Using Multivariate Canonical Correspondence Analysis Method (CCA) for managing seed collection from natural resources areas

The aim of this research was to improve programming and managing of rangeland plants seed collection. Therefore, the study of relationship of presence and stability of essential rangeland plant species with environmental factors including, soil (texture and depth), topography (altitude datum, slope degree and aspect) and geographical longitude and latitude was conducted. This study has been done in Markazi, Isfahan, Chaharmahal va Bakhtiari, Lorestan, Kordestan and Hamedan provinces in area with 45.98-51.25 ° E longitude and 31.30-36.18 N latitude and 1272-2550m altitude datum. Multivariate Canonical Correspondence Analysis Method (CCA) was used for the analysis of vegetation variation affected by environmental factors variation. The results showed that the distribution of rangeland species was mainly related, especially in Papillionaceae family to soil characteristics and topographical factors. Between the studied factors, vegetation was mainly affected by altitude datum, degree of slope, soil depth and aspect. Among environmental effective factors on vegetation distribution, some of them (topography) are fixed and some others are unstable. Seed collection from plant species that affected by variable environmental factors such as precipitation, have preference in case of drought condition. For plant species which are mainly affected by soil texture, and their distribution are locally in areas with special soil texture and depth, and high soil erodibility, it is necessary to have preference in seed collection. Accordingly, the allegiance of distribution of essential rangeland species from these environmental factors, especially Papillionaceae family, is necessary to reconsider the seed collection methods.