Dehling D Matthias, Peralta Guadalupe, Bender Irene M A, Blendinger Pedro G, Böhning-Gaese Katrin, Muñoz Marcia C, Neuschulz Eike Lena, Quitián Marta, Saavedra Francisco, Santillán Vinicio, Schleuning Matthias, Stouffer Daniel B
Centre for Integrative Ecology, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand.
Department of Biometry and Environmental System Analysis, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.
Ecology. 2020 Jul;101(7):e03028. doi: 10.1002/ecy.3028. Epub 2020 Apr 7.
The species composition of local communities varies in space, and its similarity generally decreases with increasing geographic distance between communities, a phenomenon known as distance decay of similarity. It is, however, not known how changes in local species composition affect ecological processes, that is, whether they lead to differences in the local composition of species' functional roles. We studied eight seed-dispersal networks along the South American Andes and compared them with regard to their species composition and their composition of functional roles. We tested (1) if changes in bird species composition lead to changes in the composition of bird functional roles, and (2) if the similarity in species composition and functional-role composition decreased with increasing geographic distance between the networks. We also used cluster analysis to (3) identify bird species with similar roles across all networks based on the similarity in the plants they consume, (i) considering only the species identity of the plants and (ii) considering the functional traits of the plants. Despite strong changes in species composition, the networks along the Andes showed similar composition of functional roles. (1) Changes in species composition generally did not lead to changes in the composition of functional roles. (2) Similarity in species composition, but not functional-role composition, decreased with increasing geographic distance between the networks. (3) The cluster analysis considering the functional traits of plants identified bird species with similar functional roles across all networks. The similarity in functional roles despite the high species turnover suggests that the ecological process of seed dispersal is organized similarly along the Andes, with similar functional roles fulfilled locally by different sets of species. The high species turnover, relative to functional turnover, also indicates that a large number of bird species are needed to maintain the seed-dispersal process along the Andes.
当地群落的物种组成在空间上存在差异，其相似性通常会随着群落间地理距离的增加而降低，这一现象被称为相似性的距离衰减。然而，目前尚不清楚当地物种组成的变化如何影响生态过程，也就是说，它们是否会导致物种功能角色的当地组成存在差异。我们研究了南美洲安第斯山脉沿线的八个种子传播网络，并在物种组成和功能角色组成方面对它们进行了比较。我们测试了：（1）鸟类物种组成的变化是否会导致鸟类功能角色组成的变化；（2）物种组成和功能角色组成的相似性是否会随着网络间地理距离的增加而降低。我们还使用聚类分析来：（3）基于它们所消耗植物的相似性，在所有网络中识别具有相似角色的鸟类物种，（i）仅考虑植物的物种身份，（ii）考虑植物的功能性状。尽管物种组成发生了强烈变化，但安第斯山脉沿线的网络在功能角色组成上表现出相似性。（1）物种组成的变化通常不会导致功能角色组成的变化。（2）物种组成的相似性随着网络间地理距离的增加而降低，但功能角色组成的相似性并非如此。（3）考虑植物功能性状的聚类分析在所有网络中识别出了具有相似功能角色的鸟类物种。尽管物种更替率很高，但功能角色的相似性表明，沿着安第斯山脉，种子传播的生态过程组织方式相似，不同的物种集合在当地履行着相似的功能角色。相对于功能更替而言，高物种更替率也表明，需要大量的鸟类物种来维持安第斯山脉沿线的种子传播过程。
