assessment of fire effects on surface cover changes and forage production (case study: delfan county, lorestan province, iran)

the aim of this study was to assess the regional effects of fire on the surface cover and forage production of mountainous rangelands of delfan county, lorestan province, iran. the fire took placed in june 2007 with significant effects on the vegetation characteristics in the study area. four fire affected sites were selected for sampling and a close area without fire was considered as control. sampling was carried out using a random systematic method and the size of plots was determined using the minimal area framework. the number of plots was determined using a statistical method. totally, the data of eight sites including four fire affected sites and four control sites were measured during four consecutive years in early july of each year after fire. in each site, four transects of 50m length were selected in the direction of slope as well as perpendicular to the slope and five plots were established along each transect. the characteristics of canopy cover percent, litter percent, bare soil, density and forage production were recorded and compared to the fire affected and control sites. one-way analysis of variance and duncan multiple range test were used to compare the mentioned characteristics over years in each region separately. according to the results, forage production, canopy cover percent, the density of grasses and forbs and litter cover percent increased significantly while the density and canopy cover percent of shrub species on the fire affected area has decreased significantly. on the other hand, fire had decreased bare soil cover percent significantly but it had no significant effects on the canopy cover of annual grasses.