چکیده:
It has often been stated or implied that grazing is an important factor in the land degradation process, a suggestion
supported by various research projects, and this study investigated the effect of livestock grazing on stem height, crown
cover, production, basal diameter, stem biomass, litter, leaf-stem index (leaf to stem weight) , root diameter and weight
and seed production per individual of the even-aged Atriplex canescens , by comparing two sites (grazed and non-grazed)
across Zarand, Shahreiar rangelands located in the southwestern of Tehran, Iran. For this purpose, by using systematicrandom
sampling method, four 300 m long transects were set up in each sampling area and ten quadrats were randomly
assigned per transect [8] to measure the stem height as well as the crown cover, production, basal diameter, stem biomass,
litter, leaf-stem index , seed production per individual and root biomass and diameter were measured at 3 soil depth (0-30,
30-70, >70 cm) with 4 replications within each of the two studied sites, results indicated that, grazing had no significant
influence on stem height and leaf-stem index but crown cover, production, basal diameter, stem biomass, litter, seed
production per individual, root weight and diameter of the even -aged Atriplex canescens were significantly greater than
those of the un-grazed site.
خلاصه ماشینی:
Ramezanif a Ph. D Graduate, Research Institute of Forests and Rangelands (RIFR),Tehran, Iran b Professor, Faculty of Natural Resources, University of Tehran, Karaj, Iran c Associate Professor, Faculty of Natural Resources, University of Tehran, Karaj, Iran d Assistant Professor, Science and Research Branch, Islamic Azad University, Tehran, Iran e Assistant Professor, Research Institute of Forests and Rangelands (RIFR),Tehran, Iran f Member of Scientific Board, Islamic Azad University, Science and Research Branch, Tehran, Iran Received: 5 March 2012; Received in revised form: 3 February 2013; Accepted: 11 March 2013 Abstract It has often been stated or implied that grazing is an important factor in the land degradation process, a suggestion supported by various research projects, and this study investigated the effect of livestock grazing on stem height, crown cover, production, basal diameter, stem biomass, litter, leaf-stem index (leaf to stem weight) , root diameter and weight and seed production per individual of the even-aged Atriplex canescens , by comparing two sites (grazed and non-grazed) across Zarand, Shahreiar rangelands located in the southwestern of Tehran, Iran.
For this purpose, by using systematic- random sampling method, four 300 m long transects were set up in each sampling area and ten quadrats were randomly assigned per transect [8] to measure the stem height as well as the crown cover, production, basal diameter, stem biomass, litter, leaf-stem index , seed production per individual and root biomass and diameter were measured at 3 soil depth (0-30,30-70, >70 cm) with 4 replications within each of the two studied sites, results indicated that, grazing had no significant influence on stem height and leaf-stem index but crown cover, production, basal diameter, stem biomass, litter, seed production per individual, root weight and diameter of the even -aged Atriplex canescens were significantly greater than those of the un-grazed site.