of Long Term Research Conducted by the Northeastern Research Station
||To determine and demonstrate costs and returns of selective
alternative management programs in northern hardwoods.
||expected to continue
||Bartlett Experimental Forest. Compartment 22.
North-facing slope of 20-25% at ~1100' elev. Soil: Hermon stony,
sandy loam and well-drained podzol derived mainly from granite
and granitic gneiss glacial till. Paper birch site index is
estimated to be 70' at 50 years.
Original stand was typical of old-growth northern hardwoods,
containing 61% beech, 15% yellow birch, 15% sugar maple, and
9% red maple, ash, paper birch, and other species.
||20 0.25-acre plots separated by 1-chain isolation strips.
5 blocks of 4 plots each.
|Likelihood of Locating Study Areas:
||Prep: 1933-35 clear-cut 25 year-old northern hardwood 22-acre
stand. After crop trees were selected and marked, 1 of 4 treatments
was randomly assigned to the plots in each block: 1) heavy crop-tree
thinning, 2) light crop-tree thinning, 3) species thinning,
4) control plots where no trees were removed: 1959
||~100 crop-trees were selected in each plot, or 400 per acre
to permit detailed evaluation of individual tree development.
|Variables and Sampling Frequency:
||Prior to 1959 (cutting): 100% tally of crop trees of entire
stand >0.5" d.b.h. (tally also made for trees removed in the
thinning.) 100% stand tally of crop trees >0.5" d.b.h were measured
to the nearest 0.1". For each crop tree species present on each
plot, 4 trees were selected at random and measured for: d.b.h.
and diameter at top of the 1st 16-foot long, live crown length
(1964 only), crown area (basal area of crown projection), crown
volume (crown area times crown length), crown class, crown vigor,
clear length of bole (height to 1st live or dead branch, excluding
epicormics), number and location of branches, epicormic branches,
and bole defects, bole quality class: 1959, 1964, 1969, 1975,
Number of trees per species, and d.b.h.: 1969.
Number of trees per species, d.b.h., and percentage composition/acre:
100% remeasurement tally: tree species, counts, and d.b.h.:
||The crop trees have either 1 or 2 painted blue rings near
breast height for identification. Tally was recorded on portable
data recorder (Omnidata Polycorder) by plot and species: July,
1990. Plot corners were restaked, plot boundaries and study
trees were marked: July, 1990.
||DG; some summarized but unanalyzed.
|Global Change Research Applications:
||Studies of Ecosystem Processes
Model Development and Application
|Publications and Reports:
||D. Marquis. 1969. thinning: in Young Northern hardwoods: 5-year
results. N NE-139. Upper Darby, PA: U.S. Department of Agriculture,
Forest Service, Northeastern Forest Experiment Station.
D. Marquis. 1967. clearcutting in northern hardwoods: results
after 30 years. Res. Paper NE-85. Upper Darby, PA: U.S. Department
of Agriculture, Forest Service, Northeastern Forest Experiment
W. Leak, M.S. Smith. 1997. Long-term species and structural
changes. For. Ecol. 95(1):11-20.
W.Leak, D. Solomon. 1997. Long-term growth of crop trees.
N.J. AF. (In press)
||William Leak, USDA Forest Service, P.O. Box 640, Durham NH
03824. (603) 868-7655