Abstract:This study sought to assess the effects and underlying mechanisms of anthropogenic disturbance on biomass and spatial distribution pattern in subtropical forests in central southern China. Four types of forests were chosen in a hilly area of the central Hunan Province, China, including:1) Loropetalum chinense-Vaccinium bracteatum.-Rhododendron mariesii. scrub-grass-land (LVR), 2) Loropetalum chinense-Cunninghamia lanceolata-Quercus fabri shrubbery (LCQ), 3) Pinus massoniana-Lithocarpus glaber-Loropetalum chinense coniferous-broad leaved mixed forest (PLL) and 4) Lithocarpus glaber-Cleyera japonica-Cyclobalanopsis glauca evergreen broad-leaved forest (LAG), which all suffered different degrees from human disturbances. According to the community characteristics, three or four standard plots were established and the standing biomass for the herb, shrub, and tree layers were investigated. Total harvesting method and allometric equations of biomass were established for the dominant tree species. The results showed that:(1) the total biomass increased exponentially with decreased anthropogenic disturbances (P < 0.05), while the aboveground and belowground biomass showed allometric patterns. Among different layers, the biomass in the arbor layer in LAG and PLL were not significantly different (P > 0.05), while the biomass for the shrub layer, either for different organs or the aboveground and belowground parts, increased first and then decreased in the forest stages. The biomass for the herb layer showed the opposite trend, declining first and then increasing. The standing litter crops increased gradually with declining degrees of disturbance. (2) With different degrees of human disturbance, the spatial allocation pattern of standing biomass showed high variety. The shrub and herb layers were in the dominant position in LVR community, and the biomass of the shrub layer in LCQ community showed higher contributions, while that of the herb layer declined. In PLL and LAG community, however, the biomass of the arbor layer had an absolute advantage, while the biomass in shrub, herb, and litter layers accounted for less than 10%. (3) The correlation analysis showed that total biomass was significantly positively correlated with species diversity index, contents of soil organic carbon, total nitrogen, hydrolytic nitrogen, and available phosphorus, suggesting that the change of community tree species diversity and soil nutrient content were the main causes affecting the change of community biomass during different degrees of anthropogenic disturbances.