Tree Regeneration Response to the Group Selection Method in by yhp13240

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									         Tree Regeneration Response to the Group
          Selection Method in Southern Indiana
                        Dale R. Weigel, USDA Forest Service, North Central Forest
                        Experiment Station, 81 1 Constitution Avenue, Bedford, IN
                        47421, and George R. Parker, Department of Forestry and
                        Natural Resources, Purdue University, 1159 Forestry
                        Building, West Lafayette, IN 47907-1159.


         ABSTRACT. Tree regeneration response following the use of the group selection method was studied within
         36 group openings on the NavalSurface Warfare Center, Crane Division in south centrallndiana. Two different
         aspects and three time periods since cutting were examined. The objectives were to determine whether aspect,
         age, species group, location within the opening, or their interactions had any influence on the number of stems
         or average height of the tree regeneration. Among openings up to 20 yr since cutting, yellow-poplar and
         dogwood were most abundant for stems greater than 2.5 cm diameter at breast height (dbh),and dogwood and
         cherry-ash-walnut were most abundantfor stems less than 2.5 cm dbh. The location xspecies group interaction
         also influenced the number of stems greater than 2.5 cm dbh. Stems less than 2.5 cm dbh were influenced by
         the age x species group and aspect x species group interactions. The north aspect and the oldest openings
         contained the most stemsper hectare less than 2.5 cm dbh. The interaction of age and species group influenced
         average height for stems greater than or equal to 2.5 cm dbh. Average height increased with age for stems
         greater than or equal to 2.5 cm dbh. North. J. Appl. For. 14(2):90-94.




S i n c e the 1960s, even-aged regeneration systems have been         Nearly the entire NSWC is unglaciated and lies within the
recommended for central hardwood forests (Roach and                Crawford Upland Section of the Shawnee Hills Natural
Gingrich 1968, Sander and Clark 1971). Recently, however,          Region as described by Homoya et al. (1985). It is character-
interest has been increasing in the use of group selection to      ized by rugged hills with sandstone cliffs and rockhouses.
convert central hardwood forests to uneven-aged communi-           The forest vegetation consists of oak-hickory on the upper
ties, particularly on public lands (USDA For. S e n . 1991).       slopes, with a mesic component in the coves and bottoms.
    This interest has emphasized the lack of scientific infor-     Soils in the study area are the Wellston association character-
mation about how well central hardwood species regenerate          ized as deep and moderately deep, gently sloping to very
under uneven-aged methods. Specific questions include:             steep, well-drained soils formed in loess and material weath--
How does the composition of the parent stand determine the         ered from sandstone, siltstone, and shale on uplands (USDA
composition of the future stand; what effect does opening          Soil Conserv. Serv. 1988).
size have on the type and development of regeneration, and
how does this change over time; and does the species compo-        Methods
sition vary within different portions of openings and/or
between different aspects? This paper describes patterns of           All timber sale contracts, using the group selection method,
regeneration in group selection openings by aspect and age of      from the period 1971 to 1985 were examined for potential
opening, and by location within the opening.                       sample sites. The stands were divided into three groups
                                                                   depending on the time of harvest: 6 1 0 yr (1981-1985), 11-
                                                                   15yr(1976-1980),and 16-20yr(1971-1975). Afteryear20,
Study Site
                                                                   timber stand improvement work influenced the composition
   This research was conducted on the Naval Surface War-           of the groups. Stands younger than 6 yr were still changing
fare Center (NSWC), Crane Division, located in south central       rapidly, and species dominance was not yet apparent. Group
Indiana, where the uneven-aged regeneration system has             openings in bottomlands or on ridges were not sampled.
beenused since the early 1960s. NSWC contains over 62,000             The openings were divided into two groups-north and
ac of which more than 48.000 are forested.                         south aspect-using aerial photos and topographic maps

90   NJAF 14(2) 1997
                                                                       8O
Thed•ws•ons,              315
              northaspect ø-135øandsouth      aspect 136ø-
                                                                 •'•                                            Cover
314ø,were basedon previouswork in southern      Indiana by
Hannah(1968) andVan Kley (1993). Six openings    fromeach
                                                                 •
                                                                       7o
                                                                       6o
of the three age classesfor each aspectwere randomly
         for
selected sampling.    Thus,therewere 12 openings ageper          •     5o                                 Oak
      or            per        for
class, 18openings aspect, a totalof 36 openings.        All
were examinedto verify that: (1) the aspectwas north or          •     4o
       (2)
south; the openingwasfairly distinctanddiscernible;     (3)
thesurrounding  standwasmatureuplandcentralhardwoods;                  3o
                                                                 •     2o
and (4) the opening                               to
                    wasnot an old field reverting forest.
Eachgroupopening                            (2)
                   failingto meetconditions through     (4)
was dropped,and a new one was randomly selected.The
                                                                        o
selected openings were irregularin shapeandvaried in size                   OH   YP    DOG     BM   SS   CAW      SAS   MIS
from 0.07 ha to 0.23 ha with an averagesize of .13 ha.                                  SPECIES     GROUP
   Woodyplantspecies                on
                        weresampled transects    extending
                                                                 Figure 1. Composition of the overstory of openings prior to
               to
fromthecenter theedgeof eachopening.One-meter-wide               harvest, by forest type based on NSWC inventory data.
transects were used for stems less than 2.5 cm diameter   at     (Abbreviations follow Table 1.)
breastheight (dbh, 1.37 m above ground), and 2-m-wide
transects wereusedfor all stemsgreaterthanor equalto 2.5         cover type and size class. The parent standsof the 36
cm dbh.Transects    extended upslope,  downslope, in both
                                                   and           openings  consisted 4 covertype-sizeclassgroups:
                                                                                     of                              oak-
d•rections across slope,beginning1 m from the centerof
                  the                                            hickory poletimber,oak-hickory sawtimber,mixed hard-
theopening ending theedgeof theopening defined
             and         at                         as                             and
                                                                 woodpoletimber, mixedhardwood                    The
                                                                                                       sawtimber. spe-
by thetrunks theadjacent
             of             mature  trees.
                                         Endingthetransects                      and                for
                                                                 ciespercentage sizedistribution thefour covertype-
          of
atthebase thetrees     bordering opening
                                the          followsRunkle's     sizeclass groups wereaveraged, eachgroup,fromacross
                                                                                                for
(1982) methodof measuring      extended   canopygaps.Each        the entireNSWC. All openings            for
                                                                                                sampled our studywere
         was             into
transect subdivided 1m lengths sampling  for           woody                 in
                                                                 established sawtimber    stands.
                                                                                                Singletree selection, the
                                                                                                                    in
species along the transect.Field data collectionwas com-                            the               at
                                                                 standsurrounding groupopenings, the time of harvest
pletedduringthe summerof 1991.                                   (1971-1985), resultedin the poletimberclassification  for
          (in                 and
   Height 25cmcategories) distance theplotcenter
                                           from                               in                                    of
                                                                 somestands the 1991 inventory.Fifty-threepercent the
                    were
0n 1m increments) measured species each
                                   by         for    stem less   openings  werein theoak-hickorycovertype,and47% in the
than2.5 cm dbh.Dbh (to thenearest cm), height(nearest
                                     0.1                     1   mixedhardwood    covertype.The oak-hickory         group
                                                                                                              species
                 (in             to
m), crownclass relationship theregeneration), dis-    and        wasthedominant    speciesgroupconstituting  morethan75%
rance                                            by
      from the plot center(1 m) wererecorded species       for           in
                                                                 of trees theoak-hickorycovertype,and44% of themixed
woodystems    greater thanor equalto 2.5 cm dbh.                 hardwood   cover type (Figure 1). The next most dominant
   For analysis, species
                the          wereputintothefollowingeight        species group  wasthebeech-maple  group withjustover20%
        (1)
groups: oak-hickory,(2) yellow-poplar, dogwood,
                                             (3)           (4)              in
                                                                 of thetrees themixedhardwood     covertype.Theonlyother
beech-sugar   maple, (5) shrubs  and smalltrees,(6) cherry-      species makingup morethan 10% of the originalcoverwas
ash-walnut,(7) sassafras, (8) miscellaneous
                            and                     species.     yellow-poplar,with 11% in themixed hardwood    covertype.
   Also for analysis,distance  from plot centerwas grouped       Number     of Stems > 2.5 cm Dbh
•nto three categories:center, first 4 m from plot center;                     >
                                                                    For stems 2.5 cm dbh,the numberper hectare    variedby
m•ddle,areaafter the first 4 m andbeforethe last4 m; edge,       the interactionof speciesgroup and location within the
the last 4 m of the transect.
                                                                 opening.             of       did
                                                                          The number stems notdiffer significantly       by
   Aspect was determinedin the field, and area of each           aspector time sincecutting.
opening was calculated usingthe lengthof eachtransectto             The two most dominantspecies    were yellow-poplarand
           the
determine areaof an ellipse.                                     dogwood. Compared to the other six groups, these two
   Analysisof variance,ANOVA, was usedto determine                       had               to
                                                                 species at leastdouble triple thenumberof stems        per
whetherthe variablesaspect,age, species  group,location          hectare(Figure 2). The other species   groupsdid not differ
                   or                had
w•thinthe opening, theirinteraction anyeffectonthe               significantlyexceptfor the oak-hickory, with feweststems
average         of     per        or
        number stems hectare average       height.When           per hectare.Oak-hickory also differed significantlyfrom
                         the
an effect was significant, Student-Newman-Keuls    mul-                    and
                                                                 sassafras beech-sugar     maple. Althoughthe numbers     of
tiplerangetestwasusedto determine           between
                                  differences       the          stems species
                                                                       by         groupchanged   with time sincecutting,this
means.
                                                                 interactionwas not significant.
                                                                    When the speciesgroup by location interaction was
Results
                                                                 tested, yellow-poplar, dogwood, and the miscellaneous
Parent Stand                                                     speciesgroup showed a significant difference between
  The species
            composition eachstand
                       of         wasobtained  from              locations (Figure 3). The number of stems per hectare
NSWC's mostrecentforest       data,March 1991.The
                      inventory                                  decreased  from the centerof the openingto the edgeof the
NSWC inventoryplacedeachinventoriedforeststandinto a             openingfor the miscellaneousspeciesand yellow-poplar

                                                                                                          NJAF14(2)1997 91
                                                                                    1200O
                                                       Age Class
                                                 Opening        (years)                                      Age   (years)
                                                                                                       Opening Class                a•
                          &                       •-10    11-15   16-20




            .................
                                       bc
                                                  •c _b •           c                              de
                                                                                                  cd                  • • de • • b
            bg c
              •', .....               ,' •','     •:'     •l'     •:'
                                                                                                  OH   •    DOG     BM       SS     CAW    SAS     •S
                                                                                                              SPECKS       GRO•
Figure 2. Number of stems, greeter than or equel to 2.5 cm dbh,                 Figure 4. Number of stems, less than 2.5 cm dbh, by species
by species group and age of opening. Species groups within                      group and age of opening.Speciesgroupswithin individualage
                   with similerlettersdo not differsignificently
individualageclasses                                                            clesseswith similar letters do not differ significently et • = 0.05
at • = 0.05. (Abbreviations follow Teble 1.)                                    (Abbreviations follow Teble 1.)


speciesgroups.Dogwoodcontainedthe most stemsper                                 erything else, and was secondmost abundanton the south
hectare in the middle location, but this number did not                         aspects(Table 1). Dogwoodwas significantlymore abun-
differ significantlyfrom the center location. The edge                          dant on the south aspectsand the secondmost abundant
location containedthe fewest stemsfor dogwood.The                               speciesgroup on the north aspects.The yellow-poplar
oak-hickory group did not occur in the center location,                         speciesgrouphad the fewest stemson both the north and
and slightly more stemsgrew in the edgelocationthan in                          south aspects.The oak-hickory speciesgroup was the
the middle         location.                                                    secondleast abundanton north aspects, and fourth least
                                                                                abundanton southaspects.
Number        of stems < 2.5 cm Dbh
   The interaction time sincecuttingwith species
                  of                           group,                           Average Height
andtheinteraction aspect
                  of      with species
                                     groupinfluenced                              The average height of stems _>2.5 cm dbh differed
the numberof stemsper hectarefor trees < 2.5 cm dbh.                                         by                of
                                                                                significantly the interaction time sincecuttingw•th
However, location did not.                                                      speciesgroup. All speciesgroupsshoweda height in-
  In the 6-10 yr openings,dogwoodwas significantly                              crease from the mostrecentto the oldestopenings  except
moreabundant  thanall theotherspecies groups(Figure4).                          for dogwood,                and
                                                                                              beech-maple, cherry-ash-walnut(Fig-
For openings11-15 yr old, the cherry-ash-walnutspecies                                                          in
                                                                                ure5). They wereslightlyshorter the 16-20 yr openings
groupwas significantlymore abundant    than all species                         compared to the 11-15 yr openings. In the youngest
groupsexcept dogwood.In the 16-20 yr openings,the                                         the
                                                                                openings, beech-sugar       maple (7.7 m) species group
cherry-ash-walnutspecies   groupwas significantlymore                           was significantly taller than everything else. The oak-
abundantthan all the other speciesgroups.The yellow-                            hickoryspecies  groupwasnotpresent.   Yellow-poplar(8 6
poplar group was next to least abundantin the youngest                          m) wasthe tallest species groupin the 11-15 yr openings,
openingsand least abundantin the older openings.                                and oak-hickory (5.8 m) was the shortest.In the oldest
  On north aspects(Table 1), the cherry-ash-walnut                              openings,yellow-poplar (10.1 m) was significantly the
speciesgroup was significantly more abundantthan ev-                            tallest and the oak-hickory (7.5 m) speciesgroup re-
                                                                                mained shorterthan all other speciesgroupsexceptdog-
                                                                                wood and miscellaneous.
     7O0O
                      a                               within
                                                Location
                                                                                Table 1. Number of stems per hectare, less then 2.5 cm dbh, by -
                                •                   Middle
                                                Center   Edge                   species groups and aspect.
                                                                                                                                    Aspect

                                                                                      group
                                                                                Species                                    North•                •
                                                                                                                                             South

                                                                                Oak-hickory(OH)                                 d
                                                                                                                          1,529.2         2,500.1o•
                                                                                Yellow-poplar(YP)                          965.8d         1,137.3d
                                                                                Dogwood  (DOG)                                  b
                                                                                                                          6,316.7               a
                                                                                                                                          6,152.3
                                                                                Beech-maple (BM)                                d
                                                                                                                          2,107.9               ø•
                                                                                                                                          2,205.0
              OH          YP    DOG     BM        SS     CAW      SAS     MIS              trees
                                                                                Shrubs/small (SS)                         3,899.0
                                                                                                                                c         1,275.5
                                                                                                                                                d
                                    SPECIES      GROUP                          Cherry-ash-walnut(CAW)                          a
                                                                                                                         10,012.7               b
                                                                                                                                          4,088.7
                                                                                        (SAS)
                                                                                Sassafras                                       d
                                                                                                                          1,947.2               •
                                                                                                                                          3,580.7
Figure 3. Number of stems, greater than or equal to 2.5 cm dbh,                 Miscellaneous      (MIS)
                                                                                             species                            b
                                                                                                                          5,441.4               •
                                                                                                                                          2,900.6
by species group and location within the opening. Locations
within individual species groups with similar letters do not differ             1 Means in the same column with similar lettersdo not differ significantly
significantly et • = 0.05. (Abbreviations follow Table 1.)                        at c• = 0.05.



92     NJAF14(2)1997
  12
                                OpeningAge Class(years)
                                                                             andthustheirnumbers              as
                                                                                                   decreased the sprout   clumpsself-
                      a         6-10    11-1•        16-20                   thinned.The fast growthrate of yellow-poplarandits shade
                                                                             intolerance(Beck 1990) explainsthe few yellow-poplar
                                                                             stemspresentin the < 2.5 cm class.Yellow-poplareither
              b                                         b               &b                           or
                                                                             outgrewthe competition couldnot survivein the shade.
                                                                                The height growthof the species   groupscorresponded
                                                                                                                  by
                                                                             well withmeangrowthratesobserved Yetter andRunkle
                                                                             (1986) and George (1988). For canopy gaps, Yetter and
                                                                             Runklereported mean  height        for
                                                                                                        growth dominant     stemswith
                                                                             yellow-poplarhaving the second    highestgrowthrate and
        OH        •       DOG      BM           SS           •W   S•S
                                                                             beech and northernred oak the slowest.George reported
                            SPECKS         GRO•                              averageannualheightgrowthfor dominantplot treesin a
                                                                             clearcut.Yellow-poplarhadthe second    highestgrowthrate
Figure5. Average height of stems, greater than or equal to 2.5 cm
dbh, by speciesgroup and age of opening. Speciesgroupswithin                            For
                                                                             after aspen. white,red, andblackoak, observed     growth
individualage classeswith similarletters do not differsignificantly          rateswerea foot or lessper year.
at • = 0.05. (Abbreviations follow Table 1.)


Discussion                                                                   Application

   Theparent
           stands ourstudy
                  in        weredominated theoak-
                                           by                                   We do not know the quantity and type of advanced
hickorygroup,but futurestandswill includea diversityof                       regeneration presentbeforeharvest.Sander(1978) andSander
species          by
       dominated yellow-poplar.As indicatedby the                            et al. (1983) suggested that securingoak in future stands
number of stems> 2.5 cm dbh and < 2.5 cm dbh, the oak-                                                     as
                                                                             would dependon its presence advance    regeneration prior
                           of
hickorywerethe leastabundant any species group.This                          to cutting.When oak advance               is
                                                                                                           regeneration not present in
        that
suggests the oak-hickoryspecies  groupwill not domi-                                                                   to
                                                                             sufficientquantities,stepsare necessary increasethe
                    For       >
natethefuturestand. the stems 2.5 cm, yellow-poplar                          quantity.                                 the
                                                                                       Loftis(1985, 1988)recommended useof herbi-
wasdominant all buttheyoungest
             in                        Oak-hickory
                               openings.                                     cide to removeundesirable  stems,allowingfor the increase
                                                                             in size and number of desirable ones.
remained        the
         among shortest  species      in
                                groups openings  of
all ages.                                                                       Oak stems are a minor component in the developing
   Theseresultsdiffered from thosereportedby Runkle                                  of             that
                                                                             canopy theopenings we studied.        Therearesufficient
                                      that
(1981) andBarden(1981), who suggested species   re-                          oak stems                               the
                                                                                        greaterthan2.5 cm to dominate opening in but
                in
place themselves larger canopygaps. However, their                           a subordinate position.Releaseof the mostvigorousstems
research was conducted in forest stands where shade-tolerant                 within a few yearsafterharvest may providea full canopyof
speciesdominatedthe forest canopy,and shade-tolerant                         oak in the developing canopy.
species replacedshade-tolerantones.In standswith oak-                                         that                 oak
                                                                                Thissuggests to obtainsufficient in futurestands,
hickoryoverstoriessimilarto ours,StandifordandFischer                        openings  might be locatedin areaswith abundant    oak ad-
(1980) reported decrease
               a        from 80% oak beforeharvest to                        vanceregeneration,                           be
                                                                                                 oak advanceregeneration increased
7% oak 12 to 15 yr later.Fischer
                               (1987) andGeorgeand                                           or                        be
                                                                             priorto harvest, properculturaltreatment givento oak
Fischer(1991) observed similartrendfor clearcuts the
                       a                        on                                 in
                                                                             stems the developing    canopy.
Hoosier National Forest, where oak-hickory declinedin
numbers from the originalparentstand.                                        Literature           Cited
                   did                  of
   Numberof stems vary fromthecenter theopening                                      L.S.
                                                                             BARDEN, 1981.Forest     development canopy
                                                                                                                 in           of
                                                                                                                          gaps adiverse  hardwood
           for     >
totheedge stems 2.5cmdbh.        Thecenter   locationalways                     forestof the southernAppalachian Mountains. Oikos37:205-209.
hadsignificantly              per
                morestems hectare         thandid the edge                   BEC•C,D.E. 1990.Yellow-poplar.P. 406-416 In Silvicsof North America,
                                                                                Vol. 2. USDA For. Serv.Agric.Handb.No. 654.
location.The middlelocation         had
                             always lessthanthecenter                        FISCUER, 1987.The regeneration
                                                                                     B.C.                                to            on
                                                                                                                response clearcutting the U.S.
but morethanthe edgelocation.     This can be partiallyex-                      Forest Service HoosierNationalForest.               Nat.
                                                                                                                     Wayne-Hoosier For.USFS
plainedby the fact thatyellow-poplar   wasoneof the most                                 No.
                                                                                Contract 53-52B1-5-01086.95 p.
                                                                                     D.W.
                                                                             GEOROE, 1988.Treeregeneration              to
                                                                                                                response clearcut           on
                                                                                                                                   harvesting the
dominant  species         in
                  groups the openings.       Yellow-poplar,                     HoosierNationalForest.  Ms. thesis,PurdueUniv. 124 p.
beingintolerant,        be                in
                should mostcommon themoresunny                               GEOROE, ArqD FISC•-:ER. Theoccurrence oakreproduction
                                                                                     D.W.,      B.C.        1991.               of
     in          and
areas thecenter middle               of
                             portions theopening less
                                                    and                         afterclearcut          on
                                                                                              harvesting the HoosierNationalForest. North.J. Appl.
                                                                                For. 8:144-146.
         in
common theshaded      areas        the
                            around edge theopenings
                                             of                                    P.R.                site                            in
                                                                             HArqNAU, 1968.Estimating indexfor whiteandblackoaks Indiana
(Minckler andWoerheide1965).                                                                            factors.J. For. 66(5):412-417.
                                                                               from soil andtopographical
             <
   For stems 2.5 cm dbhtherewasa significant      continual                  HOMOYA,                  J.R.         AND
                                                                                    M.A., D.B. ABRELL, ALDRICH, T.W. POST.         1985. The natural
                                                                               regionsof Indiana.Proc.Ind. Acad. of Sci.. 94:245-268.
        in            of
increase thenumber stems       fromtheyoungest     openings                  Lo•r]s,D.L. 1985.Preharvestherbicide        improves
                                                                                                                 treatment                     in
                                                                                                                                    regeneration
to the oldest,especiallycherry-ash-walnut.      This would                      southem  Appalachian hardwoods.       J.
                                                                                                                South. Appl. For. 9(3):177-180.
indicatethattherewasa steady   influx of new stems  into the                 LOFTIS, 1988.Regenerating onhigh-quality
                                                                                    D.L.                  oak                    an       P.
                                                                                                                           sites, update. 199-
                                                                                                      for
                                                                                209 in Proc.Guidelines regenerating  Appalachian hardwood stands.
openings.                         this
          Runkle(1982) reported sameinflux of seed-                             Morgantown,WV.
hngsin canopy       for
               gaps thefirst 15yr followingcanopy       gap                  MINCKLER, AND
                                                                                       L.S.,                   1965.              of
                                                                                                J.D. WOERHEIDE Reproduction hardwoods          10
creation.         the
         However, dogwood       stems wereof sprout   origin                    years           as
                                                                                     aftercutting affected site opening J.For.57:424-428.
                                                                                                          by and           size.


                                                                                                                              NJAF    1997 93
                                                                                                                                  14(2)
ROACh,B.A., ANDS.F. GINGRICH.                           for
                              1968. Even-agedsfimculture upland                  R.B.,
                                                                      STANDWORD, ANDB.C. FISCHER.    1980. Fifteen year resultsof three
  central hardwoods. USDA For. Serv.Agric. Hand.No. 355.39 p.           harvestingmethods composition development regeneration
                                                                                         on          and              of             in
RUNKLœ,                            in
        J.R. 1981. Gap regeneration some old-growthforestsof the                Indianauplandhardwoods. 408-419 in Proc.CentralHard-
                                                                         southern                     P.
  eastern United States.
                       Ecology62(4): 1041-1051.                          wood For. Conf. III. Columbia, MO.
       J.R
RUNKLE, 1982.Patterns disturbance someold-growth
                         of           in              mesic forests   USDA   FORESTSERVICE. 1991. Amendment to the Hoosier National Forest
  of Eastern NorthAmerica.Ecology63(5):1533-1546.                       landandresource    managementplan. 87 p.
       I.L.
SANDER, 1978. Silvicultural         for
                            systems the oak-hickory  foresttype.P.    USDA SOILCO•SERV^TION    SERVICE.1988. Soil surveyof Martin County,
                            forests:
     344-348in NorthAmerica's            to          1978
                                   Gateway opportunity. Joint           Indiana. 148 p.
     Cony. of SAF and CIF.                                                     J.
                                                                      VANKLEY, 1993.Ecological   landtypephase                for
                                                                                                                 classification theHoosier
       I.L.,                                  of
SANDER, ANDF.B. CLAret 1971. Reproduction uplandhardwood                NationalForest.Ph.D. Diss.,Purdue University. 436 p.
         in
  forests thecentral      USDA For.Serv.Agric.Hand.No. 405.25 p.
                    states.                                           YETTER,T.C., AND             1986. Height growthratesof canopytree
                                                                                        J.R. RUNKLE.
      I.L.,
SANDER, C.E. MCOEE,   K.G. DAY,AND R.E. WILLARD. 1983.Oak-hickory.      species southern
                                                                               in                     gaps.Castanea
                                                                                            Appalachian               51(3)157-167.
                                   for
  P. 116-120 in Silviculturalsystems the major foresttypesof the
               USDA For. Serv. Agric. Handb.445.
  United States.




94     NJAF14(2)1997

								
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