Title: LITTER DECOMPOSITION IN A SIERRA NEVADA RIPARIAN MEADOW AS A FUNCTION OF PLANT SPECIES, DISTANCE FROM STREAM EDGE, AND GRAZING Authors
|Riegel, Gregg - US FOREST SERVICE BEND OR|
Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: December 30, 2008
Publication Date: February 8, 2009
Citation: Vasquez, E.A., Riegel, G.M., Svejcar, A.J. 2009. LITTER DECOMPOSITION IN A SIERRA NEVADA RIPARIAN MEADOW AS A FUNCTION OF PLANT SPECIES, DISTANCE FROM STREAM EDGE, AND GRAZING. 62nd Society for Range Management Annual Meeting. Paper No. 1000-17. Technical Abstract: A key process in nutrient cycling is decomposition of plant litter and the potential resulting increase in soil nutrient levels. We compare the decomposition rate (k-value yr-1) of four riparian graminoids as influenced by plant species, distance from stream edge (2.5, 20, and 50 m), and grazing intensity (non-grazed, light, and moderate) in a montane meadow located in the Sierra Nevada mountains of California, USA. Above-ground biomass of Carex nebrascensis, Deschampsia caespitosa, Juncus bulticus, and Poa pratensis was clipped to the top of the litter surface and separated by species at peak standing crop. Litter was placed in mesh bags on the soil surface and allowed to decompose for 712 days. Litter bags were retrieved at fixed intervals and litter was analyzed for mass loss, total nitrogen, phosphorus, and potassium. The rates of decomposition of the four separate species were not significantly different (p > 0.05) from that of the four species combined (BIO). Although J. balticus and D. caespitosa were not significantly different (p > 0.05) from BIO, they were significantly different from P. pratensis. There was no difference in the rate of P or K loss among species, and few differences with respect to N loss. There was no evidence that the rate of decomposition or nutrient loss was a function of location from stream edge or grazing treatment. It appears that major changes in species composition would be required to influence decomposition rates in the riparian system we studied.