PARENT SESSION
Poster Session #39: Disturbance Ecology.
Thursday, August 9, 2001. Presentation from 3:30 PM to 5:00 PM. Exhibition Hall
40
Spatial heterogeneity under three different management regimes.
LaVigne, Elena1, Rodriguez, Esther1, Camilo, Gerardo1, 1
ABSTRACT- The current paradigm in ecology is that natural disturbance is an integral part of ecosystems. Logging activity can influence the quantity or quality of plant litter inputs, as well as abiotic parameters like light availability. This study compares three forest management regimes: (1) clear-cut (Reis Biological Station, Steelville, MO); (2) select tree harvest (Pioneer Forest, Salem, MO); (3) preservation (Current River Natural Area, Salem, MO). Land use history was reconstructed by the use of records, aerial photographs and interviews with managers. Current management has been in place in all sites for at least fifty years. Our objectives were to determine the spatial resolution at which management practices result in spatial patterns of abiotic parameters and forest structure. We measured canopy cover, light availability, vegetation profiles (in 0.5m intervals), dbh, temperature, and relative humidity. Tree diversity was the highest at the selective logged site, and lowest at the clear-cut. Spatial variation in abiotic parameters was at least two orders of magnitude greater at the clear cut site. The preservation site had the least spatial heterogeneity. This seems to be associated with fire suppression at this site since 1956. The select harvested site was intermediate for all factors of spatial variation. Tree species diversity clumped at 100m2 for all sites and at 225m2 for preserved and select harvest sites. Species diversity was spatially autocorrelated at all sites, with select harvest being intermediate.
KEY WORDS: spatial heterogeneity, forest management