DYNAMICS OF LITTER BIOMASS AND NUTRIENT RETURN IN CASUARINA EQUISETIFOLIA PLANTATION AS WINDBREAK ON THE COAST OF NORTH HAINAN ISLAND

In order to explore the characteristics of nutrient cycle in the plantation in coastal region in Hainan Island, we studied the litter production and nutrient return of C. equisetifolia plantation on the coast of north Hainan Island through monthly collection of litter from litter traps in fixed sampling plots during 2008-2009. The results showed that the annual litter biomass of C. equisetifolia plantation was 5.9844t?hm-2. The needle litter took up the largest percentage (88.99%). The miscellaneous litter took the second place (6.63%). And the bark + branch litter took the least percentage (4.38%). The monthly dynamic of needle litter was similar to the total litter, but the monthly dynamics of bark + branch and miscellaneous litter were slow. The annual return of three main nutrients (N, P and K) from the needle litter was 94.69 kg?hm-2?a-1 in total. The percentage in the annual return of N, P and K was 78.86%, 2.43% and 18.71%, respectively, with the sequence of N>K>P. The monthly dynamic of N return was similar with the total litter, but P and K were slow.