Determining the Most Influential Factors in the Distribution of HedysarumcriniferumBoissSpecies Using Canonical Correspondence Analysis (CCA)

Investigating the relationship between vegetation and environmental factors helps to identify factors affecting the growth and deployment of plant species.The aim of this study was to investigate the effect of environmental and management factors on the distribution of Hedysarumcriniferum in Chadegan and protected areas of Muteh in Isfahan province. A randomized stratified sampling method was used to study vegetation in these areas. A total of 30 soil samples were collected from the 80 randomly established plots and some soil characteristics were measured. Canonical Correspondence Analysis was used to explore the relationships between environmental and management factors with the species distribution using CANOCO software and Cluster analysis was also used to group the sampling plots. The results showed that Hedysarumcriniferum is not susceptible to the amounts of calcium and magnesium elements in the soil and is present in a wide range of these elements. Furthermore, this species preferred soils with a low percentage of rock and gravel (0 10%).The maximum presence of this species was on the slopes with 60-80% steepness and its presence on the slopes less than 60% and more than 80% steepness was the least. On the other hand, its presence in soils with a lower content of soil saturation (SP) and cation exchange capacity has been higher.In general, it can be concluded that Hedysarumcriniferum is more distributed in the northwestern slopes in Mouteh habitat and in the northern and eastern slopes of the Chadegan habitat in a convex form. The most influential factors in the distribution are the percentage of pebbles, the convex shape of the slopes and light grazing.