Effect of Fire on Biotic Interaction of Onobrychis curnata in Mountain grasslands

The presence of plant species together causes biotic interactions. These interactions are very complex and variable among species which facilitation and competition have the highest impact on ecosystem function. Disturbances including fire are among the environmental factors affecting the biotic interactions. This study aimed on understanding the effect of fire on biotic interactions of cushions and grassland species. Therefore, to survey the effects of fire on the biotic interaction, 30 individuals of non burned Onobrychis cornuta and also 30 individuals of burnt patches were selected. In addition, 30 paired plots for each individual was randomly established close to each patches. According to our results, the effect of fire was not significant on total cover, but fire increased the perennial forbs (from 4.7 to 11.3 %), geophytes (from 0.1 to 0.5 %), annual forbs (from 0.1 to 2.3 %), annual grasses (from 0 to 0.1 %) and also decreased the perennial grasses (from 7.2 to 4.9 %), shrubs (from 3.8 to 0.8 %) and cushions (from 1.7 to 0.4 %) and no significant effects on legumes. Only the annual grasses increased under the burned patches. According to the T-test results of total biotic interactions, fire facilitated species but it was not significant for functional groups.