Litter decomposition dynamics of Taxus contorta Griff. in western Himalayan region

Abstract

Litterfall is the essential source of organic matter and soil nutrients. The quality and quantity of litter production affect the carbon and nutrient fluxes in forest ecosystems. This study aims to determine the litter decomposition rate and macronutrients (N. P, K, Ca and Mg) in Taxus contorta Griff forests. The results showed that the maximum weight loss due to decomposition was recorded from June to October, and decay constant (K) was 0.534 during two years of study. Decomposition was significantly affected by climatic variables and positively correlated with temperature, rainfall, number of rainy days and relative humidity. The decomposing needles showed a continuous increase in nitrogen (0.97-1.27%) and phosphorus (0.11-0.13%) concentration and a gradual decrease in potassium (0.35-0.31%), calcium (0.93-0.45%) and magnesium (0.21-0.16%). Total nutrient return (37.33 kg ha-1) from the decomposing litter were observed in the order of Ca (15.09) > N (12.13) > K (5.73) > Mg (2.87) > P (1.50) through the input from different litter components, which were found in the order of needles > twigs > bark > miscellaneous litter > reproductive litter. Maximum nutrient return (15.82 kg ha-1) was observed through needle litter and was recorded as N (6.49), P (0.85), K (2.84), Ca (4.39) and Mg (1.24). Out of the total nutrients returned through needle litter, an annual release of 67% and accumulation of 33% nutrients over the forest floor of Taxus contorta was recorded.