生物多样性 ›› 2016, Vol. 24 ›› Issue (1): 30-39.DOI: 10.17520/biods.2015207

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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

郭屹立1,2, 王斌1,2, 向悟生1,2, 丁涛1,2, 陆树华1,2, 黄甫昭1,2, 文淑均1,2, 李冬兴1,2, 何运林1,2, 李先琨1,2,*()   

  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 发布日期:2016-06-12
  • 通讯作者: 李先琨
  • 基金资助:
    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 Published:2016-06-12
  • Contact: Li Xiankun

摘要:

森林生态系统地上生物量的分布格局是物种分布格局的重要内容。局域尺度内因地形差异引起的生境异质性是地上生物量分布格局形成的环境基础。本文以弄岗北热带喀斯特季节性雨林15 ha动态监测样地2011年第一次普查数据中每木个体为研究对象, 尝试以每20 m × 20 m样方内所有个体及不同径级类群的胸高断面积之和为木本植物地上生物量的衡量指标, 利用广义可加模型对喀斯特季节性雨林中胸高断面积之和的空间分布格局进行研究, 定量分析了其对7个地形因子的响应。结果表明, 洼地、山坡和山脊3种生境类型中, 所有个体的胸高断面积之和山坡最高、山脊最低, 且山脊与山坡、洼地的差异均显著; 广义可加模型结果显示, 不同地形因子对胸高断面积之和的解释偏差差异明显, 其中海拔、坡向、凹凸度、岩石裸露率对胸高断面积之和的解释偏差依次降低, 而干旱度指数、坡度和地形湿润指数解释偏差相对较小。喀斯特季节性雨林木本植物胸高断面积之和空间分布的异质性及其与地形因子之间的关系, 反映了胸高断面积之和在地形因子对土壤、水分和光照等条件重分配影响下的多重响应机制及生长策略。

关键词: 格局, 胸高断面积, 地形因子, 贡献率, 弄岗动态监测样地, 北热带喀斯特季节性雨林

Abstract:

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.

Key words: pattern, basal area, topographic factors, contribution rate, Nonggang Dynamics Forest Plot, tropical karst seasonal rainforest