Abundance and distribution of cavity trees and the effect of topography on cavity presence in a tropical rainforest, southwestern China
Abundance and distribution of cavity trees and the effect of topography on cavity presence in a tropical rainforest, southwestern China
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中国西南热带雨林空洞树的丰度和分布以及地形对空洞存在的影响
DOI：
10.1139/cjfr-2018-0044
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发表时间：
2018-09-01
影响因子：
2.2
通讯作者：
Chen, Si-Chong
中科院分区：
文献类型：
--
作者：
Liu, Jun-Yan;Zheng, Zheng;Chen, Si-Chong
空洞树在维持森林生态系统的生物多样性方面发挥着至关重要的作用，因为它们栖息着大量的鸟类、哺乳动物和其他依赖空洞的生物。然而，对热带森林中空洞树的丰度和分布的研究远不如温带森林中的普遍。此外，在热带森林中，树木特征和地形变量如何影响空洞的存在还不太清楚。我们利用地面观测对中国西南部热带雨林中 386 个物种的 27 745 棵活树进行了调查。空洞树的密度为86.3棵·ha-1，大大超过了温带森林的密度。空洞树的数量呈左偏分布，峰值在胸径（DBH）10-20厘米处。树中存在空洞的可能性随着胸径的增加而增加，尽管这种模式因物种和树冠位置而异。此外，受热带森林地形影响，空洞的存在从山谷（凹形地形和低海拔）到山脊（凸形地形和高海拔）减少。结果首次证明，除了树木胸径之外，地形也是空洞存在的良好预测因素。我们的结果表明，其他地区热带森林中空洞存在的模式也适用于亚洲热带森林。这项研究为预测热带空洞树的发生提供了指导。
Cavity trees play a crucial role in maintaining biodiversity in forest ecosystems as they host numerous birds, mammals, and other cavity-dependent organisms. However, studies on the abundance and distribution of cavity trees in tropical forests are much less common than those in temperate forests. Also, how tree characteristics and topographic variables affect cavity presence is less clear in tropical forests. We surveyed 27 745 living trees from 386 species using ground-based observations in a tropical rainforest in southwestern China. The density of cavity trees was 86.3 trees·ha–1, which dramatically exceeded that in temperate forests. The number of cavity trees showed a left-skewed distribution with a peak at 10–20 cm diameter at breast height (DBH). The probability of cavity presence in a tree increased with DBH, although the patterns varied across species and crown positions. Moreover, cavity presence, which is influenced by topography in this tropical forest, decreased from valleys (concave terrain and low elevation) to ridges (convex terrain and high elevation). The results prove for the first time that topography is a good predictor of cavity presence, in addition to tree DBH. Our results demonstrate that the patterns determined for cavity presence in tropical forests of other regions also apply to Asian tropical forests. This study provides guidance on predicting the occurrence of cavity trees in the tropics.