Abiotic, species,and habitat controls of litter decomposition in prairie and forest

Köchy, M., and S. D. Wilson (1994)

Nitrogen and mass loss in prairie (Carex sp., Stipa comata, Koeleria gracilis, Bouteloua gracilis) and aspen (Populus tremuloides) litter was measured over a summer in a complete factorial field experiment in Saskatchewan, Canada. The four treatments were litter type (grass or aspen), time (after 4, 9, 16, and 21 weeks), habitat type (prairie or aspen forest), and shading (with or without additional shade). Nitrogenloss was measured with ion-exchange resins. Grass (C:N=44) decomposed significantly faster (k [years]= 1.34) than aspen (C:N=79; k = 0.43) probably because of differences in litter quality. Habitat type and shading had no main effect, but decomposition was significantly faster in prairie plots without shade, probably due to higher temperatures. N loss in all treatments was not larger than N deposition. Analysis of total N in litter suggests that N was lost by litter fragmentation and not by biotic mineralization. The results show (1)that decomposition rate depends mainly on species identity of litter, not the abiotic environment associated with grass or aspen and (2) that N-deposition mayconceal actual N mineralization.

88. Annual Meeting of the Ecological Society of America. Savannah, Georgia (U.S.A.).
Bull. Ecol. Soc. Am. 75 Suppl. 2: 115.