Regardless the crop production, range and livestock management is unlikely to be possible. Considering the range production is essential for efficient and effective range management. This study aims to investigate the relationship between the rate of forage production and the effects of climate variables. For this purpose, forage yield of four range species including Artemisia sieberi, Scariola orientalis, Stipa atriseta, and Stachys inflate regarded as indices species was recorded in Bidalam rangeland, Fars province, Iran in a 10-year period (1998 to 2007) and then, the study continued for another two years (from 2016 to 2017). Forage yield was collected through cutting and weighing method in 60 random 2m2 plots along four 300 m transects during 12 years. Climatic parameters such as rainfall, temperature, relative humidity and sunshine periods were obtained from Abadeh weather station and used for estimation of forage yield in different growth periods of the year. The annual dry matter production of each species and sum of all species were used as dependent variables and climatic parameters were considered as independent ones using multivariate linear regression. The results showed that previous rainfall (rainy of growing season plus last year) had the highest effect on annual forage production of rangelands (R2=0.88). It was concluded that using regression analysis between annual rainfall and forage production in some indices species, the rangeland production of coming years could be estimated with high accuracy. پرونده مقاله

Ecotones are zones of gradual changes from an ecological system to another.Ecotones monitoring could be important to find out the reason for changes and limits. Inthis research satellite data were used to analyze the ecotone boundary in Fars steppicrangelands using IRS LISS III and Pan data of year 2006. The real vegetation map andecotones prepared through Geo-eye images from Google earth software and calibratedusing field study. Five soil line vegetation indices such as SAVI, MSAVI2, TSAVI,OSAVI and GESAVI from processed data were calculated. Each of these indices wasclassified by applying density slicing analysis method. Then the accuracy of producedmaps was audited with error matrix method. The results show OSAVI and SAVI had thehighest overall accuracy and kappa coefficient as 82.1% and 82% for overall accuracy and76% for Kappa coefficient, respectively. According to this research, soil line vegetationindices have intermediate accuracy for separation of arid rangelands ecotones in Iran withIRS data, although, OSAVI and SAVI perform better than the others. پرونده مقاله