In natural forests and manmade protected plantations, nutrient cycling is an important process and it involves various processes within the ecosystem. A considerable amount of nutrients are returned through litterfall in the form of leaves, twigs, bark, flowers, fruits, etc. to the soil and are made available for reabsorption. In order to study the litterfall pattern and the total amount of nutrients returned, a field experiment was conducted in an eighteen years old teak plantation at Forest College and Research Institute, Mettupalayam. The litter was col lected from the tree stands using litter traps of 1 m x 1 m size at monthly intervals for one year from January 2006 to December 2006. Thus collected litter was separated into leaves, twigs, flowers and fruits. Dry weight of each component was determined by drying to constant weight at 600 C and the mean monthly value for each plot was worked out on a unit area basis (kg ha-1). The collected litter samples were analysed for nutrient content and the nutrient returns were worked out.
Among the various litter components, leaf litterfall occurred throughout the year with wide variations among different months. The peak leaf fall occurred during February (1,703 kg ha1) and it was higher during January to June contributing 80.0 % to the total annual leaf fall. But flowers, fruits and twig fall occurred only during a particular season. Flowers recorded the highest value during December, while in case of fruits and twigs it was during March. The litterfall was higher during January to June months contributing 77.0 % to the total annual litterfall. The total annual litterfall was found to be 11,255 kg ha-1, of which the leaf litter accounted for 81.9 % to the total litterfall, followed by the twigs (6.5%), fruits (6.3%) and flowers (5.3 %).
Contents of Ca and Mg were higher in leaf litter while flowers had higher N and P contents. K content was higher in fruits while the twigs had lowest nutrient contents. The total annual return of various nutrients viz., N, P, K, Ca and Mg from the litter components were 110.26, 17.50, 35.03, 348.97 and 78.46 kg ha-1 respectively. Of the total annual nutrients return, leaf litter contributed a major share of 74.38, 12.51, 27.95, 311.91 and 65.95 kg ha-1 of N, P, K, Ca and Mg, respectively.
S Manivasakan, A K Mani, A Balasubramanian, R Santhi and V Karikalan
Forest College and Research Institute, Tamil Nadu Agricultural University, Tamil Nadu, India.