Department of Animal Ecology and Tropical Biology, Biocentre, University of Würzburg, Am Hubland, 97074, Würzburg, Germany,
Oecologia. 2014 Jun;175(2):613-23. doi: 10.1007/s00442-014-2917-7. Epub 2014 Mar 26.
Species richness patterns along altitudinal gradients are well-documented ecological phenomena, yet very little data are available on how environmental filtering processes influence the composition and traits of butterfly assemblages at high altitudes. We have studied the diversity patterns of butterfly species at 34 sites along an altitudinal gradient ranging from 600 to 2,000 m a.s.l. in the National Park Berchtesgaden (Germany) and analysed traits of butterfly assemblages associated with dispersal capacity, reproductive strategies and developmental time from lowlands to highlands, including phylogenetic analyses. We found a linear decline in butterfly species richness along the altitudinal gradient, but the phylogenetic relatedness of the butterfly assemblages did not increase with altitude. Compared to butterfly assemblages at lower altitudes, those at higher altitudes were composed of species with larger wings (on average 9%) which laid an average of 68% more eggs. In contrast, egg maturation time in butterfly assemblages decreased by about 22% along the altitudinal gradient. Further, butterfly assemblages at higher altitudes were increasingly dominated by less widespread species. Based on our abundance data, but not on data in the literature, population density increased with altitude, suggesting a reversed density-distribution relationship, with higher population densities of habitat specialists in harsh environments. In conclusion, our data provide evidence for significant shifts in the composition of butterfly assemblages and for the dominance of different traits along the altitudinal gradient. In our study, these changes were mainly driven by environmental factors, whereas phylogenetic filtering played a minor role along the studied altitudinal range.
物种沿海拔梯度的丰富度模式是有据可查的生态现象，但关于环境过滤过程如何影响高海拔地区蝴蝶组合的组成和特征，数据非常有限。我们研究了德国贝希特斯加登国家公园（Berchtesgaden National Park）海拔梯度范围为 600 至 2000 米的 34 个地点的蝴蝶物种多样性模式，并分析了与扩散能力、繁殖策略和从低地到高地的发育时间相关的蝴蝶组合特征，包括系统发育分析。我们发现蝴蝶物种丰富度沿海拔梯度呈线性下降，但蝴蝶组合的系统发育相关性并没有随海拔升高而增加。与低海拔地区的蝴蝶组合相比，高海拔地区的蝴蝶组合由翅膀较大的物种组成（平均大 9%），产卵量平均多 68%。相比之下，蝴蝶组合在海拔梯度上的卵成熟时间减少了约 22%。此外，高海拔地区的蝴蝶组合越来越多地由分布范围较小的物种主导。基于我们的丰度数据，但不是基于文献中的数据，种群密度随海拔升高而增加，表明存在相反的密度分布关系，在恶劣环境中，生境专家的种群密度更高。总之，我们的数据提供了蝴蝶组合组成发生重大变化的证据，以及沿海拔梯度主导不同特征的证据。在我们的研究中，这些变化主要是由环境因素驱动的，而系统发育过滤在研究的海拔范围内作用较小。
