Document Type : Original Article
Department of Biology, Faculty of science, Ferdowsi University of Mashhad, Mashhad, Iran
Department of Rangeland Management, College of Range and Watershed Management, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran
Study of functional and species diversity plays an important role in recognizing ecosystem function and services and is shown the type of response to environmental changes. Functional diversity refers to range and values of organism traits that affects ecosystems properties and is introduced in various ways such as number and proportional abundance of functional groups.
Materials and Methods:
This study was carried out based on identifying functional groups in safe regions of Ghamishloo National Park (Baghak, Aghel geni, Korelias, Kahvak, Tange Najaf abadi and Tange Varposht) to recognition of ecosystem function and evaluation of functional diversity between regions. For this purpose, eight quantitative traits and four qualitative traits were selected. In order to determin functional groups, at first, species – trait matrix was prepared and then, clustering analysis was carried out by Ward method and Gower similarity distance by InfoStat software. After determining the richness of functional groups, diversity of functional groups was analyzed by SDR۴ and FDiversity software.
Results and discussion:
Main functional groups of the regions were: Chamaephytes plants that have been devoted most of the leaf nutrients to the defense structure, Hemicrypyophytes plants that their leaf area is high and are more successful in light acquisition and Terophytes plants that have leaves with a short life span. The results showed that functional groups richness is the same in the six regions (three functional groups), but, because of the difference in species composition and dominant traits of the groups, functional diversity of Kahvak region was higher. According to the results, as most functional diversity indices use more than one trait to describe the various plant performances, indices that used to measurement of species diversity (Shannon Wiener, Simpson …) are inefficient.
In determining of functional diversity, it is better to use numerical functional diversity indices (Community-Weighted Mean index, …) in addition to determining the functional groups richness to get more useful information about ecosystem function.