Growth and wood density predict tree mortality in Amazon forests
Growth and wood density predict tree mortality in Amazon forests
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DOI：
10.1111/j.1365-2745.2007.01343.x
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发表时间：
2008-03-01
影响因子：
5.5
通讯作者：
Vasquez Martinez, Rodolfo
中科院分区：
文献类型：
--
作者：
Chao, Kuo-Jung;Phillips, Oliver L.;Vasquez Martinez, Rodolfo
1.林木死亡是森林生态学中的一个重要过程。我们探讨了在何种程度上热带树木死亡是一个可预测的结果，分类和个人水平的属性，通过混合物种的逻辑回归，树木直径>= 10厘米。我们在两个低地森林地区进行研究，这些地区具有明显不同的植物区系组成和动态机制--高木材密度、低死亡率的亚马逊东北部（委内瑞拉东部）和低木材密度、高死亡率的亚马逊西北部（北方秘鲁）。在这些属之间共享的区域之间没有检测到的死亡率的区域差异。这表明，植物区系组成的差异是林分水平死亡率双重区域对比的主要驱动力。在东北森林中，个体的死亡风险最好由低分类级木材密度、相对生长缓慢和较大的尺寸预测，反映了遗传学决定的生活史策略、生理胁迫和衰老.在西北森林中，木材密度低和相对生长缓慢的树木也是最危险的，但死亡概率与树木大小无关，表明衰老在该地区并不重要。合成.这项研究表明，尽管两个亚马逊地区之间的基本植物区系和动态差异，死亡风险可以预测与混合物种，基于个人的统计模型和预测是非常相似的，树木生长和木材密度都发挥重要作用。
1. Tree mortality is an important process in forest ecology. We explored the extent to which tropical tree death is a predictable outcome of taxon and individual level properties by means of mixed-species logistic regression, for trees >= 10 cm in diameter. We worked in two lowland forest regions with markedly different floristic composition and dynamic regimes - the high wood density, low-mortality northeastern (NE) Amazon (in eastern Venezuela), and the low wood density, high-mortality northwestern (NW) Amazon (in northern Peru).2. Among those genera that are shared between regions there were no detectable regional differences in mortality rates. This suggests that floristic compositional differences are a major driver of the twofold regional contrast in stand-level mortality.3. In NE forests, mortality risk of individual trees is best predicted by low taxon-level wood density, slow relative growth, and large size, reflecting phylogenetically determined life-history strategy, physiological stress and senescence.4. In NW forests, trees with low wood density and slow relative growth are also at most risk, but probability of death is independent of tree size, indicating that senescence is unimportant in this region.5. Synthesis. This study shows that despite fundamental floristic and dynamic differences between the two Amazonian regions, mortality risk can be predicted with mixed-species, individual-based statistical models and that the predictors are remarkably similar, such that tree growth and wood density both play important roles.