How do trees die? Mode of death in northern Amazonia
How do trees die? Mode of death in northern Amazonia
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DOI：
10.1111/j.1654-1103.2009.05755.x
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发表时间：
2009-04-01
影响因子：
2.8
通讯作者：
Vasquez Martinez, Rodolfo
中科院分区：
文献类型：
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作者：
Chao Kuo-Jung;Phillips, Oliver L.;Vasquez Martinez, Rodolfo
在高死亡率和低死亡率的亚马逊森林地区，树木是如何死亡的？为什么树木会以不同的方式死亡？秘鲁和委内瑞拉亚马逊河流域潮湿的低地森林。在永久地块中，>= 10 cm直径的树木记录了多次树木砍伐的模式和死亡模式（直立、折断或连根拔起）。采用Logistic回归分析了死亡方式与树径、相对生长率和木材密度的关系。在高死亡率的西北（NW）地区，多重死亡事件的发生频率高于低死亡率的东北（NE）地区，但这些事件较少，平均每多重死亡事件造成2棵树死亡。在西北地区，破损是已知的主要死亡方式（51% +/- 8%），其中一半的致命破损是由其他树木砍伐或破损造成的。生长缓慢的小树更容易折断，而不是连根拔起。在东北亚马逊地区，已知的主要死亡方式是站立死亡（48% +/- 10%）；这些树往往相对较大，生长缓慢。东北森林中折断的树木比连根拔起的树木密度低。这两个地区的主要死亡机制不同。在西北地区，它涉及生理破坏和机械破坏（小尺寸，缓慢生长和破碎模式）之间的相互作用。东北地区主要由生理衰竭（体型大、生长缓慢和站立模式）驱动。我们提出，通过创造不同大小的差距，不同的主要死亡模式将有利于来自不同功能群的物种，从而有助于保持两个地区的不同功能组成和死亡率。
How do trees die in high-mortality and low-mortality Amazonian forest regions? Why do trees die in different ways?Humid, lowland forests in Amazonian Peru and Venezuela.Patterns of multiple treefall and mode of death (standing, broken or uprooted) were recorded for trees >= 10 cm in diameter in permanent plots. Logistic regression was used to relate mode of death to tree diameter, relative growth rate and wood density.Frequency of multiple death events was higher in high-mortality northwestern (NW) than in low-mortality northeastern (NE) Amazonia, but these events were small, averaging two trees killed per multiple death event. Breakage was the dominant known mode of death (51 +/- 8%) in the NW, with half of fatal breakages caused by other treefalls or breakages. Small and slow-growing trees were more prone to breaking than uprooting. In NE Amazonia, the dominant known mode of death was standing (48 +/- 10%); these trees tended to be relatively large and slow growing. Broken trees in NE forests have a lower wood density than uprooted trees.The major mortality mechanisms differ in the two regions. In the NW it involves an interaction between physiological failure and mechanical failure (small size, slow growth and broken mode). In the NE it is mainly driven by physiological failure (large size, slow growth and standing mode). We propose that by creating different-sized gaps the different dominant modes of death would favour species from different functional groups and so help to maintain the contrasting functional composition and mortality rates of the two regions.