Aboveground Dynamics and Productivity of Major Mangrove Communities on Pohnpei Island, Federated States of Micronesia

抄録

The aboveground dynamics, biomass, productivity and carbon storage rate of major mangrove communities on Pohnpei Island, Federated States of Micronesia, were estimated using census data obtained from two 1-hectare permanent plots during about two decades. The aboveground biomass increased from 526 t ha^-1 in 1994 to 572 t ha^-1 in 2010 for the plot situated in a coral reef-type habitat, referred to as PC1, and from 637 t ha^-1 in 1994 to 744 t ha^-1 in 2011 for the plot situated in an estuary-type habitat, referred to as PE1. Both were higher than any other estimates for mangrove forests throughout the world, though the tree density decreased from 1,558 trees ha^-1 to 1,074 trees ha^-1 in PC1 and from 651 trees ha^-1 to 473 trees ha^-1 in PE1. The ratio of trees cut by local residents to all deceased trees was higher in PC1 (35%) than PE1 (15%) because of different accessibility. The potential rates of aboveground carbon storage were estimated at 1.66 t C ha^-1 yr^-1 for PC1 and 2.79 t C ha^-1 yr^-1 for PE1. The difference was considered to have resulted from different stages of succession and site environments, such as soil water EC, ground elevation and frequency of submergence by tides.