Fire-mediated dieback and compositional cascade in an Amazonian forest
Fire-mediated dieback and compositional cascade in an Amazonian forest
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DOI：
10.1098/rstb.2007.0013
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发表时间：
2008-05-27
影响因子：
6.3
通讯作者：
Peres, Carlos A.
中科院分区：
文献类型：
--
作者：
Barlow, Jos;Peres, Carlos A.
唯一完全耦合的陆地-大气全球气候模式预测，由于降水减少，亚马逊森林覆盖将普遍枯死。虽然这些预测是有争议的，亚马逊森林的结构和组成的弹性也可能被高估，因为目前的植被模型没有考虑到火灾在森林生态系统退化的潜在作用。我们研究森林的结构和组成在巴西亚马逊河流域中部的Arapiuns，评估火灾后森林恢复和经常性火灾的树种的优势格局的后果。我们调查了未燃烧和一次燃烧的森林中的树样地，在一次前所未有的火灾事件发生后1年，3年和9年，在两次燃烧的森林中，在火灾发生后3年和9年，在最近一次火灾事件发生后5年，在三次燃烧的森林中进行了检查。在未燃烧的原始森林控制地块记录的树木数量随着时间的推移是稳定的。然而，在一次和两次烧毁的森林地块，有一个显着的招聘到10-20厘米直径的胸高树大小类火灾后3至9年。考虑到第一次火灾接触后9年的树木组合组成，我们观察到（一）小乔木和最丰富的灌木和树苗之间的社区营业额的一个明确的模式，和（二）在任何四个烧伤治疗（未燃烧，一次，两次和三次燃烧）中常见的物种往往是罕见的或完全不存在的其他烧伤治疗。我们的结论是，情节野火可以导致森林结构和组成的急剧变化，与级联变化的森林组成后，每一个额外的火灾事件。最后，我们使用这些结果来评估草原化范式的有效性。
The only fully coupled land-atmosphere global climate model predicts a widespread dieback of Amazonian forest cover through reduced precipitation. Although these predictions are controversial, the structural and compositional resilience of Amazonian forests may also have been overestimated, as current vegetation models fail to consider the potential role of fire in the degradation of forest ecosystems. We examine forest structure and composition in the Arapiuns River basin in the central Brazilian Amazon, evaluating post-fire forest recovery and the consequences of recurrent fires for the patterns of dominance of tree species. We surveyed tree plots in unburned and once-burned forests examined 1, 3 and 9 years after an unprecedented fire event, in twice-burned forests examined 3 and 9 years after fire and in thrice-burned forests examined 5 years after the most recent fire event. The number of trees recorded in unburned primary forest control plots was stable over time. However, in both once-and twice-burned forest plots, there was a marked recruitment into the 10-20 cm diameter at breast height tree size classes between 3 and 9 years post-fire. Considering tree assemblage composition 9 years after the first fire contact, we observed (i) a clear pattern of community turnover among small trees and the most abundant shrubs and saplings, and (ii) that species that were common in any of the four burn treatments (unburned, once-, twice-and thrice-burned) were often rare or entirely absent in other burn treatments. We conclude that episodic wildfires can lead to drastic changes in forest structure and composition, with cascading shifts in forest composition following each additional fire event. Finally, we use these results to evaluate the validity of the savannization paradigm.