サバンナにおける草本性リターの分解による重量減少とエネルギー放出

抄録

A.K. SINGH (Lab. Ecol., Fac. Sci., Chiba Univ., Chiba, Japan), R.S. AMBASHT & K.N. MISRA (Dept. Bot., Banaras Hindu Univ., Varanasi, India). 1979. Weight-loss and energy release of decomposing grass litter in a savanna ecosystem. Jap. J. Ecol. 29 : 369-374. Decomposition studies of grass litter, with respect to weight-loss and energy release, were made during May 1976 to May 1977 in a savanna ecosystem of Chandraprabha Sanctuary (24°52′ to 24°58′ N lat., 83°3′ to 83°12′ E long.) in Varanasi forest division. Known quantity of grass litter was kept in nylon bags and placed at soil surface in savanna stand. It decomposed at a fast rate and about 93.66 per cent of the total litter decomposed within a year, out of which three seasons rainy, winter and summer accounted for 64.48,18.60 and 10.58 per cent, respectively. CO_2 evolution rate, which was measured at monthly intervals, was correlated statistically with weight-loss and moisture content of litter. Highly significant (p<0.001) relations were achieved among them. Caloric values per gram of organic matter increased significantly till the end of rainy season possibly due to preferential decaying of lower energy content substrates, and after that it decreased cotinously. Annual loss of energy in the decomposition was 93.68 per cent of the total energy placed in the litter bag. Positive linear correlation significant at 0.001 per cent level was obtained between energy release (Kcal) and weight-loss (g).