Date of this Version
Climate change models predict that ecotones, which are boundaries between two biomes, are likely to be the first place we see the effects of climate change. However, very little baseline data exist for these areas and their current community structure. In order to better understand the community dynamics of an ecotonal forest, a 2.2 ha 60- year-old upland forest in northeastern Kansas was monitored for 10 years. This oak-hickory forest at the ecotone with the tallgrass prairie biome is growing more slowly than other forests of similar species composition farther east, possibly due to lower levels of available soil moisture or nutrient-depleted soil. The aboveground biomass (122 Mg/ ha) was 15%-25% less than more eastern forests of similar composition and age. The study area contained three slightly different landscape units, typical of the regional matrix of land-use histories, edaphic characteristics, and forest compositions. A portion of the study area with a history of greater disturbance had the greatest number of small trees and a higher biomass and density of early successional species. Over the 10- year study period, differences among landscape units became less pronounced, with tree biomass and species composition becoming more uniform. We expect that in the next 50 years, the forest will become more homogenous across the study area with respect to aboveground biomass and species composition. This suggests that land-use history plays a minor role in determining community composition in this ecotonal forest, and that biological and environmental factors playa larger role.