[Carbon balance in an interplanting stand in subtropical eroded red soil region, China].

We measured the annual net biomass growth, carbon content of each component and soil heterotrophic respiration in four low-efficiency interplanting patterns, ., stands interplanting , , and in Changting County, Fujian Province, with the aim to analyze the effects of interplanting patterns on carbon storage pattern and carbon balance of low-efficiency stand. The ranges of carbon content in different organs of , , , and were 41.1%-50.1%, 42.2%-50.6%, 45.1%-48.9%, 44.7%-49.6% and 46.1%-51.9%, respectively. Carbon content of the same organ significantly differed among tree species. The pattern of interplanting and had the highest carbon stock and annual net carbon increase reserves, with values of 67.62-68.42 t·hm and 9.21-9.45 t·hm·a, respectively. Followed by the lower pattern of , , with values of 31.96-36.24 t·hm and 4.09-4.16 t·hm·a, respectively. The pure forest was the lowest, with values of 17.01 t·hm and 2.00 t·hm·a, respectively. Annual flux of soil heterotrophic respiration was following the order of interplanting pattern (7.41 t·hm·a) > interplanting pattern (5.89 t·hm·a)> interplanting pattern (5.86 t·hm·a) > interplanting pattern (4.95 t·hm·a) > pure forest (2.45 t·hm·a). Annual net ecosystem carbon balance of interplanting and patterns were 2.04 and 3.27 t C·hm·a, showing a "carbon sink" pattern. The net carbon balance in the patterns of interplanting and along with pure forest were -1.80, -0.80 and -0.45 t C·hm·a, which expressed a "carbon source" pattern. In the short-term, interplanting with or could improve the carbon income of the low-efficiency stand ecosystem.