Nutrient Movement in Litter Fall and Precipitation Components for Central Himalayan Forests

The annual total litter fall in six Central Himalayan forests ranged from 2.1 to 3.8 t C ha−1, of which 54 to 82 per cent was leaf litter, 9–20 per cent wood litter and 6–14 per cent other litter. In all forests the order of relative abundance of nutrients (kg ha-1 year-1) in litter fall was Ca (50.8–91.6) > N (47.7–72.2) > K (22.8–37.1) > P (4.1–6.4). Leaf litter accounted for 63–95 per cent of the total nutrients returned through litter fall. In these forests throughfall ranged from 71.3 to 81.4 per cent, stemflow from 0.50 to 2.16 per cent and canopy interception from 17.7 to 28.2 per cent of the gross rainfall. In the incident rainfall the concentration and annual input of Ca was the greatest and of P the least. Canopy precipitation was richer in all nutrients compared to incident rainfall. Net gain of nutrients from the canopy ranged from 0.16 kg ha-1 year-1, for P, to 17.77 kg ha-1 year-1 for K. Leaching was greatest for K and least for N. Of the total quantity of nutrients returned to the soil, 11 to 46 per cent was accounted for by precipitation components. Thus precipitation inputs play a significant role in nutrient cycling of these forests.