Effects of Defoliation
by Gypsy Moth on Stump Sprouting of Mixed Oak Stands
||To study defoliation effects on sprouting capacity, vigor,
growth, mortality and regeneration under different silvicultural
||Block 1: 1981
Block 2: 1983
||Block 1: discontinued 1992.
Block 2: discontinued 1994.
||Block 1 Clinton County, PA.
Block 2 Clear Creek State Forest, Jefferson County, PA.
||Split plot with randomized block. A 7.2-acre plot has a 2-chain
buffer between measurement areas and surrounding forest. Within
the 7.2-acre plot, two areas were designated for measuring:
a 2-acre whole plot with 1 area fenced and 1 area unfenced,
and a 1-acre split plot fenced.
6' radius plots designed to collect regeneration data in
understory: 10 per treatment in block1 and 12 per treatment
in block 2.
Design after 1993 following regeneration stand development
in clear-cut treatments only:
Block 1: 4 acres, 2 fenced and 2 unfenced measured annually.
Block 2: 2 acres, 1 fenced and 1 unfenced: measured annually
AND 4 acres, 2 fenced and 2 unfenced measured annually.
|Likelihood of Locating Study Areas:
||Block 1: Clear-cut (1981) , thinning, thinning with Timber
Stand Improvement control (1981-1982 after defoliation).
Block 2: Same treatments replicated as in block 1 without one
clear-cut and one thinning cut prior to defoliation in 1984.
Clearcuts to occur every 10 years.
Markers replaced: block1: 1992, block 2: 1994.
||Tree vigor, d.b.h. and defoliation measurements were taken
in overstory. Annual regeneration plots taken in understory
for 5 years then at 5-year intervals. 10-year regeneration measurements
include 100% inventory of all stems > 0.6" d.b.h.
|Variables and Sampling Frequency:
||Independent: cutting method (thin, thin/TSI, commercial clear-cut,
complete clear-cut), species, size class, defoliation, deer
fencing (first 5-years only).
Dependent: Sprouting capacity, sprouting vigor, sprout mortality
(& stump mortality), vigor & mortality of uncut trees
and regeneration response.
Block 1: annually 1981 to 1986 & 1992 (regeneration).
Block 2: annually 1983-1988 and 1993; 1984-1989 & 1994 (regeneration).
||Field data are verified when entered into computer. Missing
or inconsistent data are field checked.
||All data on diskettes (some summarized and some analyzed).
|Global Change Research Applications:
||Studies of Ecosystem Processes
Model Development and Application
|Publications and Reports:
||none to date.
||Kurt Gottschalk, USDA Forest Service, 180 Canfield St., Morgantown
WV 26505-3101. (304) 285-1598
Hammermill Paper Co.
PA Bureau of Forestry, Forest Pest Management Division.