Carbon storage and its distribution pattern of evergreen broad-leaved forests at different succession stages in mid-subtropical China

This paper studied the carbon(C) storage and its distribution pattern of Pinus massoniana forest,mixed P.massoniana-broad-leaved forest,and evergreen broad-leaved forest representing three different succession stages of evergreen broad-leaved forests in Yingzuijie National Nature Reserve in Hunan Province.The C storage of the three forest ecosystems was 182.86,179.84 and 229.12 Mg C·hm-2,respectively.With the largest share in trunk,the carbon stored in tree layers was the main contributor to the C storage,accounting for 59.57%-67.88%,and had an increasing trend with forest succession.The carbon sequestered in soil accounted for 31.05%-36.55%,which also increased with forest succession but had a decreasing proportion with the succession.The carbon storage of understory vegetation and litters had the least share,accounting for 0.41%-3.04% and 0.65%-2.53%,respectively,and decreased with forest succession.The ratio of biomass C to soil C storage of the three forest ecosystems was 1.96,1.69,and 2.20,respectively,and biomass C played a more and more important role in forest C sequestration during the succession from P.massoniana forest to evergreen broad-leaved forest.It was suggested that to implement near-nature forest management or simulate evergreen broad-leaved forest structure would be the main approach in promoting the carbon sequestering capacity of forest ecosystems in this region.