NUTRIENTS FROM Avicennia alba AND Rhizophora mucronata IN MANGROVE AND CRAB CONSERVATION AREA, TARAKAN CITY

Abstract

Mangrove ecosystems exhibit high productivity resulting from the decomposition of litter, which contains various nutrients such as carbon, nitrogen, and phosphorus that benefit both the mangrove plants themselves and the surrounding aquatic ecosystems. This study aims to determine the nutrient content (carbon, nitrogen, and phosphorus) of decomposed litter from Avicennia alba and Rhizophora mucronata. The study was conducted in the Tarakan City Mangrove and Crab Conservation Area, North Kalimantan, from April to June 2026, using a quantitative method with a descriptive-exploratory approach, taking into account the characteristics of the dominant mangroves at three study sites. The results showed that the decomposition rate of A. alba mangrove litter ranged from 0.22 to 0.64 grams/day and that of R. mucronata ranged from 0.25 to 0.67 grams/day; furthermore, no leaf litter from either A. alba or R. mucronata decomposed 100%. The carbon content of A. alba ranged from 9.45% to 13.45%, nitrogen from 0.64% to 0.72%, and phosphorus 0.25% to 0.29%, while the carbon content of R. mucronata ranged from 21.50% to 22.45%, nitrogen from 0.58% to 0.83%, and phosphorus from 0.06% to 0.009%. The values of the physical and chemical parameters of the water still support the decomposition process of litter.