Higher survival drives the success of nitrogen-fixing trees through succession in Costa Rican rainforests.
Higher survival drives the success of nitrogen-fixing trees through succession in Costa Rican rainforests.
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DOI：
10.1111/nph.13734
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发表时间：
2016-02
期刊：
影响因子：
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通讯作者：
D. Menge;R. Chazdon
中科院分区：
文献类型：
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作者：
D. Menge;R. Chazdon
许多热带森林中有大量具有共生固氮能力的树木。在温带森林中，众所周知，固氮植物专门从事早期演替生态位，但在热带森林中，固氮物种的演替趋势知之甚少。我们使用了一个长期的人口普查研究（1997-2013）再生低地潮湿的热带森林在哥斯达黎加记录演替模式的N固定器与非固定器，并使用基于个人的模型来确定这些趋势的人口驱动因素。在演替过程中，固氮菌相对断面积增加。在最年轻的森林中，固氮菌的生长速度快2.5倍，以相似的速度招募，并且作为非固氮菌死亡的可能性低15倍。随着继承的进行，增长和生存的差距下降，而N固定器招聘下降相对于非固定器。根据我们基于个体的模型，高存活率是固氮菌断面积增加的主要驱动力。我们的数据表明，固氮菌是成功的，整个二次演替在东北部哥斯达黎加的热带雨林，并试图了解这种成功应该集中在树的生存。
Trees capable of symbiotic nitrogen (N) fixation ('N fixers') are abundant in many tropical forests. In temperate forests, it is well known that N fixers specialize in early-successional niches, but in tropical forests, successional trends of N-fixing species are poorly understood. We used a long-term census study (1997-2013) of regenerating lowland wet tropical forests in Costa Rica to document successional patterns of N fixers vs non-fixers, and used an individual-based model to determine the demographic drivers of these trends. N fixers increased in relative basal area during succession. In the youngest forests, N fixers grew 2.5 times faster, recruited at a similar rate and were 15 times less likely to die as non-fixers. As succession proceeded, the growth and survival disparities decreased, whereas N fixer recruitment decreased relative to non-fixers. According to our individual-based model, high survival was the dominant driver of the increase in basal area of N fixers. Our data suggest that N fixers are successful throughout secondary succession in tropical rainforests of north-east Costa Rica, and that attempts to understand this success should focus on tree survival.