Cracow Pedagogical University, Institute of Biology, Kraków, Poland.
PLoS One. 2013 Jul 5;8(7):e68066. doi: 10.1371/journal.pone.0068066. Print 2013.
Thermal gradients along changes in elevation in mountainous environments are reflected by different biotas. Although there have been studies of elevation variation in bat assemblages in summer, winter changes in the same gradients remain unknown.
METHODOLOGY/PRINCIPAL FINDINGS: The objective of this study was to document changes in the species composition of bats hibernating in caves along a temperate elevational gradient. We studied 70 caves between from 300 m to 1,930 m altitude along a slope of the Carpathian Mountains in southern Poland. We recorded changes in bats, including species richness, abundance, altitudinal distribution and dominance during consecutive winters between 2003 and 2009. Similarity of dominance of faunal structure was assessed by using the Bray-Curtis similarity index. We used the generalised additive model and rarefaction to study the variation in species richness, and generalized additive mixed models to examine the effect of abiotic factors on the qualitative and quantitative structure of bat assemblages. During 351 surveys we recorded 13,856 hibernating bats from 15 species. Species richness peaked around mid-elevation (1,100-1,400 m a.s.l.) with richness declining at both higher and lower elevations. Based on the results of a cluster analysis, we could distinguish among four altitudinal zones that differed in species richness and dominance structure.
CONCLUSIONS/SIGNIFICANCE: This is the first study documenting changes in species richness and variation of structure of bats hibernating in caves along an elevational gradient. The most surprising and key finding is the fact that changes in the structure of assemblages of hibernating bats along the altitudinal gradient occurred in jumps, forming zones similar to those observed in the vegetation zones. Moreover, species richness and dominance structure of assemblages of hibernating bats in the mountains depended not only on location above sea level, but also on local geomorphologic conditions which strongly affected the microclimate of the caves.
在山地环境中，随着海拔的变化，温度梯度会反映在不同的生物群上。虽然已经有研究夏季蝙蝠组合在海拔上的变化，但同一梯度的冬季变化仍然未知。
方法/主要发现：本研究的目的是记录在沿温带海拔梯度的洞穴中冬眠的蝙蝠物种组成的变化。我们在波兰南部喀尔巴阡山脉的一个斜坡上，研究了海拔 300 米至 1930 米之间的 70 个洞穴。我们记录了蝙蝠的变化，包括物种丰富度、数量、海拔分布和优势度，这些变化是在 2003 年至 2009 年期间连续的冬季中记录的。使用 Bray-Curtis 相似性指数评估动物群结构的优势相似性。我们使用广义加性模型和稀少性来研究物种丰富度的变化，并用广义加性混合模型来检验环境因素对蝙蝠组合的定性和定量结构的影响。在 351 次调查中，我们记录了来自 15 个物种的 13856 只冬眠蝙蝠。物种丰富度在中海拔（1100-1400 米）处达到峰值，而在较高和较低海拔处则下降。根据聚类分析的结果，我们可以区分出四个在物种丰富度和优势结构上不同的海拔带。
结论/意义：这是第一个记录洞穴中冬眠蝙蝠物种丰富度和结构变化的沿海拔梯度的研究。最令人惊讶和关键的发现是，冬眠蝙蝠组合结构的变化是跳跃式的，形成了类似于植被带中观察到的那些带。此外，山地中冬眠蝙蝠组合的物种丰富度和优势结构不仅取决于海拔高度，还取决于强烈影响洞穴小气候的局部地貌条件。
