The shape of richness-productivity relationships in Tang-e-Chenar rangelands of Yazd province

In order to understand the biodiversity mechanism of ecological patterns in ecosystems and the basis for conservation and management of biodiversity, the production and species richness was measured during a year in the Tang-e-Chenar rangelands of Yazd province and the response curve of the richness of plant species along the slope of production changes was examined. Analyses of linear and nonlinear regression were used to determine the relationship between richness as dependent variables and productivity as independent variables. Fourteen species were identified in sampling in 30 plots. The average richness was calculated to 2.4 species. According to the results of the relative density in the plot 57% of the shrubs, forbs 21.5% and grasses 21.5 %, respectively. Total production was recorded about 278 g/m2 in Tangechenar that according to production values in theory hump-backed expected that this site is on the left side of the curve hump-backed. In other words, a relationship of increasing linear between production and richness should be seen in site. Relationship between production and richness in each life form was not found all of vegetation forms and have any significant correlation. It cannot be claimed that production is a good variable for predicting the richness in TangeChenar and other factors such as soil nutrients and climatic factors such as temperature and rainfall on the richness will have a greater effect on the factor of production. Based on results it can be concluded that the hump-backed hypothesis should be tested on a scale beyond the local.