Vegetation structure in old-growth stands in the Coram Research Natural Area in northwestern Montana

30 Pages·1997·1.9 MB·English

by  Elzinga, Caryl L

Historic, Archive Document
Do not assume content reflects current
scientific knowledge, policies, or practices.

USDA
^S^m UDneiptaerdtmSetanttes Vegetation Structure in
ofAgriculture
Oid-Growth Stand$%tthe
ForestService
Intermountain
Research Station Coram
Researcli
l^aliil|ai
General Technical
Report INT-GTR-364
Area in Northwest^rii :30
August 1997
Montana
Caryl L. Elzinga
Raymond C. Shearer
1
The Authors drafts of the manuscript. The manuscript was much
improved bycommentsfrom Sarah E. Greene. Sugges-
Caryl L. Elzinga is a Botanist and Ecologist witli tions for the manuscript and identification of collected
Alderspring Ecological Consulting in Tendoy, ID, which specieswere provided by Peter F. Stickney atthe Inter-
she established in 1993. She received her M.S. degree mountain Research Station, Forestry Sciences Labora-
in 1989and herPh.D.degreein 1992fromtheUniversity tory,Missoula, MT. Dr.AngelaEvenden, Program Leader
of Wisconsin-Madison, where her research focused on forthe Research NaturalAreaprogram in Region 1 ofthe
the environmental determinants of community patterns Forest Service, provided assistance with all phases of
in freshwater tidal wetlands. From 1988 to 1993 she the project. Glenn Elzinga and Susan Colt assisted in
worked as the district botanist for the Bureau of Land data collection for plots five through eight. The Hungry
Management.Astheownerand principalofAlderspring, Horse Ranger District, Flathead National Forest, pro-
hercurrentprojectsincludeanannotated bibliographyof vided access and logistical support.
monitoring literature, atechnical reference on rare plant
monitoring, and a bookon the ecology of riparian plants
ofthelntermountainWest.Shehastaughtseveralcourses Contents
on rare plant monitoring throughoutthe Western United
Page
Statesaspartofan interagencyteam.Additional profes-
sional interests include studying long-term ecological Introduction 1
changeandtheuseofintensive managementofdomes- Study Site 2
Methods 4
tic livestock to improve uplands, riparian areas, and
Western Larch Forest Cover Type: Old-Growth
irrigated pastures.
Stands 5
Raymond C. Shearer received B.S. and M.S. degrees Plot One 5
from Utah State University in Logan, UT, and a Ph.D. Plot Two 7
degreefrom the University of Montana, Missoula. Since Plot Four 9
1957 he has been a Research Silviculturist assigned to Plot Eight 10
the Intermountain Research Station's Ecologyand Man- Western Larch Forest CoverType: Young
agementofNorthern Rocky Mountain Forests Research Stand 11
WorkUnitattheForestrySciencesLaboratoryinMissoula, Plot Three 1
MT. His primary assignment has been the study of Spruce-Subalpine Fir Forest Cover Type 13
natural and artificial regeneration of western larch and Plot Five 13
associated species. He was manager of the Coram Interior Douglas-fir Forest Cover Type 14
Experimental Forest from 1957 to 1996. Plot Six 14
Plot Seven 16
Discussion 17
Acknowledgments
References 19
Dr. James Habeck established plots onethrough four Appendix: Understory Flora of the Old-Growth
in 1985 and remeasured them in 1990. He provided Forests of the Coram Research Natural Area 21
extensivereviewandsuggestionsforrevisionstothefirst
Intermountain Research Station
324 25th Street
Ogden, UT84401
Vegetation Structure in Old-Growtli
Stands the Coram Research
in
Natural Area in Northwestern
Montana
Caryl L. Elzinga
Raymond C. Shearer
Introduction growth was low-elevation fire-maintained stands of
ponderosapine{Pinusponderosa),westernlarch(Larix
Old-growth forests are viewed as an unchanging occidentalis), andDouglas-fir(Pseudotsugamenziesii
chmaxcommxmityunderclassicalsuccessionaltheory var.glauca)(Amoandothers 1985;Greenandothers
(Christensen 1988). Recently,thisparadigmhasbeen 1992).
replaced with one that views old growth as part ofa Recognizingthesedifferencesandtheresiiltingchal-
shiftingmosaicofstageclassesresultingfromdistur- lenge ofdefining old growth, the Chief ofthe Forest
bance (Sprugel 1991). Compared to classical succes- Serviceissuedin1989adirectivetoallRegionalOffices
sional theory, this view is spatially expanded to the to develop definitions for old-growth forests by geo-
landscapeorecosystemlevel,andtemporallyexpanded graphic location and ecosystem type. This was com-
to several centuries or more. This view adds the pletedforwestemMontanain 1992(Greenandothers
dimensionsoftemporalandspatialvariabilitytoman- 1992).
agementofnaturalareassetasidetoprotectexamples Definitionsthatfocusonstandstmcturalcharacter-
ofold-growthforests. Domanagersarrestorallowthe istics, such as species composition and tree diameter,
slow changes associated with community processes areconsideredobjectiveandoperational.Thisapproach
andthe rapid changes causedby catastrophicdistur- isthemostcommononeusedinthe oldgrowthdefini-
bances such as fire? tions currently being developed by land management
The paradigm of classical successional theory is agencies such as the U.S. Forest Service and the Bu-
diffic;ilt to apply to forests with old trees that are reau of Land Management (Green and others 1992;
maintainedbyperiodiclow-intensityfire(Mehl1992). Hamilton1993;Vora1994).Developmentofthesedefi-
Old-growth forests firstbecame amanagementissue nitions,however,ishamperedbyhmitedknowledgeof
in the forests ofWashington and Oregon west ofthe old-growthstandcharacteristics.Whilestmcturalchar-
Cascades, and many definitions were developed that acteristicsfornaturalold-growthstandsintheCoastal
used concepts of successional climax (Franklin and and Cascade area ofthe Pacific Northwest are fairly
Spies 1991;Marcotandothers 1991). Thesewest-side well docimiented, published stand descriptions for
forestsareprimarilyaffectedbywithin-stand(autoge- NorthemRockyMountainforestsarelargelylimitedto
nic) processes ofsuccession, and some authors argue second-growthmanaged stands (Moeur 1992).
thattrueoldgrowthhasonlydevelopedintheabsence Foreststandstmcture,understorycomposition,and
of outside stand-initiating disturbances (Hayward tree seedling composition were measured in eight
1991; Oliver and Larson 1990). This paradigm does permanent tenth-hectare plots in three forest cover
not match stand-development patterns in the North- types (EjTe 1980): Engelmann spmce/subalpine fir
emRockyMountains. Manystandsbeginwithahigh- (SAFcovertypenumber206),westemlarch(212),and
intensity stand-replacingfire, and rarely achieve suc- interior Douglas-fir (210). These plots were estab-
cessional climaxbefore another stand-replacingevent lished within the Coram Research Natural Area to
intervenes (Fischer and Bradley 1987). Many of the docimient long-term changes in vegetation composi-
oldest stands are dominated by long-lived fire-depen- tion and stmcture, thus the use as descriptors ofold
dent serai species that were historically maintained growth is ancillary to their primary purpose. Sam-
andprotectedfromcrownfirebyrepeatedimderbums phng methodology is not optimal for the purpose of
(Achuff1989;Amoandothers1985;FischerandClayton standdescription;thedetailedplotdatadoes,however,
1983;Habeck1988).Themajorityofpresettlementold present a rare snapshot of the vegetation in stands
1
thataregenerallyconsidered"oldgrowth."Dominant ^3
Westernlarch.90-120yearsold
treesinthese stands areusuallymorethan200years Y/AWesternlarch,200+yearsold
old, and some are as old as 500 years (Tobalske and I 1 InteriorDouglas-lir200+yearsold
others 1991). llllllllllSpoice-Subalpinefir240+yearsold
Wetmeadow
I
Study Site Research Natural Area
TheCoramResearchNaturalAreaislocatedwithin
the Coram Experimental Forest on the Flathead Na-
tionalForest,nearHungryHorse,MT, 16kmsouthof
thewestentrancetoGlacierNationalParkand45km
northeastofKalispell,MT(fig. 1). The CoramExperi-
mentalForest,includingtheCoramResearchNatural
Area,wasdesignatedaBiosphereReservebytheMan
and the Biosphere Program of the United Nations
Educational, Scientific and Cultural Organizationin
1976. The 340 ha Coram Research NaturalArea was
recommended in 1937 to preserve examples of old-
growthwesternlarchandinteriorDouglas-firstands,
and was officially designated as a Forest Service
Research Natural Areain 1988 (Wellner 1988).
Annual precipitationin the Coram Research Natu-
ral Area averages 89 cm at the lower elevations and
over 102 cm along the upper boundary (Fames and
others 1995).Approximately70percentoftheprecipi- Figure 2—Vegetation types and location of
tationoccursduringthewinterandearlyspringmonths permanent monitoring plots within the Coram
as snow. Temperature averages 16 °C during the Research Natural Area.
summer months. Frost-free days are approximately
150, but frost may occur in any month. Elevations
range from 1,067 to 1,463 m, with most slopes south-
west facing. One small ephemeral stream occurs in another on the southern boundary, both draining to
the center ofthe Coram Research Natural Area, and thewestandcontainingsomenorthwest-facingslopes.
Slopes range from 5 to 50 percent.
Approximately 80 percent of the Coram Research
NaturalAreaisforestedwithstandsofmixedwestern
larchandDouglas-firmorethan200yearsold(fig. 2).
About three-fourths of these stands classify as the
Society of American Foresters (SAF) western larch
cover type (Eyre 1980), even though they contain
nearlyanequalmixofDouglas-firandwesternlarch.
Approximately one-fourth of the mixed stands are
dominated by Douglas-fir and are classified as SAF
InteriorDouglas-fircovertype.About10percentofthe
Research Natural Area is a younger (100 year old)
mixedwesternlarch/Douglas-firstandthatbelongsto
the western larch cover type. The remaining 10 per-
cent ofthe Research Natural Area is composed of a
smallpatch(5ha)ofspruce-subalpinefircovertype,a
wet meadow, and a 10 ha area ofwestern larch cover
type that contains a codominant western white pine
Figure1—LocationoftheCoramExperimental element. Othercommontrees are subalpinefir{Ahies
Forest and Coram Research Natural Area in lasiocarpa),anEngelmann/whitesprucehybrid{Picea
Montana, U.S.A.
2
22 = = =
engelmannii xP.glauca) (Habeck andWeaver 1969), prolongedabsenceoffire, Douglas-firwillbecompeti-
western white pine {Pinus monticola), western hem- tivelyexcludedonthesesitesby ;moreshade-tolerant
lock(Tsugaheterophylla), andmorerarely, lodgepole species.Onafewdriersites,however,Douglas-firmay
pine (Pinus contorta), and western redcedar {Thuja function as the climax dominant. Fire maintains an
plicata).Mostoftheareaisclassifiedasasubalpinefir open parklike stand, dominated by large, old trees
climaxseriesorhabitattype,withpatches ofwestern (Fischer and Bradley 1987).
hemlock and Douglas-fir types (Pfister and others Basedontreeagesandfirescartransects(Amoand
1977). Sneck 1977), most ofthe Research Natural Area has
Western larch often initiates after stand-replacing experienced no catastrophic stand-replacing distur-
fires (Parker 1982) and then persists for 300 to 700 bances for more than 350 years (Sneck 1977). The
years (Barrett and others 1991; Fischer and Bradley 40,000haHalfMoonfirethatstartedAugust23, 1929,
1987).Itisthemostfire-resistantconiferintheNorth- was the last stand-replacing fire to bum near the
em Rocky Mountains (Fischer and Bradley 1987). Coram Research Natural Area (Gisbome 1929). In
Some individuals within a stand may survive severe 1890, a lightning-caused fire began on the Coram
firesduetothick,fire-resistantbarkandreplacement Experimental Research Natural Area and burned a
ofheat-killedfoliageviaepicormicbranching(Barrett small area within the northwest comer of the Re-
andothers1991).Withoccasionalseverefireandmore searchNaturalArea(Sneck 1977).
common nonlethal underbums, western larch domi- Lightningstormsfrequentlyoccurovertheareaand
nance ofthe standmaybe perpetuatedas"fire-main- strikes are numerous. Most storms are accompanied
tained old growth" (Davis 1980; Fischer and Bradley by moderate to heavy showers; few fires start in
1987; Habeck and Mutch 1973). In the prolonged proportion to the intensity ofthe storms (Coram Ex-
absence offire, these old-growth larch stands will be perimentalForest 1961). OnAugust 14, 1951, alight-
replaced by more shade-tolerant species (subalpine ning-causedfirebegannearthecenteroftheResearch
fir, spruce, and western hemlock) as succession pro- NaturalArea andwas limitedtoless than 0.04haby
ceeds (Schmidt and Shearer 1990). thesuppressioncrew.Thisistheonlyotherknownfire
Douglas-fir functions as either a serai or climax to bum within the boundary ofthe Coram Research
species, depending on the site (Pfister and others NaturalAreasincethe1890fire.Fiveotherlightning-
1977). MostDouglas-firfoundinthe CoramResearch caused fires, (three in 1940, one in 1941, and one in
NaturalArea occurs withwesternlarchon sites that 1951) occurred within a 1.6 km band around the
wouldbedominatedbysubalpinefiratclimax. Inthe Research NaturalArea.
—
Table 1 Coverand habitattypes, dominanttree species, and site attributesforpermanentplots in tlie Coram Research Natural
Area, northwestern Montana.
Plot Age SAFcovertype Habitattype° Dominantcanopyspecies" Slope Aspect Elevation
m
Years Percent Degree
azimuth
1 200+ Western larch 212 ABLA/CLUN/ARNU Western larch, Douglas- 15 240 1,090
fir, western white pine
2 200+ Western larch 21 ABLA/CLUN/ARNU Western larch, western Flat 1,085
white pine
3 ICQ Western larch 21 ABLA/CLUN/ARNU^ Douglas-fir, western larch 25 210 1,115
4 200+ Western larch 212 TSHE/CLUN/ARNU Douglas-fir, western larch, <5 280 1,075
spruce, western white pine
5 240+ Spruce-subalpinefir206 ABLA/CLUN/ARNU Spruce, Douglas-fir, 23 278 1,100
western larch
6 300+ Interior Douglas-fir210 PSME/LIBO/SYAL Douglas-fir, western larch 49 241 1,190
7 200+ Interior Douglas-fir 210 ABLA/CLUN/XETE Douglas-fir 22 250 1,355
8 200+ Western larch 212 ABLA/CLUN/XETE Western larch, Douglas-fir 27 257 1,370
BasedonPfisterandothers1977.Speciescodes:ABLA Aijieslasiocarpa;ARNU Aralianudicaulis;CLUN=Clintoniauniflora;LIBO Lmaea
borealis; PSME= Pseudotsugamenziesir, SYAL= Symphoricarposalbus;TSHE= Tsugatieterophylla;XETE=Xerophyllurr)tenax.
Firstspecieslisted ismostabundant; remainingspeciesareinorderofabundance.
"^Seralburnedsite, lacking indicatorspecies.
3
Methods The Coram Research Natural Area was mapped
using SAF forest cover types (Wellner 1988); these
In 1985, four long-term baseline monitoring plots formed the basis for plot selection and placement.
were established within or near the Coram Research Possible sampling locations within each cover type
NaturalArea(Habeck 1985)andremeasuredin 1990. were identified using aerial photographs and cover
All were established in western larch cover types: type maps. After field reconnaissance of the target
three in 200 plus year old stands and one in the 100 stand,plotlocationwasselectedtorepresentthestand
plusyearoldstand(fig. 2;table 1). Plottwo, oneofthe canopystructureandunderstorycompositionobserved
threeold-growthwesternlarch plots, was placedona withinthestand. Plotswereplacedinareasthatwere
site with codominant western white pine. Plots one, relativelyhomogeneous, avoidingobvious ecotones or
two, and three were placed in subalpine fir habitat discontinuities. Plot design and sampling methodol-
types; plot four was placed in a western hemlock ogygenerallyfollowsGreene(1984). Plots are perma-
habitattype(table 1).Allfourplotswereatthelowest nently monumented at the center and at the four
W
elevations onthewesternedge ofthe ResearchNatu- cardinal points (N, S, E, and from true north) with
ral Area. steelfenceposts(fig. 3).Plotsare 1,000m^(0.1ha)(not
Management personnel identified a need for addi- corrected for slope).
m
tional plots to include forest cover types and habitat All trees were tagged at breast height (1.4 from
typesthatwerenotrepresentedinthe originalmoni- ground) with aluminum numbered tags affixed with
toringsystem.In1993,plotssixandsevenwereplaced aluminum nails. Tree diameterbreast height (d.b.h.)
instandsof200plusyearoldinteriorDouglas-fir one was measured at the tag to ensure that repeat mea-
,
ina200plusyearold spruce-subalpine fir stand, and sureswouldbedoneatthesamespot. Diameterswere
plot eight was placed in an upper elevation 200 plus estimated to the nearest 0.01 inch with a steel d.b.h.
year oldwestern larch stand (fig. 2; table 1). tape and converted to metric measures. Only trees
greaterthan2.5 cm diameteratthebaseweretagged
and measured.
On each plot, fiveto 12 trees were cored at d.b.h. to
Fullplot=1,000m^(0.1 ha) determine age. Trees were chosen to represent the
N rangeofd.b.h.classesforeachspeciesoccurringonthe
plot. Cores that missed center slightly were extrapo-
lated to the approximate date. Five to 10 years were
addedto d.b.h. years to get the age oforigin.
Treeslessthan 2.5 cm atthebase andgreaterthan
3 cm tall were measured as seedlings in four 12.5 m^
m
subplots. Seedlingsubplots are 10 from plotcenter,
locatedonthe45°anglefromeachcardinalpoint(fig.3).
Subplot centers are marked with iron rebar or metal
stakes.
Seedlings were either tagged with a metal tag se-
curedto the groundwith alarge nail, placed 10 cm in
front ofthe seedling toward the center stake (for the
four 1993 plots), or tagged with an aluminum tag
loosely tiedto the seedlingitself Seedlings were also
mappedinthe 1993 plots bymeasuringdirectionand
distancefromthe center stake. Heightwas measured
to the nearest centimeter, and the diameter at base
wasevaluated andclassifiedinto one ofthe following
diameterclasses: 1(lessthan0.5cm);2(0.5to 1.0cm);
3 (1.1 to 1.5 cm); 4 (1.6 to 2.5 cm).
Li(ntoeurin1t5ermcepttratnrsaencstesc,t: ((otai=50) Shrub andherbaceous coverwasmeasuredonplots
total=60msample) one through four using the methodology proposedby
Figure 3—Design of permanent plots illustrating Greene (1984). Shrub canopy cover was measured
plot dimensions and location of line intercepts, along four line-intercept transects (Bonham 1989),
m
seedling subplots, and understory herbaceous eachbeginning2 fromthecenterpost,stretchingto
microplots. 17 m(15mlengths, 60minall)ononeofthecardinal
4
points(fig.3).Herbaceousfrequencyandcanopycover
was estimated along these same transects in 50
microplotseach20x50cminsize(Daubenmire 1959).
Twelve microplots were placed along the north and
m
southlines,withmicroplots startingatthe6 point,
placed every meter, with the inner comer of the
microplot on the meter mark of the tape. Thirteen
microplots, beginning at 5 m, were placed along the
westandeastlines. Northand southmicroplotswere
placed on the east side of the line, east and west
microplots on the north side. Within each microplot,
canopycoverofeachspecieswas classifiedinto seven
coverclasses:t(0to 1percent); 1(1to5percent);2(6to
25 percent); 3 (26 to 50 percent); 4 (51 to 75 percent);
5 (76 to 95 percent); 6 (greater than 95 percent).
Analternativesamplingapproachwasusedforplots
fivethrougheighttobesureallcommonspeciesonthe
plotwererecordedandtoreducethetime requiredto
sample 50 microplots. Understory vegetation cover
was recorded in each quadrant (NE, SE, SW, NW) of
theplot(250m^)usingthefollowingcoverclasses:t(0 —
to1percent),c(1to5percent), 1(6to15percent),2(16 Figure 4 Plot one is located within the
tpoer2c5enpetr)c(eJnetn),se3n(a2n6dtoot3h5epresr1c9e9n2t)).,E1a0c(hgrqeuaatderratnhtanwa9s5 Atybpiee,sAlraasliioacanrupdai/cCaluilnitsonpihaausneifaltora1,h0a9b0itamt
m elevation;treesincludeold-growthwestern
surveyed by ocular reconnaissance in parallel 1
larch, Douglas-fir, andwesternwhitepine;
swaths for approximately 30 minutes. Species were common shrubs include mountain maple
recorded for presence and then estimated for cover to and serviceberry; herbaceous understory
the neEirest percent at the end ofthe reconnaissance isdominatedbyqueencupbeadlily,Hooker
period andrecordedinthe proper coverclass. fairybell, and subshrub twinflower (from
Permanent photopoints were estabUshed at each centertoward south post).
plot, usingthe plotmonuments forrelocation. Photos
weretakenwiththeplotstakeinthebottomcenterof
thephoto,withthephototakeninacardinaldirection
m
(N,S,E,orW).Atminimum,eightphotosweretaken, fig. 2). The canopy, about 35 high (table 2), is
one photofrom each ofthe four exterior poststoward dominated by 200 to 300 year old western larch and
the center of the plot, and a second photo in the Douglas-firand100to150yearoldwesternwhitepine
oppositedirection,facingawayfromtheplot.Atsome (fig. 4). The mid canopyis 100 to 150 year old spruce
ofthe plots, additional photos were taken from the
centeroftheplotorintheothertwocardinaldirections
from an outer post. —
Species nomenclature follows Hitchcock and Table 2 Plot one in the Coram Research Natrual Area.
Cronquist(1973).Allplantswereidentifiedtospecies Characteristics of representative trees measured
or collected andidentified laterinthe lab. in1990.Ageisbasedonringcountsofcoresatd.b.h.
Plotdata,includingphotographs,aremaintainedby Species Age D.b.h. Height
the Natural Areas Program and by the Silviculture Year cm m
Research Work Unit, both located at the Intermovm-
Abies lasiocarpa 55 21.3 20
tain Research Stationin Missoula, MT.
Abies lasiocarpa 75 23.4 14
Larixoccidentalis 255+ 62.7 35
Western Larch Forest Cover Type: Larixoccidentalis 283 47.7 35
Piceasp. 125 22.8 17
Old-Growth Stands
Pinus monticola 140 53.1 37
Pinus monticola 125 44.4 38
Plot One
Pinusmonticola 140 49.1 35
Pinus contorta 165 45.7 29
Plot one is in a western larch stand on a gentle (15
Pseudotsuga menziesii 113 41.6 27
percent) southwest-facing slope at the low-elevation
Tsugaheterophylla 70 17.8 12
boundaryoftheCoramResearchNaturalArea(table1;
5
—
andlodgepolepineand50to70yearoldsubalpinefir, mountainpinebeetle{Dendroctonusponderosae),this
western hemlock, and western white pine (table 2). species would likely remain an important canopy
The lower canopy is almost exclusively subalpine fir species as succession continues (Mouer 1992); seven
and spruce. The understory is relatively open except white pine trees, however, have already died. It is
forclumps ofyoung subalpine fir (fig. 4), possibly the likelythatadditionalmortalitycausedbyblisterrust
resultofanunderbumin1905(Sneck1973). Basedon will occur.
the understory composition and the abimdance of Recruitment of seedlings is rare, with an average
regeneratingsubalpinefirandspruce,thestandclas- density of 0.18 seedlings per m^ (table 4). No larch
sifiesasaAbieslasiocarpalClintoniauniflorahabitat have been recruited into the stand, and only a single
ty^e,Aralianudicaulisphase(Pfisterandothers1977). Douglas-firseedlingoccurs inthefour subplots. Four
Trees—Larch are the largest trees in the canopy, ofthe nine seedlings found in the four seedling sub-
rangingfrom33to67cmd.b.h.,withatotalbasalarea plots are subalpine fir. The remaining four are all
on the 0.1 ha plot of1.88 m^, (about 37 percent ofthe westernwhite pine.
totalplotbasalarea)(table3).Larcharealsotheoldest Shrubs Spiraea betuUfolia, Lonicera utahensis,
trees on the plot, with one cored tree 283 years old and Vaccinium globulare are most common in the
(table 2). The tallest trees on the plot are western lowershrublayer,whileAcerglabrumandAmelanchier
white pine. Douglas-fir is also common in the over- alnifolia are most common in the upper shrub layer
story, andoccursoccasionallyinthesmallerdiameter (appendix).Totalshrubcover,excludingthesubshrub,
classes. Linnaea borealis, is about 30 percent.
Subalpinefirandsprucerepresentabout43percent Herbs—The herbaceous understory is dominated
ofalltreesontheplotinthe2.5to 12.5cmsizeclasses, byClintoniauniflora,Disporumhookeri, andthesub-
a clear indication ofsuccessional trend.
shrubLm/iaeaborealis(appendix).Twenty-eighther-
The presence of western white pine in nearly all baceous species were identified within the sampled
diameter classes, including seedlings (table 4), sug- microplots onthe plot. There are no species uniqueto
gestsregularestablishment.Westernwhitepinecom-
plot one among the eight permanent plots sampled,
prises23 percentofallthetreesontheplotandabout
but one species,Fragaria virginiana, is onlyfoundin
30 percent ofthe total plot basal area. In the absence
this plot and plot eight.
ofwhite pine blister rust {Cronartium ribicola) and
—
Table3 PlotoneintheCoramResearchNaturalArea.Numberofliveanddeadtreesandtotalbasalarea(cm )oflivetreesbyspeciesandd.b.h.class(cm)measured
in 1990.
ABUA LAOC PIEN PICO PIMO PSME TSHE Total
Basal Basal Basal Basal Basal Basal Basal Basal
Diameter Live area Live area Live area Live area Live area Live area Live area Live area
class (dead) (s.d.)" (dead) (s.d.) (dead) (s.d.) (dead) (s.d.) (dead) (s.d.) (dead) (s.d.) (dead) (s.d.) (dead) (s.d.)
cm
2.5-5.0 11(1) 118.3 4 33.3 15(1) 151.6
(4.3) (1.9)
5.1 -7.5 4 102.0 8 233.4 3(1) 101.6 1 22.7 16 459.7
(4.3) (8.5) (8.1)
7.6-12.5 9 749.4 10(1) 822.8 6(1) 501.3 1 110.8 26(1) 2,184.3
(20.8) (24.5) (22.8)
12.6-20.0 1(1) 258.6 12 2,495.9 3(5) 515.1 1 310.1 1 249.3 18(1) 3,829.0
(52.2) (33.0)
20.1 -30.0 2 781 8 2 741.5 1 698.5 3 1,440.2 8 3.662.0
(54.1) (52.6) (207.1)
30.1 -45.0 1 874.8 2 1,537.2 (2) 6 6,907.5 2 2,339.3 11(2) 11,658.8
(30.8) (368.6) (279.7)
45.1 -60.0 5 11,317.1 1 1,640.3 3 6,327.8 1 2,332.8 10 21,618.0
(463.9) (183.8)
60.1 -75.0 2 6,618.1 2 6,618.1
(314.5)
>75.0 0 0.0
Total 27(2) 2,010.1 8(0) 18,810.0 38(1) 5,864.1 2(2) 2,338.8 24(7) 15,793.5 5(0) 5,004.9 2(0) 360.1 106(5) 50,181.5
"Standarddeviationoftheaveragebasalareaisincludedasameasureofthevariabilityoftreeswithineachclass.
6