hazard a nd pro v i de con d i ­
ti on s for faster d ecompos i ti on and i ncorpora t i on of orga n i c ma tter i nto the
so i l . A l though spec i fi c i n forma t i on i s not avai l a bl e , we a s s ume that mech a n i cal
treatme n t wou l d resu l t i n ( 1 ) reten t i on of most orga n i c ma tter , ( 2 ) suff i c i en t
expo s ure o f mi nera l soi l for natural Dougl a s - f i r regenera t i on , ( 3 ) good access
.
for c u l tura l opera t i ons , ( 4 ) s u bs ta n t i a l red u c t i on of bru sh dens i ty , and
( 5 ) m i n i mum soi l compaction whe re equ i pment ope rates l a rgely on a n o rga n i c
&I Persona l commun i ca t i on w i th D r . C . T . Dyrnes s , Pa c i fi c No rthwe s t Fore s t
and Range Experiment Sta t i on , October 1 97 2 .
J - 23
ma tter "cus h i on . " Poss i bl e l i mi t a t i o n s to mechn i ca l l y trea ti ng s l a s h i nc l ude :
( 1 ) el i mi n a t i o n of a dvanced regenera t i on , ( 2 ) h i gh cos t , ( 3 ) s teep topogra phi ,
( 4 ) reduced but prol onged s l a s h hazard , a n d ( 5 ) so i l compacti on where a n o rga n i c
cus h i on j s not present . Where nutri ents l i m i t ra te of decompos i t i on , pos i ti o n­
i ng l a rge quanti t i es of s l a s h c l o s e to or wi th i n the s o i l may cause temporary
n i trogen defi ci enci es ; however , a pplyi ng fert i l i zer may speed decompo s i t i on a nd
d i rec tl y benefi t regenera t i on . Mea ns for accel era t i ng ra tes of natural decom­
pos i t i on shoul d be researched .
The di ffi cul ty of mechan i cal trea tment i ncrea ses wi th s i ze and qens i ty of
harv e s t res i dues ; where soi l compact i o n i s a poten ti a l probl em , tractor u s e
shoul d be l i mi ted t o dry so i l cond i t i ons . For sma l l trees or good u ti l i za t i on ,
mov i ng l a rge tracto rs over bru s h and l ogg i ng debr i s may be s uffi c i en t ; tractors
s houl d fol low a twi s ti ng path so tha t trac k s d i s turb the fores. t fl o o r . However ,
a t the o ther extreme c haracteri z ed by l a rge ol d - growth debri s and poor u ti l i za­
t i o n , huge equ i pment mi ght be neces s a ry to reduce s i ze and h e i ght o f the s l a s h ,
crea te enough spo ts o f mi neral so i l for na tural regenera ti o n , and i mprove access
fo r s ubsequent cul tural opera t i o n s .
Remo v i ng Res i dues from S i te
The cos t and effects of remo v i ng res i dues from the s i te for use and d i sposal
el sewhere wi l l obv i ously depend on the s i ze and amount of materi a l removed .
These vari abl es a nd the mea ns for remo v i ng the s l a s h wi l l determi ne the extent
o f ha zard reduc t i o n , mi neral s o i l d i s turbance , access for cul tural opera t i ons ,
l o s s of organ i c ma t ter , and potenti a l for eros i on . Thi s res i d ue t rea tment method
i s a fur ther extens i on of current trends toward i nten s i ve u ti l i za t i on a nd YUM
yard i ng ; further i nforma t i on i s n eeded to determi ne s i tua t i ons i n wh i ch th i s
techn i que has advan tages over o ther opti ons .
SUMMARY DI SCUSS ION
The l and ma nager ' s deci s i o n s - - i f , how , and where to tre a t fores t res i dues-­
a re admi ttedly compl ex ; h i s dec i s i ons wi l l d epend on rel a t i ve or abso l u te val ues
g i v e n to vari ous ma na gement obj ect i ves and the i r i nterrel ati o n s h i ps . Thus , pl ans
for fi na l harves t of ma ture and espec i a l l y overma ture s ta nds o f Dougl a s - fi r
s houl d be i ntegra ted wi th s i 1 vi cu 1 tura l p l a n s for regenera t i ng and tend i ng the
new s tand . Moreover , these pl a n s s hou l d be fi tted to careful l y a s s es s ed s tand
and s i te cond i t i ons wh i ch exi s t o r may exi s t after l ogg i ng . I n mos t s i tua t i o ns ,
proper cho i ce and execu t i o n of l ogg i ng o r res i due treatment methods wi l l probably
el i m i nate need for add i t i ona l s i te prepara t i on or remed i a l s i te resto ra t i on
acti v i ti es .
NaturaZZy regenerating. DougZas- fir . -- Cu rren t1 y , we .have i ns u ffi c i en t a nd
frequently contra d i ctory evi dence to j udge wh i ch methods of res i due treatment
a re mos t l i kely to pro v i d e sati s fa c to ry na tural regenera t i o n of Dougl a s - fi r .
The s ucces s o r fa i l ure o f res i due trea tment wi l l depend o n i ts d i rect effec ts
on exi s t i ng seedl i ngs and seed and on i nd i rec t effects on env i ronmental factors
wh i ch are cri ti cal for s ucces s ful regenera t i o n a t spec i fi c l ocati ons .
There i s genera l agreement that mi neral so i l i s the mo s t d es i rabl e seed
bed for surv i va l and growth of Dougl a s - fi r . Expo sed o r d i s turbed mi neral so i l
favors seed l i ng s urv i val by reduc i ng vegeta t i ve competi t i o n for so i l mo i s ture
a nd pro v i d i ng more moderate s u rfac e tempera tures a nd mo i s ture rel a t i ons than
tho s e exi s ti ng on und i s tu rbed orga n i c ma ter i a l s . Yet , tre a tments wh i ch expos
J - 24
"\
"
mi neral so i l a l s o des troy overhead cover wh i ch provi des heat and fros t pro te c t i o n
and reduces r i s k of accel erated eros i on . Thu s , a general need for s uffi c i en t ,
wel l -di s tri b u ted s eed beds of mi neral so i l mu s t be bal anced aga i n s t a spec i fi c
need at some s i tes to provi de adeq u a te shade or fro s t protec t i on .
,
I
I
). Exposed m i neral so i l may be obta i ned by mechan i cal l y remov i ng or brea k i ng
the ma tted fo res t fl oor (duff ) o r mi x i ng i t wi th mi neral so i l ; the fores t fl oor
can al so be removed by burn i n g . At four l oc a t i ons in sou thwe s tern Was h i n g to n ,
mi neral soi l exposed by mechan i ca l mean s ( l ogg i ng ) prov i ded a s i gn i fi cantly
h i g her s toc k i ng percentage after aer i a l seed i ng of Dou gl a s - fi r than that exposed
by burni ng , lI The amount of soi l d i s turbance accompanyi ng l oggi ng opera t i ons i s
con tro l l a bl e so that more or l es s mi neral s o i l can be exposed ; however , t h i s
con tro l may i ncrea se l oggi ng cos ts . For exampl e , to fac i l i tate regenerat i on
effo rts by i ncreas i ng the amount of so i l and bru s h d i s turbance norma l l y res u l t i ng
from s kyl i ne yardi ng sys tems , cha i ns or tube s wi th p'ro trud i ng hoo k s have been
dragged back and forth by the yard er after l oggi ng (Sommer 1 973 ) . I f seedl i ng s
qre to b e pl anted , a dequate s i te prepara t i on c a n us ual ly b e achi eved by scal p i ng
out seedl i ng l oc a t i ons wi th hand too l s , i f a ccess wi th i n the u n i ts has been
achi eved through good u ti l i za t i on , s l a s h fi res , or mac h i ne pi l i ng of res i dues .
I n general , a ny l oggi ng method or res i due trea tmen t wh i ch i ncreases the
amount of exposed mi neral soi l at s u ff i c i ent mi cro s i tes throughout the tre a tment
area s houl d rank h i gh for achi evi ng natural regenera t i o n . Broadcas t burn i ng can
provi de an a ddi ti onal 8 to 43 percent exposed or d i s turbed mi neral so i l ; the
of cat and s kyl i ne yard i ng sys tems whi ch
i ncrease wi l l be g reatest after
m i n i mi ze so i l d i s turbance over the l oggi ng uni t . Stocki ng percentage of Dougl as ­
f i r averaged two t o three ti mes greater on burned than o n und i s turbed s eed beds
after 14 cl e a rc u ts were aeri a l l y s eeded wi th Dougl a s - fi r i n no rthwes tern
Was h i ngton ( see foo tnote 7 ) . Where spec i e s o ther than Dougl a s - fi r are accept­
abl e , however , there i s l i ttl e need to expose addi t i onal mi neral so i l by
broadcast b u rn i ng . ' Thu s , there wa s no d i fference i n' average s tock i ng ( a l l
coni fers ) on burned a nd unburned pl ots i n sou thwes tern Was h i n g ton and western
Oregon (Morr i s 1 97 0 ) and burned and unburned mi l acre pl ots i n wes tern Oregon .
Thu s , broadca s t burn i ng crea tes mo re mi neral so i l seed , be ds , but there i s
no cons i stent i mprovement of s toc k i ng from natural o r hel i copter- di ss emi n a ted
seed . Depend i ng o n the l ocal si tuati on , burn i ng affects othe r env i ronmental
factors whi ch are cri ti ca 1 to seedl i ng survi va 1 . For exampl e , I saac I s numerous
i nves ti gati ons of na tura l regenera t i on of Dougl a s - fi r cl earl y showed the need
for s hadi ng to i ncrease i n i ti al surv i v a l and hei ght g rowth . He observed that
"dead " s ha d e of s tumps , l og s , and overhead sl a s h was pre ferabl e to l i vi ng shade
of vegeta t i on ; moreover , tha t " l i v i ng " shade of cl umpy , shrubby vegetati on was
more des i rabl e than that provi ded by conti nuous s tands of herbaceous i nvader s .
Morri s ( 1 9 7 0 ) fo und that broadcas t burn i n g d i d no t a ffect the coverage by
11 Rona l d S tewart. A study of Dougl a s - fi r a er i al seedi ng . Unpubl i s hed
report No . 4 , Wa s h i ngton State Departmen t of Natural Resources , Olymp i a , 25 p . ,
1 966 .
, Eug ene R . Ma noc k . Unpubl i s hed prel i mi nary report , I nforma t i on No . 5 :
Seed sourc e effec ti veness s tudy . Oregon S tate Board o f Fores try. 1 965 . On fi l e
a t Forestry Sc i ences La bora to ry , O l ympi a , Wa s h i ngto n .
J-25
herbac eous vegeta t i o n b u t d i d reduce the propo rtion of mo s t s hrubby veg eta t i o n ,
except where buri ed Ceanothus seeds were stimu l a ted i n to germi n a t i on , p roduc i ng
characteri s t i cal l y heavy cover . Presumabl y , other res i due trea tments wou l d
a l so red uce the proporti on of shrubby vegeta tion but wi tho ut s t i mu l a t i ng Ceanothus
spec i es and other spec i es i n wh i ch germi na tion i s s t i mu l a ted by hea t .
The effect o f l ogg i ng and res i due treatment on ex i s t i ng s h ru b by vegeta t i o n
c a n b e s i gn i fi ca n t i n secur i ng regenerati on . Because of i ts co n t i nuous , rather
than cl umpy , growth hab i t , sal monberry is parti cul a r l y und es i rabl e i n the Coa s t
Ra nges ; thus , a ny tre a tment--fo r exampl e , s l a s h burn i ng - -wh i c h reduces s a l mon­
berry wou l d favor Dou g l a s -fi r regenera t i on . We do not know what effect the
i ncreased amount o f s o i l d i s turbance assoc i a ted wi th other s l a s h treatments
woul d have on the d i stri b u t i on and gro /th of sal monberry . Shrubby vegeta t i on
hav i ng a more cl umpy habi t may i mprove the seedl i ng env i ronment by p rov i d i ng
shade or fros t protec t i o n . - Except where fi re s t i mu l a tes the g ermi na t i o n o f
certa i n brush spec i es , a l l res i due trea tments are l i ke l y to h a v e a t l ea s t a
tempo ra ry advers e effect on growth rate of c l umpy vegeta t i on s uch a s v i n e mapl e
or rhododendron . Thus , wi th extreme res i due treatment , bo th dead and l i v i ng
shade wi l l be reduced to a mi n i mum . Whether th i s mi n i mum wi l l s ti l l prov i de
s uff i c i en t modera t i on of the seedl i ng mi crocl i ma te wi l l , of course , depend on
the severi ty of s i te . When mi n i mum quanti t i e s o f seed a re ava i l a bl e , a s on
adverse s i tes , we s hou l d probabl y a ttempt to max i mi ze shad e , parti
cul arly dead
.
shade of l ogg i ng s l a s h .
I n brus h hazard area s , scari fi cati on from l ogg i ng o r l i g h t to med i um burns
sel dom provi des s uffi c i e n t we l l -di s tri buted expos ure of mi neral s o i l and
remova l of competi ng v eg eta i on to i ns ure adequate natural reg enera ti on of
Dougl a s - fi r . For exampl e , on hi gh- to med i um-q ual i ty s i tes of the Coa s t
Ranges , a rel i abl e prac t i ce i s to pl ant after getti ng as much s ca r i fi ca t i on a s
prac t i ca l wi th cabl e l og g i ng fol l owed by burn i ng wi th d ry so i l cond i t i ons .
The l a rge res erves of so i l n i trogen and rap i d , geta ti onal s ucces s i on on these
s i tes wi l l probably mi n i mi ze the nega. t i ve effects of thes e tre a tmen ts on s i tQ
produ cti vi ty .
Other res i due trea tmen ts wi l l vary by type of seedl i ng mi cro s i te . Wi th
the pos s i bl e excep t i on of some mechan i cal trea tmen ts , s uch as o n s i te cru s h i ng or
ch i pp i ng of s l a s h , res i du e trea tments shoul d i nc rease expo s ure of mi neral soi l
and reduce protecti ve cove r . However , the effec ts of the s e methods must be
surmi sed untj l the vari o u s types of mi cros i tes resul ti ng from spec i fi c h a rvest­
i ng and res i due trea tme n t combi nati ons are known and correl a ted wi th seedl i ng
growth and s urvi val .
Maintaining soi l pro4uotivity . - -As deta i l ed prev i o us l y , es i du e trea tments
can a ffec t s hort- a nd l ong- term soi l producti v i ty through i mmed i a te effect on
vegeta t i on , fo res t fl oor , and the s u rface so i l . Subsequent effects wi l l be seen
on other natural proce s s e s , s uch as seconda ry s ucces s i on and s o i l eros i o n , wh i ch
can remedy or extend the i n i t i a l effec ts of l ogg i ng and res i d u e trea tmen t . Where­
as the l a nd ma nager genera l l y s tr i ves to maximi ze the amo u n t of mi neral soi l
exposed by res i due tre a tment and thus reduce ri s k of wi l dfi re a nd c o s ts of
regenera t i ng Dougl a s - f i r , th i s confl i c ts di rec tly wi th h i s general obj ecti ve to
mi n i mi ze d i s turbance o f the soi l to protect so i l produc t i v i ty . Obv i o u s l y , some
tradeoffs are nec e s s a ry e i ther by accepti ng l o s s of producti v i ty o r by fo l l owi ng
res i d u e trea tment wi th some remed i a l meas ures to ma i n ta i n or i mprove producti vi ty .
J
Effec ts of remo va l o r d i sturbance of res i due , vegeta ti o n , a nd the fo res t
fl oor va ry . M i n i ma l reducti ons i n producti v i ty a re l i ke l y to occ u r on h i gher
J-26
qual i ty s i tes wh i ch commonl y have ( 1 ) a rel a ti vely l a rg e capi tal of n i trogen and
orga n i c ma tter in the mi neral so i l ; ( 2 ) deep , we l l -drai n ed soi l s wi th h i gh
i nfi l tra ti on rates and moi s ture - hol di ng capac i ty ; s uc h soi l s have mi n i ma l poten­
t i a l for s urface eros i on and ma s s movement , or are l es s affec ted if these occur ;
( 3 ) favorabl e cl i ma t i c cond i ti ons wh i c h compensate for reducti ons i n chemi c a l o r
phys i c a l proper t i e s of the so i l ; and ( 4 ) rap i d se cond a ry s ucces s i on by a wi de
vari ety of pl a n ts whi c h rees ta bl i s h a nu tr i e n t and organ i c cycl e and freq uently
a dd ni trogen through symb i o t i c N-fixa t i on . However , the fact that Dougl a s - fi r
growth on h i g h-qual i ty s i tes can be i mproved by n i trogen ferti l i zer s ug g e s ts
tha t s i te producti vi ty may have been reduced by past n a tural or man-cau sed
acti vi ti es .
Fores ted a reas of l ow or med i um s i te qual i ty have l es s tota l n u tr i ent and
organi c ma tter capi tal and a h i gher proporti on. of thi s d i s tri buted on the forest
fl oor and i n the s tand ; bo th these aboveg round sources are vul nerabl e to d e s truc­
ti on by fi re . Restri cted soi l depth or l arg e conten t of gravel or roc k outcrops
fur ther reduce the nutri e n t and moi s ture s torage capac i ty of the so i l . Thu s ,
some soi l s have l es s tol erance for l os s e s of n u tr i en t or orga n i c ma tter through
fi re or surfac e eros i on . The l and ma nager mu s t choose h i s l ogg i ng a nd res i du e
treatment methods c a reful l y for s u c h s i tes .
Choosing an appropriate residue treatment . - - We s e t up a hypo the ti c a l , yet
typ i cal , res i due s i tua t i on i n the mi d- Oregon Cascades and made the fol l owi ng
a s s umpti ons :
(,
1 . Obj ecti ve : The ma nager des i res to convert the ex i s ti ng ol d- growth s ta nd
to a wel l - s toc ked s ta nd of Dougl a s - fi r for future i n ten s i ve management for wood
produc t i on ; effects of t i mber ma nagement on thi s u n i t mu s t be compa t i bl e wi th
current wa ters hed and recrea ti onal uses in the enti re dra i nage .
2 . Regenera t i on sys tem : Dougl a s - fi r regenera t i on i s des i red ; i ns uffi ci ent
advance regenera t i on of heml oc k and s i l ver-fi r i s pres e n t . Because of s o u th­
wes terl y a s pect and probab i l i ty of many dorma n t seeds i n the forest fl oor , heavy
Ceanothus devel opmen t , espec i al l y a fter broadc a s t burn i n g , i s ant i c i pated . Pl ant­
i ng is fea s i bl e , a l though at l ea s t 25-percent fi rs t-yea r mortal i ty i s expec ted .
Res i due trea tments whi ch reduce heavy sl a s h concentrati ons (more than 1 foo t
( 30 . 5 cm) deep ) wi l l reduce pl a n ti ng costs , yet these s ame trea tments wi l l reduce
dead shade and i ncrea se access for deer brows i ng . Cos t per s urvi vi ng tree wi l l
thus depend on the need for shade and deer protect i on d u r i ng the fi rs t yea rs
a fter pl a n ti ng .
Adequate natural regenera t i on of Dougl a s - fi r i s a l s o pos s i bl e . Thi s 20­
acre (8 . 1 - ha ) , el onga ted u n i t - - 5 chai n s by 40 cha i ns ( 1 00 . 6 m by 804 . 6 m ) - - i s
surrounded by ma ture Dougl a s - fi r ; a modera te- to-good seed crop i s pred i cted
wi th i n 2 years of l oggi ng . Res i due treatments wh i ch l eave l i ght sl a s h are
probabl y des i rabl e fo r seed and seedl i ng surv i va l - - p rov i d i ng no acc i dental fi re
occurs .
3 . Di sease : Numerous Poria weirii foc i are i n the proposed c l earcu t .
I nfected s tumps , roots , a nd butt chunks are reservo i rs of i nocul um for renewed
i nfec ti on . These res i dues shoul d be confi ned . to the exi s t i n g foci , reduced to
sma l l er s i zes' , and not pu s hed 'i n to the so i l ( Nel son and Harvey 1 974 ) .
4 . Fuel s : Desp i te a n t i c i pated cl ose s ta ndards of u ti l i zation , l arge amounts
of res i due- - 1 50 tons per a c re ( 336 metr i c to ns per ha ) - - of a l l s i zes wi l l rema in
J - 27
a fter cl earcut harves t of ol d g rowth . Fuel type wi l l be H X/X , i . e . , h i g h to
extreme rate-of-s pread a nd extreme res i s tance- to-con trol . I g n i t i b i l i ty w i l l be
h i gh i n rotted wood that i s general on a rea . Ra te-of- spread expected to decrea s e
.
to . H-M ( h i gh to modera te ) i n 5 years a s t h e fi ner fl a s hy fuel s dete ri o rate .
5 . Ri s k of fi re : Wel l - t ra vel ed pub l i c- use road through u n i t .
subj ect to l i ghtn i ng s to rms sev era l days eac h summe r .
Area i s
9
6 . Fi re detec t i o n a nd con trol : Area i s readi l y v i s i b l e to a i rcra ft pa trol .
Report i ng time by publ i c travel i ng through the a rea , at l ea s t 30 mi n u tes to .
'
nearest phone ; i n i t i a l attack 45 m i n u tes from reporti ng .
7 . Terra i n : Moderate ; 30- percent s l opes nea r ri dgetop wi th moderate
d i ssection pe,rmi t trac tor l og g i ng a nd l ocal i zed pi l i ng or cru s h i ng of l og g i ng
s l a s h . R easonabl e but not exep t i onal care mus t be taken to mi n i mi z e the d i s ­
turbance of the mi neral s o i l , espec i a l l y near s treams ; ea rthmov i ng from spur
and skid road cons truct i o n mus t be mi n i ma l .
8 . Soi l product i v i ty : Low ; th i s shal l ow , imma ture soi l has very gravel l y ,
cl ay l oam tex ture ; compac ti on i s l i ke l y i f trac tors are used o n bare , mo i s t
so i l ; accel erated sheet and g u l l y eros i on a re l i ke l y where mi n era l so i l i s
exposed ; conserva ti on o f orga n i c ma t te r and n i trogen i s h i g hl y, des i ra bl e .
9 . Water ' qual i ty : I ncrease i n' s uspended sed i ments i n the sma l l s tream
pas s i ng through the un i t wou l d cause s i l ta t i on of a nearby recrea t i ona. l l a ke
a nd s hou l d be avo i ded .
,
1 0 . Recrea t i on : The u n i t i s rea d i l y observed from severa l , we l l - vi s i ted
vantage po i nts ; deer hun t ers and gen era l publ i c ' wi l l v i s i t the a rea .
.
1 1 . Wi l dl i fe :
a re expected .
Heavy deer u s a g e a nd seed , depreda t i o n by b i rd s and m i c e
We prov i de our rati ngs of several res i du e trea tment methods for obta i n i ng
g i ven ma na gement obj ecti ves on thi s hypothet i ca l si tua t i on ( ta b l e 4 ) . Only the
i n i ti al cos ts of appl yi ng a i ven res i due trea tment are con s i dered . Obvi ous l y ,
the pas s i ve di sposal sys tem ( natural decompo s i t i o n ) has the 'l east ' i n i t i a l cos ts ,
and o ther procedures req u i re added costs ; i nc reased d i sposal co s ts , however , ca n
encourage better uti l i za ti on or decrea s e o ther costs of manag emen t . Mecha n i cal l y
chi pp i ng or cru s h i ng or mac h i ne p i l i ng are expe n s i ve treatments wh i ch a re l i mi ted
in appl i ca t i on to those a rea s acces s i bl e to heavy mac h i n ery a nd not s ubj ect to
soi l compac t i on . Remov i ng res i dues from the s i te i s probably the most expens i ve
res i due trea tment cons i d e red ; for exampl e , experi ence wi,th YUM yard i ng by the
U . S . Fore s t Serv i ce has s hown that removi n g sma l l l og s - -mi n i mum of 1 0 feet (3 m )
wi th 8- i nch ( 20 . 3 cm ) d i ameter i n s i de bark a t l a rge end - - i ncreased yard i ng cos ts
a s much a s $ 500 per acre , a l thou g h some addi ti ona l uti l i zati on d i d occur .
Rati ng res i due trea tments for the i r effects on atta i n i n g s a t i factory
na tura l Dougl as-fi r regenera t i o n proved extremel y di ffi cul t , even wi th a s s ump­
t i ons a bout the hypothet i ca l cl earcu t . Succe s s fu l natural regene ra t i on requ i res
Persona l corre s pondence wi th Ron Johnson , Fores ter , Olympi c Na ti ona l
Fores t , October 1 972 .
J - 28
Ta bl e
4 . - -Ra ting of several residue, treatmen
methode for a hypo theticaZ clearcutll
Trea tmerit
Manag ement obj ecti ve and subobj ec t i ve
1. No
treatment
M i n i m i ze production costs per
a cre a nd per u n i t of products
removed
Res i due trea tment Doug l a s -fi r regenera t i o n
lIa tura 1 r:. 1
P l anted '§"
Stand acces s i bi l i ty Pro tection or ri s k
F i re
I nsects
D i sease Repl acements
N ( S } ferti l i z i ng
Eros i on control
112
3
5
5
5
3
1
3
2
5
5
2
2
2
2
1
5
5
!I Ra ti ngs from ] (mos t favora b l e ) to
YUH
5
5
5
1
4
4
2
2
2
4
3
1
4
:
§I 1
3
5
5
2
2
3
3
3
5
5
5
1
3
3
3
3
4
2
2
,4
5
4
3
3
2
4
2
2
2
3
RemoveY
1
4
4
Maximum compa t i bi l i ty a nd
benef i t to
Wa ter qual i ty
Recrea t i on
Wi l dl i fe
1/ Equ i va l ent to
2
4
Conserve f i ne orga n i c ma tter
M i n i mum d i sturbance
Mi n i mum compa c t i on
g; Treatment not fea s i bl e o
3
3
2. Mai ntai n soi l producti v i ty
3. P i l e wi hout
burnY
4
1
5
3
2
§I
1
2
2
3
3
1
( l ea s t favorabl e ) for attai n i ng g i ven management o bj ec t i ves .
s teep s l opes ( exceedi ng about
40
percent ) .
yard i ng .
if Poten t i a l h i g her cost because s l a s h fi res can esca p e .
C o s t p e r surv i vi ng
l an ted tree ( p l a n ti ng costs and survi val are v a r i a bl es ) .
§I
Rate a s 2 , i f s l ash pi l ed on Poria foc i or s l a s h c h i pped and l eft above so i l ( personal corres pondence
wi th Earl Nel son , Research Pa thol og i s t , Forestry Sc i ences Labora tory , Corval l i s , Orego n , June 1 97 4 ) .
adequate s ed fa l l , germi nati on , and s u rvi va l wh i ch a re u n i formly d i s tr i buted
over the c 1 earc u t . I f o n e o r more of these fac tors are i n ad equate , then a tta i n­
i ng the ma nagement obj ecti ve of a wel l - s tocked u n i t s oon a fter the removal of
the preced i ng s tand i s i mpos s i bl e .
Fu rther ref i n ement of th i s rel a t i v e cos t : benefi t a n a l ys i s wi l l reqU i re
mea suri ng the effects of vari ous res i du e treatments a nd a s s i gn i ng dol l a r v a l ues
to cos ts and poss i bl e benef i ts from res i due trea tmen ts . For exampl e , how much
i s soi l fert i l i ty reduced? What i s the cost of a vo i d i ng o r correcti ng th i s l os s ?
Cu rrent l y , we know t h a t preservi ng s o i l ferti l i ty i s a part i cu l a r l y i mportant
management obj ecti ve on i mmatu re so i l s , wh i ch a re common to s teep , roc ky s l opes .
As l a nd ut i l i za t i o n becomes more i n tens i v e , forestry i s trad i t i onal l y rel egated
to soi l s wh i c h a re ma rg i na l for othe r u s es . Yet i mma ture s o i l s ca n l ea s t a fford
d ama ge , beca use soi l mo i s ture capa c i ty and nutri ent capi tal are l ow ; moreov e r ,
soi l s on s teep s l opes a re h i g h l y subj ect to damage , because of grea ter s o i l d i s ­
tu rba nce a s s oc i a ted wi th l og g i ng on steep s l opes and g rea ter poten t i a l for
J-29
eros i o n . I rrespec ti ve o f soi l type and terra i n , the l a nd ma nager i s adv i sed to
pl ace the protecti on of h i s soi l resource h i g h among h i s othe r mana gemen t
obj ecti ves .
Cho i ce of res i du e trea tment me thod has fewer compl exi ti e s a nd l e s s i mpo r­
ta nce when Doug l a s - f i r i s regenera ted by p l a n t i ng or when mo re to l era n t tree
spec i es a e acceptabl e . Large quan t i ti es of s l a s h a s s o c i ated wi th no res i due
treatment or mi n i ma l treatment advers e l y affect the i n i ti al cos t of pl a n t i ng
and u s ual l y pro v i d e havens for smal l mamma l s wh i ch often use s e eql i ngs for food
( Dimock 1 974 ) ; ye t i n o the r s i tuati ons , the se same res i dues c a n i ncrea se
survi val and growth of the seedl i ng s by be i ng obstacl es to rad i a ti on, a nd b rows i ng
deer . Thus , i t i s di ffi c u l t to genera l i ze about the net ga i n from res i due
trea tment on surv i val a nd g rowth of pl anted Doug l as -fi r . For the h a rs h s i te of
our hypo the ti cal c l earcu t , we pred i cted tha t reduci ng the amo u n t of s l a s h on the
ground wou l d prov i de the l owe s t cos t per surv i v i ng seedl i ng .
CONCLUSIONS AND RECOMMENDATIONS
RES I DUE S I TUAT I ONS AND TREATHENT PRACT I CES N E E D I NG REV I S ION
We cannot sugge s t a ny compl etely new practi ces but can empha s i ze oppor­
tun i t i es and precaufi ons that s hou l d become rou t i ne i n the s l a s h d i sposal
dec i s i on .
1 . Coord i na ted efforts shou l d be accel erated i n the Doug l a s - fi r reg i o n
toward i mprovi ng economi c c l i ma t e and i nterdi s c i pl i nary tec hno l ogy fo r more
compl ete convers i o n of resi dues to usefu l products .
2 : A deta i l ed exam i n a t i on of cond i ti o n s , a t each l oca t i o n s houl d rout i nely
precede the s l a s h d i sposai dec i s i on ; . for exampl e :
,
A . Conservati on of orga n i c matter a nd assoc i a ted n u tr i e n ts i s
parti cul a rl y c r i ti ca l on s teep , sha l l ow , or s tony so i l , i n wh i ch a l arge
fract i on of the s i te ' s n u t r i e n t and orga n i c ma tter cap i tal coul d be l os t by
burn i ng or removal . Such sbi l a re exten s i v e througho u t the Doug l a s - fi r reg i on ;
s l a s h burni n shou l d not be done routi nely on these so i l s . Moreover , mechan i ca l
rear rang emen t of the ma ter i a l shou l d b e mi n i m i zed to avo i d so i l d i s turbance a nd
red i stri bution or l os s of orga n i c ma tter .
B . I n contras t , o n hi g he s t q ua l i ty s i tes where a sma l l er frac t i o n of
the org n i c mat ter and nutr i en t capi tal is a bove the mi neral so i l , burn i ng of
s l a s h may be the mos t econom i c a l or l ea s t dama g i ng method for s l a s h d i s po s a l and
control of compe ti ng vegeta ti on .
C . Adeq uacy and d i s tr i b u t i on of coni ferous seedl i ngs ami d the res i dues
shou l d be ca refu l l y a s s e s s e d before res i due trea tment . Wherever pas t experi ence
i nd i cates probabl e fa i l ure in reprodu c i ng Dou g l a s -fi r , we shou l d avo i d des troyi ng
a dvance reproduc t i on of th i s or other spec i e s .
J - 30
N EEDED RESEARCH
1.
Deve l op n ew a nd economi cal use s for u nmerchantabl e ma teri a l .
2 . E s tabl i sh or rees tabl i s h perma nent pl ots t o quan t i fy aDd compare the l on g - term effects o f v a r i o u s fi re and nonf i re res i du e trea tmen t s on vegeta t i ona l
devel opment a nd s i te produc t i v i ty . For exampl e , the ree s ta b l i s hment of some of
the 60 pa i red-observa t i o n pl ots ( burned v s . unburned ) tha t we re e s ta bl i s hed i n
1 946 (Morri s 1 970 ) i s most d e s i rabl e . Beca u se h i s pl o ts and those of others
i nvesti ga ti n g the effects of res i due trea tments we re l oca ted on moderate l y deep ,
rel ati 'vely s tone-free so i l s , addi ti onal pl o t s wi l l be necess a ry to samp l e s h a l l ow
or extremel y s tony so i l s , parti c u l a r.l y on s teep s l opes . Such s i tes are exten­
s i vely d i s tri bu ted , rel a t i v e l y u n i n v es t i g a ied , and undoubted l y more s u s cep t i bl e
to damage through man ' s acti v i ti es ; they shou l d rec e i ve research pri ori ty .
3 . Si nce mos t o f our current knowl edge perta i ns to the effec ts of broad­
c a s t burn i ng , dete rmi n e the effec ts of a l terna ti ve method s of resi due trea tment .
For exampl e , wh a t are the amounts and d i s tr i buti on of v a r i o u s mi cro s i tes res u l t­
i ng from cru s h i n g , remov i ng , or c h i ppi n g res i dues? How do the se affect the
regenera t i o n and g rowth of Doug l a s -f i r and a s s oc i a ted speci e s ?
4 . Determi n e the i mportance of spec i fi c fores t res i du e s i n nutri ent cycl i ng
and s i te produc t i v i ty .
5 . Deve l op a resi due treatment i nd ex expres s i ng the need for and r i s ks o f
res i du e d i sposal treatment ; extend i ng prev i ou s work by Fahnestock ( 1 960) i n
I da ho i s d e s i rabl e . The i ndex s hou l d i nc l ude at leas t the fo l l owi n g facto rs and
the i r i n terac ti on :
A . Val u e s to be protec ted and the i r suscepti b i l i ty to damage by wi l d­
fi re and var i ous methods of res i du e trea tment : esti a ted amounts of n i trog en
conta i ned i n t he fores t fl oor , l oggi n g s l a s h , and so i l ; percentage of u n i t
adequately s toc ked wi th- advance reg enera t i on ; a nd poten t i a l for soi l eros i on .
B.
Quan'ti ty and fl ammabi 1 i ty .
C.
Ri s k and i gn i ti bi l i ty .
D.
Ava i l a b i l i ty o f fi re protec ti on .
E.
C l i mate and mi croc l i ma te .
F.
Pro babl e rate of natural decompo s i t i o n and hazard reducti on .
6 . Devel op an i ndex or deci s i on l og i c tabl e quan t i fyi n g the need for
s i te prepa r a t i o n for natural or pl a nted regenera t i on a nd the prQba b l e cos ts
and ri s k s of v a ri ous opti ons for a t ta i n i ng thi s i n i nd i v i du a l s i tua ti ons .
7 . Qu a n t i fy the vul nerabi l i ty of vari o u s tree speci e s to f i re and mecha n i ­
cal damage and i denti fy the degree to wh i ch prec a u t i onary mea s ures must be taken
to avo i d d ama ge to these speci e s when trea t i n g l o g i ng s l a s h i n th i nn i ng a nd
shel terwood opera ti ons .
J - 3l 8 . Fi nd prac ti cal mea ns to i ncrea se rate of natural decompo s i t i o n by mod i ­
fyi ng phys i ca l o r chemi cal properti es of the res i du e o r so i l ; we shou l d be a b l e
to red uce fi re and d i sease hazards and i mprove orga n i c ma tter and nutri ent cycl ­
i ng i n our ma naged s ta nds . Add i n g n i trogen ferti l i zer and protecti ng or p l a nt­
i ng ni trogen - fi xi ng pl a n ts or other pl a n ts wh i ch pro v i d e eas i l y decompo sabl e
orga n i c ma tter a re mea ns for i nc reas ing the decompo s i t i o n rate of more res i s ta n t
res i dues .
IMPL I CAT I ONS FOR RES I DUE-TREAT I NG EQU I PMENT
1 . Accel era te devel opment of equ i pment capa b l e of remov i ng at l ea s t the l a rger pi eces of l ogg i ng res i dues at l owe r cos t s . 2 . I nc reased u ti l i za t i on wi l l proba bly redu ce s l a s h qua n t i ti es from regen­
era t i o n cuts ' i n young-growth ti mber so that burn i ng i s not neces s a ry for fi re
control or access for pl anti ng . When natural reg enera t i on i s d e s i red , some s i te
, preparati on mea s ures may be neces s a ry to eXpose mi neral so i l s uffi c i entl y . On
gentl e grou nd , tra c tors can eas i l y hand l e thi s opera t i on . Fo r s teep ground , how­
ever , there is a need fo r devel opi ng effi c i e n t eq u i pment for preparation of seed
ber r
CURRENT AN D PERTINENT RESEARC H PROGRAMS
ABOUT RESIDUE MANAGEMENT, NATURAL REGENERATION,
A N D GROWTH OF D OUGLAS-FIR
I . . Uni vers i ty of Bri ti s h Col umbi a , Vancou v e r
A.
B.
Soi l s Depa r tmen t and Facu l ty of Fdtes try
1.
Impact of harves ti ng on so i l propert i e s , mea n s and rate of recovery
from ha rves ti ng d i s tu rbances
2.
Stud i es of h i g h el eva t i o n soi l s
U n i v e rs i ty Resea rch Fores t
1.
2.
3.
II.
J - 32
Natural and arti fi c i a l regenera ti on
.
Mecha n i z a t i o n of s i l v i cu l tural prac t i ces
Si te prepara t i on
Canad i a n Fores try Serv i ce Vancouver Fore s t Products Labo ratory
A.
Logg i ng methods
B.
Compl ete tree u ti l i za t i on
C.
Uti l i za ti o n o f fore s t res i dues
III.
Uni vers i ty of Wa s h i ngton Col l eg e of Fore s t Resources , Seattl e
A . S i te prepara ti on and reg enera ti on
B.
Effects of sewa ge s l udge o n decompos i t i on of fore s t res i dues a nd nutri ent cyc l i ng
C . Effect of ti mber ha rves t i ng on soi l and water
D . Effect of vari ous s i l vi cul tural sys tems o n fores t res i dues and
regenera t i on
IV.
Weyerhaeuser Compa ny Researc h Center
A.
Effects of l oggi ng and s i te prepa ra t i on o n regenera t i on B . Natural regenera t i o n
V . Paci fi c Northwes t Fores t and Range Expe r i ment Sta t i on
A . Fores try Sci ences Laboratory , Ol ymp i a , Was h i ngton
1 . Shel terwood sys tems for s tand regenera t i on
2. An i mal damage reduc t i o n
B . Fores tr
Sci ences Labora tory , Corva l l i s , Oregon
1 . Regenera t i o n i n sou thwe s t Oregon
2 . Effect of ma nagement prac t i ces o n nutr i e n t and water cycl e s
C . Seattl e Un i t , Sea ttl e , Was h i n g to n
1 . Logg i ng sys tems
2.
VI .
Harves ti n g methods for l ogg i ng res i du e reducti on
Oregon State Uni vers i ty , Corva l l i s
A . Soi l s Depa rtment
1 . Nature a nd propert i es of fore s t h umus
B . School of Fo res try
1 . So i l compa c t i o n and tree growth
2 . Uti l i za t i on o f fore s t res i dues
J - 33
LITERATURE CITED
Anonymous
1 92 9 .
Seedl i ng s u rv i val on burn ed and unburned s urfaces .
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USDA For . Serv o
Portl and , Oreg .
Abee , Al bert , a nd Deni s Lavender
1 972 . Nutr i ent cycl i ng i n throughfa l l and l i tterfal l i n 4 50-ye a r-o l d
Doug l a s - fi r s ta nds . In Proceed i ng s - - Research o n coni ferou s fores t
ecosys tems - - a sympos i um , p . 1 33-1 43 , i l l u s . Pac . Northwe t For . &
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Aho , Pau l E .
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Pac i fi c Northwe s t , a s ta te-of-k nowl edge compend i um . USDA Fo r . Serv o
Gen . Tech . Rep . PNW-24 . Pac . No rthwe s t For . & Range EXp . Stn . ,
Portl and , Oreg .
A 1 1 en , S . E .
1 964 . Chemi cal a s pects o f heather burn i ng .
i l l us .
J . Appl . Ecol . 1 : 347 - 367 ,
Atzet , Thoma s , and R . H . War i ng
1 970 . Sel ecti ve fi l ter i ng of l i g ht by con i fero u s fores ts a nd ml n l mUm l i ght
energy req u i rements for reg enera t i o n . Can . J . Bo t . 48 : 21 63- 2 1 67 ,
i l l us .
Austi n , R . C . , and R . F . Strand
1 960 . The use of s l owl y-sol ubl e ferti l i zers ' i n fore s t pl a n t i ng i n the
Paci fi c Northwe s t . J . For . 58 ( 8 ) : 61 9-627 , i l 1 us .
Baker , J . , and V . H , 'Phe l ps
1 969 . Growth response a nd c hemi cal compos i ti on of Doug l a s - fi r seed l i ng s on
burned a nd unburned s o i l sampl es . For . Res . Lab . Inf. Rep . BC-X-29 ,
1 0 p . , i l l us . V i c tori a , B . C .
Berntsen , Carl M .
1 958 . A test pl a n t i ng of 2-0 and 3-0 Doug l a s - fi r trees on a s teep south sJ ope . USDA For . Serv o Pac . Northwe s t For . & Range Exp . Stn . Res . Note 1 65 , 4 p . Portl a nd , Oreg . Bever , Dal e N .
1 954 . Eval u a t i on of factors a ffec ti ng natural reproduct i on of fores t trees i n central we stern Oregon . Oreg . Sta te Boa rd Fo r . Res . Bul l . 3 , 4 9 p . , i l l us . Bol l en , Wal ter B .
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J - 34
, ,
"
Brown , G eorge W .
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i n the Paci fi c Northwest , a state-of- k nowl edge compend i um . USDA For.
Serv o Gen . Tec h . Rep . PNW-24 . Pac . Northwe s t For . & Range Exp . S tn . ,
Por tl a nd , Oreg .
'-.
Chi l ds , Thoma s W.
1 93 9 . Decay o f sl a s h o n cl ear-cu t areas i n the Dougl a s - f i r reg i on .
37 ( 1 2 ) : 955-9.59 .
.
J . For .
Cochran , P . H .
1 968 . C a n thi nn i ng sl a s h cause a n i trogen def i c i e ncy i n pumi c e soi l s of
central Oregon? USDA For . Serv o Res . Note PNW-82 , 1 1 p . Pac . North­
we s t For . & Range Exp . Stn . , Portl and , Oreg .
DeBano , L . F .. , a n d R . M. R i ce
1 97 3 . ' Wa ter - repeTl en t soi l s :
7 1 ( 4 ) : 220-2 23 , i l l us .
the i r i mpl i c a t i o n s i n forestry .
DeBel l , D . S . , a n d C . W . Ral s ton
'.
1 970 . R e l ease of n i trogen by burn i ng l i gh t for e s t fuel s .
Am . P roc . 34 ( 6 ) : 936-938.
J . For .
Soi l Sci . Soc .
Del l , John D . , a n d Frankl i n R . Ward
1 971 . Logg i ng res i due o . pougl a s - f{r reg i on c l e arcu ts - -wei ghts and
vol u mes . USDA Fgr . Serv o Res . Pap . PNW-1 1 5 , 1 0 p . , i l l us . Pac .
Northwe s t For . & Range Exp . Stn . , Portl a nd , Ore g .
.
_
D i ce , S tephen F .
1 97 0 . The bi omass and nutri ent fl ux i n the second g rowth Doug l a s -fi r
e co sys tem . Ph . D . d i s s . , Un i v . Wash . , eattl e .
D imock , Edward J . , I I . '
A n i ma l popul a t i on s and dama g e . In Env i ronmental effects of forest
1 974
res i dues management in the Pac i fi c Northwe s t , a s ta te-of-knowl edge
compend i um . USDA For . Serv o Gen . Tec h . Rep . PNW 2 4 . Pac . Northwest
F or : & Range Exp . Stn . , Por l and , Ore .
.
.
•
Dyrness , C . T
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the H . J . And rews Exper i mental Fore s t . USDA For . Serv o Res . Note
PNW-31 , 1 3 p . , i l l us . . Pac . Northwest For . & Range Exp . S tn . ,
Portl a n d , Oreg .
•
Erod i bi l i ty and ero s i on potenti a l of fore s t ·watersheds .
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,
,
.
.
:
.
,
.
"
Na t l . Sci .
,
.
1 97 2 . Soi l s u rface cond i ti ons fol l owing bal l oo n l ogg i n g . USDA For. Serv o
Res . Note PNW-1 82 , 7 p . , i l l us . Pac . Northwes t For . & . Ra ng e Exp .
S tn . , Portl and , Oreg .
,
"
J-35 ____
,
1 957 .
C . T . Youngberg , and Robert H . Ruth
Some effec ts of l og g i n g and sl a s h burn i n g on phys i ca l so i l properti e s
i n the Corval l i s wa ters hed . USDA For . Serv o Pac . Northwest F o r . &
Range Exp . Stn . , Res . Pap . 1 9 , 1 5 p . , i l l u s . Portl and , Oreg .
Edg ren , J ames W . , and Wi l l i am I . Ste i n
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dues management i n the Pac i fi c Northwe s t , a s ta te-of- knowl edge
compend i um . USDA For Serv o Gen . Tec h . Rep . PNW-24 . Pac . Northwest
For . & Range Exp . Stn . , Portl a nd , Oreg .
Fahnes toc k , George R .
1 960 . Logg i n g s l a s h fl amma b i l i ty . USDA For . Serv . , I n termt . For .
Exp . Stn . Res . Pap . 58 , 67 p . , i l l u s .
&
Range
Fore s t Soi l s Commi ttee of the Dou gl a s - f i r Reg i on
1 957 . An i n trod u c t i o n to the forest s o i l s of the Dou g l a s -fi r reg i on of the
Pac i f i c Northwest . Un i v . Wa s h . , Sea ttl e .
Fowl e r , W . B .
1 974 . f1i crocl i ma t e . In Env i ronmenta l effects of for e s t res i dues manage­
ment i n the Pac i fi c Northwest , a state-of-knowl edge compend i um .
USDA For . erv . Gen . Tec h . Rep . PNW-24 . Pac . Northwe s t For . & Ra nge
Exp . Stn . , Port l a nd , Oreg .
F ra n k l i n , J erry F . , a nd C . T ., Dyrne s s
1 969 . Vegeta t i on of Oregon a n d Was h i ngton . USDA For . Serv o Res . Pap .
PNW-80 , 21 6 p . ,, ' i l l u s . Pac . Northwe s t For . & Range Exp . Stn . ,
Portl and , Oreg .
Fredr i ksen , R . L .
'
1 971 . Compar a t i v e c hemi cal wa ter qua l i ty
natura l a d d i s tu rbed s treams
fol l owi ng l og g i ng and sl a'sh burn i ng . In Proc ee d i ngs of a sympos i um ,
Fores t l and u s e s and stream env i ronmen t 1 970 : 1 25- 1 37 , i l l us . Oreg .
State U n i v . , Corval l i s .
Fri tschen , Leo , Harl ey Bovee , Konrad Buettner, and others
1 97 0 . Slash fi re a tmosphe r i c pol l u ti on . USDA For . Serv o Res . Pa p . PNW-97 ,
42 p . , i 1 1 u s . Pac . Northwest For . & Range EXp . Stn . , Portl and ,
Oreg .
Garr i son , George A . ; and J u s t i n G . Smi th
1 974 . Ha b i ta t of gra z i ng a n i ma l s . In Env i ronmental e ffec ts of fo res t
res i dues mana gement i n the Pac i fi c Northwe s t , a s ta te-of- knowl edge
compend i um . USDA For . Serv o Gen . Tec h . Rep . PNW-24 . Pa c . North­
wes t For . & Range Exp . Stn . , Port l and , O reg .
G e s s e l , Stanl ey P . • and A . N i hat Bal c i
1 963 . Amou n t and compo s i t i on o f forest ,f l oors under Wa s h i ngton coni ferous
fore s t s . In Fores t- s o i l rel a t i on s h i ps i n North Amer i ca , p . 1 1 - 23 ,
i l l us . Corval l i s : Oreg . Sta te Uni v . Pre s s .
D . W . Co l e , a n d E . C . Ste i n brenner
1 972 . N i trogen bal a nces i n fore s t eco sys tems of the Pac i fi c Northwe s t .
Soi l B i o l . B i ochem . 5 : 1 9-34 .
.."....,- .
____
J - 36
"
,
Gratkows k i , H .
1 967 . Ecol ogi c a l con si dera t i o n s i n bru s h control . In Herb i c i des and vege­
ta t i on ma na gement , sympo s i um proceed i ng s , p . 1 24 - 1 4 0 . Corval l i s :
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Brushfi el d rec l ama t i on and type convers i on . In Envi ronmental effects
of fores t re s i d u es ma nagement in the Pac i fi c Northwes t . USDA For .
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Portl a nd , Oreg .
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a fores t ecosys tem . 1 67 p . Ph . D . d i s s . , Uni v . Was h . , Seattl e .
and Da1 9' W . Col e
----'l�97 1 . I n fi uence of s l a s h bu rn i ng on i on transport in a fo res t so i l .
we s t Sci . 4 5 ( 2 ) : 1 00-1 06 , i l l u s .
North­
Hal l i n , W i l l i am E .
1 968a . So i l mo i s ture ten s i on vari a t i o n on cu tovers i n sou thwe s tern Oregon .
USDA For . Serv o Res . Pap . PNW-58 , 1 8 p . , i l l u s . Pac . Northwes t For .
& Range Exp . Stn . , Portl and , Oreg .
1 968b . Soi l s urface temperatures on c tovers i n sou thwe s t Oregon .
Serv o Res . Note PNW :78 , 1 7 p . , i l l us . Pac . Northwe s t For.
J
Exp . Stn . , Portl a nd , Oreg .
&
USDA For .
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Hermann , R i c ha rd K . , and Wi l l i am W . Ch i l cote
1 96 5 . Effect of seedbeds o n germi n a t i o n a n d s urvi val of Dougl a s - fi r .
O reg : State U n i v . For . Res . La b . Res . pap . 4 , 28 p . , i l l us .
Hofmann , J u' l i us V .
1 924 . The natural regenera t i on of Dougl a s fi r i n the Pac i fi c Northwe s t .
U . S . Dep . Ag r i c . Dep . Bu l l . No . 1 200 , 6 2 p . , i l l u s .
Hoover , M . D . , a nd H . A . Lunt
1 952 . A key for the c l a s s i f i ca t i on of fores t h umus types .
Am . Proc . 1 6 ( 4 ) : 368-370 , i l l u s .
So i l Sci . Soc .
Howa rd , James O .
1 971 . Vol me of l og g i n g resi d ues i n Oregon , Was h i ngton , and Cal i fo rn i a - ­
i n i ti al res u l ts from a 1 969- 70 s tudy . USDA For . Serv o Res . Note
PNW-1 6 3 , 6 p . Pac . Northwest For . & Range Exp . Stn . , Portl a nd ,
.
Oreg .
I saac , L eo A .
1 938 . Fa c tors a ffec t i n g establ i s hmen t of Doug l as fi r seedl i n gs .
Dep . Agri c . C i rc . No . 486 , 45 p .
1 943 . Repr09u c t i ve ha b i ts of Dougl a s - fi r . . 1 07 p .
L a throp Pac k . For . Fou nd .
U.S.
Was h . , D . C . : Charl e s
J -37
1 949 . Can we save the seed crop? USDA For . Serv o Pac . No rthwes t Fo r .
Range Exp . Stn . Res . Note 56 , 2 p . Portl a nd , Oreg .
__
&
and Howard Hop k i n s
1 937 . T he fores t so i l of the Doug l a s - f i r reg i on and changes wrought upon
it by l oggi n g and sl a s h burn i ng . Ecol ogy 1 8 : 264-279 .
J emi son , G . M . , and Ner1 e S . Lowden
1 974 . t·1anagemen t and research i mpl i ca t i ons . In Envi ronmenta l , effects o f
fores t res i dues ma nagemen t i n the Pac i fi c Northwe s t , a s tate-of­
knowl edge compend i um . USDA For . Serv o Gen . Tech . Rep . PNW- 24 . Pac .
Northwe s t For . & Range Exp . Stn . , Portl and , Oreg .
Johnson , No rman E . , Ke i th R . Shea , and Ri c hard L . Johnsey
1 97 0 . t ortal i ty a nd deter i o ra t i o n of l ooper- ki l l ed heml ock i n we s tern ·
Was h i ngton . J . For. 6 8 ( 3 ) : 1 62-1 63 , i l l us .
Ke i j ze r , Steven de , and R i c ha rd K . Herma nn
1 96 6 . Effects of envi ronmen t on hea t to l erance of Doug l a s - fi r seedl i Q gs .
For . Sc i . 1 2 ( 2 ) : 21 1 - 2 1 2 , i l l u s .
Krueger , Kenneth W . , and Wi l l i am K . Ferrel l
1 96 5 . Comparati ve photo syn t he t i c and "re s p i rato ry responses to temperature
and l i g ht by Pseudotsu a menziesii var. menziesii a nd v a r . g uoa
seedl i ngs . Eco l ogy 46 ( 6 ) : 7 94-801 , i l l us .
Lavender , Den i s P . , Morri s H . Bergma n , and Lyl e D . Cal v i n
1 95 6 . Natural regenera t i on o n s taggered setti ngs . Oreg . Sta te Boa rd For .
Res . Bun . No . 1 0 , 36 p . , i l l u s .
.,
Lopu s h i n s ky , W . , and G . O . Kl ock
1 97 4 . Transp i ra t i on of con i fer seed l i n g s i n rel a t i on to soi l water
potent i a l . For . Sci . 2 0 : 1 81- 1 86 , i l l u s .
Mart i n , Robert E . , and Arthur P . Brac kebusch
1 974 . F i re hazard and confl a g ra t i on preven t i on . In Env i ronmental e ffect s
o f fores t res i d u e s ma nagemen t i n t h e Pac i fi c Northwe s t , a s tate-of­
kRow1 edge compend i um . USDA For . Serv o Gen . Tech . Rep . PNW- 24 .
Pac . Northwe s t For . & Range EXp . S tn . , Portl and , Oreg .
Merse reau , R . C . , a n d C . T . Dyrness
1 972 . Accel erated ma s s was t i ng a fter l og g i ng and s l a s h burn i ng in wes tern
Oregori . J . Soi l & Water Conserv . 27 ( 3 ) : 1 1 2 - 1 1 4 , i l l us .
Mi nore , Don
1. 971 . Shade benef i t s Dougl a s - fi r i n southwe s tern Oregon cutover a rea .
Tree Pl a n t . Notes 22 ( 1 ) : 22-23 , i l 1 u s .
1 972 . Germi nati on and earl y growth of coas tal tree spec i e s on orga n i c seed
bed s . USDA For . Serv o Res . Pap . PNW-1 35 , 1 8 p . , i l l us . Pac . North­
wes t For . & Range Exp . Stn . , Portl a nd , Oreg .
J -38
,
,
I
t i tchel l , Russel G . , and Charl es Sartwel l
1 974 . I ns ects and other arthropods . In Ertvi ro nmental effects of fo res t
res i dues ma nagement i n the Paci fi c Northwes t , a s ta te-of- knowl edge
compend i um . USDA For . Serv o Gen . Tech . Rep . PNW- 24 . Pac . Northwe s t
Fo r . & Range Exp . S tn . , Portl and , Oreg .
.
Moore , Duane G . , and Logan A . Norri s
1 974 . Soi l proces ses a nd i ntroduced chemi cal s . In Envi ronmenta l effec ts
of fores t res i dues ma nagement i n the Pac i fi c Northwes t , a s ta te- of­
knowl edge compend i um . USDA For . Serv o Gen . Tech . Rep . PNW-24 . Pac .
Northwe s t For . & Ra nge Exp . S tn . , Portl and , Oreg .
,
\
(
I
Morri s , Wi l l i am G .
,
1 958 . I n fl uence of s l a s h burni ng on regenera t i o n , o ther pl a n t i ng cover ,
and fi re hazard i n the Do ugl as-fi r reg i on ( a progress report ) .
USDA For . Serv o Pac . Northwest For . & Range Exp . S tn . Res . Pap .
29 , 49 p . , i 1 1 u s . Portl and , Oreg . '
1 970 . Effec ts of s l a s h burn i n 9 i n overma ture s tands of the Doug l a s - fi r
reg i o n . For . Sci . 1 6 ( 3 ) : 258-270 , i 1 1 us .
Neal , John L . , Ernes t Wri g h t , a nd Wal t r B . Bol l en
1 965 . Burn i ng Dougl a s - fi r s l as h : Phys i cal , chemi ca l , a nd mi crob i al effects
i n the so i l . Oreg . State Uni v . For . Res . Lab . Res . Pap . , 32 p . ,
i 1 1 us .
Nel son , E . E . , and G . M . Harvey
. 1 974 . D i s ea s e s . In Envi ronmental effects of forest res i dues ma nagement i n
the Pac i fi c No rthwe s t , a s tate-of- knowl edge compend i um . USDA For .
Serv o G en . Tech . Rep . PNW- 24 . Pac . Northwes t For . & Range Exp . S tn . ,
Portl and , ,Oreg .
Ra l s ton , Charl es W . , and G l yndon E . Hatchel l
1 971 . Effects of prescri bed burni ng on phys i ca l properti es of so i l .
Pre s cr i bed burni ng sympos i um proceed i ngs , p . 68-84 , i l l us .
Southea s t . For . Exp . S tn . , Ashevi l l e , N . C .
In
Reukema , Dona l d L .
1 964a . L i tter fal l i n a young Doug l as-fi r s tand a s i nfl u enced by thi nn i ng .
USDA For . Serv o Res . Note PNW-1 4 , 8 p . , i l l u s . Pac . Northwe s t Fo r .
& Range EXp . Stn . , Portl ind , Oreg .
1 964b . Some effects of freeze i nj ury on devel opment of Doug l a s - fi r .
wes t Sci . 38 ( 1 ) : 1 4 -1 7 , i l l us .
North­
Rothacher , J a c k , and Wi l l i am Lopushi nsky
1 974 . Soi l s tabi l i ty a nd wa ter yi el d and qual i ty . In Envi ronmental effects
of fo res t res i dues ma na gement in the Paci fi c Northwes t , a s ta te-of­
knowl edge compendi um. USDA For . Serv o Gen . Tec h . Rep . PNW- 24 . Pac .
Northwe s t For . & Ra nge Exp . Stn . , Portl a nd , O reg .
Rothac h e r , J a c k S . , and Jerry F . Fra nkl i n
1 964 . Ferti l i zer pel l ets i mprove growth of pl a n ted Doug l a s - fi r on an
u nfavorabl e s i te . Tree P l a n t . Notes 67 : 9 - 1 1 , i l l u s .
J-39
Ruth , Robert H .
1 974 . Regenera ti on a nd growth of wes t-s i de mi xed con i fers . In Env i ronmenta l
effec ts of fores t res i dues mana gement i n the Pac i fi c Northwe s t , a
s ta te- of-knowl edge compend i um . USDA For . Serv o Gen . Tech . Rep . PNW- 24 .
Pac . Northwe s t Fo r . & Range Exp . Stn . , Portl and , Oreg .
Seidel , K . W .
1 974 . Na tural Regenera t i o n of, ea s t-s i de con i fe r forests . In Envi ronmenta l
effects of fores t res i dues ma na gement i n the Pac i fi c Northwe s t , a
state-o f-k nowl edge compend i um . USDA For . Serv o Gen . Tech . Rep .
PNW-24 . Pac . Northwe s t For . & Range Exp . Stn . , Portl a nd , Oreg .
S i l en , Roy Ragnar
1 96 0 . Lethal s urface temperatu res and the i r i n te rp reta t i on for Doug l a s -fi r .
1 70 p . , i l l u s . . Ph . D . the s i s , O reg . State Un i v . , Co rva l l i s .
So i l Sci ence Soc i e ty of Ameri ca , Commi ttee on Term i n o l ogy
1 965 . Gl o s s a ry of so i l s c i en c e terms . So i l Sc i . Soc .
330- 351 , i l l us .
Am .
Proc . 29 (3 ) :
Sommer , Herma nn C .
1 973 . Manag i ng s teep l and for t i mber prod u c t i on i n the pa ci fi c Northwe s t .
J . For . 71 ( 5 ) : 270-273 , i l l us .
Ste i n brenner , Eugene C .
1 971 . Log g i ng sys tems
So i l con s i d erat i ons i nfl uenc i ng ma na gement pol i c i es .
t i o n . Wes t . For . & Conserv . Assoc . Proc . 1 971 :
In Wes tern reforesta
.
21 -23 .
o
Stro thma n [ Strothma nn ) , Rudol p h O .
1 97 2 . Dougl a s - fi r i n northern Cal i forn i c,t ; . Effects of s hade on g ermi na ti on ,
survi val , and growth . USDA For . Serv o Res . Pap . PSW-B4 , 1 0 p . ,
i l l us . Pac . Sou thwe s t For . & Range EXp . Stn . , Berkel ey , Cal i f .
Swanston , D . N . , and C . T . Dyrne s s 1 973 . Stabi l i ty of s teep l a nd .
J . For . 71 ( 5 ) : 264- 269 , i l l u s . Tappe i ne r , John Cummi ngs , I I
1 966 . Natura l regenera t i o n of Doug l a s - fi r (Pseudotsuga menziesii (M i rb . )
Franco va r . menziesii ) o n Bl odgett Fores t i n the mi xed con i fer type
i n the S i e rra Nevada of Ca l i forn i a . Ph . D . the s i s , Un i v . Cal i f . ,
Berkel ey . .
Tarra nt , Robert F .
1 954 . Effec t of s l a s h burn i ng on so i l pH . USDA For . Serv o Pa c . Northwest
For . & Ra nge Exp . Stn . Res . Note 1 02 , 5 p. Po rtl and , O reg .
1 956 . Effects of s l a s h bur n i ng on some so i l s of th e Dougl a s - f i r re i o n .
So i l Sci . Sot . Am . Pro c ; 20 (3 ) : 40B-41 1 , i l l u s .
and Ernes t Wri ght
1 95 5 . Growth of Dougl a s - f i r seedl i n g s after sl a s h burn i ng . USDA Fo r . Serv o
Pac . Northw s t For . & Ra nge Exp . Note 1 1 5 , 3 p . , i l l us . Portl a nd ,
Oreg .
--.=.
__
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,
Wa ga r , J . A l a n
1 974 . Recreati onal and estheti c cons i dera t i ons . In Env i ronmenta l effects
of fores t resi dues ma nagement i n the Pac i fi c Northwes t , a s ta te-of­
knowl edge compend i um . USDA For . Serv o Gen . Tech . Rep . PNW-24 . Pac .
Northwes t For . & Range Exp . Stn . , Portl and , O reg .
'f
Wagener , Wi l l i s W . , and Haro l d R . Offord
1 972 . Loggi ng s l a s h : i ts breakdown and decay at two fo res ts i n northern
Cal i fo rni a . USDA For . Serv o Res . Pap . PSW-83 , 1 1 p . , i l l us . Pac .
Southwest For . & Range EXp . Stn . , Berkel ey , Cal i f .
Wal ker , R . B . , D . R . M . Scott , D . J . Sal o , and K . L . Reed
1 972 . Terre s tri al process s tud i es i n coni fers : a rev i ew . In Proceedi ngs - ­
Research o n coni ferous fo res t ecosystems - - a sympo s i um , p . 21 1 - 225 .
Pac . Northwe s t For . & Range EXp . Stn . , Portl and , Oreg .
Wal l , Bri an R .
1 969 . Projected devel opments of the ti mber economy of the · Col umbi a -North
Pac i f i c Reg i on . USDA For . Serv o Res . Pap . PNW-84 , 87 p . , i l l u s .
Pac . Northwe s t For . & Range Exp . Stn . , Portl and , O reg .
Wa r i ng , R . H .
1 96 9 . Fores t pl ants of the eas tern S i s k iyous : the i r envi ronmental and
veg eta t i onal d i s tri buti on . Northwe s t Sci . 43 ( 1 ) : 1 - 1 7 , i l l u s .
Wri g h t , Ernes t , and Robert F . Tarra nt
1 958 . Occ ur rence of myco rrhi zae after l oggi ng and s l a s h burn i ng i n the
Dou g l a s - fi r fores t type . USDA For . S erv o Pac . Northwe s t For . &
Ra nge Exp . Stn . Res . Note 1 60 , 7 p . , i l l u s . Portl and , O reg .
Yerkes , Vern P .
1 960 . Occ urrenoe of shrubs and herbaceous vegeta t i on a fter c l earcutt i ng
o l d- g rowth Doug l a s - fi r i n the O regon Cascades . USDA For . Serv o
Pac . , Northwes t For . & Range EXp . S tn . Res . Pap . 34 , 1 2 p . Portl and ,
O re g . ,
Zavi t kovs ki , J . , Mi chael Newton , and Babi ker El - Ha s s a n
1 969 . Effec ts of s nowbrus h on g rowth of some coni fers .
242 - 246 , i l l us .
J . Fo r . 67 ( 4 ) :
J-41