Plant niche breadths along environmental gradients and their relationship to plant functional traits
Plant niche breadths along environmental gradients and their relationship to plant functional traits
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DOI：
10.1111/ddi.12815
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发表时间：
2018-12-01
影响因子：
4.6
通讯作者：
Hemp, Andreas
中科院分区：
文献类型：
--
作者：
Costa, David Schellenberger;Gerschlauer, Friederike;Hemp, Andreas
目的研究植物生态位宽度是否因温度、降水和扰动梯度的竞争而随物种丰富度的增加而减小。我们认为生态位最优、生态位宽度和生态位体积与植物的功能性状有关，反映了植物的竞争能力和对环境胁迫的适应能力。最后，我们希望确定以最容易发生环境变化的小生态位宽度的物种为主的栖息地。定位方法坦桑尼亚乞力马扎罗山南坡。利用969个样地的存在/缺失数据，利用广义线性模型计算了1492种植物的物种分布模型。我们推导了生态位宽度、最优值和体积，并利用主成分回归分析了它们与植物功能性状的关系。结果主要结论生境宽度随海拔、降水和干扰的增加而增加。群落平均高程、生态位宽度和生态位体积随物种丰富度的增加而减小。植物功能性状对生态位最优和生态位宽度的贡献率分别为40%和50%。大小和生长性状对生态位宽度均有显著的预测作用，而生殖策略性状对降水梯度的预测作用不显著。我们的研究结果支持生态位宽度随温度升高而减小的观点，这可能是由于多样化率增加和物种丰富度增加引起的竞争的结果。然而，生态位宽度-物种丰富度格局在其他梯度上的复杂性表明，除了竞争之外，还有其他协变量影响物种生态位宽度。乞力马扎罗山周围的热带稀树草原以生态位宽度较窄的植物种类为主，表明该地区对热带稀树草原向田野和草地的转变具有较强的敏感性。
Aims We tested whether plant species niche breadths decrease with increasing species richness due to competition on temperature, precipitation and disturbance gradients. We assumed that niche optima, niche breadth and niche volume are related to plant functional traits, indicating competitive ability and adaptation to environmental stress. Finally, we wanted to identify habitats dominated by species with small niche breadths most prone to environmental change. Location Methods Southern slopes of Mount Kilimanjaro, Tanzania. We calculated species distribution models for 1,492 plant species based on the presence/absence data on 969 plots using generalized linear models. We derived niche breadths, optima and volumes and investigated their relationship with plant functional traits with principal component regression to account for high trait correlations. Results Main conclusions Niche breadths of individual species increased with elevation, precipitation and disturbance. Averaged community elevation niche breadth and niche volume decreased with increasing species richness. Plant functional traits explained about 40% and 50% of the variation in niche optima and breadths, respectively. Size and growth traits were significant predictors of niche breadths on all gradients, whereas traits indicating reproductive strategy were not significant on the precipitation gradient. Our results support the notion of decreasing niche breadth with increasing temperature, possibly a result of competition due to increased diversification rates and hence species richness. However, the complexity of the niche breadth-species richness patterns on the other gradients shows that additional covariables shape species niche breadths apart from competition. Plant species with narrow niche breadths dominated natural savannas around Mount Kilimanjaro, indicating strong sensitivity to the ongoing conversion of savanna to fields and grasslands.