P. 1 

# OAR Box 1781 Prepped by Ollie Stewart



# Document

Number: 

# 9 ) 11-1- 1 Docket Number: 

# A-90-37

Printed 10/29/2008 10:46:18 AM Sheet 9 of 142P. 2



### Unite d State s Departmen t o

f Agriculture Fores t Service Northeaster n Fores

t Experiment Statio n Genera l Technica l Repor t NE-15 1 

# ml TL-TJ-I L



# Screenin g Procedur

e t o Evaluate Effects o fAi rPollutio n o n Easter n Regio n Wildernesses Cite d as Class I Ai rQualit

yAreas Mar yBet h Adam s Dal e S . Nichol s C . Anthon yFedere r Keit h F . Jense n Harr yParrot tP. 3



## Abstrac t Th e USD AForest Service' s Easter n Regio n manages eigh twildernes s areas that hav e bee n designate d as Class I ai rqualityareas b yth e Federa l Clea n Ai rAct . A s par t o fthi s legislation , Federa l lan d manager s ar e require d t o consul twit h ai r pollutio n regulator

s o n th e potentia l impacts o fpropose d ai rpollutio n emissions includin g phytotoxi cgase s an d acidi cmaterials—o n th e ai rquality-relate d value s (AQRVs) o

fthes e wildernesses . Application s fo rPreventio n o fSignifican t Deterioratio n (PSD) permits mus t b e reviewe d an d commente d o n b yth e Federa l lan d manager . Thi s publicatio n provide s th e manage rwit h a procedur e to rapidl y scree n thes e application s t o determin e whic h shoul d hav e detaile d review . Th e screenin g approac h i s a regiona l modificatio n o fa nationa l mode l develope d b y th e Forest Service i n 1988 . I n 1990 , th e Eastern Region , Northeaster n an d Nort h Centra l Fores

t Experimen t Stations , an d th e Northeaster n Area , State an d Private Forestr ysponsore d a worksho p o fscientist s an d lan d manager s t o obtai n advice o n regionalizin g thi s screenin g procedure . Tw o loadin g level s fo rvariou s pollutants wer

e established . Th e "re d line " i s th e loadin g leve l abov e whic h AQRV s ar e expecte d t o b e adversel yaffected . Th e "gree n line " i s th e loadin g leve l belo wwhic h n o advers e impacts ar e expected . Withi n th e intermediat e "yello wzone " effects are uncertain . Th e publicatio n describe s th e criteri a use d t o establis h re d an d gree n lin e values , th e AQRV s fo reac h wilderness , an d th e relatio n betwee n th e two .



## Th e Author

s MAR YBETH ADAM S i s a Supervisor ySoi l Scientistwit h th e USD AFores t Service , Northeaster n Fores t Experimen t Statio n a

tParsons , Wes

tVirginia . DAL E S . NICHOLS i s a Researc h Soi l Scientistwit h th e Nort h Centra l Fores t Experimen t Statio n a

t Gran d Rapids , Minnesota . C . ANTHON YFEDERE R i s a Researc h Foreste rwit h th e Northeaster n Fores t Experimen t Statio n a

t Durham , Ne

wHampshire . KEIT H F . JENSE N i s a Supervisor yPlan t Physiologistwit h th e Northeaster n Fores t Experimen t Statio n a

t Delaware , Ohio . HARR YPARROT

Ti s Regiona l Hydrologist wit h th e USD AFores tService' s Eastern Regio n a

t Milwaukee , Wisconsin . Manuscript receive d fo rpublicatio n 1 Februar y199 1

Northeaster n Fores

t Experimen t Statio n 5 Radno rCorporate Cente r 100 Matsonfor

d Road , Suite 200 P O Bo x677 5 Radnor , Pennsylvani a 19087 Septembe r199 1P. 4 

## Introductio n Fores tServic e lan d manager s nee d informatio n abou tth e effect s o fai rpollutio n o n wildernes s area s tha thav e bee n designate d a s Clas s I b yth e Clea n Ai rAc t(Publi cLaw 95-95) . Regulation s pursuan t t o tha tAc trequir e tha tth e U.S . Environmenta l Protectio n Agenc yan d Stat e ai r pollutio n emissio n regulator s consul t wit h "federa l lan d managers " (FLMs ) o n potentia l impact s t o th e "ai rquality relate d values " (AQRVs ) o fClas s I areas . I n turn , manager s o fClas s I area s ar e require d t o revie wpreconstructio n application s fo rai rpollutio n emissio n permits . Calle d Preventio n o fSignifican t Deterioratio n (PSD ) permits , thes e ar e require d fo r"major " ne wai rpollutio n emissio n source s an d majo rmodification s ofexistin g sources . Majo ri s define d her e a s certai n catagorie s o fsource s (fo rexample , coal-fire d powe rplants ) emittin g mor e tha n 10 0 ton/y ro fan y pollutant , o ran yothe rsourc e emittin g mor e tha n 25 0 ton/y r (4 2 U.S.C . 74779(1)) . Ther e ar e eigh tNationa l Fores tClas s I ai rqualit yarea s i n th e USD AFores t Service' s Easter n Regio n (Regio n 9 ) (Fig . 1) . Eac h area , designate d a s wildernes s befor e th e 197 7 amendment s t o th e Clea n Ai rAct , i s a mandatoryClas s I are a becaus e i ti s large rtha n 5,00 0 acre s (Clea n Ai rAc t Sect . 162) . Th e worksho p upo n whic h thi s reporti s base d wa s precede d b ya meetin g o fNationa l Fores tmanager s an d scientist s i n 198 8 atth e Institut e o fEcosyste m Studjes , Millbrook , Ne wYork . At tha tworkshop , attendee s develope d a green-yellow-re d (G-Y-R ) screenin g mode l (Fo x e t al . 1989 ) tha t suggest s thre e alternativ e conclusions :

•Advers e impact s ar e unlikely : pollutan tloading s les s tha n gree n line . •Uncertai n impact : pollutan tloading s i n yello wzone . •Predicte d advers e impact : pollutan tloading s wil l excee d re d line . Th e purpos e o fthi s report i s t o describ e adaptatio n o fa G-Y- R mode l fo rEaster n Regio n Clas s I areas , an d t o describ e inventoryan d monitorin g informatio n need s an d researc h need s identifie d b yworksho p attendees . Wildernes s Ac t Th e Wildernes s Actof196 4 (Publi cLaw88-557 ) establishe d th e Nationa l Wildernes s Preservatio n Syste m "t o secur e fo r th e America n people a n endurin g resourc e ofwilderness. " Th e Act describe s wildernes s as : ...undevelope d Federa l lan d retainin g it s primeva l characte r an d influence , withou tpermanen t improvement s o rhuma n habitation , whic h i s protecte d an d manage d s o a s t o preserv e it s natura l condition s an d whic h generall yappear s t o hav e bee n affecte d primaril ybyth e force s ofnature , wher e th e influenc e o fpeople i s substantiall yunnoticeable . Th e Fores tServic e i s responsibl e fo rensurin g th e preservatio n o fth e wildernes s characte rofcongressionall y designate d Nationa l Fores t wildernesses . Lightning-cause d fire s ar e allowe d t o bur n unde rprescribe d conditions , bu t roads , motorize d equipmen tan d mechanica l transport , landin g o faircraft , mos tcommercia l enterprises , an d permanen t structure s an d installation s ar e prohibited . Specia l exception s i n som e wildernes s legislatio n allo wfo r minera l exploratio n an d development , acces s t o privat e land , maintenanc e an d us e o fairstrips , and , i n Alaska , nativ e us e fo rsubsistence . Clea n Ai rAc t Th e Clea n Ai rAc t(CAA ) amendment s o f197 7 establishe d a progra m fo rth e preventio n o fsignifican t deterioratio n o fai r quality . Certai n wildernesse s an d Nationa l Park s establishe d befor e Augus t 197 7 wer e designate d b yth e CAAa s mandatoryClas s I areas . AClas s I designatio n allow s smal l increment s o fadditiona l ai rpollutio n abov e baselin e level s withi n th e are a s o lon g a s th e nationa l ambien tai rqualit y standard s ar e complie d wit h an d th e AQRV s o fth e Clas s I are a ar e no t adversel yaffected . Th e baselin e level s ar e thos e existin g a t th e tim e o fth e firs tPS D applicatio n fo ra n are a (4 2 U.S.C . 7479(4)) . Th e allowabl e increment s ar e give n i n 4 2 U.S.C . 7473 . Wildernesse s establishe d afte r Augus t7 , 1977 , ar e Clas s I I areas , a s i s mos t o fth e country . Clas s I I area s ma yreceiv e a large rincremen t ofai r pollution . State s ma yredesignat e thes e Clas s I I area s t o Clas s I , bu tredesignatio n t o Clas s I ha s no t occurre d fo r an yEaster n Regio n Nationa l Fores t Clas s I I area . Th e CAAcharge s th e FL M wit h responsibilit yfo rprotectin g th e AQRV s ofClas s I areas . Addresse s o fFores t Servic e official s wit h responsibilit yfo rth e Clas s I area s o fth e Easter n Regio n ar e include d i n Appendi xII . AQRV s ar e feature s o rpropertie s tha t ar e importan t fo rpreservin g wildernes s characte ran d tha t coul d b e adversel yaffecte d b yai rpollution . A n advers e impac t t o AQRV s i s define d a s a n impac tofmagnitud e suc h tha tth e purpos e fo rwhic h th e are a wa s establishe d a s wildernes s wil l no t b e met . Ne wsourc e an d majo rmodificatio n permi tapplicant s submi t plan s t o th e ai rpollutio n emissio n regulatory authoritie s (EP Ao rStat e wit h EP Aoversight) . Whe n a propose d source' s emission s mayhav e a n impac t o n a Clas s I area , regulator s ar e require d t o notif yth e FLM . Th e FL M the n evaluate s potentia l AQR Vimpact s an d consult s wit h th e regulator s o n whethe reffects o n th e Clas s I are a ar e adverse . Apermi t shal l no t b e issue d "i n an ycas e wher e th e Federa l Lan d Manage rdemonstrate s t o th e satisfactio n ofth e Stat e tha t th e emission s fro m suc h a facilit ywil l hav e a n advers e impac to n th e ai rquality-relate d value s (includin g visibility ) o fsuc h lands... " (CAASectio n 16 5 (d)) . Apermi t mayb e issue d eve n i fClas s I increment s wil l b e exceeded , bu t Clas s I I increment s wil l b e complie d wit h "i n an ycas e wher e th e owne ro roperato rofsuc h a facilit ydemonstrate s t o th e satisfactio n o fth e Federa l Lan d Manager , an d th e Federa l Lan d Manage rs o certifies , tha t th e emissio n increase s wil l hav e n o advers e impac t t o th e ai rquality-relate d value s o fsuc h land s (includin g visibility)... " (CAASectio n 16 5 (d)) . Th e FL M migh thav e a s fe wa s 3 0 day s t o evaluat e impact s t o AQRV s an d respon d t o th e regulatory authorit yafte ra permi t applicatio n i s determine d t o b e complete .

### r

o Boundar yWater s Cano e Are a 

# FORESTS AN D CLAS S I AI R QUALITYAREA S

Lye^Broo k

Wildernes s

NATIONA LFOREST S EASTER N REGIO N

ICA U 10 0 

### Hercule s Glade s Wildernes s Figure 1.—Class I area s i n USDAForest Service' s Easter n Region .P. 6

Regiona l Worksho p Objective s Objective s o fth e Fores tServic e i n holdin g th e regiona l worksho p wer e to : 1 . Obtai n advic e o n screenin g criteri a fo rth e AQRV s of eac h Easter n Regio n Clas s I area . 2 . Publis h a report tha t ca n b e use d b yNationa l Fores t manager s t o identif yscreenin g criteri a fo rassessin g th e impact s t o AQRV s an d tha tdescribe s th e rational e fo r criteri a selection . Prio rt o thi s workshop , th e Nationa l Fores tstaffha d develope d genera l wildernes s an d AQR Vdescription s fo rth e eigh tClas s I wildernes s area s (se e Appendi xI) . Visibility , th e onl yAQR Vspecificall ymentione d i n th e Clea n Ai rAct , i s importan ti n al l o fth e Easter n Regio n Clas s I area s excep t Rainbo wLak e Wildernes s o fth e Chequamego n Nationa l Forest . However , establishin g screenin g criteri a fo rvisibilit yi s reserve d fo ra separat e nationa l workshop . Scientist s investigatin g th e effects o fai rpollutio n o n fores t an d aquati cecosystem s wer e invite d t o participat e a tth e regiona l workshop , a s wer e representative s o fnumerou s organization s wit h a n interes t i n forests , wilderness , ai r quality , an d PS D permitting . Staffo fth e si xEaster n Regio n Nationa l Forest s wit h Clas s I ai rqualit yareas , th e Regiona l Office , th e Fores t Servic e Souther n Region , an d th e Washingto n Offic e als o wer e invited . Worksho p participant s ar e liste d i n Appendi xII . I n developin g PS D screenin g guidelines , terrestria l an d aquati cecosystem s wer e initiall yconsidere d separately . Worksho p attendee s wer e divide d int o terrestria l an d aquati cecosyste m groups , an d eac h grou p wa s subdivide d int o tw o team s whic h addresse d th e PS D screenin g proces s individually . Eac h ecosyste m grou p me tan d identifie d area s o fagreemen tan d area s ofdivergen topinio n an d the n develope d inventoryan d monitorin g informatio n need s an d priorit yresearc h needs . Individua l participant s als o offere d advic e t o th e chairperso n o fthei rteam ; chairperson s di d no t attemp t t o establis h a consensus . Eac h ecosyste m grou p approache d th e tas k differently , primaril ybecaus e o fdifference s i n availabl e informatio n an d curren t knowledg e abou t th e systems . Th e terrestria l ecosyste m grou p determine d tha tlan d manager s ca n bes t determin e impac tcriteri a fo rterrestria l AQRV s an d tha t th e criteri a wil l varyconsiderabl yamon g th e Clas s I areas . Thus , th e grou p focuse d o n providin g a decisionmakin g frame wor k an d genera l resource s fo revaluatin g possibl e impact s o n AQRVs . Becaus e acidificatio n effect s o n aquati csystem s ar e bette runderstoo d tha n fo rterrestria l systems , th e aquati c ecosyste m grou p conclude d tha t sufficien tinformatio n i s availabl e t o establis h re d line-gree n lin e value s fo rth e eigh t Clas s I areas . Bot h terrestria l an d aquati cecosyste m group s agreed o n th e nee d fo rcertai n basi cinformatio n abou tcurren tai r qualit yan d predicte d changes . Participant s i n bot h group s note d th e lac k

o fbasi cinformatio n fo rth e Clas s I area s an d th e uncertaint yo fcurren t knowledg e fo rpredictin g effects . Therefore , worksho p product s include d identificatio n o f inventoryan d monitorin g informatio n need s an d priorit y researc h needs . 

## Screenin g Approac h Th e followin g four-ste p screenin g approac h wa s identified : 1 . Identif yth e AQRVs . Th e FLM s mus t d o this . 2 . Obtai n Resourc e Information . T o evaluat e a PS D applicatio n fo rpossibl e effect s o n Clas s I are a AQRVs , th e FL M require s informatio n includin g a n inventoryo fflor a an d faun a (communities , species , an d gener a list s fo rbot h wildlif e an d plants , an d threatene d an d endangere d specie s presen t o n th e wildernes s area) ; soil s (p H o fuppe rhorizons , catio n exchang e capacity , bas e saturation , tota l bases) ; wate rresource s (hydrolog yo flake s an d streams , wate r chemistryinformation : pH , aci d neutralizin g capacity , bas e cations , sulfate , aluminum) ; an d ai rqualit y(concentration s o fozon e an d sulfu rdioxide , an d estimate s o fnitroge n an d sulfu rloadin g t o th e ecosystems) . I fthi s informatio n i s no t alread yavailable , obtainin g thi s informatio n shoul d b e a n immediat e priority . 3 . Determin e Exposur e o fAQRV s t o Ai rPollution . Manager s us e predicte d incremen t i n emission s an d curren t level s o fai rpollutio n exposur e o n th e wildernes s t o calculat e th e tota l exposur e (o rloading ) tha t ca n b e expecte d a s a resul t o fapropose d facility . Applicant s wil l provid e informatio n o n th e projecte d emission s fro m ne w facilities . I finformatio n o n ozone , sulfu rdioxid e concen trations , an d N an d S loading s ar e no tprovided , th e FLM s shoul d immediatel ynotif yregulator s tha t th e applicatio n i s incomplete . FLM s shoul d reques ttha tregulator s evaluat e ai rpollutio n emission s an d projections . Th e Fores tServic e ma ynee d t o convert th e informatio n provide d b yth e applicant s t o value s tha treflec t effect s o n th e th e entir e ecosystem . Cumulativ e atmospheri cdepositio n shoul d b e considere d an d concentratio n value s shoul d b e represen tativ e ofusual ambien t ai rqualit yan d meteorologica l condition s an d ai rpollutio n episodes . I n cas e o fdoub t abou t usual conditions , worst-cas e ai rqualit yan d meteorologica l condition s shoul d b e used . 4 . Determin e Impact o n AQRVs . Th e FLM s compar e th e tota l cumulativ e exposur e wit h th e evaluatio n criteri a (re d an d gree n lines ) fo rth e sensitiv e wildernes s component s tha t ar e AQRVs . Thes e criteri a ca n b e used , i n consultatio n wit h th e regulator , t o determin e i flevel s are : (1 ) Sufficientl y hig h tha t impact s ar e predicte d (abov e th e re d line) ; (2 ) Sufficientl ylo wtha timpact s ar e no texpecte d base d o n curren tknowledg e (les s tha n gree n line) ; o r(3 ) Withi n th e "yello wzone " an d impact s ar e uncertai n bu tth e probabilit y ofadvers e impact s increase s a s red-lin e criteri a ar eP. 7

approached . I t i s critica l tha t a cumulativ e impac t analysi s b e done . Eve n wit h decrease s i n acidi cai rpollutan t loadin g o fClas s I area s tha t ma yresul tfro m 199 0 amendment s t o th e CAA , advers e impact s o n AQRV s ca n continue . Aquati c an d terrestria l evaluation s shoul d b e considere d an d compare d accordin g t o th e relativ e importanc e o fspecifi c AQRV s withi n th e Clas s I area . Althoug h worksho p participant s generall yagree d t o th e approac h describe d i n thi s report , som e individual s disagree d wit h th e screenin g approac h develope d b yFo xe t al . (1989) . PS D permi tapplicant s ma ychoos e t o us e mor e comple xmodelin g approache s an d ther e b yproduc e mor e precis e answers . 

## Curren t Level s o

fPollutio n Th e PS D permi tscreenin g proces s focuse s o n tw o type s o f pollutants , phytotoxi cgase s an d acidi cmaterials . Th e phytotoxi cgase s o fconcer n ar e ozon e (O3) an d sulfu r dioxid e (S0 2 ) . Th e acidi cpollutant s includ e severa l form s of sulfu r(S ) an d nitroge n (N) . Dat a need s fo rth e screenin g proces s are : 1 . Ozone : Secon d highes thourl yaverag e concentration s durin g th e growin g season . 2 . Sulfur : Averag e annua l S0 2 concentration s o r3-hou r maximu m S0 2 concentrations ; Tota l S deposition : precipitation , drydeposition , an d clou d wate rdeposition . 3 . Nitrogen : Tota l N deposition : precipitation , dry deposition , an d clou d wate rdeposition . Estimate s o fcurren tai rconcentration s an d depositio n rate s o fthes e pollutant s ar e show n i n Table s 1-3 . Th e ozon e concentration s (Tabl e 1 ) i n som e Clas s I area s wer e estimate d fro m nearb ymonitorin g station s i n th e EP AAIR S (Aerometri cInformatio n an d Retrieva l System ) networ k (som e analyse s provide d b yAlle n Lefohn , AS LAssociates , Helena , MT) , an d fro m Fores tServic e ozon e monitor s nea r th e Clas s I areas . Othe rozon e value s wer e provide d b yth e Appalachia n Mountai n Club , Universit yo fMassachusetts , an d Wisconsi n Departmen to fNatura l Resources . Mea n annua l S0 2 concentration s (Tabl e 2 ) wer e derive d fro m th e Regiona l Aci d Depositio n Mode l (RADM ) use d by th e Nationa l Aci d Depositio n Assessmen t Progra m (NAPAP ) 199 0 assessment , an d provide d b yRobi n Dennis , Atmospheri cScienc e an d Modelin g Division , U.S . EPA , Researc h Triangl e Park , Nort h Carolina . Tabl e 1 .—Ozon e concentrations , secon d highes t 1-h raverage 8 Clas s I are a GreatGulf

/ Pres . Range-Dr

yRiver" 5 Ly e Brook 1 1 Doll ySods/Otte rCree k Rainbo wLake c BWCA W Hercule s Glade s Elevatio n Hig h Low Hig h Low Low Ozon e concentratio n

198 9

12 9 7 4 10 0 10 1 10 3 8 4 8 0 6 4 ppb 198 8

145 9 7 N A 12 5 14 6 9 9 10 1 8 3

aEPAAerometri cInformatio n an d Retrieva l Syste m networ k data . b Dat a provide d byAppalachia n Mountai n Clu b an d Universityof Massachusetts . cDat a provide d b yWiisconsi n Departmen to fNatura l Resource s (Florenc e Countysite) . Tabl e 2.—Mea n annua l SO , concentrations , 1982-85 8 Clas s I are a Grea tGulf/Pres . Range-DryRive r Ly e Broo k Doll ySods/Otte rCree k Rainbo wLak e BWCA W Hercule s Glade s S0 2 concentratio n ug/m 3 4. 0 7. 3 20. 3 2. 4 1. 1 3. 0

aDerive d fro m Regiona l Atmospheri cDepositio n Mode l (RADM) .

B BP. 8

Sulfu ran d nitroge n depositio n rate s (Tabl e 3 ) ar e show n fo r we t depositio n (rai n an d snow) , drydeposition , an d drople t o rclou d deposition . Fo rwe tdepositio n w e use d dat a fro m th e Nationa l Atmospheri cDepositio n Network/Nationa l Trend s Networ k

(NADP/NTN ) t o estimat e mean , volume weighte d S0 4 -S , N0 3 -N , an d NH 4 - N concentration s i n th e rai n an d sno wateac h Clas s I area , the n multiplie d concentration s b ymea n annua l precipitatio n amount s t o estimat e annua l we t S an d N depositio n rate s fo reac h area .

Tabl e 3.—Estimate d mea n annua l S an d N depositio n rate s Clas s 1 are a Grea tGulf/ Pres . Range Dr yRive r Ly e Broo k Doll ySods / Otte rCree k Rainbo wLak e BWCA W Hercule s Glade s Eleva t m Hig h Lo w Mea n Hig h Lo w Mea n Hig h Lo w Mea n Mea n Mea n Mea n Sulfu rdepositio n o n Wet aDry b 175 0 1 0 27 5 9 85 0 1 1 25 0 1 0 125 0 1 5 57 5 1 3 37 5 4 55 0 3 32 5 6 2

3 3 3 6 6 2 2 3 Coud c 1 0

- 3 * " 5 —

-

-

- Tota l kn/ 2 2 1 1 1 6 1 7 1 3 1 4 2 6 1 9 2 1 6 5 9 Nitroge n Wet aDry* 1 ha/hr— 6 5 6 5 1,1 . T O 4 3 5 3 3 3 3 4 4 3 2 3 depositio n Cloud 0 Tota l 6 1 5 8 1 1 2 1 1 

## a 9 

### 4 m

- 1 4 1 6 7 5 8

aFro m NADP/NT N networ k data . We t depositio n rate s ar e th e product s o fmea n annua l precipitatio n amount s an d mea n S an d N concentration s i n precipitation . Mea n concentration s wer e estimate d fro m isoplet h map s derive d fro m mea n volume-weighte d concentration s a tNAD P sites . b Derive d fro m Regiona l Atmospheri cDepositio n Mode l (RADM) , provide d b yRobi n Dennis , EPA , Researc h Triangl e Park , NC . cEstimate d fro m high-elevatio n depositio n dat a fro m severa l Northeaster n U.S . sites , a s summarize d b yLovet t an d Kinsma n (1990) . d Estimate d fro m CORE/Satellit e sit e data , a s presente d b ySisterso n e t al . (1990) . Drydepositio n o fS an d N occur s mostl ya s S0 2 an d HN0 3 gases . Estimate s o fdr yS depositio n wer e derive d fro m th e RAD M mode l an d provide d b yRobi n Dennis . Measurement s o fdr yN depositio n a t th e eigh t CORE/Satellit e site s indicat e tha t dr yN depositio n i s abou t 3 5 percen to fwe tplu s dr yN depositio n i n th e Northeast , an d abou t4 5 percen to fwe t plu s dr yN depositio n i n th e Midwes t (Sisterso n e t al . 1990) . W e use d thes e value s t o estimat e dr yN depositio n o n eac h Clas s I area . A t high-elevatio n sites , concentration s o fS0 4 , N0 3 , an d NH 4i n clou d wate rar e 5 t o 2 0 time s greate rtha n i n precipitation . Site s abov e abou t1,00 0 m i n elevatio n ca n receiv e a s muc h S an d N fro m clou d depositio n a s fro m we t deposition . W e use d depositio n dat a fro m severa l high elevatio n site s i n th e Easter n Unite d States , a s summarize d b yLovet t an d Kinsma n (1990) , t o estimat e clou d depositio n o n th e high-elevatio n portion s o fth e Clas s I wildernes s area s i n Vermont , Ne wHampshire , an d Wes t Virginia , location s fo rwhic h ther e ar e n o actua l clou d depositio n data . Averag e annua l we t depositio n ha s bee n changin g ove r time . Emissio n o fS0 2 i n th e Easter n Unite d State s ha s decline d slightl yove rth e pas t 1 5 years , an d S0 4 deposition , at leas t at th e long-term stud ysit e atHubbar d Broo k i n Ne wHampshire , ha s decrease d proportionall y (Driscol l e t al . 1989) . Emissio n an d depositio n o fN0 3 i s constan t o rcontinue s t o increase . Fores tmanager s nee d t o b e awar e o fth e S0 4decreas e an d o fth e year s ove r whic h averag e value s hav e bee n calculated . Year-to-yea r variatio n i n depositio n i s large , s o man yyear s ofrecor d ar e neede d befor e statisticall ysignifican t trend s ca n b e detected .

## Terrestria l Ecosystem s P. 9

Potentiall ySensitiv e Component s Sulfu rca n affec ta terrestria l ecosyste m i n tw o ways : direc t effect s o fS0 2 an d indirec t effect s o ftota l S loading . Sulfu r dioxid e ma yno taffec t th e soil s o fa n ecosyste m bu tca n hav e significan timpact s o n th e healt h an d vigo rofsom e plan t species . Fo rexample , aspe n (Populus) exhibi t lea f injuryan d reduce d growt h whe n expose d t o S0 2 (Davi s an d Wilhou r1976) . Tota l S loadin g include s al l form s o fS tha t ente ra n ecosystem : we t sulfate , dr ysulfate , an d S0 2 . Sulfat e form s o fS ma yb e detrimenta l t o wildernes s ecosystem s b yremovin g bas e cation s fro m soils , causin g change s i n th e soi l solutio n an d increasin g th e leachin g o f nutrient s fro m th e ecosystem . Th e leachin g o fcalciu m an d othe rbase s fro m soi l exchang e sites , whic h ca n resul t fro m elevate d sulfu rdeposition , increase s th e acidit yofth e soi l solution , decreasin g th e availabilit yo fnutrient s fo rplan tgrowth . Th e reductio n i n p H als o wil l increas e th e concentratio n o faluminu m i n th e soi l solution , whic h ca n lea d t o aluminu m toxicity . Aluminu m toxicit yeffect s ma yb e intensifie d b ylo wlevel s ofcalciu m whic h ca n occu rafte rlon g period s ofhig h loading s of sulfat e an d nitrate . Nitrogen , unlik e sulfur , i s a growth-limitin g nutrien ti n man y fores t ecosystem s an d doe s no taccumulat e i n inorgani c form s i n th e soil . I t i s rapidl yincorporate d int o biologica l component s o fth e ecosyste m suc h a s plants , animals , an d microorganisms . Lo wlevel s ofnitroge n depositio n i n wildernes s area s ma yinitiall ycaus e increase d growt h an d vigo ro fth e vegetation . However , a s nitroge n loadin g continues , a n imbalanc e o fnutrient s i n th e ecosyste m ma y occu ran d th e leachin g o fnitrat e fro m th e ecosyste m ma y increase . A n imbalanc e i n nutrient s coul d resul t i n specie s replacemen t du e t o difference s i n nitroge n efficiencie s an d t o change s i n physiologica l processe s suc h a s dormanc y initiation . Nitroge n depositio n i n exces s ofwha tth e biologica l system s ca n utiliz e lead s t o nitrificatio n an d increase d leachin g o fnitrat e an d associate d cations . Whe n a syste m reache s thi s poin to fnitrat e leaching , i ti s considere d nitroge n saturated . Ozon e i s no t forme d directl yat poin tsource s an d thu s i s no t a PS D incremen t pollutant . However , i tshoul d b e evaluate d i n al l permi t application s a s i ti s considere d th e mos t widesprea d an d phytotoxi cai rpollutant . I t i s produce d i n th e environmen tb yth e photochemica l reactio n betwee n NO xan d hydrocarbons , wit h th e latte ra "criteria " pollutant . Ambien tozon e concentration s i n som e area s ofth e country ar e sufficientl yhig h t o caus e visibl e injury , reduc e photosynthesi s an d growth , an d induc e prematur e lea f senescenc e o fman ysensitiv e plan tspecies . Example s ofvegetatio n tha t ma yb e sensitiv e t o ozon e o r sulfu rdioxid e ar e liste d i n Table s 4 an d 5 . Thes e ar e no t exhaustiv e listing s o fal l potentiall ysensitiv e species , no r ar e the ylist s ofplant s tha talway s wil l b e sensitiv e t o ai r pollution . Rather , the yca n b e use d b ymanager s t o asses s whethe rther e i s a likelihoo d o fsensitiv e vegetatio n o n th e wildernes s area . Littl e i s know n abou t th e sensitivit yt o thes e tw o pollutant s o frar e an d endemi cplan t specie s an d understoryan d shrubb yvegetation , an d ther e i s littl e informatio n o n th e sensitivit yofterrestria l invertebrat e o r vertebrat e population s t o thes e pollutants .

Tabl e 4.—Partia l list o

ffores t specie s sensitive t o ozon e an d sulfu rdioxide 8 Commo n nam e Scientifi cnam e

SENSITIV E T O OZON E Gree n as h (Fraxinus pennsylvanica) Whit e oa k

(Quercus alba) Whit e pin e (Pinus strobus) Jac k pin e (Pinus banksiana) Virgini a pin e (Pinus virginiana) Tulip-popla r(Liriodendron tulipifera) Blac k cherr y(Prunus serotina) b - c Whit e as h (Fraxinus americana) 0 Milkwee d (Asclepias sbriaca) b - c Aste r(Aster spp.) b Blueberry(Vaccinium spp.) c Elderberry(Sambucus canadensis^ SENSITIV E T O SULFU R DIOXID E Bigtoot h aspe n Tremblin g aspe n Yello wbirc h Whit e pin e Jac k pin e (Populus grandidentata) (Populus tremuloides) (Betula alleghaniensis) (Pinus strobus) (Pinus banksiana)

aExcerpte d fro m Davi s an d Wilhou r(1976 ) unles s otherwis e indicated . b Base d o n observation s offolia rsymptom s i n Clas s I wildernes s area s i n Whit e Mountai n Nationa l Fores tan d Gree n Mountai n Nationa l Fores t (Smit h an d Mannin g 1990) . cBase d o n observatio n o ffolia rsymptom s i n Otte rCree k an d Doll ySod s wildernes s areas , Monongahel a Nationa l Fores t (Jackso n an d Arbucc i 1989) .P.1 0

Tabl e 5.—Partia l lis t o flichen s sensitiv e t o sulfu rdioxide . Th e mos t sensitiv e specie s ar e presen t onl ybelo w4 0 ug / m 3 (averag e annua l levels) . Th e column s o fnumber s afte r th e specie s names ar e th e publishe d limit s o fpresenc e an d absenc e i n u g SO , /m 3 Specie s Bryoria furcellata Bryoria implexa Bryoria trichodes Caloplaca

flavorubescens Catillaria griffithii Cetraria chlorophylla Cladonia bellidiflora Dimerella

lutea Evernia divaricata Hypogymnia

tubulosa Lecanactis

abietina Lecidea nylanderi Lecidea vemalis Lobaria pulmonaria Ochrolechia

pallescens Physcia semipinnata Ramalina

americana Ramalina

calicaris Ramalina

fraxinea Rhinodina

papillata Usnea filipendula Usnea florida Usnea variolosa Xanthoria

candelaria Presence/absenc e

1 3 t o 26/2 6 t o 5 2 1 0 t o 30/ - 1 3 t o 26/2 6 t o 5 2 30/3 5 26/ - 1 0 t o 30/ - 8/1 6 t o 2 4 30/ - 10/ - 1 0 t o 30/ - 10/ - 13/1 3 t o 2 6 26/2 6 t o 3 4 26/2 6 t o 3 4 1 6 t o 24/ - 30/3 5 13/1 3 t o 2 6 30/3 5 30/3 5 13/1 3 t o 2 6 1 0 t o 30/ - 30/ - 26/ - 1 6 t o 24/ - Referenc e 3 6 3 1, 6 2 6 8 1 6 6, 8 6 3 4 1,4,5, 6 8 1 3 1,6*, 7 3 6 1 2 8 1 . Hawkswort h an d Ros e 1970 . 2 . LeBlan c1969 . 3 . LeBlan cetal . 1972 . 4 . LeBlan cetal . 1974 . 5 . Nas h 1976 . 6 . Tras s 1973 . 7 . Hawkswort h an d Ros e 1976 . 8 . Johnso n 1979 . I n general , site s tha tar e th e mos t sensitiv e t o increase d sulfu rloadin g ar e thos e mos t likel yt o exhibi teffects o f increase d level s o fsulfu ro n soils : leachin g ofbases , dro p i n pH , an d increase d A l solubility . Thes e migh tinclud e site s wit h shallo wsoil s o rthos e wit h soil s wit h lo wbas e saturation . Soil s develope d fro m outwas h sand s o rsandston e weathering , coars e soil s ove rbedrock , etc . probabl yar e th e mos t susceptible . Soil s derive d fro m limestone,.suc h a s thos e foun d i n th e Hercule s Glade s Wildernes s Area , ar e no t likel yt o b e susceptibl e t o th e effects o fincrease d deposition . Soi l acidificatio n i s discusse d i n greate rdetai l i n th e sectio n o n aquati cecosystems . Wildernes s soil s tha t alread yar e N-saturate d o rar e severel yN-limite d ma yb e sensitiv e t o increase d nitroge n loading . On e exampl e o fa nitrogen-saturate d communit yi s th e high-elevatio n spruce-fi rforest s i n th e souther n Appalachians . Als o a t ris k ar e old-growt h communitie s tha t us e smal l amount s o fnitroge n o rrecycl e larg e amount s i n litterfall . Shallo wsoil s o rsoi l o flo wbas e saturatio n ma yb e susceptibl e t o chang e (catio n leaching , acidification , mobilizatio n o fmeta l ions ) wit h increase d N loading . However , dee p soil s wit h hig h bas e saturatio n wil l b e affecte d b yN leachin g onl yafte rlon g periods . Anothe rscenari o i n whic h additiona l nitroge n coul d hav e a n effec t entail s nitroge n actin g a s a fertilizer : thi s ca n b e a negativ e o ra positiv e effect . Thes e impact s canno t b e assesse d ove rth e short term . Fo rexample , i fa particula r plan t associatio n i s foun d onl yo n infertil e sites , continuou s addition s o fnitroge n coul d chang e tha t associatio n o r eliminat e i t b ycreatin g a n environmen t wher e othe rplant s ca n compet e mor e successfull ytha n th e origina l species . Rar e an d endemi cplant s ofte n ar e foun d o n suc h uniqu e sites . Thus , th e manage rshoul d tak e a carefu l loo k at communitie s tha t currentl yar e foun d onl yo n nutrient poo rsites . Relationshi p o fSensitiv e Component s t o AQRV s Th e AQRV s describin g terrestria l component s o fth e wildernes s area s ar e writte n t o cove rbroa d characteristic s suc h a s vegetation . Thes e broa d characteristic s mus t b e divide d int o smalle rcomponents , suc h a s th e particula r specie s o ftrees , plants , an d lichens , s o tha tth e sensitiv e component s ca n b e identifie d an d documented . Man yo fth e sensitiv e component s describe d i n th e previou s sectio n ma y no tb e importan t component s o fth e AQRV s fo ra particula r wildernes s area . I t i s importan t tha t eac h wildernes s are a b e considere d o n a separat e basi s b yth e FLM . I t als o i s importan t fo rth e FL M t o evaluat e bot h terrestria l an d aquati csystem s a s sensitivit ywil l vary , a s reflecte d i n re d an d gree n lin e values . Assessment s shoul d incorporat e th e mos t sensitiv e components .P.1 1

Gree n Lin e an d Re d Lin e Value s Screenin g criteri a (Tabl e 6 ) shoul d b e applie d o n a case-by cas e basis , usin g ai rqualit ysn d meterologica l condition s fro m eac h wildernes s wher e available . However , becaus e th e availabl e informatio n o n ai rqualit yan d ecosyste m component s i s limited , th e sam e gree n an d re d lin e value s hav e bee n selecte d fo ral l eigh t Easter n Regio n Clas s I areas . Obviou s exception s ar e pointe d out . Tabl e 6.—Terrestria l gree n an d re d screenin g value s Pollutan t Gree n lin e Re d lin e

SULFU R DEPOSITIO N S0 2 (annua l mean ) < 5 ug/m 3 > 4 0 ug/m 3 (3-h rmax . mean ) < 10 0 ug/m 3 > 20 0 ug/m 3 Tota l (al l form s ofsulfur ) 5 t o 7 kg/ha/y r> 2 0 kg/ha/y r

NITROGE N DEPOSITIO N Tota l nitroge n 5 t o 8 kg/ha/y r> 2 0 kg/ha/y r OZON E Growin g season , secon d highes t 1 h raverag e ^ 8 0 pp b > 12 0 pp b

Th e tota l depositio n o rexposur e value s ar e compare d wit h th e green-line/red-lin e mode l t o determin e th e appropriat e cours e o faction . Gree n lin e value s wer e se ta tlevel s at whic h i t wa s reasonabl ycertai n tha tn o significan tchang e woul d b e observe d i n ecosystem s tha tcontai n larg e number s o fsensitiv e components . Conversely , re d lin e value s wer e selecte d a tlevel s atwhic h i twa s reasonabl y certai n tha ta significan t chang e woul d occu ri n bot h th e sensitiv e an d toleran t component s ofth e ecosystem . Limite d foliag e injur yo rsympto m developmen t ca n occu r o n sensitiv e specie s atth e selecte d gree n lin e value s fo r ozon e an d S0 2 . However , th e significanc e t o th e wildernes s ecosyste m o fthi s foliag e injuryma yb e minor . Studie s hav e demonstrate d tha tplant s wit h foliag e exhibitin g ai rpollutan t damag e symptom s ca n continu e t o growatcompetitiv e rates . Thus , th e relationshi p offolia rinjuryt o th e AQRV s o f a particula rwildernes s wil l determin e th e significanc e of suc h sympto m development . Additionally , gree n lin e level s wer e no t selecte d t o assur e th e protectio n o fth e mos t sensitiv e geneti cmateria l i n th e ecosystem . Thi s approac h wa s take n becaus e th e AQRV s wer e establishe d t o protec t th e curren t ecosystem , whic h woul d b e expecte d t o continu e eve n i fpart o fth e geneti cmateria l ofon e o rmor e specie s wa s lost . I fth e AQRV s ar e revise d ata late rdat e t o includ e sensitiv e geneti cmaterial , th e gree n lin e value s ma ynee d t o b e lowered . Th e gree n lin e (3-h rmaximu m peak ) S0 2 valu e o f10 0 ug/m 3 (o rlong-ter m averag e o f5 ug/m 3 ) wa s selecte d becaus e n o significan t large-scal e visibl e injuryo rphysiologica l impact s ar e expecte d o n an yspecie s i n th e ecosyste m belo wthes e levels , base d o n publishe d literature . Th e re d lin e value s (3-h rmaximu m pea k

valu e o f20 0 ug/m 3 o r4 0 ug/m 3 yearl y average ) wer e selecte d becaus e simila rlevel s hav e bee n demonstrate d t o b e harmfu l t o man yo fth e specie s foun d i n th e wildernes s area s i n Regio n 9 . However , th e effec t o f S0 2 o n vegetatio n wil l varywit h severa l parameters , includin g th e concentration , duration , an d frequenc yo f peak s i n th e growin g season . Th e gree n lin e valu e fo rtota l S loadin g i s 5 t o 7 kg/ha/yr . Thi s i s approximatel yth e loadin g i n BoundaryWater s Cano e Are a an d Rainbo wLake s Wildernes s Area ; t o date , n o advers e effect s hav e bee n observe d i n thes e areas , s o th e grou p believe d tha t thi s valu e represent s th e lowes t leve l a t whic h w e ca n estimat e n o effects . However , aquati c system s ma yb e mor e sensitiv e an d cumulativ e effect s shoul d b e considered , particularl yfo rwatershed s approachin g thei rsulfat e adsorptio n capacity , a s i n Doll y Sod s an d Otte rCree k

wildernes s area s (Se e discussio n o n aquati cecosystems) . Th e re d lin e valu e o f2 0 kg/ha/y rma yb e expecte d t o caus e catio n leachin g fro m mos t o fth e wildernes s soil s i n Regio n 9 . Supportin g thi s observatio n i s th e calculatio n tha tsoi l 3 0 c m dee p wit h a bul k

densit yo f1. 1 kg/ Lreceivin g a sulfu r loadin g o f2 0 kg/ha/y rcoul d achiev e a reductio n o f1 me q i n bas e cation s withi n abou t 2. 6 y r(Fo xe tal . 1989) . However , th e los s migh t b e les s i fth e soi l containe d mor e fre e calciu m carbonate , a s i s th e cas e fo rth e Hercule s Glade s Wilderness , o ri fth e sulfu rabsorbin g capacit yofth e soi l i s high . Fo rN , a gree n lin e o f5 t o 8 kg/ha/y rwa s selecte d becaus e thes e ar e th e level s tha tar e currentl ydeposite d i n th e mor e "pristine " wildernes s area s o fRegio n 9 (BWCAW , Rainbo w Lake , Hercule s Glades) . T o date , th e declin e o fre d spruc e a t hig h elevation s i s th e onl ysignifican t chang e i n ecosyste m structur e o rfunctio n tha tmigh tresul t fro m increase d N o rS deposition . Th e re d lin e valu e o f2 0 kg/ha/y ro ftota l nitroge n wa s selecte d becaus e most , i fno t all , ofth e wildernes s soil s wil l leac h nitrat e an d associate d bas e cation s i fthi s leve l o fN inpu t i s maintained . Ozone , lik e S0 2 , exist s i n th e environmen ta s a ga s an d it s impac t o n vegetatio n depend s o n man yvariables , includin g concentration , duration , frequenc yo fpeak s an d environmenta l condition s suc h a s temperatur e an d humidity . Th e ozon e value s give n i n Tabl e 6 represen t th e secon d highes t 1-h raverag e i n th e growin g season . Thi s valu e i s reasonabl ywel l correlate d wit h plan tresponse , thoug h researc h i s currentl yunde rwa yt o improv e o n thi s variabl e b yincludin g som e influenc e o faccumulate d effects . I t i s recommende d tha tsom e typ e ofcumulativ e inde xtha tweight s th e hig h concentration s mor e tha n th e lowe rconcentration s b e develope d a s soo n a s possible . 8P.1 2

Th e gree n lin e valu e fo rozon e fo ral l wildernes s ecosystem s wa s se t a t 8 0 pp b (secon d highes t1-h rmean). N o significan t chang e i s expecte d i n th e ecosyste m i fozon e remain s belo wthi s level . However , o n th e basi s o favailabl e information , i t i s reasonabl e t o conclud e tha tsom e sympto m developmen to rlea fsenescenc e ma yb e expecte d eve n a t thi s lo wlevel . Th e re d lin e valu e wa s se ta t12 0 pp b (secon d highes t 1-h rmean) . A t thi s level , ozon e wil l reduc e plan t growt h an d th e competitiv e abilit yo fman yspecies . Sensitiv e specie s ma yb e eliminate d fro m th e ecosystem . I n additio n t o short-ter m ozon e effects bein g important , th e effec t o fozon e i s cumulativ e fo reac h individua l i n th e ecosystem . Aplan t weakene d b yozon e i n on e seaso n i s i n a poore rcompetitiv e positio n a tth e beginnin g o fth e secon d seaso n tha n a nonsensitiv e plant . Afte rtw o o rmor e season s i t i s weakene d eve n furthe runti l i tma yb e eliminated . Th e PS D recommendation s wil l depen d o n th e relativ e importanc e o fth e differen tplan tspecie s i n th e plan t communit ya s a n AQR Vwithi n eac h wilderness . 

## Aquati c Ecosystem s Potentiall ySensitiv e Component s Th e abilit yo fa lak e o rstrea m t o buffe rincomin g acids , i.e. , it s acid-neutralizin g capacit y(ANC ) o ralkalinity , depend s primaril yo n th e emoun t o fbicarbonat e (HCO3 ) i n th e wate r an d th e rat e a t whic h i ti s supplie d fro m th e watershed^ . Bicarbonat e suppl ydepend s o n watershe d geologyan d hydrology . I n th e watershed , HC0 3 i s produce d b yth e reaction s o fwate ran d carbo n dioxid e (o racid s fro m atmospheri cdeposition ) wit h carbonat e mineral s suc h a s calcit e an d dolomite , an d catio n aluminu m silicat e mineral s lik e feldspar s an d micas . Thes e weatherin g reaction s releas e HC0 3 int o solution , accompanie d b yapproximatel y equa l amount s (o n a n equivalen tweigh to rueq/ Lbasis ) o f bas e cations—calciu m (Ca) , magnesiu m (Mg) , sodiu m (Na) , an d potassiu m (K) (Stum m an d Morga n 1981) . Ho wmuc h HC0 3 an d othe rmineral-weatherin g product s actuall yreac h a lak e o rstrea m depend s o n th e flo wpath s o fwate rthroug h th e watershed . Wate rtha tmove s rapidl yove rth e lan d surfac e o ralon g shallo wsubsurfac e pathway s usuall y contain s muc h les s dissolve d materia l tha n wate rtha ttake s a slow , dee p rout e t o a lak e o rstream . Groun d wate ri s typicall yhig h i n dissolve d ions . Lake s an d stream s wit h stron g groun d wate rinput s usuall yhav e hig h bufferin g capacities . I n additio n t o alkalinit ysupplie d b yth e minera l weatherin g i n th e watershed , som e alkalinit yi s generate d b yin-lak e processe s o fS0 4an d N0 3 reductio n an d b yio n exchang e wit h th e botto m sediment s o flakes . Thi s ca n b e a significan tsourc e o fAN C i n lake s wit h onl yminima l input s o fHC0 3 . In-lak e alkalinit yproductio n i s a muc h mor e significan tsourc e o fAN C i n lake s tha thav e lon g hydrologi c flushin g times , severa l years , tha n i n lake s tha tflus h mor e frequently . I n peatlands , th e retentio n o fS0 4an d it s reductio n t o sulfide s an d organi cform s a s wel l a s th e reductio n o fN0 3 t o N gasse s b ydenitrificatio n als o ar e significan t ANC-producin g processe s (Turne re t al . 1989) . Whe n a sensitiv e lak e i s subjecte d t o aci d loading , eithe r fallin g directl yo n th e lak e a s precipitatio n an d dr y depositio n o rflowin g i n fro m th e surroundin g watershed , incomin g acid s ar e neutralize d b yHC0 3 , whic h i s consume d i n th e process . I fHC0 3 i s consume d faste rtha n i t i s supplie d b yminera l weatherin g i n th e watershe d an d b y in-lak e processes , the n AN C eventuall yfall s t o zer o an d th e lak e become s acidic . Bake re t al . (1989 ) foun d tha tS0 4i s th e dominan tacidi c anio n i n surfac e waters . At present , N0 3 generall y contribute s littl e acidit yt o lake s i n th e Unite d States . Nitrat e ma yb e a significan tsourc e o facidit yi n som e streams , especiall ydurin g episodi cflo wevent s resultin g fro m rai n storm s an d snowmelt . Organi canion s ar e a n importan t sourc e o facidit yi n man ylake s associate d wit h peatlands , especiall yi n th e uppe rMidwest . Concentration s o fS0 4i n surfac e water s ar e typicall yvery lo wwher e depositio n i s low , an d increas e i n a nearl ylinea r fashio n a s depositio n increase s (Sulliva n e tal . 1988 ; Bake r e t al . 1989) . Brakk e e t al . (1989 ) estimate d background , pre industria l S0 4level s i n lake s wit h lo wbas e catio n concentration s i n th e Easter n Unite d State s t o b e abou t 1 0 t o 1 5 ueq/L . Whil e surfac e wate rS0 4generall yincrease s wit h deposition , ther e i s considerabl e variatio n i n thi s relationshi p du e t o difference s i n th e suppl yofS0 4fro m natura l geologi csources , a s wel l a s difference s i n th e amount s o fS0 4retaine d b yth e watershe d b ysoi l adsorption , reduction , an d othe rprocesses . • * Sulfat e ca n b e retaine d i n th e soi l b yadsorptio n t o hydrou s oxide s o firo n (Fe ) an d aluminu m (Al ) an d th e edge s o f1: 1 cla yminera l particle s (Boh n e t al . 1986) . Highl yweathere d soil s normall ycontai n considerabl e quantitie s o fF e an d A l hydrou s oxide s an d 1: 1 clays an d hav e hig h capacitie s t o adsor b S0 4 . Lake s an d stream s i n th e Southeaster n Unite d State s contai n lo wamount s o fS0 4relativ e t o S0 4 deposition . Muc h o fth e S0 4tha tfall s o n thes e watershed s apparentl yi s absorbe d b yth e old , highl yweathere d soil s o f th e regio n an d doe s no t reac h surfac e waters , a tleas t a t present . I n th e future , les s S0 4wil l likel yb e retaine d b yth e soi l a s S0 4adsorptio n site s becom e saturated . I n th e Northeas t an d Midwest , relativel ylittl e S0 4i s retaine d b y th e soil . I n contras t t o S0 4 , N0 3 i s take n u p rapidl ybyaquati can d terrestria l biot a an d thu s doe s no t appea rt o promot e lak e acidificatio n i n mos tcases . At present , essentiall yal l o fth e N deposite d fro m atmospheri csource s i n watershed s o f lake s i n th e Northeas t an d Midwes t appear s t o b e retaine d b yth e terrestria l portion s o fth e watershed s o rutilize d b y th e aquati cbiot a (Bake re t al . 1989) . On e exceptio n i s a grou p o flake s i n th e Adirondac k Mountain s i n Ne wYor k wher e N0 3 contribute s u p t o 1 7 percen t o fth e stron g aci d anion s an d appear s t o b e associate d wit h short-ter m variatio n i n p H an d aluminu m (Henrikse n an d Brakk e 1988) . Terrestria l ecosystem s tha thav e receive d hig h level s o fN depositio n fo rman yyear s maybecom e N saturate d an d export significan t amount s o fN0 3 . Henrikse n an d Brakk e (1988 ) estimate d th e "nitrat e mobilit yfactor " (N F ) fo rlake s i n Norway . Thi s factor , define d a s th e rati o ofN0 3 t o S0 4P.1 3

i n runof ffro m a watershe d divide d b yth e rati o i n tota l N0 3 an d S0 4input s t o th e watershed , expresse s th e mobilit yo f N0 3 (an d thu s it s contributio n t o lak e acidification ) a s a fractio n o fth e mobilit yofS0 4 . Mea n value s o fN Ffo r individua l countie s i n Norwa yrange d fro m 0.0 5 t o 0.54 , an d increase d wit h N0 3 depositio n rat e an d amoun t ofrunoff . Whil e lake s i n th e Northeas tan d Midwes t generall yappea r t o b e littl e affecte d byN deposition , th e sam e ma yno tb e tru e fo rsom e streams . Bake re tal . (1989 ) showe d a n approximatel ylinea rrelationshi p betwee n we tN depositio n an d N0 3 i n stream s i n th e Easter n Unite d States , bu t th e effec t o fN depositio n o n stream s appear s t o b e small , compare d t o tha t o fS0 4 . Strea m N0 3 concentration s ar e onl y1 0 t o 3 0 percen to fS0 4concentration s at th e sam e we t S sn d we tN depositio n rates . Increase d amount s ofS0 4(an d i n som e case s NOg ) anion s fro m atmospheri cdeposition , movin g throug h th e soi l an d enterin g surfac e waters , mus tb e accompanie d b y equivalen t amount s o fcations . I n soil s i n whic h abou t 1 5 percen t o rmor e o fth e negativ e exchang e site s ar e occupie d b ybas e cations , Ca , Mg , K , an d Na , muc h o fth e increas e i n solutio n catio n concentratio n wil l consis t of thes e bas e cations . However , i n lo wbase-saturate d soil s (les s tha n 1 5 percent) , du e t o a comple xserie s o fprocesse s involvin g th e presenc e o fhig h partia l pressure s o fC0 2 ga s i n soil , th e equilibriu m amon g carboni cacid , H , an d HC0 3 , an d th e reactio n o fH cation s wit h th e soi l exchang e sites , muc h ofth e increase d catio n loa d i n soi l solutio n an d i n discharg e wate rt o lake s an d stream s wil l b e mad e u p ofH an d A l specie s (Reus s an d Johnso n 1985) . Thes e hydroge n ion s hav e a n acidifyin g effec t o n surfac e waters . Dissolve d A l i s toxi ct o fis h an d othe raquati corganisms . Fo rexample , dissolve d A l i n exces s o f20 0 ug/ Li s toxi ct o broo k trou t (Schofiel d an d Trojna r1980 ; Bake ran d Schofiel d 1982) . tha tar e unaffecte d b yaci d depositio n an d tha t d o no t contai n larg e amount s o forgani canions . Atmospheri c depositio n increase s S0 4(an d i n som e case s NOg ) i n surfac e waters . T o maintai n th e charg e balanc e betwee n cation s an d anion s i n solution , a n aci d deposition-induce d increas e i n surfac e wate rS0 4(an d NOg ) mus tb e accompanie d b ya n increas e i n cation s du e t o increase d minera l weatherin g an d catio n leaching , and/o rb ya decreas e i n ANC . I n veryaci d waters , a n increas e i n A l cation s ma yoccu ri n plac e ofa los s o fANC . Henrikse n (1984 ) define d a usefu l factor , F , fo rdescribin g th e respons e o fsurfac e wate rchemistryt o acidi c deposition . Th e valu e o fF relate s th e increas e i n th e concentratio n ofbas e cation s i n surfac e wate rt o th e increas e i n S0 4resultin g fro m S0 4deposition : F = chang e i n bas e cations/chang e i n S0 4 Th e valu e o fF range s fro m 0 t o 1 . I fF = 1 , bas e cation s increas e wit h S0 4i n respons e t o aci d depositio n whil e surfac e wate rAN C i s unchanged . I fF = 0 , surfac e wate r AN C decrease s a s S0 4increase s whil e th e concentratio n o f bas e cation s remain s constant . I n water s i n whic h N0 3 depositio n contribute s t o acidification , F shoul d b e considere d i n term s ofth e chang e i n th e surfac e wate r concentratio n ofS0 4+ N0 3 . Th e valu e o fF fo ra particula r lak e o rstrea m i s determine d byth e characteristic s o fth e individua l watershed . I n area s o freadil yweatherabl e calcareou s bedroc k

an d soils , F approache s 1 . Fo rvery dilut e lake s sn d streams , F approache s 0 a s hydrauli c residenc e time s i n soils , minera l weatherin g rates , an d soi l bas e saturatio n decreas e (Brakk e e t al . 1990) . Brakk e e t al . (1990 ) develope d a metho d t o estimat e F fo r individua l lake s fro m bas e catio n concentrations : Acidi csoi l wate rma ypercolat e dee p int o th e soi l rathe r tha n flowin g directl yint o a lak e o rstream . I fthi s wate r come s i n contac twit h weatherable , bas e cation-containin g mineral s i n th e subsoi l o rth e underlyin g bedrock , i tma yb e neutralize d befor e reachin g surfac e waters . Durin g bas e flo wconditions , th e wate rflowin g i n stream s typicall ycome s fro m relativel ydee p soi l wate ro rgroun d water . Durin g snowmel t o rfollowin g larg e storms , however , streamflo w ofte n i s dominate d b yshallo wsoi l water . I n area s impacte d b yheavyatmospheri caci d loadings , sensitiv e stream s wit h neutra l o rslightl yalkalin e pH' s durin g bas e flo wmayhav e severel ydepresse d pH' s an d toxi clevel s o fdissolve d aluminu m durin g episodi csnowmel tan d stormflo wevent s du e t o th e flus h o facidi cAl-lade n soi l wate rint o th e stream s (Swistoc k

e t al . 1989) . Thes e episode s mayhav e detrimenta l impact s o n strea m fisherie s (Gun n an d Kelle r 1984 ; Gage n sn d Sharp e 1987) . Simila repisode s o fp H depressio n an d elevate d A l level s als o hav e bee n see n i n lake s durin g snowmel t i n region s ofhig h aci d deposition . Becaus e approximatel yequa l amount s ofbas e cation s an d HC0 3 ar e release d byweatherin g o fcarbonat e an d aluminu m silicat e minerals , th e rati o betwee n AN C an d bas e cation s i s typicall yclos e t o 1: 1 i n lake s an d stream s F = sin(9 0 BC*/S) , wher e BC * = th e su m o fnon-marin e bas e cation s i n th e lak e an d S = th e valu e o fBC * atwhic h F = 1 . Dat a fro m lake s i n souther n Norwa yindicat e tha t th e valu e ofS i s betwee n abou t 20 0 an d 40 0 ueq/L . Brakk e e t al . (1990 ) estimat e tha t F i s abou t 0. 2 t o 0. 4 fo rdilut e lake s i n th e Wester n Unite d State s an d 0. 4 t o 0. 7 fo racidi clake s i n th e Adirondacks . I n a revie wo fbiologica l effects ofsurfac e wate r acidification , Bake re t al . (1990 ) conclude d tha t th e chemica l constituent s mos t influencin g th e biot a ar e pH , inorgani cmonomeri c(non-polymerized ) aluminum , an d Ca , wit h surfac e wate rp H bein g th e singl e mos timportan t parameter . Fis h o rothe raquati corganism s appea rt o b e littl e affecte d s o lon g a s th e p H remain s at 6. 5 o rhigher ; however , noticeabl e advers e effect s begi n t o occu ra s p H decline s t o abou t 6.0 . Th e mos t acid-sensitiv e fis h species , suc h a s th e fathea d minno w(Pimephales promelas), experienc e reproductiv e failur e at pH' s nea r6.0 . Som e importan t foo d organism s suc h a s th e opossu m shrim p (Mysis relicta) disappea rat pH' s slightl ybelo w6.0 . Betwee n p H 6. 0 an d 5.5 , man yspecie s ofzooplankton , mayflies , 1 0P.1 4



### mollusks , minnows , an d gam e fis h ar e adversel yaffected . I n general , fis h egg s sn d fr yar e mor e sensitive t o acidit

y tha n adul t fish , an d fis h population s succum b t o reproductive failure s a

t pH' s abov

e whic h adul t fis h ca n survive . I n lakes wher

e th e averag e p H i s belo

w5.0 , mos

t fis h species , nearl yal l mollusks , an d manyothe rgroup s o f bottom-dwellin g organism s ar e eliminated , th e foo d we b i s severel ydisrupted , an d mats o falga e frequentl ycove rlak e bottom s (Magnuso n et al . 1984) . I n studyin g th e relationshi p betwee n p H an d th e distributio n o ffis h specie s i n 138 lakes i n Wisconsin , Rahe l an d Magnuso n (1983) foun d that severa l specie s o fminnow s (Cyprinidae)

an d darter

s (Etheostoma

spp. ) wer

e absen ta

t pH' s belo w6.0 . Blac k

crappi e (Pomoxis

nigromaculatus), muskellung e (Esox

masquinongy), smallmout h bass (Micropterus

dolomieui), walleye (Stizostedion vitreum). an d norther n pik

e (Esox lucius) wer e absen t a

t pH' s belo

w5.5 . A fewspecie s suc h as th e bluegil l (Lepomis macrochlrus)

an d yellowperc h (Perca

flavescens)

survive an d reproduce successfull ya

t p H 4.5 . I n a n artificiall yacidifie d Canadia n lake , reproductive failure i n fathead minno woccurre d belo

w abou t p H 6.0 , i n lak

e trou t (Salvelinus

namaycush)

belo w abou t p H 5.6 , an d i n whit e sucke r(Catostomus commersoni) belo wabou t p H 5. 0 (Schindle ret al . 1985) . Broo k trou t (Salvelinus

fontinalis)

cannot survive a

t p H level s belo

w4. 8 t o 5. 2 (Bake ret al . 1990) . Aluminu m solubilityincrease s rapidl ya s p H decrease s belo wabou t 6. 0 (He m 1985) , bu t th e chemistr yo fA l i s complexand , consequently , its toxi ceffects o n th e biota ar e highl yvariable . Som e A l i n surface water s i s boun d to organi cmolecule s an d i s relativel ynontoxi c(Bake retal . 1990) . Thi s ca n be a n importan t facto ri n water s colore d b

y drainag e fro m wetlands . Abov e abou t p H 4.5 , dissolve d monomeri cA l ion s ten d t o polymeriz e (He m 1985) . I n general , th e inorgani cmonomeri cfractio n i s considere d th e toxi ccomponent . Concentration s o finorgani cmonomeri cA l abov e 1 0 to 5 0 ug/ Lcaus e advers e biologica l effects (Bake r et al . 1990) . Dissolve d A l (monomeri cplu s polymeric ) i n exces s o f20 0 ug/ Lha

s bee n foun d to be toxi ct o broo k trou t (Schofiel d an d Trojna r1980 ; Bake ran d Schofiel d 1982) . Aquati corganism s ca n generall ytolerat e highe rA l concentration s an d lowe rpH' s i n water s that contai n highe r concentration s o

fCa . A t C a concentration s belo

w10 0 to 150 ueq/L , smal l change s i n A l ca n b e importan t (Bake ret al . 1990) . Gree n Lin e an d Re d Lin e Value s Selectio n o

fgree n an d re d lin e value s fo raquati cAQRV s was a two-ste p process . First , w e determine d th e surface wate rAN C valu e abov

e whic h norma l health yaquati cbiota woul d be presen tan d aquati cecosystem s woul d b e unlikel y t o b e adversel yaffected—th e gree n lin e AN C value , an d th e AN C belo wwhic h aquati cecosystem s woul d Jjkelyb e adversel yaffected—th e re d lin e AN C value . W e selecte d gree n an d re d lin e AN C value s thatw e believe d wer

e indicative o

fth e overal l healt h o

faquati cecosystem s an d were applicabl e t o al l eigh tClass i wildernes s areas . Th e secon d ste p wa

s t o estimate th e gree n an d re d lin e depositio n rate s o

fS an d N fo reac h Class I area . Th e gree n lin e depositio n rate s ar

e th e rate s o

ftota l S an d N depositio n a

twhic h w e estimate d tha

tth e AN C o

fth e mos t sensitive lak

e o rstrea m i n eac h Class I are a woul d remai n above th e gree n lin e value . Th e re d lin e depositio n rate s fo r eac h Class I are a ar

e thos e tota l S an d N depositio n rate s a twhic h w e estimate d th e mos

tsensitive lak

e o rstrea m woul d hav

e a n AN C belo

wth e re d lin e value . W e selecte d 25 ueq/La

s th e gree n lin e AN C value . Twentyfive ueq/Li s abou tth e lowe rlimi to fth e rang e o

fAN C value s ove rwhic h th e lan d manage rca n be reasonabl y certai n thatfis h an d othe raquati corganism s wil l be unaffecte d b

ylo wpH . A s Figur e 2 shows , essentiall yal l clea rlake s (colo rless tha n 25 Pt-Co units ) wit h ANC' s o f2 5 ueq/ Lo rmor

e hav e air-equilibrate d pH' s o

fa tleast6.5 . Thes e lake s shoul d hav

e a normal , health ybiota . Because o finputs o forgani cacid s fro m peatland s o rothe rwetlands , som e moderatel ycolore d lake s (colo rbetwee n 25 an d 75) wit h ANC' s o

ffro m 2 5 t o 50 ueq/Lhav e pH' s betwee n 6. 5 an d 6.0 . Whil e marginal , thes e lake s shoul d stil l hav e essentiall ynorma l faun a an d flora populations . Afewhighl y colore d lake s (colo rgreate rtha n 75) i n thi s AN C rang e hav e pH' s a s lo was 5.5 ; som e o

fth e mos tacid-sensitive specie s probabl ywoul d be absen tfro m thes e lakes . Belo w2 5 ueq/Lo

fANC , surface wate rpH' s dro p sharply . Smal l losse s o

fAN C resul ti n relativel ylarg e decrease s i n pH . Belo wa n AN C o

f1 0 ueq/L , air-equilibrate d pH' s fal l into th e rang e i n whic h chroni cadvers e biologica l effects ca n b e anticipate d (Fig . 2) . W

e selecte d 1 0 ueq/La

s th e re d lin e valu e AN C valu e fo rchroni co rlong-term effects . Thi s i s a mor e conservative re d lin e AN C valu e tha n th e - 5 ueq/ Lre d lin e that was used i n th e origina l screenin g process (Fo xetal . 1989) .



### 1 1

*P.1 5



### C L 

# ANC , /zeq/ l

5 0 -4 0 -3 0 -2 0 -1 0 

## 0 1 0 2 0 3 0 4 0 5 0 -<—I—'—I—'—I—•—I—i—I—i—l—'—I—•—I—•—I—• - 

# 7. 5 7. 0 6. 5 X 

# 6. 0 C L 

# 5. 5 5. 0 4. 5 T

# 4. 0 LAK E COLOR , Co-P t UNITS

° 2 5 OR LES S * 2 5 T O 7 5 * 7 5 OR MOR E

O O _4 A 0 0 , 

### •<PR A

### *°O°5>*° T 

# •

t „ o . O o ' ' 

# ° All®*" " ^

' ** A

# '

A

### o< ? ** * VT O ^ * T



# 9. 0 8. 5 8. 0 7. 5 7. 0 6. 5 6. 0 5. 5 5. 0 4. 5 4. 0 3.5-I—'—I—•—I— * • LAK E COLOR , Co-P t UNITS o 2 5 OR LES S * 2 5 T O 7 5 * 7 5 O R MOR E

H 

### 1 1 - H 1 1 - 

### H 1 r- 

# -10 0 -5 0 0 5 0 10 0 15 0 20 0 25 0 30 0 35 0 40 0 ANC , fieq/\ Figur e 2.— Relationshi p o

fAN C an d p H i n 2,11 7 lake s i n th e Easter n an d Western Unite d State s (data fro m Kanciru k et al . 1986 an d Eiler

s etal . 1987) .



### 1 2P.1 6

I n aquati cecosystem s tha tar e adapte d t o natura l episodi c p H depressions , AN C an d p H ca n probabl yfal l belo wth e chroni cre d lin e valu e fo rshortperiod s withou tsignifican t injur yt o th e biota . Fo rexample , episode s wit h pH' s belo w 5.0 , ANC' s belo wzero , an d elevate d A l concentration s fo r2 t o 5 day s ma yb e require d befor e broo k trou tar e adversel y affecte d (Bake re t al . 1990) . I n thei rrevie wo fepisodi c acidificatio n o fsurfac e waters , Wigingto n e t al . (1989 ) classifie d a n episod e a s likel yt o impac taquati cbiot a i fth e p H minimu m i s 5. 0 o rles s an d th e AN C fall s belo wzero . W e selecte d 0 ueq/ La s th e episodi cre d lin e AN C value . T o estimat e th e gree n an d re d lin e rate s o ftota l S deposition , i.e. , th e depositio n rate s tha twil l resul ti n gree n an d re d lin e AN C value s fo reac h wildernes s area , w e use d availabl e water-qualit ydata , ou rbes testimate s o f depositio n rates , an d empirica l relationship s betwee n S depositio n an d concentration s o fS0 4 , bas e cations , an d AN C i n lak e an d strea m water . Whil e ou restimate s see m reasonable , w e recommen d tha tth e gree n an d re d lin e depositio n rate s presente d her e b e use d a s interi m value s unti l additiona l dat a ca n b e collecte d an d a mor e thoroug h analysi s ca n b e undertaken . Thi s effortshoul d involv e comparison s o fth e results o fmultipl e technique s suc h a s othe rempirica l models , simulation s usin g model s lik e MAGI C (Modellin g th e Acidificatio n o fGroundwate ri n Catchments ; Cosb ye t al . 1985a,b ) an d ILWA S (Integrate d Lakes-Watershe d Acidificatio n Study ; Gherin i e tal . 1985) , an d paleolimnologica l studie s (se e sectio n o n researc h needs) . On e concer n i s tha t empirica l relationship s suc h a s thos e use d her e impl ytha tsurfac e wate rchemistr yi s currentl yi n equilibriu m wit h deposition . However , MAGI C simulation s o f wate rchemistr yi n Norwa yan d th e Easter n Unite d State s projec t tha ti fdepositio n continue s a t it s presen t rat e o r eve n decrease s slightl y( 5 percent) , sensitiv e lake s an d stream s wil l continu e t o acidif y(Cosb ye tal . 1989 ; Sulliva n etal . 1991) . O n th e basi s o fth e relationshi p betwee n N depositio n an d N0 3 concentration s i n stream s show n b yBake re tal . (1989 ) an d th e N0 3 mobilit yfactor s fo rNorwegia n lake s an d stream s estimate d b yHenrikse n an d Brakk e (1988) , w e estimat e tha t a give n depositio n rat e o fN ha s 2 0 percen to f th e acidificatio n effec t o fth e sam e rat e o fS deposition . Th e acidifyin g effect s o fN o n surfac e water s canno tb e considere d separatel yfro m th e effect s o fS , bu ta tpresen t an d a tth e curren t depositio n rates , S appear s t o b e muc h mor e effectiv e tha n N a s a n acidifyin g agen tfo rsurfac e water s i n th e Unite d States . Therefore , w e hav e estimate d gree n an d re d lin e depositio n rate s fo rS alon e an d fo rS + 2 0 percen t o fN , bu t no tfo rN alone . Again , thes e shoul d b e regarde d a s interi m value s unti l th e effects o fN depositio n o n eac h Clas s I are a ca n b e assesse d mor e accurately . Specifi cdetermination s wer e mad e fo reac h wildernes s are a an d ar e discusse d i n fiv e section s (Ne wHampshir e an d Vermont , Wes tVirginia , Wisconsin , Minnesota , an d Missouri) . Ne wHampshir e an d Vermont : Presidentia l Range Dr yRiver , Grea t Gulf , an d Ly e Broo k Wildernesse s Chemistrydat a fro m lake s an d stream s i n an d adjacen t t o thes e wildernes s area s sho wtha tthes e water s ar e acidi c an d ver ysensitiv e t o furthe racidificatio n b yatmospheri c deposition . Bas e catio n concentration s rang e fro m abou t 7 5 t o abou t15 0 ueq/L . ANC' s rang e fro m aboufl O ueq/ Lt o les s tha n zero , an d pH' s ru n fro m th e lo w4' s t o th e hig h 5's . Th e pH' s o fwater s wit h bas e cation s i n th e 12 0 t o 15 0 ueq/ Lrange , mostl ystrea m reache s a tth e lowe ran d middl e elevations , generall yru n fro m abou t5. 1 t o 5.5 . Water s wit h bas e catio n concentration s belo w10 0 ueq/L , mostlyhighe r elevatio n lakes , hav e pH' s fro m 4. 4 t o 4.8 . Th e mos t complet e chemistr ydat a se tfo ran yo fth e stream s an d pond s i n th e Presidentia l Range-Dry River/Grea t Gul fare a i s fro m Gibb s Brook , whic h originate s a fe whundre d yard s t o th e wes t o fth e Presidentia l Range/DryRive rWildernes s boundary . Th e Gibb s Broo k watershe d i s simila rgeologicall yan d topographicall yt o th e Presidentia l Range-DryRive ran d Grea t Gul fWildernes s Areas , an d th e chemistr yo fGibb s Broo k shoul d b e representativ e o fwate rchemistrycondition s i n th e Wildernesses . Th e p H o fGibb s Broo k range s fro m abou t 5. 1 an d 5. 4 durin g bas e flo wconditions . AN C i s onl y occasionall yabov e zero . Durin g hig h flows fro m snowmel t an d storms , th e p H fall s t o betwee n 4. 5 an d 5.0 . Bas e catio n concentratio n i s abou t12 0 ueq/L . Sulfat e average s abou t 10 0 ueq/L . Chlorid e (Cl ) i s low , les s tha n 1 0 ueq/L . Mos t o fth e availabl e wate rchemistrydat a fo rth e Ly e Broo k Wildernes s ar e fro m Bour n Pond . Bour n Pon d i s chemicall y simila rt o Gibb s Brook ; it s p H range s fro m abou t 4. 8 t o 5.5 , wit h a n averag e o fabou t 5.2 . AN C i s typicall yi n th e - 5 t o + 5 ueq/ Lrange . Th e p H an d AN C generall yar e lowes t i n th e sprin g an d earl ysummer . Bas e cation s averag e abou t 11 0 ueq/L , S0 4abou t 10 0 ueq/L , an d C l abou t 1 0 ueq/L . Thes e dat a ar e indicativ e o fsurfac e waters tha t hav e bee n significantl yimpacte d b yacidi cdeposition . Marin e source s o fS0 4an d othe rion s appea rt o b e small , a s evidence d b y th e lo wC l conten t o fth e waters . I fw e assum e a n averag e backgroun d (preindustrial ) concentratio n o fS0 4i n th e surfac e wate ro fabou t 1 5 ueq/ L(Brakk e e t al . 1989) , a n organi canio n concentratio n o fabou t 1 0 ueq/L , an d a catio n enrichmen t facto r(F ) o f0. 5 t o 0. 6 (se e Brakk e e tal . 1990) , the n w e estimat e tha t Bour n Pond , Gibb s Brook , an d th e othe rpond s an d stream s i n thes e area s hav e suffere d a n AN C los s o fabou t 3 5 t o 4 0 ueq/ Ldu e t o acidi cdeposition . Acidificatio n o flake s i n th e Adirondac k Mountain s i n Ne w Yor k ha s bee n estimate d b yus e ofth e MAGI C model . Th e media n chang e i n AN C fo rth e Adirondac k lake s sinc e preindustria l time s wa s estimate d t o b e -4 6 ueq/ L(Sulliva n e t al . 1991) . Thi s compare s wel l wit h th e AN C losse s estimate d her e fo rth e surfac e water s o fth e Presidentia l Range-DryRiver/Grea t Gul fan d Ly e Broo k areas . Paleolimnologica l studie s o fdiatom s i n Adirondac k lak e sediments , however , sugges t a somewha t smalle rlos s o f AN C (Sulliva n e t al . 1991) . 1 3P.1 7

Man yo fth e stream s i n thes e thre e wildernes s area s contai n population s ofbroo k

trout , typicall ya tth e lowe ran d middl e elevations . Thes e population s ar e stil l viabl e bu tprobabl y ar e stresse d b yth e acidi ccondition s o fth e stream s sn d th e los s ofANC . At highe relevations , i n th e headwater s o f thes e stream s ar e severa l smal l pond s tha tar e to o acidi ct o support permanen t trou t populations . Som e o fthese , suc h a s Bour n Pond , ar e though t t o hav e supporte d permanen t population s o fbroo k

trou ti n th e past . I n a surve yo ffis h populations , Langdo n (1984 ) foun d onl ytw o specie s o ffis h i n Bour n Pond—brow n bullhea d (Ictalurus nebulosus), a highl yacid-toleran tspecies , an d broo k trout , whic h i s regularl ysupplemente d b ystocking . Fisk e (1987 ) foun d a scarcit yo facid-sensitiv e macroinvertibrat e specie s i n Bour n Pond . Langdo n (1984 ) relate d th e lo wnumbe ro ffis h specie s i n Bour n Pon d an d othe rsensitiv e souther n Vermon t lake s t o lo wp H an d hig h A l concentrations . Presen ttota l S an d N depositio n rate s ar e estimate d t o b e abou t 1 4 t o 1 6 an d 9 t o 1 1 kg/ha/yr , respectively , i n th e Grea t Gulf/Presidentia l Range-DryRive ran d Ly e Broo k Wildernesse s (Tabl e 3) . Th e ANC' s an d pH' s o fth e pond s an d stream s i n thes e area s currentl yar e a t o rbelo wbot h th e chroni can d episodi cre d lin e values . Th e existin g broo k trou t an d othe raquati corganism s ar e likel yt o b e experiencin g stres s an d damage ; additiona l depositio n wil l caus e additiona l damage . Som e highe relevatio n population s ma yalread yhav e bee n destroyed . Therefore , w e believ e tha t th e presen tS an d N depositio n rate s fo r thes e wildernes s area s ar e a to reve n abov e th e re d lin e values . W e estimat e th e re d lin e tota l S depositio n rat e t o b e 1 4 t o 1 6 kg/ha/yr , an d th e re d lin e S + 2 0 percen to fN t o b e 1 6 t o 1 8 kg/ha/yr . T o achiev e th e gree n lin e AN C valu e o f2 5 ueq/L , mos t of th e surfac e water s i n th e Grea tGulf/Presidentia l Range-Dry Rive ran d Ly e Broo k

Wildernesse s woul d hav e t o increas e i n AN C b y1 5 t o 2 5 ueq/L , whic h woul d requir e a substantia l reductio n i n deposition . Gallowa ye t al . (1984,1987 ) ha s estimate d th e backgroun d (preindustrial ) concentratio n o f S0 4i n precipitatio n t o b e 5 t o 7 ueq/L . Give n 1,20 0 t o 1,60 0 m m o fannua l precipitation , w e estimat e backgroun d S depositio n (we tplu s dry ) i n th e Grea t Gulf/Presidentia l Range-DryRive ran d Ly e Broo k Wildernesse s t o hav e bee n 1. 5 t o 2 kg/ha/yr . W e estimat e surfac e wate rS0 4t o hav e increase d byabou t8 5 ueq/ Love rbackground . Thi s i s a n increas e i n S0 4o fabou t 6 t o 7 ueq/ Lfo reac h 1 kg/ha/y rof S deposition . I fw e assum e tha tsurfac e wate rS0 4wil l decreas e at thi s sam e rat e i n respons e t o a decreas e i n S deposition , an d tha tAN C wil l increas e a t4 0 t o 5 0 percen to f th e rat e o fS0 4decreas e (i.e. , F = 0. 5 t o 0.6) , the n a ' decreas e i n S depositio n t o abou t6 t o 8 kg/ha/y rwil l b e necessaryt o achiev e gree n lin e AN C values . Thi s i s simila r t o th e 3 ueq/ LAN C increas e fo reac h 1 kg/ha/y rdecreas e i n S depositio n projecte d fo rAdirondac k lake s byth e MAGI C mode l (Sulliva n e t al . 1991) . Thus , w e estimat e th e gree n lin e tota l S depositio n rat e t o b e 6 t o 8 kg/ha/y ran d th e gree n lin e S + 2 0 percen t ofN depositio n rat e t o b e 7 t o 9 kg/ha/yr . Wes t Virginia : Doll ySod s an d Otte rCree k Wildernesse s Th e bedroc k

ofth e Doll ySod s an d Otte rCree k Wildernesse s consist s ofth e Pennsylvania n ag e Conemaug h Group , Alleghen yFormation , an d Pottsvill e Group , underlai n b yth e Mississippia n ag e Mauc h Chun k Grou p an d Greenbrie rGrou p (Cardwel l e t al . 1986) . Thes e ar e sedimentarymaterials—bed s o fsandstone , siltstone , shale , conglomerate , an d som e limestone . Th e Pennsylvania n strat a als o contai n numerou s coa l beds . Limeston e i s mor e prevalen t i n th e Mississippia n groups ; th e Greenbrie ri s predominatel ylimestone . Th e abilit yo fth e stream s i n thes e wildernes s area s t o sustai n population s o ffis h an d othe raquati corganism s i s closel yrelate d t o bedroc k geology . Stream s tha t aris e i n an d flo wthroug h th e Lowe rPennsylvania n material s ten d t o b e to o acidi ct o suppor t fish . Stream s influence d b yth e Mississippia n rock s ten d t o b e mor e suitabl e fo raquati clife . Simila rgeologyextend s northwar d int o Pennsylvania . Studie s i n th e Laure l Hil l are a o fsouthwester n Pennsylvania , abou t 12 0 k m nort h o fth e Otte rCree k an d Doll ySod s Wildernesses , showe d tha twate rfro m spring s an d seep s emanatin g fro m Alleghen yan d Pottsvill e strat a ha d ANC' s clos e t o zer o an d pH' s i n th e 4's . I n contrast , wate rfro m th e Mauc h Chun k ha d ANC' s o fabou t 10 0 ueq/ L an d pH' s i n th e 6' s (Dinicol a 1982 ; Sharp e e t al . 1984) . Som e ofth e Alleghen yan d Pottsvill e strat a contai n pyrit e (FeS 2 ) tha t produce s S0 4an d aci d a s i t oxidizes . Pyriti c material s appea rt o b e a sourc e o fnatura l acidit yi n man yo f th e tributar ystream s i n th e Otte rCree k an d Re d Cree k systems . I n additio n t o natura l source s o facidity , th e stream s i n th e Doll ySod s an d Otte rCree k Wildernesse s receiv e a larg e aci d loa d fro m atmospheri cdeposition . W e estimat e th e mea n annua l tota l depositio n rat e o fS an d N t o b e abou t 2 1 an d 1 6 kg/h a (Tabl e 3) , th e highes tamon g al l th e Clas s I wildernes s area s i n th e Easter n Region . A t present , th e soil s ofth e Doll ySods/Otte rCree k are a appea rt o b e retainin g b yadsorptio n 4 0 t o 5 0 percen t o fth e S0 4 deposite d fro m th e atmospher e base d o n researc h o n a n adjacen t watershe d (Helve yan d Kunkl e 1986) . Thi s retentio n o fS0 4provide s t o th e stream s som e leve l of protectio n fro m th e ful l effect s ofS0 4deposition . Eventually , th e S0 4adsorptio n capacit yofth e soil s wil l b e saturated , an d thi s protectio n wil l b e lost . Decrease s i n th e capacit yo fth e soi l t o adsor b sulfat e an d resultan t increase s i n strea m wate rsulfat e concentration s hav e bee n documente d i n recen t year s i n som e Nort h Carolin a stream s (Wayn e Swank , USD AFores t Service , Southeaster n Fores t Experimen t Station , Coweet a Hydrologi cLaboratory , pers . commun.) . Otte rCreek , th e mai n strea m i n th e Otte rCree k Wilderness , an d Re d Creek , whic h drain s th e Doll ySod s Wilderness , hav e man ysimilarities . Bot h stream s hav e som e wetlan d acreag e i n thei rheadwaters , particularl yRe d Creek , whic h ha s broa d gentl e slope s ove rmuc h ofth e uppe rwatershed . I n thes e headwate rareas , bot h stream s ar e sensitiv e t o acidification , bu tar e stil l capabl e o fsupportin g som e fis h 1 4P.1 8



### species . Durin g norma l flowconditions , th e p H i n muc h o f th e Red Cree k

headwater

s ma ytypicall yb e i n th e 6's , bu t th e Lef t Fork i s mor e aci d an d ma

yb e close rt o p H 5 (Do n Gasper , Wes

t Virgini a Divisio n o

fNatura l Resources , unpublishe d data) . Uppe rRed Cree k contain s a goo d populatio n o

fcree k chu b (Semotilus

atromaculatus), whit e sucker , an d variou s daces . Th e headwater s portio n o

fRed Cree k i s chemicall ysuitabl e fo rbroo k trou t (marginally) , bu t ofte n i s to o warm fo rtrou t becaus e o fbeave rdams . Th e extrem e headwater

s o fOtte rCree k

(upstrea m fro m th e wildernes s boundary

) does contai n broo k

trout . Belo wthes e headwate rreaches , bot h stream s ar e affecte d b yth e influ xo

fwate rfro m acidi ctributar ystreams . Stream s suc h as Fishe rSprin g Run , Stonecoa l Run , an d Littl e Stonecoa l Ru n that flowint o Red Creek , an d YellowCreek , Devil' s Gulch , an d Moor

e Ru n that ente rOtte rCreek , are ver yacidi can d contai n elevate d concentration s o fAl . Stonecoa l Ru n typicall yha s a p H o f4. 0 t o 4.5 , an d A l level s o fabou t 18

0 to 50 0 ug/L . Stonecoa l Ru n has a base catio n concentratio n o

fabou t 9 0 ueq/Lan d a S0 4

### concentratio n o f abou t 17 0 ueq/L ; AN C i s less tha n zero . I n YellowCree k an d Devil' s Gulch , pH' s betwee n 3. 7 an d 4. 0 an d tota l A l concentration s fro m 40 0 t o 60 0 ug/Lare typical , an d pH' s as lo was 3. 3 t o 3. 4 an d tota l A l concentration s as hig h as 90 0 t o 1,20

0 ug/ Lhav

e bee n measure d durin g hig h flow conditions . Downstrea m fro m its headwaters , Red Cree k becorrjes to o acidi cto suppor

t fis h except durin g lo

wflowperiod s fro m lat e sprin g throug h th e fall . Throughou t th e Doll ySod s Wildernes s belo

wth e headwate rreach , th e p H o fRed Cree k typicall yranges fro m th e mi d 4' s t o th e hig h 5's . Th e lowes t pH' s occu ri n th e lat e winte ran d i n sprin g durin g snowmelt , an d followin g rai n storms . Th e highest pH' s ar e recorde d durin g lo

wflowperiod s o

fth e summe ran d fall . Th e averag e bas e catio n concentratio n o fRe d Creek , jys t above Stonecoa l Run , i s abou t 150 ueq/L , an d S0 4 

### averages abou t 14

0 ueq/L . ANC' s rang e fro m less tha n zer o t o a hig h o

fabou t 1 5 ueq/L . Withi n th e Doll ySod s Wilderness , th e onl ypar

t o fth e Red Cree k

syste m belo

w th e headwater

s that appear

s capabl e o

fsustainin g fis h i s a n abandone d channe l o

fRe d Cree k

fe d b ysevera l spring s an d seeps that emerg e fro m bedroc k strat a o fth e Mauc h Chun k Group . Thi s spring-fe d channel , wit h suitabl e wate r qualityan d spawnin g an d rearin g areas , harbor s a small , self-sustainin g populatio n o fbroo k trout . I n th e summe ran d fall , fis h fro m thi s spring-fe d channe l ente rRed Cree k an d ma ymigrate a fewmile s upstrea m (Do n Gasper , Wes t Virgini a Divisio n o

fNatura l Resources , pers . commun.) . Wit h n o competition , thes e fis h gro wquickly ; however , they d o no t appea rto survive th e acidi cspringtim e condition s i n Red Creek . Th e chemistr

yo fOtte rCree k

i s altere d jus t befor

e i tflows int o th e Otte rCree k

Wildernes s b

ya facilitythat add s limeston e t o th e wate rt o rais e its p H an d AN C t o sustai n a broo k trou t fisher

yi n th e stream . Upstrea m ofth e limin g operation , Otte rCree k

i s acidic , wit h pH' s o

ffro m less tha n 4. 0 to abou t 5.5 . Th e onl ytributar yo fOtte rCree k

i n whic h th e presence o

fbroo k trou t ha s bee n documente d i s Turkey Run , whic h flows int o Otte rCree k fro m th e northwesta fe

w mile s upstrea m fro m th e lowe rWildernes s boundary . I ti s notknow n i fTurkeyRu n stil l contain s trout ; th e last fisherie s surveyo n thi s strea m wa s conducte d som e twent

y year s ago . On e othe rstrea m i n th e Otte rCree k Wilderness , Shaver s Lic k Run , i s chemicall ysuitabl e fo rtrou ti n it s lowe r reaches , bu tit s fis h populatio n ha s no tbee n documented . Shaver s Lic k Ru n rise s nea rth e lowe ren d o fih e Wildernes s an d doe s notdischarg e into Otte rCreek . Ther e are indication s o

fincrease d acidit

yo fth e stream s i n th e Doll ySod s an d Otte rCree k Wildernesse s du e t o acidi c deposition . Th e Wes

tVirgini a Divisio n o

fNatura l Resources ha s bee n monitorin g wate rqualityan d fis h population s fo r manyyear

s i n Otte rCree k

an d othe rnearbystreams . Thei r data sho wa long-ter m tren d o

fincreasin g strea m acidity an d fis h populatio n effects i n poorl ybuffere d mountai n streams . I n earl yJune , 1990 , followin g severa l day s o f heav yrain , a p H o

f3. 7 wa s recorde d i n Otte rCree k jus t abov e th e limin g facility(Barr

yEdgerton , Monongahel a Nationa l Forest , pers . commun.) . Fis h population s i n Otte r Cree k ar e artificiall ymaintaine d b yliming , an d fis h populatio n data fro m Red Cree k ar e insufficien tt o sho

wa trend . Data fro m othe rnearbystream s sho wa recen tlos s o

f fis h du e t o acidification . Th e p H an d AN C o

fRed Cree k

an d its tributarie s are presentl ybelo

wbot h th e chroni can d episodi cre d lin e values , exceptfo rth e headwate rare a an d a reac h o f abandone d strea m channe l fe d b ysevera l smal l spring s an d seeps fro m th e Mauc h Chun k Group , a s describe d earlier . I n th e absence ofth e limin g operation , th e p H an d AN C o f Otte rCree k

woul d b e belo

wth e re d lin e values . Th e onl y stream s i n th e Otte rCree k Wildernes s tha

tma ybe capabl e o fsustainin g fis h population s withou tlimin g ar e TurkeyRu n an d Shaver

s Lic k Run . Th e aquati cecosystem s o fth e Otte r Cree k an d Doll ySod s Wildernesse s ar e unde rconsiderabl e stres s fro m a combinatio n o fnatura l an d deposition-derive d acidity . Additiona l acidi cloading s fro m S an d N depositio n wil l furthe rstres s th e aquati cecosystems , an d wil l jeopardiz e th e existin g population s o ffis h an d othe raquati c organisms . Curren ttota l S an d N depositio n rates ar e estimate d t o be 2 1 an d 1 6 kg/ha/yr , respectively , i n th e Doll ySod s an d Otte r Cree k Wildernesse s (Tabl e 3) . Du e to adsorptio n o f4 0 t o 5 0 percen to fth e depositiona l S0 4

### load b yth e soils , th e effective S depositio n rate i s estimate d t o b e abou t1 1 t o 1 3 kg/ha/yr . A

s th e S0 4

### adsorptio n capacit yo fth e soi l i s depleted , th e effective depositio n rate wil l increas e an d eventuall yapproac h th e actua l depositio n rate . Since strea m p H an d AN C value s alread yar e belo wth e re d lin e value s (o rwoul d b e withou tliming) , w e estimat e th e re d lin e tota l S depositio n rate fo rth e Otte rCree k an d Doll ySod s Wildernesses , give n th e eventua l saturatio n o fth e S0 4 

### adsorptio n capacity , to be th e curren teffective rate o f1 1 to 1 3 kg/ha/yr . W

e estimate th e re d lin e S + 2 0 percen to fN depositio n rate to be abou t1 4 to 1 6 kg/ha/yr . 1 5P.1 9

Availabl e historica l dat a indicat e tha tth e natura l p H an d AN C o fRe d Cree k

an d Otte rCreek , i n th e absenc e ofan y anthropogeni caci d loadings , probabl ywer e a to rbelo wth e gree n lin e values , an d tha tan yadditiona l aci d loading s fro m depositio n woul d b e detrimental . Thus , w e estimat e th e gree n lin e S an d N depositio n rate s t o b e clos e t o backgroun d levels . Wisconsin : Rainbo wLak e Wildernes s Th e 2 2 lake s i n th e Rainbo wLak e Wildernes s ar e seepag e lakes . The yreceiv e muc h o fthei rwate rfro m direc t on-lak e precipitation ; th e remainde ri s fro m seepag e of groundwater . The yhav e n o surfac e wate rinputs . Severa l o f thes e lake s ar e sensitiv e t o acidi cdeposition . Th e 1 3 lake s fo rwhic h wate rchemistr ydat a ar e availabl e hav e ANC' s fro m abou t1 0 t o abou t6 0 ueq/L . Thei rpH' s rang e fro m 5. 6 t o 6.3 , an d averag e abou t 5.9 . Bas e catio n concentration s rang e fro m abou t 8 0 t o 17 0 ueq/L . Thes e ar e summertim e data ; i n th e spring , ANC' s an d pH' s mayb e lowe rdu e t o meltin g snow . Th e lake s fal l int o tw o group s wit h regar d t o sensitivity . Eigh to fth e 1 3 hav e summe rANC' s o fabou t1 0 t o 3 0 ueq/L . Th e othe rfiv e lake s ar e les s sensitive , wit h ANC' s i n th e 5 5 t o 6 0 ueq/ Lrange . Th e bas e catio n an d AN C concentration s ofseepag e lake s suc h a s thes e depen d largel yo n th e proportio n ofwate r supplie d b ygroundwater . Ahydrologi cstud yo ffou r norther n Wisconsi n seepag e lake s showe d tha tthre e ofth e lake s wit h mea n ANC' s rangin g fro m 2 1 t o 11 8 ueq/ L receiv e fro m 3 t o 1 5 percen t o fthei rwate rfro m groundwater , whil e th e fourt h lak e wit h a mea n AN C of38 4 ueq/ Lreceive s 3 0 percen t groundwate r(Garriso n e tal . 1987) . Th e AN C o fa seepag e lak e i n Uppe rMichiga n wa s observe d t o dro p fro m 17 8 t o 2 2 ueq/ Love ra 5-yea rperio d whe n drough t condition s substantiall yreduce d th e inpu tof ANC-ric h groundwate r(Webste re tal . 1990) . Fisherie s survey s hav e bee n conducte d o n 1 2 o fth e 1 3 lake s i n th e Rainbo wLak e Wildernes s fo rwhic h wate r chemistrydat a ar e available . Th e tw o larges tlake s contai n largemout h bas s (Mlcropterus salmoides), an d anothe rha s bee n stocke d wit h rainbo wtrou t{Salmo gairdneri). Severa l hol d bluegill , perch , an d othe rpanfish , an d a variet yof minnow s an d roug h fish . N o fis h wer e foun d i n fou rlakes . Th e presenc e o rabsenc e offis h appear s t o b e relate d t o winte rsurvival . Th e fishles s lake s ar e amon g th e smalles t an d mos t shallo wo fth e lake s surveyed . O n th e basi s ofth e relationshi p betwee n bas e catio n concentration s an d F valu e suggeste d byBrakk e e t al . (1990) , a reasonabl e estimat e ofth e F valu e fo rth e mos t sensitiv e o fthes e lake s i s abou t0.4 . However , sinc e mos t o fth e wate ri n thes e lake s i s fro m direc t on-lak e precipitatio n an d doe s no treac twit h th e soil s an d mineral s i n th e watershed , catio n enrichmen tprobabl yi s minimal . Th e ILWA S mode l wa s use d t o simulat e wate rchemistry response s t o change s i n S depositio n i n tw o low-AN C seepag e lakes , Crysta l an d Vandercook , i n north-centra l Wisconsi n (Che n e tal . 1986 ; Garriso n e tal . 1987) . Thes e simulation s indicate d F value s o fclos e t o zero . W e estimat e F t o b e abou t0. 2 fo rth e mos tsensitiv e Rainbo wLak e Wildernes s lakes . Th e S0 4concentration s o fth e lake s i n Rainbo wLak e Wildernes s rang e fro m abou t 4 0 t o 6 0 ueq/L . Backgroun d S0 4concentration s fo rdilut e lake s i n th e Easter n Unite d State s hav e bee n estimate d a t abou t 1 5 ueq/ L(Brakk e e t al . 1989) . Thi s indicate s tha t th e Rainbo wLak e Wildernes s lake s hav e incurre d a n averag e S0 4increas e o fabou t 3 5 ueq/ Labov e backgroun d concentration s du e t o anthropogeni cS deposition . I fF = 0.2 , the n the yhav e incurre d AN C losse s o fabou t 2 5 ueq/ Ldu e t o aci d deposition . Tw o o fth e 1 3 lake s fo rwhic h dat a ar e availabl e hav e mea n ANC' s o f1 0 t o 2 0 ueq/L , wel l belo wth e gree n lin e valu e of 2 5 ueq/ Lan d int o th e yello wzone . Th e mea n ANC' s o ffiv e othe rlake s ar e abou t equa l t o th e gree n lin e valu e o f2 5 ueq/L—som e individua l AN C measurement s fro m thes e lake s als o fal l int o th e yello wzone . Thes e lak e chemistr y dat a indicat e tha t th e curren tS depositio n rat e o fabou t 6 kg/ha/y r(Tabl e 3 ) i s i n th e yello wzon e betwee n th e re d lin e an d gree n lin e values . Onl ya smal l increas e i n S depositio n woul d b e require d t o reduc e th e AN C o fth e mos t sensitiv e o fthes e lake s t o th e re d lin e valu e o f1 0 ueq/L . O n th e basi s o fGallowa ye t al.' s (1984,1987 ) estimat e o f backgroun d S0 4concentratio n i n precipitatio n o f5 t o 7 ueq/ Lan d a n averag e annua l rai n an d snowfal l o fabou t 80 0 m m i n northwester n Wisconsin , w e estimat e th e backgroun d S depositio n rat e o n th e Rainbo wLak e Wildernes s t o hav e bee n abou t 1 t o 1. 5 kg/ha/yr . Lak e wate r S0 4appear s hav e increase d b yabou t 3 5 ueq/ Love r background , a n increas e i n S0 4ofabou t7 t o 8 ueq/ Lfo r eac h kg/ha/y ro fS deposition . A s a comparison , ILWA S simulation s ofCrysta l an d Vandercoo k Lake s (Che n e t al . 1986 ; Garriso n e t al . 1987 ) projecte d a S0 4chang e o fabou t 6 t o 8 ueq/ Lfo reac h kg/ha/y rchang e i n S deposition . Give n a n annua l averag e o fabou t80 0 m m o fprecipitatio n an d abou t 30 0 m m o frunof f(Geraght ye tal . 1973) , a 1 kg/ha/y rincreas e i n S depositio n coul d increas e S0 4 concentration s i n norther n Wisconsi n lake s b ya s muc h a s 2 0 ueq/L , i fn o S0 4wer e retaine d b yreductio n i n wetland s an d lak e sediment s o rb yadsorptio n i n uplan d soils . Bake r e t al . (1986 ) develope d a mode l tha t showe d tha t i n lake s wit h lon g hydrauli cretentio n time s (severa l years ) typica l of lo wAN C seepag e lakes , S0 4reductio n i n th e lak e sediment s ca n reduc e S0 4concentration s i n th e wate rby 5 0 percen t o rmore . O n th e basi s o fILWA S simulations , Garriso n e t al . (1987 ) estimate d tha t i fS0 4reductio n wer e eliminated , th e S0 4concentration s o fCrysta l an d Vandercoo k

Lake s woul d increas e b yalmos t10 0 percent . I fth e F valu e ofthes e lake s i s abou t0.2 , the n a n increas e i n th e curren t6 kg/ha/y rtota l S depositio n rat e o fabou t 1. 5 t o 2. 5 kg/ha/y rwoul d b e sufficien t t o decreas e th e AN C o f th e mos t sensitiv e o fthes e lake s t o les s tha n th e re d lin e valu e o f1 0 ueq/L . Similarly , a decreas e i n S depositio n o f simila rproportion s coul d increas e th e AN C ofth e mos t 1 6P.2 0

sensitiv e lake s t o th e gree n lin e valu e o f2 5 ueq/L . Thes e estimate s compar e wel l t o th e ILWA S simulatio n o fCrysta l an d Vandercoo k

Lake s i n whic h a 5 0 percen t chang e i n S depositio n ( a chang e o fabou t 3 kg/ha/yr ) wa s projecte d t o caus e a 2 0 ueq/ Lchang e i n lak e AN C (Che n e t al . 1986 ; Garriso n e tal . 1987) . W e estimat e th e gree n an d re d lin e S depositio n rate s fo rth e Rainbo wLak e Wildernes s t o b e abou t3. 5 t o 4. 5 kg/ha/y ran d 7. 5 t o 8. 5 kg/ha/yr , respectively . Th e correspondin g estimate d gree n an d re d lin e depositio n rate s o fS + 2 0 percen to fN ar e abou t 4. 5 t o 5. 5 an d 9. 0 t o 10. 5 kg/ha/yr , respectively . Minnesota : Boundar yWater s Cano e Are a Wildernes s I n contras tt o th e Rainbo wLak e Wildernes s lakes , mos t o f th e BWCAWlake s ar e drainag e lakes . Muc h o fthei r hydrologi cinpu t i s fro m surfac e runof ffro m thei r watersheds . BWCA Wwater s ar e moderatel ysensitiv e t o sensitiv e wit h regar d t o acidi cdeposition . Abou t7 5 percen t o fth e lake s hav e ANC' s o f20 0 ueq/ Lo rless , an d abou t 3 5 percen t hav e les s tha n 10 0 ueq/L . However , onl yabou t5 percen thav e ANC' s belo w5 0 ueq/L , an d non e i s belo wth e AN C gree n lin e valu e o f2 5 ueq/L . Bas e catio n concentration s o fth e mos t sensitiv e lake s ar e abou t 13 0 t o 14 0 ueq/L . Th e pH' s o feve n th e mos tsensitiv e lake s generall yar e 6. 5 o rgreater . Asmal l proportion , perhap s 2 percent , hav e pH' s betwee n 5. 5 an d 6.5 ; thes e ar e typicall y dark-colore d lake s influence d b ynaturall yacidi cflrainag e fro m peatlands . Th e mos t sensitiv e BWCAWlake s appea r t o hav e sufficien tbuffe rcapacit yt o handl e th e presen t depositiona l loading s o fS an d N . Th e fis h population s i n lake s an d stream s i n th e BWCA War e typicall yhealth yan d abundant . watershe d S0 4retentio n processes , a n increas e i n S depositio n o f1 kg/ha/y rcoul d increas e BWCA Wlak e SC 4 b y2 0 t o 2 5 ueq/L . However , considerin g th e importanc e o f S0 4reductio n i n lak e botto m sediment s an d i n peatland s i n th e watershed , w e estimat e th e actua l increas e i n lak e S0 4 fro m eac h kg/ha/y rincreas e i n S depositio n t o b e abou t 1 2 t o 1 5 ueq/L . Give n F value s o f0.6 , w e estimat e a n AN C decreas e o f5 t o 6 ueq/ Li n sensitiv e BWCA Wlake s fo reac h kg/ha/y rincreas e i n S deposition . Fo rth e mos tsensitiv e BWCAWlake s fo rwhic h w e hav e data , thos e wit h ANC' s o fabou t 4 0 ueq/L , w e estimat e tha t a reductio n o f1 5 ueq/ Lt o th e gree n lin e AN C valu e o f2 5 ueq/ Lwoul d resul tfro m a S depositio n increas e o fabou t 2. 5 t o 3. 0 kg/ha/yr . A n additiona l 2. 5 t o 3. 0 kg/ha/y rwoul d furthe rreduc e ANC' s t o th e re d lin e valu e o f1 0 ueq/L . Th e presen t tota l S depositio n rat e i n th e BWCA Wi s abou t5 kg/ha/y r(Tabl e 3) . W e estimat e th e gree n lin e S depositio n rat e t o b e abou t 7. 5 t o 8. 0 kg/ha/y ran d th e re d lin e S depositio n rat e t o b e 1 0 t o 1 1 kg/ha/yr . Th e gree n an d re d lin e value s fo rS + 2 0 percen t ofN depositio n woul d b e abou t 9 t o 1 0 an d 1 2 t o 1 3 kg/ha/yr , respectively . I n 1982 , th e Stat e o fMinnesot a passe d th e Aci d Depositio n Contro l Act . Unde rthi s legislation , th e Minnesot a Pollutio n Contro l Agenc yconducte d a n analysi s t o determin e a S depositio n limi t tha t woul d protec tth e mos t sensitiv e lake s an d stream s i n Minnesot a fro m acidification . Thi s limi twa s se t a t 1 1 kg/ha/y ro fwe t S0 4deposition . Fro m th e relationshi p betwee n we t an d dr yS depositio n i n th e 3WCA W(Tabl e 3) , 1 1 kg/ha/y ro fwe t S0 4i s equivalen t t o abou t 6 kg/ha/y ro ftota l (we t plu s dry ) S deposition . Thi s i s somewha t lowe rtha n ou rgree n lin e estimat e fo rth e BWCAW . Th e mos t sensitiv e BWCA Wlake s fo rwhic h w e hav e dat a hav e ANC' s o fabou t4 0 ueq/L . The ycoul d sustai n a n AN C los s o f1 5 ueq/ Lwithou tfallin g belo wth e 2 5 ueq/ Lgree n lin e value . Give n bas e catio n concentration s o f13 0 t o 14 0 ueq/L , w e estimat e (usin g th e metho d o fBrakk e e t al . 1990 ) th e F valu e o fthes e lake s t o b e abou t0.6 . Consequently , w e estimat e tha ta n AN C los s o f1 5 ueq/ Lwoul d resul tfro m a lak e S0 4increas e o fabou t3 5 t o 4 0 ueq/L . I n th e BWCAW , th e relationshi p betwee n S depositio n rat e an d lak e S0 4concentration s i s difficul tt o deriv e fro m comparison s o festimate d backgroun d precipitatio n an d lak e S0 4concentration s wit h presen tvalues . Man yo fth e BWCA Wlake s li e o n geologi cformation s tha tcontai n extensiv e low-grad e sulfid e deposit s (Sim s an d More y 1972) . Therefore , estimate s o faverag e backgroun d S0 4 concentration s fo reaster n lake s (e.g. , Brakk e e tal . 1989 ) ar e to o lo wfo rman yBWCA Wlakes . Nichol s an d McRobert s (1986 ) foun d tha tlake s nea rth e easter n en d o f th e BWCA Wcontaine d abou t 5 0 ueq/ Lmor e S0 4tha n woul d b e expecte d fro m S depositio n alone . Averag e annua l precipitatio n i n th e BWCAWi s abou t 67 5 t o 72 5 mm . Annua l runof faverage s abou t25 0 t o 30 0 m m (Geraght ye t al . 1973) . I n th e absenc e o fin-lak e o r Missouri : Hercule s Glade s Wildernes s Th e Hercule s Glade s Wildernes s lie s o n th e southwester n portio n o fth e Ozar k

Plateau . Th e geologi cformation s tha t mak e u p th e Ozar k

Platea u ar e predominantl ylimeston e an d dolomite . Th e carbonat e mineral s i n thes e rock s provid e a larg e bufferin g capacit yagains t th e effect s o f acidi cdeposition . Sample s take n fro m Lon g Creek , th e mai n strea m i n th e wilderness , i n th e summe ro f199 0 ha d AN C an d bas e catio n concentration s o fabou t 4,00 0 t o 6,00 0 ueq/L . Springtim e concentration s ar e probabl y substantiall ylowe rbu t shoul d provid e abundan t buffering . A sampl e take n fro m Beave rCreek , whic h flows alon g th e northwester n boundaryo fth e wildernes s fo ra short distance , ha d a p H o f8. 0 an d a n AN C exceedin g 2,00 0 ueq/L . Th e impoundment s o n th e Whit e River , jus t wes t an d sout h o fHercule s Glade s Wilderness , typicall yhav e pH' s i n th e 7. 2 t o 7. 8 rang e an d ANC' s o f1,00 0 t o 2,00 0 ueq/L . Becaus e o fth e hig h bufferin g capacit yo fthi s area , th e presen t estimate d tota l S an d N depositio n rate s o f9 an d 8 kg/ha/yr , respectively , (Tabl e 3 ) pos e n o threa t t o aquati c ecosystems . W e estimat e th e gree n lin e S depositio n rat e t o b e greater—perhap s muc h greater—tha n 3 0 kg/ha/yr , an d th e S plu s 2 0 percen to fN rat e t o b e greate rtha n 3 5 kg/ha/yr . W e di d no t attemp t t o estimat e re d lin e values . 1 7

_

## Informatio n Need s P.2 1



### Inventor yan d Monitorin g Worksho p participant s identifie d man yinformatio n need s fo rsuccessfu l respons e t o PS D permi tapplications , bu t indicate d th e primar ynee d wa s fo rthoroug h characterizatio n an d inventoryo fth e wildernes s areas . Existin g inventory dat a fo reac h o fth e wildernes s area s i n Regio n 9 shoul d b e assemble d fro m it s man ysource s an d locations , an d informatio n gap s b e fille d a s soo n a s possible . Th e biologica l resource s o feac h are a shoul d b e characterized , an d shoul d includ e listing s o faquati can d terrestria l flor a an d fauna , an d description s o fecosystems . Soil s shoul d b e describe d t o th e famil yleve l (Soi l Surve yStaff1987) . Bedroc k typ e an d geologi cformation s als o shoul d b e characterized . Informatio n o n pollutan tdeliveryt o eac h are a shoul d b e quantified . Particula remphasi s shoul d b e give n t o identifyin g threatene d an d endangere d specie s an d thos e tha t ar e particularl ysensitiv e t o ai rpollutants . Monitorin g entail s continue d measuremen to fth e statu s o f th e syste m ove rtime . Monitorin g need s fo raquati csystem s includ e atmospheri cloadin g o fpollutants , chemica l characteristic s o fstrea m o rlak e waters , an d presenc e o r absenc e o fpotentiall ysensitiv e recepto rspecies . Fo r terrestria l ecosystems , reliabl e monitorin g ofspecie s richnes s a s wel l a s ai rqualit yan d depositio n i s necessary . Monitorin g fo rbot h aquati can d terrestria l system s mus t b e consisten tan d o fhig h quality . Worksho p participant s suggeste d a samplin g protoco l of collectio n ofwate rsample s 3 time s a yea ri n everythir d year . Timin g o fsamplin g migh t includ e springtim e snowmel t pea k flow , summe rlo wflow , an d autum n turnover . Strea m chemistr yofte n i s affecte d b ylarg e precipitatio n events . Chemistryo fsensitiv e seepag e lake s ma yb e influence d by annua l o rmultiyea rprecipitatio n pattern s tha t affec t groundwate rlevel s an d lak e inputs . Long-ter m samplin g i s neede d t o separat e annua l an d seasona l variation s i n wate r chemistr yfro m pollutant-induce d changes . Th e "best " time s fo rsamplin g an d th e intensit yofsamplin g require d wil l depen d o n th e area , an d mor e detaile d determination s ar e needed . Monitorin g ofbiologica l resource s als o i s needed . Detectio n o fpopulatio n change s fo ran yspecifie d organis m i s extremel ydifficul t du e t o hig h natura l variation , bu t potentiall ysensitiv e recepto rorganism s shoul d b e monitore d fo rthei rpresenc e o rabsence . Historica l record s shoul d b e consulte d t o establis h th e existenc e o fpreviou s population s o forganisms . Birds , fish , aquati cinvertebrates , amphibians , an d diatom s ar e candidate s fo rmonitoring . Biomonitorin g o fvegetatio n fo rpollutan t injurysymptom s als o ca n b e done . Biomonitorin g program s mayb e limite d becaus e th e sensitivit yo fman yrar e an d endemi cplant s t o ai rpollutant s i s no t known . Monitorin g ofozon e shoul d b e th e firs tpriorit yfo rterrestria l ecosystems . Ozon e concentration s ca n varysignificantl y wit h elevation , an d thi s elevationa l gradien tshoul d b e take n int o consideratio n whe n locatin g monitorin g stations . Curren t ozon e effect s i n wildernes s area s als o shoul d b e assesse d throug h biomonitoring . Thi s alread yha s begu n o n th e Doll ySods , Ly e Brook , an d Grea tGul fWildernesses , an d ca n b e implemente d fairl yeasil yat othe rsites . Becaus e o fth e restriction s place d o n wildernes s use , an d du e t o th e hig h biologica l complexit yo n som e o fthes e easter n wildernesses , traditiona l method s ofozon e monitoring , althoug h wel l developed , ma ynee d som e modifications . Monitorin g o fdepositio n o fth e majo rcation s an d anion s i n precipitatio n (we tdeposition ) shoul d continu e t o b e carrie d ou t at th e existin g NADP/NT N stations . Th e Fores t Servic e shoul d ensur e tha t fundin g i s maintaine d fo roperatio n o f NADP/NT N site s tha t ar e relevan tt o Clas s I wildernes s areas . I n additio n t o th e NADP/NT N network , applicabl e dat a ma yb e availabl e fro m severa l othe rwe tdepositio n networks , fo rexample , MAP3S , UAPSP , CAPMON , an d APIOS- C (se e Sisterso n e tal . 1990) . I fn o NADP/NT N o r othe rnetwor k

site s ar e applicabl e t o a certai n wilderness , provisio n shoul d b e mad e fo restablishin g an d maintainin g a n equivalen t monitorin g site . Wate rchemistr ymonitorin g shoul d b e conducte d o n a subsampl e ofsurfac e water s i n eac h Clas s I wildernes s area . Thi s subsampl e shoul d includ e th e mos t sensitiv e lake s an d streams , o rth e water s o fgreates t concern . Researc h Need s Drydepositio n i s a n importan tcomponen t o ftota l deposition , bu t i s no twel l quantified . I n thi s report , estimate s o fdr yS depositio n wer e derive d fro m th e Regiona l Aci d Depositio n Mode l (RADM ) describe d b y Chan g e tal . (1987 ) a s percentage s o fwe t S deposition . Dr y N depositio n rates , a s percentage s o fwe tN deposition , wer e estimate d fro m dat a fro m CORE/Satellit e site s a s summarize d b ySisterso n e t al . (1990) . Anothe rmetho d of estimatin g dr ydepositio n entail s measurin g throughfal l chemistr yatspecifi csites . Th e throughfal l metho d ha s bee n use d o n severa l researc h areas . Se e Sieverin g (1987 ) fo ra n analysi s ofth e metho d an d Lindber g e tal . (1986 ) fo ra cas e study . Dr

ydepositio n als o ca n b e estimate d bymultiplyin g ambien t concentration s b y"depositio n velocities. " Ambien t concentration s o fS an d N form s ar e measure d at abou t 5 0 site s i n th e Nationa l Dr yDepositio n Networ k

(NDDN) , sponsore d b yth e U.S . EPA . Althoug h estimate s of depositio n velocitie s ar e give n i n th e USD AFores t Service' s Ai rResourc e Handbook , depositio n velocitie s vary considerabl y(order s ofmagnitude ) fo rdifferen tS an d N species , fo rdifferen tsurface s suc h a s forest , grassland , water , an d bar e rock , an d fo rdifferen t atmospheri c conditions . Pollutan tdepositio n velocitie s shoul d b e develope d fo rsubarea s ofeac h Clas s I wilderness . I n mountainou s areas , th e depositio n ofpollutant s dissolve d i n clou d droplet s ont o vegetatio n surface s at hig h elevation s 1 8P.2 2

ca n excee d we t plu s drydeposition . Clou d depositio n begin s t o b e importan ta t elevation s o fabou t85 0 t o 90 0 m an d increase s wit h elevation . Knowledg e o fhigh-elevatio n depositio n b yan yproces s i s sparse , althoug h som e informatio n i s availabl e fro m th e Mountai n Clou d Chemistry Progra m (Mohne n 1990) . T o fil l th e informatio n ga p abou t high-elevatio n deposition , Lovet t an d Kinsma n (1990 ) sugges ta n increase d densit yofdepositio n monitorin g site s i n mountainou s regions ; specifi cstudie s o fwet , dry , an d cloudwate rdepositio n alon g elevationa l gradients ; an d investigation s o fth e factor s tha tregulat e depositio n i n mountainou s area s t o allo wextrapolatio n o fresult s t o othe r sites . Becaus e o fth e difficultie s o fcarryin g ou tintensiv e depositio n studie s i n designate d wildernes s areas , th e abilit yt o extrapolat e dat a t o wildernes s site s i s important . Fo rman ypollutants , model s tha t describ e th e link s betwee n emission s an d pollutan t loadin g ar e no tavailable . Mos t notably , i t i s no t wel l know n ho wozon e concentration s at a particula rlocatio n ar e relate d t o emission s ofvolatil e organi ccompounds . Additionally , researc h o n th e relatio n of S0 2 emission s an d S0 4exposur e i s needed . Sorel yneede d i s informatio n abou t th e effect s ofcumulativ e exposur e o n th e ecosystem s o fconcern . Depositio n reduction s wil l no t necessaril yb e immediatel yreflecte d i n improvement s i n wate rqualit yo rdiminishe d effect s upo n organisms . Continue d depositio n a teve n lowe rrate s coul d resul ti n acidificatio n o fsom e surfac e waters . Atpresent , cumulativ e exposur e migh tb e bes tassesse d byth e us e ofsimulatio n models . I T o asses s cumulativ e impact s an d potentia l impact s of predicte d change s i n deposition , simulatio n model s suc h a s ILWA S (Gherin i e t al . 1985 ) an d MAGI C (Cosb ye t al . 1985a,b ) ar e useful . Suc h model s ca n b e use d t o estimat e dose-respons e function s fo rindividua l wildernesse s o rthei r componen t parts . Thes e function s ar e independen to fan y particula rPSD , s o modelin g nee d onl yb e don e onc e rathe r tha n i n respons e t o eac h PS D application . Bot h ILWA S an d MAGI C hav e bee n i n us e fo rsevera l year s an d alread yma y hav e bee n calibrate d an d ru n fo rwatershed s simila rt o man yofth e Clas s I area s discusse d here . Thi s coul d significantl ydecreas e th e cos tofdat a collectio n an d calibration . Becaus e ofth e uncertaintie s an d biase s inheren ti n an ymethod , prediction s o fth e respons e o fth e Clas s I wildernes s area s t o acidi cdepositio n shoul d b e mad e usin g a combinatio n ofmethods , includin g simulatio n model s lik e ILWA S an d MAGIC , empirica l steady-stat e model s (e.g . Brakk e an d Henrikse n 1989 ) (wit h som e adjustmen t fo rin-lak e AN C productio n (Bake re tal . 1986 ) wher e appropriate) , an d paleolimnologica l studie s ofdiato m communities . Th e Fores tServic e shoul d plac e a priorit yo n assemblin g th e appropriat e dat a an d runnin g thes e model s fo ral l Clas s I area s i n th e Easter n Region . Th e procedur e describe d i n thi s report i s interim . Th e recommende d criteri a wil l chang e wit h th e dramaticall y changin g stat e o fscienc e i n ai rpollutio n effects . Manager s an d scientist s wil l hav e t o revie wthes e change s an d adjus t th e criteri a an d possibl yth e procedure . W e recommen d that : 1 . Representative s ofth e Easter n Region , th e Northeaster n Fores tExperimen tStation , th e Nort h Centra l Fores t Experimen t Statio n an d Northeaster n Area-Stat e & Privat e Forestryperiodicall yrevie wth e applicabilit yofthi s screenin g procedur e an d jointl yrecommen d change s neede d i n th e criteria ; 2 . Nationa l Fores t an d researc h projec t staffannuall ymee t t o assur e effectiv e inventoryan d monitorin g ofresourc e condition s i n Clas s I areas , t o assur e tha t manager s ar e usin g recen t researc h results an d t o hel p researcher s understan d th e problem s o fmanagers . 

## Acknowledgmen t Participant s at th e Ma y199 0 Fores tServic e worksho p i n Oconomowoc , Wisconsin , provide d advic e o n a screenin g procedur e fo ridentifyin g impact s t o th e AQRV s o fNationa l Fores tEaster n Regio n Clas s I ai rqualit yareas . Worksho p participant s als o wer e give n a n opportunit yt o revie wth e draf t o fthi s report ; w e als o obtaine d pee rrevie wb y scientist s wh o wer e no t atth e meeting . Dr . Lewi s Ohman n o fth e Nort h Centra l Fores tExperimen tStation , Dr . Christophe rEaga rofth e Northeaster n Fores t Experimen t Station , an d Jame s Byrn e o fth e Fores t Service' s Washingto n Offic e provide d revie wcomment s o n th e fina l draft .

1 9

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e Cited P.2 3

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sa c frysurviva l durin g sprin g snowmelt . Canadia n Journa l o fFisherie s an d Aquati cScience . 41 : 319-329 . Hawksworth , D . L. ; Rose , F . 1970 . Qualitativ e scal e fo r estimatin g sulphu rdioxid e ai rpollutio n i n Englan d an d Wale s usin g epiphyti c lichens . Nature . 277 : 145-148 . Henriksen , A. ; Brakke , D . F . 1988 . Increasin g contribution s ofnitroge n t o th e acidit yo fsurfac e waters i n Norway . Water , Ai r& Soi l Pollution . 42 : 183-201 . Jackson , W . A. ; Arbucci , L . 1989 . Ozon e symptom s wer e presen t o n bloindlcato rplant s a t th e Otte rCree k Wildernes s an d Doll ySod s Wilderness , Monongahel a Nationa l Forest , 1989 . Morgantown , WV : U.S . Departmen t o fAgriculture , Fores t Service , Northeaster n Are a Stat e an d Privat e Forestry . Johnson , D . W . 1979 . Ai rpollutio n an d th e distributio n o f corticolou s lichen s i n Seattle , Washington . Northwes t Science . 53 : 257-263 . Kanciruk , P. ; Eilers , J . M. ; McCord , R . A. ; Landers , D . H. ; Brakke , D . F. ; Linthurst , R . A . 1986 . Characteristic s o f lake s i n th e Easter n Unite d States , volum e III : dat a compendiu m ofsit e characteristic s an d chemica l variables . EPA/600/4-86/007 C Washington , DC : U.S . Environmenta l Protectio n Agency . Langdon , R . W . 1984 . Fisherie s statu s i n relatio n t o acidit yi n selecte d Vermon t lakes . Montpelier , VT : Vermon tAgenc yofEnvironmenta l Conservation , Departmen t ofWate rResource s an d Environmenta l Engineering . Wate rQualit yDivision . LeBlanc , F . 1969 . Epiphyte s an d ai rpollution . In : Ai r pollution : proceeding s ofth e firs t Europea n congres s o n th e influenc e o fai rpollutio n o n plant s an d animals . Wageningen , Netherlands . [Publishe rnam e unknown] : 211-221 . LeBlanc , F. ; Rao , D . N. ; Comeau , G . 1972 . Th e epiphyti c vegetatio n ofPopulus balsamlfera

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2 2P.2 6



## Appendi xI Genera l Descriptio n o

fAi rQuality-Related Values fo rEaster n Regio n Class I Areas

DOLL YSOD S WILDERNES S Location : Size : 10,21 5 acre s Monongahel a Nationa l Fores tDesignated : 197 5 Easter n Wes t Virgini a Latitude : Elevation : 2,62 0 t o 38 ° 57'30 " t o 39 ° 02'30 " 4,12 2 fee t Longitude : 

### 79 ° 19't o 79 ° 24'30 "

Genera l Descriptio n Doll ySod s Wilderness , whic h i s o n th e Alleghen yPlateau , i s name d fo rth e pionee rDahl e famil ywhic h owne d an d cleare d som e ofth e lan d fo rpastur e ("sods " i s a n ol d ter m fo rgrassland) . I t i s abou t1 0 mile s fro m Petersburg , Wes t Virginia , an d 17 5 mile s fro m Washington , D.C . Evidenc e o fhuma n presenc e i n th e are a i s apparent . Remnant s o fth e extensiv e networ k o froad s an d trail s necessaryt o harves t timbe ri n th e lat e 1800' s an d earl y 1900' s ca n stil l b e seen . Grazing , onc e a n importan tuse , n o longe roccurs . Ahars h climat e resemblin g tha tfoun d muc h farthe rnort h i s a majo rinfluence . Vegetation . Second-growt h beech , birc h an d maple , dens e rhododendron , laurel , blueberry , an d othe rheat h vegetatio n ar e common , a s ar e wetlan d communities . Re d spruc e i s commo n i n th e uppe relevations , an d som e oa k i s foun d at lowe relevations . Wildlife . Deer , blac k

bear , bobcat , beaver , grouse , turkey , woodcock , rabbit , an d numerou s othe rbirds , mammals , amphibians , an d reptiles , includin g th e easter n timbe r rattler , inhabi t th e wilderness . Weather . Th e climat e i s sever e an d temperature s ar e cool . Fros t ca n occu ra t an ytim e bu ti s rar e durin g mos tofth e summer . Prevailin g westerl ywind s blo wmos to fth e time , an d th e uppe relevation s ofte n ar e covere d b ycloud s o rfog . Annua l precipitatio n i s abou t 5 5 inches . Frequen tan d sudde n weathe rchange s ar e common . Ai rQuality-Relate d Value s Sceni cBeauty . Th e sceni cbeaut yofth e Doll ySod s Wildernes s i s a primaryattractio n fo rit s users . Feature s includ e roc k

escarpment s whic h provid e panorami cview s o f th e deepl yincise d Re d Creek , th e high-elevatio n plateau , mountai n summits , an d surroundin g ridg e lines . Visua l diversit yi s enhance d b ycontrastin g wetland/bo g associations , high-elevatio n spruce , mixe d hardwoods , an d earl ysuccessiona l vegetatio n suc h a s blueberry . User s enjo yth e sens e o fsolitud e an d a variet yo flandform s an d associate d vegetativ e communitie s an d wildlife . Extensive thicket s o frhododendro n an d mountai n laure l throughou t th e wildernes s provid e pleasin g diversit ydurin g thei r flowerin g period . Lowe rRe d Cree k i s rock-strew n an d fas t flowing , an d periodicall yflow s ou t o fth e channel . It s water s ar e staine d reddish-brow n fro m th e wetland s an d othe r vegetatio n i n th e creek' s uppe rreaches . Mos tofth e recreatio n us e withi n th e Doll ySod s Wildernes s occur s alon g Re d Creek . Vegetation . Th e overstoryi s dominate d b ya mixtur e of second-growt h norther n an d Alleghen yhardwood s whic h ar e 6 0 t o 8 0 year s old . Ther e ar e separat e component s o f oak , heath , an d associate d species . Spruc e i s presen t at highe relevations . Ther e ar e scattere d pocket s o f wetland/bo g associations , an d abou t 100 0 acre s i n a grass/for b stage . Extensiv e thicket s o frhododendro n an d mountai n laure l ar e foun d throughou t th e wilderness . Water . Re d Cree k

i s th e dominan twate rresourc e ofthi s wilderness . Fe d b ynumerou s tributaries , th e cree k i s staine d reddish-brow n wit h tanni cacid s fro m headwate r wetland s an d othe rvegetation . Al l water s ar e aci d an d unproductive . Re d Cree k ha s historicall ybee n a margina l fishery . Odor . Th e natura l smell s ofth e fores tar e a n importan t valu e t o wildernes s users . Conifers , hardwoo d lea flitter , an d wildflower s provid e pleasan t odor s whic h enhanc e th e outdoo rexperience . Wildlife . Avariet yo fmammals , birds , reptiles , an d amphibian s inhabi t th e wilderness , includin g th e Chea t Mountai n salamander , a federall yliste d threatene d species . Som e nongam e fis h specie s ar e present , includin g th e uncommo n pear l dace . Ther e i s a smal l populatio n o fnativ e broo k trou t i n Re d Creek .

OTTE R CREE KWILDERNES S Location : Size : 20,00 0 acre s Monongahel a Nationa l Fores t Designated : 197 5 Easter n Wes t Virgini a Latitude: . Elevation : 1,83 0 t o 38 ° 55'30 " t o 39 ° 03'30 " 3,91 2 fee t Longitude : 

### 79 ° 35 ' to 79 ° 42 ' 30 "

Genera l Descriptio n Otte rCree k

Wildernes s i s locate d abou t 1 0 mile s northeas t o fElkins , Wes t Virginia . Otte rCree k run s 1 1 mile s throug h a valle yan d i s followe d b ya trai l alon g it s 1,200-foo t dro p t o th e Dr yFor k River . Paralle l mountai n ridge s tha treac h height s of3,90 0 fee t encircl e a 4-mile-wid e ova l watershe d wit h numerou s smal l stream s flowin g int o Otte rCreek . Vegetation . Th e wildernes s wa s logge d durin g th e lat e 1800' s an d earl y1900' s an d agai n betwee n 195 8 an d 1972 . Mos tofth e wildernes s i s no wforeste d wit h second-growt h stand s o fnorther n hardwood s an d Alleghen ymixe d hardwoods . Nearl yimpenetrabl e stand s o fwaxy-leave d rhododendro n cove rextensiv e portion s ofth e area , makin g off-trai l hikin g difficult . Re d spruc e occupie s som e ofth e highe relevation s an d ther e ar e som e smal l freshwate r wetlan d communities . 2 3P.2 7

Wildlife . Blac k

bear , white-taile d deer , bobcat , beaver , wil d turkey , grouse , snowsho e hare , cottontai l rabbit , salamander , an d numerou s othe rbird , mammal , amphibian , an d reptil e species , includin g th e timbe rrattler , inhabi t th e wilderness . Ther e i s a smal l populatio n o fbroo k trou t i n Otte rCree k

du e t o improve d wate rqualit yfro m a n artificia l limin g station . Weather . Coo l temperature s prevai l an d fros tmayoccu r durin g an ymont h ofth e year . Th e are a receive s abou t 5 5 inche s o fprecipitatio n annually . Ai rQuality-Relate d Value s Sceni cBeauty . Th e sceni cbeaut yo fth e Otte rCree k watershe d i s highl yvalue d b yit s users . Panorami cview s of nearl yth e entir e watershe d ar e obtaine d fro m a numbe ro f larg e roc k

cliffs . Th e visua l resourc e include s th e Otte r Cree k valle yan d mountain s whic h ris e mor e tha n 3,80 0 fee t abov e se a level . Visua l diversit yi s provide d b ya numbe rof smal l freshwate rwetland s an d roc k outcrops . Man yuser s experienc e a sens e o fsolitud e an d peac e whe n the yar e i n th e mature , second-growt h fores ttha t als o provide s visua l diversit ythroug h a variet yo ftre e an d shru b species . Otte r Cree k itsel fi s a clear , clea n mountai n stream , tumblin g ove r boulder s i n alternatin g smal l waterfall s an d pools . Muc h of th e recreatio n us e i n th e wildernes s occur s i n an d nea r Otte rCreek . Vegetation . A n overstoryo fsecond-growt h norther n hardwood s an d Alleghen ymixe d hardwoods dominate s th e Otte rCree k

Wilderness . Re d spruc e i n th e highe relevation s provide s visua l an d vegetativ e diversit yyea raround . A 59-acr e patc h o fvirgi n re d spruc e an d hemloc k o n Shaver s Mountai n provide s a remnan to fth e preloggin g er a timbe r foun d i n Otte rCreek . Anothe rinterestin g featur e i s a 50-year-ol d stan d o fplante d Norwa yspruce , approximatel y 20 0 acre s i n size . Extensiv e rhododendro n thicket s ar e common , an d thei rseasona l flowerin g provide s a n attractiv e understory . Otherwise , th e groun d an d herbaceou s understoryi s lackin g i n th e richnes s an d diversit yfoun d a t othe rlow-elevatio n mesi csites . Ther e ar e limite d area s o f limeston e bedroc k

wher e a mor e divers e understory vegetativ e mi xprovide s visua l variety . Smal l freshwate r wetland s an d thei rassociate d plan t communitie s provid e additiona l vegetativ e diversity . Water . Otte rCree k

i s th e dominan twate rresourc e ofthi s wilderness . Severa l smalle raci d an d unproductiv e tributarie s flo wint o th e mai n stream . Wate rqualit yi n Otte r Cree k i s no t representativ e o fnatura l condition s du e t o a n artificia l limin g facilit ytha toperate s i n it s headwaters . Water s ar e col d an d clear , an d tributarie s generall yar e staine d brow n fro m tanni cacids . Wate rqualit yi s importan t t o wildernes s user s fo rdrinkin g purposes . Wate rqualit yo f Shaver s Lic k

Run , a perennia l strea m withi n th e wildernes s tha t i s no t a tributar yt o Otte rCreek , i s bette rtha n tha to f th e tributaries . Odor . Th e natura l smell s o fth e fores t ar e a n importan t valu e t o wildernes s users . Conifers , hardwoo d lea flitter , an d wildflower s provid e pleasan todor s whic h enhanc e th e enjoymen t o fbein g outdoors . Wildlife . Wildernes s visitor s enjo ya variet yofgam e an d nongam e animals . Otte rCree k i s hom e t o numerou s birds , larg e an d smal l mammals , reptiles , amphibians , an d fish . Th e Virgini a norther n flyin g squirrel , a federall yliste d endangere d species , occupie s th e uppe relevation s o fth e wilderness . Th e threatene d Chea t Mountai n salamande ri s foun d i n th e wildernes s uplands . Ther e ar e population s o f nativ e broo k

trou t i n Otte rCree k

du e t o improve d wate r qualit yfro m th e artificia l limin g facilit ya t it s headwaters .

GREA TGUL F WILDERNES S Location : Size : 5,55 2 acre s Whit e Mountai n Nationa l Fores tDesignated : 197 5 Nort h Centra l Ne wHampshir e Latitude : Elevation : 1,68 0 t o 44 ° 15 ' 00 " t o 44 ° 22 ' 30 " 5,80 7 fee t Longitude : 71°15'00 " Genera l Descriptio n Th e Grea t Gul fWildernes s i s shape d lik e a larg e amphitheater—th e norther n an d wester n boundarie s follo w th e ridg e o fth e Presidentia l Range . Th e stee p cliff-lik e wall s o fthi s rang e surroun d a clea rmountai n lak e an d numerou s cascadin g streams . Th e wildernes s feature s hig h mountai n peaks , glacia l cirques , an d uniqu e tundr a an d krummhol z vegetation . Th e Grea t Gul fWildernes s i s small ; road s paralle l th e boundaryfo rconsiderabl e distances . Nearb yi s heavil yuse d Mt . Washingto n Stat e Park . A s a result , th e wildernes s receive s muc h da yuse . Vegetation . Hardwood s cove rth e lowe rslopes ; mixe d birches , maples , an d spruce-fi rblanke t midslopes ; an d pur e spruce-fi rcover s th e uppe rslopes . Part s o fth e majo rridge s ar e abov e timberlin e wit h krummhol z vegetation . Wildlife . Wildlif e i s no t a prominen t feature , thoug h deer , blac k bear , grouse , hare , an d a variet yo fbird s associate d wit h hig h mountai n slope s ar e foun d i n th e wilderness . Weather . Th e weathe ri s strongl yinfluence d b yth e elevatio n an d geographi clocation . Th e Grea tGul f Wildernes s lie s betwee n tw o majo rpath s o fweather-syste m movemen t whic h ca n caus e dramati cchange s i n loca l weathe rconditions . I ti s no t uncommo n fo rtemperature s t o b e i n th e sunn y80' s i n th e valley s an d 3 0 t o 4 0 degree s coole ro n th e summit s wit h hig h winds , rain , an d fog . Wind s i n exces s of10 0 mile s pe rhou rhav e bee n recorde d fo r 2 4P.2 8



### ever ymont h o

fth e year . Averag e annua l precipitatio n i s 6 0 inche s wit h 25 t o 30 percen t fallin g as snow ; averag e annua l snowfal l i s 160 t o 240 inches . Ai rQuality-Relate d Values Because o

fcontiguityan d similarities , AQRV s fo rthi s wildernes s ar

e include d wit h thos e fo rth e Presidentia l Range-Dr yRive rWilderness . PRESIDENTIA L RANGE-DR YRIVE R WILDERNESS Location : Size : 27,38 0 acre s Whit e Mountai n Nationa l Forest Nort h Centra l Ne

wHampshir

e Designated : 197

5 Latitude : 44 ° 07 ' 30 " t o 44 ° 15 ' 00 " Elevation : 88 0 t o Longitude : 5,41 3 feet 71 ° 15'00 " t o 71 ° 22'30 "

Genera l Descriptio n Th e Presidentia l Range-Dr yRive rWildernes s feature s mountai n peak

s rangin g fro m 3,00 0 to 5,40 0 feet , som e areas abov

e timberline , distinctiv e geologi cformations , an d uniqu e biologica l communities . Th e northwest boundar yi s th e ridg e o

fth e Presidentia l Rang e an d th e th e Appalachia n Trai l (a Nationa l Sceni cTrail ) run s alon g th e norther n an d wester n boundary . Vegetation . Hardwood s occupyth e lowe rslopes ; mixe d birches , maples , an d spruce-fi rblankets th e midslopes ; an d pure spruce-fi rcover

s th e uppe rslopes . Aportio n o fth e majo rridge s i s abov

e timberlin e wit h typica l krummhol z vegetation . Wildlife . Wildlif e i s no

t a prominen t feature o

fthi s wilderness , thoug h deer , blac k

bear , grouse , hare , an d a variet yo fbird s associate d wit h hig h mountai n slope s ar e foun d here . Weather . Th e weathe ri s strongl yinfluence d b yth e elevatio n an d geographi clocation . Th e Presidentia l Rang e lie s betwee n two majo rpath s o fweather-syste m movement whic h ca n caus e dramati cchange s i n loca l weathe r conditions . I t i s no

t uncommo n fo rtemperature s t o b e i n th e sunn y80' s i n th e valleys an d 30 t o 40 degree s coole r o n th e summits wit h hig h winds , rain , an d fog . Wind s i n excess o f100 mile s pe rhou rhave bee n recorde d fo rever y mont h o fth e year . Averag e precipitatio n i s 6 0 inche s wit h 2 5 to 30 percen t fallin g a s snow ; averag e annua l snowfal l i s 160 t o 240 inches . Ai rQuality-Relate d Value s Th e Grea t Gul fan d Presidential-Dr yRive rWildernesse s ar

e separate d b

yth e summi t o

fMt . Washington . Because o f thei rproximit

yan d becaus e theyhav

e numerou s feature s i n common , includin g geology , wate rresources , visua l range , alpin e areas , wildlife , an d vegetation , th e AQRV s fo rbot h areas ar e nearl yidentical . Sceni cBeauty . Th e interplayo frugge d for m an d varyin g vegetatio n makes bot h wildernesse s highl yscenic . Theyare dominate d b

yhig h mountai n peaks , larg e expanse s abov e timberline , distinctive geologi cformations , an d vegetative communitie s rangin g fro m deciduou s low-elevatio n forests t o uniqu e alpin e vegetation . Rock cappe d peak

s an d ridg e line s provid e outstandin g sceni cvistas . As reporte d i n earlie rplannin g efforts , "...th e rugge d characte ro

fth e slope s an d surroundin g peak s (i n th e Grea

t Gul fWilderness ) whic h shu ti n th e valley , lend s a feelin g o f remoteness " an d "Th e stee p timbere d slope s an d valleys an d rugge d roc k

cappe d mountai n peak

s (i n th e Presidentia l Range/Dr

yRive rWildernesses ) allowon e t o fin d th e solitud e an d peace on e need s i n th e populou s Northeastt o refres h on e physicall yan d spiritually. " Vistas ar e a n especiall yimportan tcomponen to fth e sceni c value s o fthes e areas . Th e hig h elevation s i n an d aroun d thes e wildernesse s allowview s o fmanyo fth e peak

s an d valleys surroundin g th e norther n par to fth e Whit e Mountai n Nationa l Forest . Th e elevation s als o place portion s o fth e wildernesse s int o ful l viewfo rmanymile s around . View s fro m th e alpin e zone , particularl ythati n th e Presidentia l Range , mak

e thes e wildernesse s som e o fth e mos theavil yhike d areas i n th e Nationa l Forest . Th e Grea t Gul fan d Presidentia l Range/Dr yRive rWildernesse s provid e considerabl e enjoymen tfo rvisitors lookin g int o th e wildernesse s fro m outsid e thei rboundaries . Th e road s encirclin g th e areas offe rsceni cview s o fextremel yvarie d an d distinctiv e terrai n an d vegetatio n durin g an d afte rth e colo rseasons . Th e opportunit yto experience thes e wildernes s vistas i s partl yresponsibl e fo rth e greatnumbe r o fvisitors to thi s par

to fNe wHampshire . Vegetation . Ther

e ar e fou rdistinc

tbioti ccommunitie s i n thes e two wildernesses : alpine , subalpine , spruce-fir , an d deciduou s forestcommunities . Som e o fthes e ar e uniqu e an d importan ti n themselves ; other s ar e importan tbecaus e thei rpresence withi n th e wildernes s lend s diversit yi n habitatan d i n experience s fo rrecreationalists . Withi n an d surroundin g th e Grea tGul fan d th e Presidentia l Range/Dr yRive rWildernesse s i s th e largestalpin e are a i n th e Eastern Unite d States , commonl ycalle d th e Presidentia l Rang e alpin e zone . I n thi s regio n there ar e approximatel y 1 3 squar e mile s o falpin e plan tcommunities . Th e largest singl e uni to

fthi s uniqu e habitati s th e Presidentia l Rang e alpin e zon e i n th e White Mountai n Nationa l Forest , whic h cover s approximatel y7. 5 squar e miles . Th e alpin e plants ar

e a n importan tresource o fthi s zone . Manyar e a tth e extrem e souther n limi to fthei rrange . Ther

e ar e onl yabou t 11 0 specie s o fplants abov

e timberline , approximatel y7

5 o fwhic h ar e considere d tru e alpin e plants . O fthese , on e species , Potentilla robbinsiana, i s foun d nowher

e els e i n th e world . 2 5P.2 9

Th e subalpin e bioti ccommunit yi s ofte n terme d th e "stunte d forest. " I trepresent s th e transitio n fro m th e spruce-fi rcommunit yt o th e krummholt z t o th e alpin e community . Vegetatio n her e i s heavil yimpacte d b ywind , snow , an d ice . Tree s ar e a tangle d an d dens e ma t ofbirch , spruce , an d fi rwhic h rarel yexcee d 1 5 fee t i n height . Ther e i s potentia l habita ther e fo rth e norther n bo g lemmin g an d th e Canad a lynx . Th e spruce-fi rbioti ccommunit yconsist s o fhigh-elevatio n spruce-fi rstands . Tree s her e attai n norma l heigh t an d th e canop yappear s a s a mosai co fspruce-fi rtops , dea d masts , an d smal l opening s create d b yfalle n dea d trees . Soil s ar e shallo wt o ledg e an d slope s generall yar e steep . Wit h it s protectio n withi n a wildernes s an d th e lac k o floggin g impact s fro m earlie ryears , thi s stan d ca n continu e t o evolv e a s a n old-growt h stand . Deciduou s communitie s ar e foun d atlowe relevation s i n th e tw o wildernes s areas . Specie s consis to fmixe d norther n hardwoods alon g wit h som e easter n conifer s alon g strea m bottoms . I t appear s a s a norma l deciduou s fores t settin g fro m withi n an d a s a n unbroke n canop yfro m highe r viewpoints . Th e importanc e o fthi s communit yrelate s t o th e diversit yi tprovides , it s unbroke n canopy , it s spectacula r color s i n fall , an d it s potentia l a s a protecte d old-growt h forest . Wildlife . Severa l specie s o fanimal s foun d i n th e alpin e zon e ar e o fparticula rconcern . Amon g the m ar e th e norther n bo g lemming , an d tw o specie s o fbutterfly , th e Whit e Mountai n Fritillaryan d th e Whit e Mountai n arctic . Th e greates t populatio n o fth e latte ri s foun d i n th e Grea tGul fi n a n are a calle d th e "Co wPasture. " Water . Cool , crystal-clea rstream s an d eve rpresen t cascade s ar e a n importan t componen to fth e "close-u p view s an d sounds " i n th e tw o wildernesses . Th e associate d biologi c communitie s o fthes e wate rbodie s als o ad d t o th e diversit y o fth e areas . Man yo fth e large rstream s contai n population s o fwil d broo k

trou twhic h ar e isolate d fro m downstrea m population s b yledges , cascades , an d waterfalls . Mos s carpet s th e rock s ofth e smalle rheadwate rstreams . Wit h fe whigh-elevatio n pond s i n th e Whit e Mountains , th e thre e name d pond s withi n th e tw o area s ar e unique . Thes e smal l ponds , whic h coul d b e calle d tarn s o rcirqu e lakes , ar e smal l an d shallo wwit h smal l drainag e basins . Sta rLak e i s a 1-acre pon d locate d abov e 5,00 0 fee ti n th e Grea t Gul f Wilderness . Spauldin g Lak e i s a 0.2-acr e pon d locate d at 4.30 0 fee ti n th e Grea tGulf . Desolatio n (o rRed ) Pon d i s a shallo w3-acr e pon d locate d a t3,80 0 fee ti n th e Presidentia l Range/DryRive rWilderness . Th e Grea t Gul fha s tw o majo rtributarie s t o th e Peabod y River : th e Wes t Branc h o fth e Peabod yan d Parape t Brook . Numerou s smalle rmountai n stream s drai n hig h i n thi s watershed . Th e Presidentia l Range/DryRive rha s a majo r tributar yt o th e Sac o River : th e DryRiver . Th e uppe rhal fo f th e RockyBranc h watershed , anothe rmajo rSac o Rive r tributary , als o i s withi n thi s wilderness . Ther e ar e numerou s tributar ystream s drainin g int o bot h rivers . Odor . Part o fth e experienc e associate d wit h a visi t t o th e wildernes s i s th e natura l scent s o fth e surroundin g forest . Th e smel l o ffalle n leaves , th e scen t o fa rainstorm , swee t odor s fro m balsa m fir , an d th e crisp , clea n smel l abov e tre e lin e al l contribut e t o th e visitor' s experience .

LY E BROO KWILDERNES S Location : Size : 15,50 3 acre s Gree n Mountai n Nationa l Fores t Sout h Centra l Vermon t Designated : 197 5 Latitude : 43 ° 07 ' 30 " Elevation : 80 0 t o Longitude : 2,90 0 fee t 73 ° 00 ' Genera l Descriptio n Name d afte rLy e Brook , whic h flow s throug h th e wester n hal fo fth e area , Ly e Broo k Wildernes s i s locate d o n a high countr yplatea u wit h lakes , bogs , an d thre e hollow s wher e brook s flo woffth e platea u an d int o th e valle ybelow . Ly e Broo k Fall s i s on e ofVermont' s highes t waterfalls . I n 1916 , a fir e create d a larg e meadow-lik e openin g know n a s "Th e Burning, " whic h run s alon g th e ridgeto p i n th e southwester n parto fth e area . Th e are a wa s extensivel ylogge d i n th e earl y1900's . A networ k ofrailroa d line s carrie d th e timbe rfro m th e platea u dow n t o Manchester . Remnant s o frailroa d grade s an d ol d loggin g road s remai n throughou tmos t o fth e area . Weather . Th e genera l climat e i s coo l yea rround . Summe r temperature s rang e fro m 40° F at nigh tt o 80° F durin g th e day . Averag e winte rtemperature s rang e fro m -10° F a t nigh t t o 25° F durin g th e day . Frequen tan d sudde n weathe r change s ar e common . Sno wusuall yfall s a thighe r elevation s bylat e Novembe ran d last s unti l earl yApril . Vegetation . Approximatel y8 0 percen t o fth e are a ha s stand s o fnorther n hardwoods—maple , beech , an d birch . Othe rimportan t specie s ar e re d spruce , balsa m fir , an d hemlock . Wildlife . White-taile d deer , blac k bear , turkey , an d beave r ar e common . Smal l pond s an d stream s contai n broo k an d brow n trout . Ai rQuality-Relate d Value s Sceni cBeauty . Th e wildernes s sit s o n a platea u o n th e wester n edg e o fth e Gree n Mountains . Muc h o fwha t a perso n see s i s dominate d b yth e surroundin g vegetation . A ttime s i t ca n b e lik e walkin g throug h a gree n tunnel . Opening s provid e view s o fStratto n Mountai n t o th e northeas t an d Moun t Equino xt o th e west . View s als o affor d glimpse s o fth e valle ytha tlie s betwee n th e Gree n an d Teconi cMountains . Ly e Broo k Falls , on e o fth e highes tfall s i n th e area , i s stee p an d ledgy . Portion s o fth e Broo k an d Fall s ar e shade d b yancien t hemloc k an d fir . 2 6P.3 0

Vegetation . Th e fores twithi n th e wildernes s i s a mixtur e of spruce-fi ran d norther n hardwoo d stands . Remnant s ofth e origina l spruce-fi rfores t ca n b e foun d o n th e stee p slope s nea rLy e Brook . Mos t ofth e wildernes s wa s logge d earlie r i n thi s century , s o mos t tree s ar e les s tha n 8 0 year s old . Pape rbirc h i s givin g wa yt o spruc e an d hardwoods . "Th e Burning, " a 200-acr e openin g create d b ya devastatin g fores t fir e i n 1916 , i s dominate d b yshrub s an d scattere d whit e pines . Wildlife . Th e wildernes s form s a cor e o fmature , closed canop yvegetation , habita t necessaryfo rth e surviva l o f "interior " dwellin g species . Thes e specie s ar e no t adapte d t o lif e outsid e ofclose d canop ywoodland s an d suffe r greatl yfro m predatio n an d parasitis m whe n force d t o dwel l nea rope n lands . Severa l neotropica l immigran tsongbird s fal l int o thi s category , includin g Blackburnia n an d worm eatin g warblers . Water . Tw o significan tattraction s t o th e wildernes s ar e Ly e Broo k an d Bour n Pond . Ly e Broo k flows th e lengt h o fan d i s containe d almos tentirel ywithi n th e wilderness . Th e strea m i s a headwate rtributar yt o Battenkill , a world-famou s trou t fishery . Ly e Broo k

ha s it s ow n nativ e broo k trou tfishery . Bour n Pon d i s a popula rdisperse d recreatio n an d backpac k campin g area . Th e pon d attract s a variet yofwildlife . Loons , whic h hav e becom e uncommo n withi n Vermont , ar e see n o n th e pond . Th e pon d tend s t o b e acidi cwit h a p H rang e o f 5. 0 t o 5.5 . Dissolve d organi cmatte rgive s th e pon d a ligh t te a color . Th e aci d neutralizatio n capacit yi s nearl yzer o an d dissolve d aluminu m i s abnormall yhigh . Odor . Ly e Broo k

i s characterize d bya variet yo fnatura l woodlan d odors . Th e smel l o fmolderin g hardwoo d leave s i s eviden t throug h th e hardwoods . Whit e pine s len d a distinc t fragranc e t o "Th e Burning, " whic h contrast s wit h th e mor e . pungen todo ro fnearb ybogg yspruc e stands . Th e variet yof scent s aroun d Bour n Pon d change s wit h th e season s an d eve n th e tim e ofday .

HERCULE S GLADE S WILDERNES S Location : Size : 12,31 4 acre s Mar k Twai n Nationa l Fores t Souther n Missour i Designated : 197 6 Latitude : 36 ° 37 ' 30 " t o 36 ° 45 ' Elevation : 76 0 t o Longitude : 1,36 0 fee t 92 ° 50 ' 30 " t o 93 ° 00 '

Genera l Descriptio n Hercule s Glade s Wilderness , 6 0 mile s southeas t of Springfield , consist s ofope n grassland , foreste d knobs , stee p rockyhillsides , narro wdrainages , an d limeston e roc k outcroppings . Ther e ar e thre e hig h knob s tha t stan d ou t fro m th e oute rhig h ridges : Uppe ran d Lowe rPilo tKnobs , an d CoyBald . Fro m th e lat e 1800' s t o th e 1950's , an yare a no t fence d wa s considere d "ope n range " an d th e glade s wer e heavil y graze d b ylarg e number s o fhorses , cattle , an d hogs . Today , cattl e grazin g i s stil l permitte d withi n th e area . Vegetation . Th e thinnes t soil s hav e a prairi e vegetatio n intermingle d wit h easter n redcedar , smoketree , winge d elm , aromati csumac , chinkapin , an d pos t oak . A s th e soil s becom e deeper , large rtree s dominat e wit h a mixtur e o f chinkapi n oak , whit e ash , pos t oak , blackjac k oak , an d easter n redcedar . Th e glad e area s support gras s specie s commo n t o th e grea t prairies : bi g an d littl e bluestem , India n grass , prairi e dropseed , sid e oat s grama , an d switchgras s ar e common . Associate d forb s includ e black-eye d susan , severa l specie s ofconeflower , shootin g star , Missour i primrose , an d prairi e clover . Rare , threatene d an d endangere d plant s suc h a s ciliat e bluestar , blazin g star , stonecrop , an d trelease s larkspu rals o ar e foun d o n th e glades . Wildlife . Wildlif e withi n th e are a i s typica l ofth e glad e country . Bi g gam e consist s ofwhite-taile d dee ran d wil d turkey . Smal l gam e include s squirrel , raccoon , rabbit , fox , an d bobcat . Bir d lif e include s quail , hawk , owl , an d numerou s smal l songbirds . Othe rwildlif e foun d onl yi n th e glad e countrybecaus e o fthei rrelatio n t o th e prairi e gras s communitie s includ e collare d lizard , stingin g scorpion , roa d runner , an d th e Bachman' s sparrow . Weather . Th e Ozar k

climat e i s mil d enoug h t o mak e visit s possibl e throughou t th e year . Pea k us e season s ar e sprin g an d fall . Hercule s Glade s contain s limite d open-wate r source s an d onl yportion s o fLon g an d Can e Creek s contai n wate ryea rround . Ai rQuality-Relate d Value s Sceni cBeauty . Th e sceni cbeaut yofth e Hercule s Glade s Wildernes s i s uniqu e i n th e Ozar k Regio n ofsout h Missouri . Th e rugge d landscap e i s characterize d b yhig h knobs , locall yknow n a s balds , whic h offe ra spectacula rvie wo fth e rugge d landscape , an d contrastin g vegetativ e communitie s featurin g bot h a tal l gras s prairi e an d a foreste d landscape . Visitor s t o th e wildernes s can , wit h a shorthike , experienc e panorami cview s an d visua l contrast s betwee n th e fores t an d tal l grass-prairi e vegetativ e communitie s fro m eithe ro r bot h o fth e twi n Pilo t Knobs , tw o hig h bald s fro m whic h th e entir e wildernes s are a ca n b e viewed . Th e mos t heavil y visite d spo t i n th e wildernes s i s a waterfal l o n Lon g Creek . Vegetation . Vegetatio n withi n th e Hercule s Glade s Wildernes s i s a stud yi n contrasts , an d perhap s it s mos t outstandin g natura l feature . Aton e extrem e i s th e oak hickoryforest . Atth e othe rar e extensiv e area s ofopen , tal l grass-prairi e vegetatio n featurin g flowers , grasses , an d forbs . 2 7P.3 1

Water . Lon g Creek , whic h flow s throug h th e cente rofth e wilderness , i s a n intermitten t strea m bu t ha s pool s ofwate r throughou t th e year . Th e entir e watershe d o fLon g Cree k i s containe d i n th e Wilderness . Moderat e rainfal l i s sufficien t fo rwate rt o flo wswiftl ydow n Lon g Cree k ove rdolomitic limeston e boulder s an d natura l steps , givin g th e cree k a n appearanc e ofhavin g thousand s ofsmal l waterfalls . Tributarie s t o Lon g Cree k ar e th e numerou s uplan d waterway s o rhollow s which , du e t o th e hig h runoffpotentia l ofth e shallo wsoils , als o becom e swiftl yflowin g stream s durin g rainstorms . Th e chemistryo fth e wate ri s dominate d b ycalciu m an d magnesiu m bicarbonates , an d p H i s slightl y alkaline . Nutrien t level s ar e lo wand , i n th e absenc e o f stor m wate rrunoff , strea m waters ar e remarkabl yclear . Wildlife . Visitor s t o th e Hercule s Glade s Wildernes s Are a hav e th e uniqu e opportunit yt o observ e wildlif e indigenou s t o bot h forest s an d prairi e lands . Th e wildlif e include s man y larg e an d smal l mammals , reptiles , an d birds . Uniqu e an d unusua l specie s ofnongam e bird s ar e th e bal d eagle , red taile d hawk , grea t horne d owl , grea tblu e heron , an d pileate d woodpecker . Specie s dependen to n th e tal l gras s prairi e communit yar e th e collare d lizard , stingin g scorpion , roa d runne ran d Bachman' s sparrow . Rare , threatene d o rendangere d specie s includ e Bachman' s sparrow , Cooper' s hawk , sn d th e long-taile d weasel . Reptile s foun d i n th e forest , fores t fringe , o rprairi e area s includ e th e copperhead , pygm y rattlesnake , an d easter n timbe rrattlesnake . Fis h specie s includ e largemout h an d smallmouthe d bass , roc k bass , gree n sunfish , longea rsunfish , an d numerou s specie s of sucker s an d minnow s capabl e o fexistin g i n a n intermitten t stream . Odor . Th e natura l odo ro fa combinatio n offores tan d grasslan d prevail s an d enhance s one' s enjoymen t ofth e area . Vegetation . Maple , whit e pine , balsa m fir , aspen , an d pape r birc h ar e dominan t tre e specie s withi n th e wilderness . Wildlife . Deer , blac k

bear , ruffe d grouse , re d fox , skunk , otter , beaver , muskrat , weasel , snowsho e hare , gre y squirrel , mink , loons , woodpeckers , warblers , flycatchers , sparrows , jays , crows , finches , hawks , owls , waterfowl , bal d eagles , bass , perch , trout , an d bluegil l ar e common . Weather . Summer s ar e pleasantl ycoo l an d breez ywit h a fe wday s o f90-degre e temperature s eac h year . Winte r night s ca n dro p t o -30° F o rlower . Precipitatio n average s 3 0 inche s a yea ran d fall s mostlydurin g th e summe r months . Sno wusuall ybegin s i n Novembe ran d reache s a dept h o f2 4 t o 3 6 inches . Ai rQuality-Relate d Value s Sceni cBeauty . Visitor s i n th e sprin g an d summe rexperienc e a lush , green , norther n hardwoo d forest , colorfu l wildflowers , an d smal l kettl e lake s o fth e hummockyterrain . Autum n present s a dazzlin g arra yo fcolor s and , a s th e leave s fall , th e hummockytopograph ycreate d byancien t glacier s i s mor e easil yseen . Subtl e change s i n topograph yar e mos t eviden t i n winte rwhe n sno wcovers th e groun d an d deciduou s leave s n o longe robscur e one' s view . Water . Th e Rainbo wLak e Wildernes s i s note d fo rit s beautifu l lakes , whic h provid e a ric h habita t fo rfish , furbearers , an d aquati cplants . Th e lake s provid e recreatio n opportunitie s fo ranglers , naturalists , an d canoeists . Th e wildernes s contain s 2 2 kettl e lake s tha t rang e i n siz e fro m 1 t o 3 3 acres . Wate renter s thes e landlocke d lake s b ywa yof direc t precipitatio n an d undergroun d flo wfro m th e watershe d an d leave s b ysubsurfac e seepag e an d evaporatio n a t th e surface . Th e lak e wate ri s extremel ysof t an d lo wi n nutrient s an d dissolve d minerals . RAINBO WLAK E WILDERNES S Location : Size : 6,38 8 acre s Chequamego n Nationa l Fores t Northwester n Wisconsi n Designated : 197 5 Latitude : 46 ° 22' 30 " t o 46 ° 27'

30 " Elevation : 1,10 0 t o Longitude : 1,32 5 fee t 91 ° 15't o 91 ° 22'30 "

Genera l Descriptio n Rainbo wLak e Wildernes s i s a densel yvegetated , primitiv e fores t landscap e containin g 1 5 undevelope d lake s tha t ar e 5 acre s o rlarge ri n size , an d nin e ponds . Al l th e lake s an d pond s ar e landlocked ; ther e ar e n o streams . Si xmile s ofth e Nort h CountryNationa l Sceni cTrai l travers e th e area . Ol d loggin g road s provid e acces s t o othe rpart s ofth e wilderness . Visitor s t o th e wildernes s gai n acces s t o 1 8 ofth e lake s alon g uplan d shoreline s an d ar e abl e t o se e severa l fee t int o th e clea ro rligh t brow n water . Fou rofth e lake s hav e a rich , dar k

stai n du e t o peatlands . Vegetation . Th e vegetatio n contribute s significantl yt o th e sceni cbeauty , variety , an d richnes s o fth e wilderness . Norther n hardwoo d fores t i s th e dominan t vegetation . Wildlife . Th e wildernes s contain s a variet yoflarg e an d smal l mammals , birds , an d fish . Uniqu e specie s includ e th e fisher , pileate d woodpecker , an d ovenbirds . Th e commo n loo n inhabit s som e lakes . Althoug h rarel yseen , timbe r wolve s enhanc e th e wilderness' s characte ran d th e experience s o fvisitors . A tleas t on e wol fregularl yuse s th e Rainbo wLak e Wilderness , an d othe rwolve s mak e occasiona l us e ofth e area . Odor . Th e fragrenc e ofnatura l odor s i s a subtl e bu t integra l part ofth e wildernes s experience . Leaflitter , conifers , fungi , water , an d wildflower s provid e a pleasan taroma . 2 8P.3 2

BOUNDAR YWATER S CANO E ARE AWILDERNES S Size : 1,086,95 4 acre s Designated : 196 4 Location : Superio rNationa l Fores t Northeaster n Minnesot a Latitude : 47 ° 45 ' t o 48 ° 30 ' Longitude : 90 ° 00 ' t o 92 ° 30 ' Elevation : 1,26 0 t o 2,30 1 fee t Genera l Descriptio n Th e norther n lake s an d river s o fth e BoundaryWater s Cano e Are a Wildernes s borde rCanad a an d for m parto fth e "Voyageur s Highway " o fth e fu rtrade . Aportio n ofth e are a wa s se t asid e i n 192 6 t o preserv e it s primitiv e character . I n 1939 , additiona l are a wa s declare d roadless , an d i n 196 4 th e wildernes s receive d it s presen t designation . Pristin e lake s forme d whe n glacia l ic e melte d centurie s ago—mor e tha n 1,10 0 lake s ar e 1 0 acre s o rlarger . Heavil y foreste d land , roc k

formations , wetlands , an d lake s dominat e th e landscape . Vegetation . Th e variet yofflower s i n thi s wildernes s include s subarcti cspecie s an d nearl y3 0 nativ e specie s of wil d orchids . Principa l conifer s ar e jac k pine , whit e pine , an d re d pine . Als o commo n ar e whit e an d blad k spruce , balsa m fir , norther n white-cedar , an d tamarack . Principa l broad-leave d tree s ar e quakin g aspe n an d pape rbirch . Wildlife . White-taile d deer , moose , blac k bear , fisher , loon , an d th e las t substantia l populatio n o ftimbe rwolve s i n th e contiguou s Unite d State s inhabi tth e wilderness . Gam e fis h includ e walleye , norther n pike , lak e trout , an d smallmouthe d bass . Wildlife . Wildlif e viewin g o rexperiencin g evidenc e o fwildlif e Weather . Th e are a ha s variabl e temperature s an d rai n fro m < e -9- . observin g track s o rhearin g howl s an d bir d calls ) i s highl yvalue d b yBWCA Wusers . Hundred s o fspecie s o f birds , mammals , reptiles , amphibians , an d insect s inhabi t th e wilderness . Th e BWCAWi s on e ofth e las t vestige s ofa viabl e timbe rwol fpopulatio n i n th e Unite d States . Th e sound s ofa distan thowlin g wolfpac k hav e forme d a lastin g impressio n o n th e part o fman yusers wh o hav e campe d overnigh ti n o rnea rth e wilderness . Campsite-raidin g blac k bears ofte n for m a simila rthoug h sometime s les s favorabl e impression . Water . Approximatel y1,17 5 lake s o f1 0 acre s o rlarge r compris e 260,00 0 acre s (2 4 percent ) o fth e BWCA W surfac e area . Th e uniqu e opportunit yfo rrecreationa l canoe/boa t trave l offere d b yhigh-qualit yinterconnecte d lake s an d waterway s i n a largel yundisturbe d sceni cfores t environmen t wa s th e primaryforc e behin d th e wildernes s designatio n fo rth e BWCAW . Fifty-seve n percen to fth e lake s hav e a n aci d neutralizin g capacit yles s tha n 20 0 ueq/L , bu t onl y1 percen t ha s a p H les s tha n 6 . Sevent ypercen t o fth e lake s ar e considere d "dar k water " du e t o dissolve d organi ccarbo n resultin g fro m extensiv e peatland . Bedroc k exposure s ar e a commo n feature , shapin g th e beds , shores , an d bottom s o fBWCAWlake s an d streams . Th e presenc e ofsulfid e ore s i n bedroc k likel ycontribute s t o relativel yhig h concentration s ofbackgroun d sulfat e i n som e o fthes e waters . Lake s an d stream s ar e habita t fo rwalleye , norther n pike , bass , crappie , sunfish , lake , brook , an d brow n trout , an d severa l othe rfis h species . Fishin g i s a popula rwildernes s use . Vegetation . BWCAWi s characterize d b yth e specie s associate d wit h th e norther n Minnesot a Glacia l Lak e Basin . Visua l diversit yi s highes t durin g th e fall . Groun d an d herbaceou s understoryo fnativ e berrie s an d aquati c specie s lik e wil d ric e ar e gathere d bysom e recreationist s an d ar e a valuabl e foo d sourc e fo rman yanima l species . Man yspecie s ofsensitiv e plants , includin g ram's-hea d ladyslippe ran d norther n comandra , inhabi t portion s o fth e BWCAW . Liche n flor a ofth e BWCAWi s diverse , an d liche n specie s know n t o b e sensitiv e t o ai rpollutant s ar e commo n throughou t th e are a (n o significan t void s i n distribution) . Maythroug h September . Averag e high-lo wtemperatures : 77 ° t o 42°F ; day s o frain : 1 4 t o 1 6 pe rmonth . Averag e seasona l temperature s ar e 42° F i n spring , 64° F i n summer , 45° F i n fall , an d 12° F i n winter . Ai rQuality-Relate d Value s Sceni cBeauty . Th e sceni cbeaut yo fth e BWCAWi s highl y value d b yit s users . Visua l experience s encountere d b y mos t user s consis t o fshorelin e view s an d inspirin g water reflecte d sunset s acros s lakes/river s fro m campsites , portages , o rmidlak e vantag e point s (fro m boat s o rcanoes) . Outstandin g shorelin e feature s includ e lichen-covere d bedroc k cliff s an d boulders ; boulder-strew n lak e inlet s an d outlets ; waterfall s an d rapids ; shorelin e wetland s wit h sphagnum , labrado rtea , o rleathe rlea fan d sparsel y timbere d wit h blac k

spruc e o rtamarack ; th e big-tre e characte rofindividua l o rclustere d old-growt h re d an d whit e pine , an d th e contras t establishe d byintermingle d aspe n an d conife rstands . Bal d eagle s an d ospre yar e commo n nea rth e shoreline s of lake s an d rivers , an d thes e bird s an d thei rnest s ar e commonl ysee n b yboater s an d canoeists . Commo n loon s ar e plentiful , thei rsightin g an d call s a n expecte d part o fth e BWCAWexperienc e fo rmos t wildernes s user s durin g th e open-wate rseason . Odor . Th e natural smell s ofth e fores t ar e a n importan t valu e t o wildernes s users . Odor s i n thi s wildernes s ar e associate d wit h natura l feature s suc h a s conifer s an d wildflower s an d th e sulfurou s odor s ofgase s tha t escap e fro m swamp s an d shallo wlakes . 2 9P.3 3



## Appendi xI I Additiona l Informatio n Protocol for Monitoring

Atmospheric

Deposition U.S . Environmenta l Protectio n Agency . 1977 . Qualit y assuranc e handboo k

fo rai rpollutio n measuremen t systems , vol . II . Ambien t ai rspecifi c methods . EPA-600/4-77-027a . Researc h Triangl e Park , NC : U.S . Environmenta l Protectio n Agency .

General Reference

for Estimating

Atmospheric

Deposition

in Region 9 Pinkerton , J . A. ; Lefohn , A . S . 1987 . Th e characterizatio n o fozon e dat a fo rsite s locate d i n foreste d area s of th e easter n Unite d States . Journa l o fth e Ai rPollutio n Contro l Association . 37:1005-1010 . Herrick , C . N . 1990 . Acidi c deposition : a n inventoryo f non-federa l research , monitorin g an d assessmen t activity . Washington , DC : Nationa l Aci d Precipitatio n Assessmen t Program . Hogsett , W . E. ; Olszyk , D. ; Ormrod , D . P. ; Taylor , G . E . Jr. ; Tingey , D . T . 11987 . Ai rpollutio n exposur e system s an d experimenta l protocols : vo l I . USEP ARep . EPA/600/3-87/037a . Corvallis , OR : U.S . Environmenta l Protectio n Agency , Environmenta l Researc h Laboratory . Kimball , K . D. ; Doucette , J . E. ; Allen , G . A. ; Rancourt , K . 1989 . Monitorin g ozon e nea rth e Grea t Gul fan d Dr y River/Presidentia l Wildernesses : summaryreport an d 198 9 data . Gorham , NH : Appalachia n Mountai n Club . Legge , A . H. ; Krupa , S . V. , eds . 1990 . Acidi c deposition : sulphu ran d nitroge n oxides . Boc a Raton , FL : Lewi s Publishers . O'Brien , J . T . 1990 . Evaluatio n o fozon e damag e t o vegetatio n o n th e Ly e Broo k Wildernes s i n 1989 . Surv . Rep . Durham , NH : U.S . Departmen to fAgriculture , Fores tService . Fores t Servic e Official s Responsibl e fo rClas s I Area s i n Regio n 9 REGIONA LFORESTE R USD AFores t Servic e 31 0 W . Wisconsi n Avenu e Milwaukee , W l 5320 2 Staff : Jerom e Thomas , 414-297-3659 ; Harr yParrott , Ext . 334 2 Grea t Gul fan d Presidential-Dr yRive rWildernes s FORES TSUPERVISO R USD AFores t Servic e Whit e Mountai n Nationa l Fores t 71 9 Mai n Stree t P O Bo x63 8 Laconia , N H 0324 7 Staff : Rand yFerrin , 603-528-872 1 Ly e Broo k

Wildernes s FORES TSUPERVISO R USD AFores t Servic e Gree n Mountai n Nationa l Fores t Federa l Buildin g P O Bo x51 9 Rutland , VT05701-051 9 Staff : Wayn e Kingsley , 802-773-034 3 Doll ySod s an d Otte rCree k Wildernesse s FORES TSUPERVISO R USD AFores t Servic e Monongahel a Nationa l Fores t 20 0 Sycamor e Stree t Elkins , W V26241-396 2 Staff : BarryEdgerton , 304-636-180 0 Hercule s Glade s Wildernes s FORES TSUPERVISO R USD AFores t Servic e Mar k Twai n Nationa l Fores t 40 1 Fairground s Ron d Rolla , M O 6540 1 Staff : Geral d Gott , 314-341-744 3 Rainbo wLake s Wildernes s FORES TSUPERVISO R USD AFores t Servic e Chequamego n Nationa l Fores t 117 0 4t h Avenu e Sout h Par k Falls , W l 5455 2 Staff : Dal e Higgins , 715-762-246 1 BoundaryWater s Cano e Are a Wildernes s FORES TSUPERVISO R USD AFores t Servic e Superio rNationa l Fores t P O Bo x33 8 Federa l Buildin g 5t h Avenu e Wes t an d 1st Stree t Duluth , M N 5580 1 Staff : Robert Berrisford , 218-720-669 2 3 0P.3 4

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Dr . MaryBet h Adam s USD AFores t Servic e Northeaster n Fores t Experimen tStatio n Timbe ran d Watershe d Laboratory P.O . Bo x40 4 Parsons , W V2628 7 Professo rHarol d S . Adam s Dabne yS . Lancaste rCommunit yColleg e Clifto n Forge , VA2442 2 Dr . Jame s Bennet t Nationa l Par k

Servic e Institut e o fEnvironmenta l Studie s Universit yo fWisconsi n 1040WARFBIdg . 61 0 Walnu t Stree t Madison , W l 5370 5 Mr . Robert Berrisfor d USD AFores t Servic e Superio rNationa l Fores t P.O . Bo x33 8 Duluth , M N 5580 1 Mr . Donal d Bilye u USD AFores t Servic e Chequemego n Nationa l Fores t 117 0 4t h Avenu e Sout h Par k Falls , W l 5455 2 Mr . Ji m Byrn e USD AFores t Servic e Watershe d an d Ai rManagemen t P.O . Bo x9609 0 Washington , D C 20090-609 0 Mr . GaryCar r USD AFores t Servic e Androscoggi n Range rDistric t Whit e Mountai n Nationa l Fores t 8 0 Gle n Roa d Gorham , N H 0358 1 Mar k Cleveland USD AFores t Servic e Gree n Mountai n Nationa l Fores t P.O . Bo x51 9 Rutland , VT05701-051 9 Dr . Michae l Coffma n Champio n Internationa l Corporatio n 70 0 Mt . Hop e Avenu e 48 0 Evergree n Wood s Bangor , M E 0440 1 Mr . Jac k Crave n USD AFores t Servic e 31 0 W . Wisconsi n Avenu e Milwaukee , W l 5320 3 Professo rDonal d D . Davi s Pennsylvani a Stat e Universit y Departmen t o fPlan t Patholog y Bldg . 21 1 Buchou t Lab . Universit yPark , PA1680 2 Mr . Oti s Durha m USD AFores t Servic e Whit e Mountai n Nationa l Fores t P.O . Bo x63 8 Laconia , N H 0324 7 Mr . Dewayn e Durs t Ai rBranc h USEP AR772 6 Minnesot a Avenu e Kansa s City , M O 6610 1 Dr . Christophe rEaga r USD AFores t Servic e Northeaster n Fores t Experimen tStatio n 5 Radno rCorporat e Cente r 10 0 Matsonfor d Roa d « Radnor , PA1908 7 Mr . BarryEdgerto n USD AFores t Servic e Monongahel a Nationa l Fores t 20 0 Sycamor e Stree t Elkins , W V26241-396 2 Ms . Pamel a Edward s USD AFores t Servic e Northeaster n Fores t Experimen t Statio n Timbe ran d Watershe d Laboratory Bo x40 4 Parsons , W V2628 7 Dr . C . Anthon yFedere r USD AFores t Servic e Northeaster n Fores t Experimen t Statio n P.O . Bo x64 0 Durham , N H 0382 4 Mr . Rand yFerri n USD AFores t Servic e Whit e Mountai n Nationa l Fores t P.O . Box63 8 Laconia , N H 0324 7

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Professo rTo m Fros t Trou tLak e Laboratory Universit yo fWisconsi n Rt . 1 , Bo x7 Boulde rJunction , W l 5451 2 Professo rDav e Griga l Universit yofMinnesot a Dept . Soi l Scienc e 199 1 Uppe rBufor d Circl e St . Paul , M N 5518 0 Ms . Charlen e Hagedor n USD AFores t Servic e Wayne-Hoosie rNationa l Fores t 81 1 Constitutio n Avenu e Bedford , I N 4742 1 Mr . Lloy d Hendrickso n USD AFores tServic e Easter n Regio n 31 0 W . Wisconsi n Avenu e Milwaukee , W l 5320 3 Mr . Mik e Hert h USD AFores tServic e Monongahel a Nationa l Fores t 20 0 Sycamor e Stree t Elkins , W V26241-396 2 Mr . Dal e Higgin s USD AFores t Servic e Chequamego n Nationa l Fores t 117 0 4t h Avenu e Sout h Par k Falls , W l 5455 2 Mr . RobertHollingswort h USD AFores t Servic e Easter n Regio n 31 0 W . Wisconsi n Avenu e Milwaukee , W l 5320 3 Ms . Laur a Hudnel l USD AFores tServic e Chippew a Nationa l Fores t Cas s Lake , M N 5663 3 ProfessorRudol fB . Husa r Cente rfo rAi rPollutio n Impac tan d Tren d Analysi s Washingto n University , Bo x112 4 St . Louis , M O 6313 0 Mr . Willia m Jackso n USD AFores tServic e Stat e & Privat e Forestry 18 0 Canfiel d Stree t Morgantown , W V2650 5 Dr . Keit h Jense n USD AFores t Servic e Northeaster n Fores tExperimen t Statio n 35 9 Mai n Roa d Delaware , O H 4301 5 Professo rDavi d F . Karnosky Schoo l o fForestryan d Woo d Product s Michiga n Technologica l Universit y Houghton , M l 4993 1 Dr . Kennet h D . Kimbal l Appalachia n Mountai n Clu b Pinkha m Notc h Cam p Gorham , N H 0358 1 Mr . Do n Knaue r Wisconsi n DN R Bo x792 1 Madison , W l 5370 7 Dr . RobertKohu t Boyc e Thompso n Institut e Cornel l Universit y Ithaca , N Y1485 3 Mr . Danie l Kucer a USD AFores t Servic e Stat e & Privat e Forestry 5 Radno rCorporat e Cente r 10 0 Matsonfor d Roa d Radnor , P A1908 7 Dr . Alle n S . Lefoh n AS LAssociate s 11 1 N . Las t Chanc e Gulc h Suit e 4 A Helena , M T5960 1 Dr . Steve n E . Lindber g Oa k Ridg e Nationa l Laboratory P.O . Bo x2008 , Bldg . 150 5 Oa k Ridge , T N 3783 1 Dr . GaryLovet t Institut e o fEcosyste m Studie s CaryArboretu m BoxA B Millbrook , N Y1254 5 Dr . Ala n Lucie r NCAS I 26 0 Madiso n Avenu e Ne wYork , N Y1001 6 Professo rWillia m Mannin g Universit yo fMassachusett s Dept . o fPlan t Patholog y Amherst , M A0100 3 ProfessorThoma s Marke e Cente rfo rLak e Superio rEnvironmenta l Studie s Universit yofWisconsi n - Superio r Superior , W l 5488 0

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Mr . Robert Ma y USD AFores tServic e Mar k Twai n Nationa l Fores t 40 1 Fairground s Roa d Rolla , M O 6540 1 Mr . Patric k

Merchan t USD AFores tServic e Wayne-Hoosie rNationa l Fores t 81 1 Constitutio n Avenu e Bedford , I N 4742 1 Mr . Richar d Poiro t Ai rPollutio n Contro l Progra m Vermon t Departmen t o fEnvironmenta l Conservatio n Buildin g 3 Sout h 10 3 Sout h Mai n Stree t Waterbury , VT0567 6 Mr . Charle s Span n Wes t Virgini a Ai rPollutio n Contro l Commissio n 155 8 Washingto n St . Eas t Charleston , W V2531 1 Mr . Manfre d Milk e USD AFores tServic e Stat e & Privat e Forestry 199 2 Folwel l Avenu e St . Paul , M N 5510 8 Dr . Dal e S . Nichol s USD AFores t Servic e Nort h Centra l Fores tExperimen t Statio n 183 1 Highwa y16 9 Eas t Gran d Rapids , M N 5574 4 Mr . Jame s O'Brie n USD AFores tServic e Stat e & Privat e Forestry P.O . Bo x64 0 Durham , N H 0382 4 Mr . HarryParrot t USD AFores t Servic e 31 0 W . Wisconsi n Avenu e Milwaukee , W l 5320 3 Dr . Donal d Porcell a Environmenta l Assessmen tDept. EPR I 341 2 Hillvie wAvenu e Pal o Alto , C A9430 3 Dr . Jerom e Thoma s USD AFores t Servic e 31 0 W . Wisconsi n Avenu e Milwaukee , W l 5320 3 Dr . E . S . Verry USD AFores t Servic e Nort h Centra l Fores tExperimen tStatio n 183 1 Highwa y16 9 Eas t Gran d Rapids , M N 5574 4 Professo rClif fWetmor e 22 0 Biologica l Science s Universit yo fMinnesot a St . Paul , M N 5511 8 Mr . Willia m Woodlan d USD AFores t Servic e Monongahel a Nationa l Fores t Chea t Range rDistric t Parsons , W V2628 7 Mr . Gaylor d Yos t USD AFores t Servic e Easter n Regio n (RRWL ) Federa l Plaza , Roo m 50 0 31 0 W . Wisconsi n Avenu e Milwaukee , W l 5320 3

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