Decomposition of dominant plant species litter in a semi-arid grassland

Dominant plant species in semi-arid environments differ in their effects on litter decomposition. The present study was conducted to investigate the contribution of dominant plant species found in a natural semi-arid grassland to nutrient cycling through their litter decomposition. Aboveground litter (stems and leaves) of Dichanthium ischaemum, Chrysopogon gryllus, Festuca ovina and Trifolium purpureum was placed on the soil for 24 months and chemical characteristics were monitored. The rate of mass loss from stems was significantly lower than that of leaves for all species. The influence of mesh size on the studied parameters for both leaves and stems was similar in most cases for the grass species, Chrysopogon and Festuca (e.g. litter, lignin, TNSC, Energy and Total C, N, K, Ca). Generally, mean decomposition rate (k' = k x 10(5)) had the highest value for Trifolium (k' = 188), followed by Dichanthium (k' = 133), Chtysopogon (k' = 120) and Festuca (k' = 118). Chrysopogon and Festuca by being the most dominant species in the grassland and having low decomposition rates contribute more organic matter to the soil. (C) 2003 Elsevier Science B.V. All rights reserved.