A Quantitative Assessment of the Structure and Functions of a Mature Bottomland Hardwood Community: The Iatt Creek Ecosystem Site
We report our efforts, initiated in 1995, to quantify ecological processes and functions in a relatively undisturbed, mature hardwood forest. The 320-ha site is located in central Louisiana on the upper reaches of Iatt Creek, an anastomosing minor stream bottom. The forest is a mature sweetgum (Liquidambar styraciflua L.)-cherrybark oak (Quercus pagoda Raf.) dominated community with over 70 woody plant species present. Soils are Typic Glossaqualfs. Flooding is flashy, occurring primarily in the dormant season. Initial analyses indicate major overstory species groups do respond to elevational differences within the bottom. Aboveground net primary productivity (NPP) averages 14200 kg per ha per year. Fine litterfall transfers average 8520 kg per ha per year with 63 percent as leaf fall. In contrast to an adjacent pine upland, leaf litter decomposition, as measured by mass loss, was initially greater in the bottomland, but in the second year there was little difference between sites. Pure sweetgum and red oak subgenera Elythrobalanus) decomposed significantly faster than pine needles in both environments. A diverse avian and aquatic populatlon is evident.