Plant functional type approach for a functional interpretation of altitudinal vegetation zones in the Alborz Mts., Iran

作     者：Halime MORADI Farideh ATTAR Jens OLDELAND 

作者机构：Department of Plant Sciences School of Biology College of Science University of Tehran Biodiversity Ecology and Evolution of Plants Biocentre Klein Flottbek and Botanical Garden University of Hamburg 

出 版 物：《Journal of Mountain Science》 (山地科学学报（英文）)

年 卷 期：2017年第14卷第11期

页      面：2257-2269页

核心收录：

学科分类：07[理学] 0713[理学-生态学] 

基　　金：the DAAD (Deutscher Akademischer Austausch Dienst) for a grant to H.M. (57214227) 

主　　题：Elevation Indicator Species Analysis Ordination Leaf traits Trait-environment relationships 

摘      要：Mountains are an excellent system for evaluating ecological and biogeographical patterns. The obvious variations of the environmental factors along the altitude create different zones with adapted plant assemblages. However, few studies make use of plant functional type(PFT) for describing the variation of vegetation along altitudinal gradients. A PFT is a group of taxa with similar traits which respond similarly to the environmental gradients. In this study, we used PFTs as indicators describing five vegetation zones in the western Alborz Mt, Iran from 2000 – 4500 m. The plant trait data presented here covers six plant traits including growth form, stemleaf ratio, spinescence, hairiness, leaf consistency and plant height of 297 species. We considered altitude and soil factors to test the importance of environmental variables. We applied a multivariate analysis of three table ordination, i.e. environmental, species, and traits data to identify the PFTs. We further applied fourth-corner statistic to quantify trait-environment relationships. A constrained hierarchical clustering was used to detect five altitudinal zones and two zones of low and high nitrogen concentration. With regard to altitude wediscuss the distribution of species, traits and PFTs. Growth form, plant height and stem-leaf ratio were significantly related to altitude and nitrogen. We identified 19 PFTs from which 18 were significantly associated to one or more altitudinal zones. While the lower altitudinal zones contain a variety of PFTs higher altitudes contain less PFTs with the highest altitude containing only one single PFT, tiny rosette plants with soft mesomorphic leaves. We identified grazing and climatic harshness as well as rockiness as the most important drivers of the distribution of plant functional traits and types across the studied gradient.