Climate-related variables and geographic distance affect fern species composition across a vegetation gradient in a shrinking hotspot
Climate-related variables and geographic distance affect fern species composition across a vegetation gradient in a shrinking hotspot
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DOI：
10.1080/17550874.2013.843604
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发表时间：
2015-01
影响因子：
1.5
通讯作者：
A. L. de Gasper;P. V. Eisenlohr;A. Salino
中科院分区：
文献类型：
--
作者：
A. L. de Gasper;P. V. Eisenlohr;A. Salino
背景：大西洋森林生物群落是保护优先事项的首要热点，但蕨类植物物种组成的变化以及驱动这些变化的因素仍然知之甚少。在巴西南部圣卡塔琳娜州发现的植被梯度构成了一个有趣的环境模型来研究这种模式。目的：我们分析了南大西洋森林植被梯度中蕨类植物物种组成的变化以及可能影响它的变量。方法：我们使用元数据，对 40 个样本单元（50 × 50 km2）的物种发生、环境和空间数据应用聚类分析（TWINSPAN 和 WPGMA）、排序（DCA）、回归（OLS 和 GWR）和方差划分。结果：生物气候变量，主要是与湿度有关的变量（水是蕨类植物繁殖的重要介质）和地理距离，与蕨类植物物种组成的变化有关。可能与中立过程有关的扩散限制可以用来解释地理距离的重要性。总体而言，植物区系组成的决定因素仍然存在很大的不确定性。结论：我们的研究首次在大西洋森林中强调了环境决定论和扩散限制对蕨类植物物种组成变化的重要作用。
Background: The Atlantic Forest biome is a top hotspot for conservation priorities, but the variations in fern species composition and the factors driving these are still poorly known. The vegetation gradient found in the state of Santa Catarina, southern Brazil, constitutes an interesting environmental model for examining such patterns. Aims: We analysed the variation in fern species composition across a vegetation gradient in the southern Atlantic Forest and the variables that might influence it. Methods: We applied cluster analysis (TWINSPAN and WPGMA), ordination (DCA), regression (OLS and GWR) and variance partitioning to species occurrence, environmental and spatial data in 40 sample units (50 × 50 km2), using metadata. Results: Bioclimatic variables, mainly those related to humidity (water being an essential medium for fern reproduction), and geographic distance were related to variation in fern species composition. Dispersal constraints, probably related to neutral processes, could be evoked to explain the significance of the geographic distance. Overall, a great deal of uncertainty remained with regard to the determinants of floristic composition. Conclusions: Our study emphasises, for the first time in the Atlantic Forest, a significant role of environmental determinism and dispersal constraints on the variation of fern species composition.