COMPARISON OF LITTER DYNAMICS IN NATIVE AND EXOTIC RIPARIAN VEGETATION ALONG THE MIDDLE RIO-GRANDE OF CENTRAL NEW-MEXICO, USA

Exotic plants and river regulation have changed riparian ecosystems th roughout the south-western U.S. We compared litter dynamics at sites d ominated by native cottonwoods or erode saltcedar in the Middle Rio Gr ande Valley of central New Mexico. Litter production was greater at co ttonwood sites and may have increased after experimental flooding in c ottonwood but not in saltcedar. Decomposition was similar for both typ es of leaves and increased with experimental flooding for both. Forest floor litter was greater at cottonwood sites; litter storage decrease d after flooding at the saltcedar site but not at the cottonwood site. Flooding may help reduce the impact of fires by increasing decomposit ion and reducing the standing stock of forest floor organic matter. (C ) 1998 Academic Press Limited.