Litter Decomposition in Tropical Plantations Impact of Climate and Substrate Quality

The present paper deals with the decomposition rate of four tree species viz. Shorea robusta (Sal), Tectona grandis (Teak), Eucalyptus spp. (Eucalypts) and Pinus roxburghii (Pine) in relation to their chemical composition and climatic factors. Leaf litter decomposition followed the order : Sal (1.67) > Teak (1.65) > Pine (1.35) > Eucalypts (1.34). In general, values for higher decomposition rate were observed during rainy season and lowest during winter except Pine and Sal, where these lower values were obtained during summer season. Invariably, rainfall, number of rainy days, soil moisture and temperature showed positive correlation with decomposition rate. The multiple correlation (R²) showed that cumulative effect of rainfall and temperature was also positively significant. As far as chemical constituents of litter are concerned N and Mg is positively related with decomposition rate while Lignin, Holocellulose and Lignin/Nitrogen ratio showed negative correlation with decomposition rate. No correlation was obtained with P, Ca, K, alcohol soluble, ether soluble and hot water extractives.