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### 喀斯特季节性雨林木本植物胸高断面积分布格局及其对地形因子的响应

1. 1 广西喀斯特植物保育与恢复生态学重点实验室, 广西壮族自治区/中国科学院广西植物研究所, 广西桂林 541006;
2 广西友谊关森林生态系统国家定位观测研究站, 广西凭祥 532699
• 收稿日期:2015-07-18 接受日期:2015-11-02 出版日期:2016-01-20
• 通讯作者: 李先琨 E-mail:xiankunli@163.com
• 基金项目:
基金项目: 国家自然科学基金(31500342)、广西自然科学基金(2015GXNSFBA139050)和中国科学院西部之光项目(人字(2014) 91号)

### Responses of spatial pattern of woody plants’ basal area to topographic factors in a tropical karst seasonal rainforest in Nonggang, Guangxi, southern China

Yili Guo1, 2, Bin Wang1, 2, Wusheng Xiang1, 2, Tao Ding1, 2, Shuhua Lu1, 2, Fuzhao Huang1, 2, Shujun Wen1, 2, Dongxing Li1, 2, Yunlin He1, 2, Xiankun Li1, 2, *()

1. 1 Guangxi Key Laboratory of Plant Conservation and Restoration Ecology in Karst Terrain, Guangxi Institute of Botany, Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences, Guilin, Guangxi 541006
2 Guangxi Youyiguan Forest Ecosystem National Research Station, Pingxiang, Guangxi 532699
• Received:2015-07-18 Accepted:2015-11-02 Online:2016-01-20
• Contact: Li Xiankun E-mail:xiankunli@163.com

Spatial patterns of aboveground biomass are important aspect of species distribution patterns, whereas the environmental heterogeneity caused by the topographical differences in the scope of local scales is the environmental basis for the formation and evolution of this pattern in natural forest systems. In this study, we examined the spatial patterns of total basal area of woody plants, to quantitatively analyze the response mechanisms of the spatial patterns of total basal area to the seven topographic factors using a generalized additive model in a fully mapped 15 ha permanent plot in a northern tropical seasonal rainforest in a karst landscape in southern China. We used the total basal area of all the individuals and each DBH class in each 20 m × 20 m quadrat as a standard to measure the value of aboveground biomass of woody plants. Results showed that the hillside had the highest total basal area but the lowest was found at the ridge of the three habitat types. The total basal area of the ridge was significantly different between the hillside and the depression. Topographic factors had definite effects on the total basal area of woody plants, with the following sequence: elevation > aspect > convexity > rock-bareness rate (RBR) > altitude above channel (ACH) > slope > topographic wetness index (TWI). All topographical factors were statistically significant with the exception of the TWI and slope showing marginally significant. The relationships between the spatial variation of total basal area of woody plants and topographic factors reflected the response mechanisms and growth strategies of woody plants in a tropical seasonal rainforest under the effects of the redistribution of soil, water and light conditions.