Forest floor mass,litterfall and nutrient return in Central Himalayan high altitude forests

Dynamics of forest floor biomass, pattern of litter fall and nutrient return in three central Himalayan high elevation forests are described. Fresh and partially decomposed litter layer occur throughout the year. In maple and birch the highest leaf litter value was found in October and in low-rhododendron in August. The relative contribution of partially and more decomposed litter to the total forest floor remains greatest the year round. The total calculated input of litter was 627.7 g m^-2 yr^-1 for maple, 477.87 g m^-2 yr^-1 for birch and 345.9 g m^-2 yr^-1 for low-rhododendron forests. 49–61% of the forest floor was replaced per year with a subsequent turnover time of 1.6–2.0 yr. The annual nutrient return through litter fall amounted to (kg ha^-1 yr^-1) 25.5–56.1 N, 2.0–5.4 P and 9.9–23.3 K. The tree litter showed an annual replacement of 26–54% for different nutrients and it decreased towards higher elevation. The nutrient use efficiency in terms of litter produced per unit of nutrient was higher in present study compared to certain mid- and high-elevation forests of the central Himalaya.