Assessment and comparison of production and diversity of grassy species of woody rangelands with open Rangelands in Fandoghlou semi-dense ecosystems, Ardabil

The main objective of this study was to evaluate the effect of tree species canopy on production and diversity of grass species in the understory of trees in Fandoghlou, Ardabil. The study area was selected after extracting similar geomorphological units of Fandoghlou, Shoghal Dareh and Niaragh. Inventory was conducted by systematic random sampling and dimension of plots was determined regarding the structure of vegetation. The number of plots was selected using statistical formulas, and the list of species, canopy cover, litter, rock, and bare soil percentage were recorded. Sampling in open and forested rangelands was done in four slope classes including 0-10, 10-20, 20 -35 and 35-50% and in four geographical aspects including northern, southern, eastern and western. The results showed that the highest vegetation cover percentage was observed in the understory of trees in Fandoghlou, Niaragh and Shoghal Dareh in slope classes of 10-20%, respectively, with 20, 25 and 25%. The highest vegetation cover in open rangelands were observed in slope classes of 10-20%, respectively, with 81, 86 and 86%. The northern aspect compared to other aspects had the highest vegetation cover in both rangelands. According to the results, the highest production was observed in open rangelands, showing a significant difference with forested rangelands. In addition, the production of grass species and interaction of rangeland type and aspect showed significant differences in the study rangelands. Accordingly, production in the open rangelands of northern slopes was significantly higher as compared with forested rangelands. On the other hand, the results of diversity and evenness indices in open and forested rangelands showed that the highest amounts of these indices were observable in forested rangelands.