Mangrove ecosystem C-stocks of Lamongan, Indonesia and its correlation with forest age

Mangrove forests are extremely productive ecosystems that provide a wide range of ecosystem services including a globally significant carbon (C) storage. However, the forests and their habitats have degraded as result of expanding agriculture, aquaculture industry and coastal development. The threats diminish their C sequestration capacities; consequently, C stored in the habitats would also be released, increasing levels of greenhouse gases in the atmosphere. The purpose of this study was to estimate the ecosystem C-stocks of the mangrove forests of Lamongan, Indonesia and to assess the correlation between ecosystem C stocks and forest age. Sampling was carried out at 12 quadrat plots in four distinct areas to determine the biomass of above-And belowground trees, downed deadwood, saplings and seedlings, and soil C stocks. On average, the mangrove ecosystems of Lamongan stored 261.81 ± 43.82 Mg C ha-1. The youngest (± 15year-old) and the oldest (± 100year-old) forest stored 167 ± 22.9, and 349.95 ± 106.5 Mg C ha-1 respectively, which significantly correlated with the forest ages. The %C of soil increased with depth and 46% of ecosystem C stocks was stored in the soil. As the soil was only sampled from the depth of 0-30 cm, the soil and ecosystem C stocks value could be much higher than the estimation. These findings suggest that the mangrove forests of Lamongan store a substantial amount of C; therefore, it is necessary to protect and sustainably manage them to minimize the anthropogenic threat.