Plant Diversity of Bio-environmental Units with Respect to Some Soil and Geopedologic Characteristics in the Mountain Rangeland Ecosystem

Nowadays, the need for sustainable resources management has led to introducing new methods for classification of managed resources. The importance of plant species diversity and its management and considering to the new methods for determining management units encouraged to initiate this research. In this study, the relationship between environmental factors and plant diversity was investigated. Therefore, six key areas were selected within four landscape units. Then, in each area, soil and vegetation sampling were done along 6 100m transects. Along each transect, 10 1×1m plots were established with a distance of 10 m between the two plots. In each plot, plant species were listed and the soil samples were then collected from some of plots located in the beginning, intermediate and the end of transects from two depth i.e. 0-15 and 15-30cm. Twenty-one environmental factors were measured as well as Simpson and Shanon diversity indices. The results of Principle Component Analysis showed that soil texture, saturated humidity, particulate organic matter (carbon), carbon of macroaggregate-associated, EC, bulk density, percentage of maco-and microaggregate and, slope and elevation had the highest impact on plant diversity. In addition, the correlation results showed that sand percentage in deeper layer of soil had negative correlation and other studied factors had positive correlation with bio-environmental variations. According to our results, soil physico-chemical characteristics are enough good for ecological assessments.