Dekomposisi Serasah Mangrove Avicennia alba dan Kontribusinya Terhadap Nutrien Perairan di Desa Bagan AsahanKecamatan Tanjungbalai Kabupaten Asahan

Abstract

Bagan Asahan Village is one of the waters located in the Estuary of Asahan River and has extensive mangrove forest land. Reduced species of A. alba mangrove will lead to reduced litter production. The lack of information on the decomposition of mangrove leaf litter resulted in the community tend not to care about the benefits of A. alba mangrove species and litter that can increase the content of nutrients in the waters. The purpose of this research is to measure the decomposition and to know the nutrient content of carbon (C), nitrogen (N) and phosphorus (P) leaf litter of A. alba which is released during decomposition in Bagan Asahan Village, Tanjungbalai Sub-district of Asahan Regency. Theresearch was conducted in February-April 2017. This research was conducted using purposive sampling method by looking at the availability of mangrove A. alba species in the asahan chart. Based on research result of carbon nutrient content (C) at A. alba leaves highest day to 60 station I 18,85% terendan station III 11,58%. Nitrogen nutrient elements (N) highest value day to 60 station III 2, 62% terandah day to 90 station II 2.29%. The highest phosphorus (P) phosphorus value of 30 and 60 days with the same value at station III was 0.03% day low to 90 II station 0.01%. The result of C / N ratio is known the highest C / N value day to 90 station II 6.44%. The lowest C / N value of day to 30 station III is 4.70%. Shrinkage of dry weight of litter decreased dramatically in the 90th day observation period with the highest average station II that is 21.70 g of station II at 2.13 g compared to the initial weight of 50%. The highest value of decomposition rate between stations on day 90 at station III 2.81 day lows 90 to 0.52. The average constant value of the highest decomposition rate (k) between the 15th day station at station 41.70 day 90th lowest at station III is 1.66.