Must of questions about diversity and species richness don't have answer yet. Whereas conservation from ecosystem and its function cause to interaction which do in ecosystem, in this research in part of Kurdistan Saral grasslands in two section with light grazing (site I) and heavy grazing (site II) have been engage to relationship between species richness and production (standing crop) and also hump-shape model between species richness and production. In this two site 209 plots were sampled on random-systematic method. Regression analyses were carried out using species richness as dependent variable, and production as independent variable. Results showed that in site I, species richness has positive liner and quadratic with total production (p<0.05). Relationship between species richness with grasses production of site II and production of total area was not significant (p>0.05). Positive liner and quadratic relationship between species richness with herbs production and total production of site II and total area was significant (p<0.05). In this research, negative relationship didn't observed. Hump-shape model has been observed between species richness with herbs production and total production of site II and both area; this show a peak in species richness at a low to intermediate level of biomass. So, under moderate grazing, with optimum production, diversity and species richness will preserved; and this matter is necessary to strategy of management of grasslands.
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