بررسي تاثير هلالي هاي آبگير بر خاك و پوشش مراتع منطقه نارون خاش

چكيده انگليسي :

71 Effects of Semi Circular Bunds on Rangeland Vegetation and Soil in Naroon Region Khash Abdolvahed delavri av delavari@gmail com Date of Submission 2014 09 22 Department of Natural Resources Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Hossein Bashari hbashari@cc iut ac irSupervisor Mostafa Tarkesh Esfahani m tarkesh@cc iut ac irAbstractRange improvement practices improve the quality and quantity of forage and animal production Modifying physical characteristics of rangeland will change the structure and functionality ofrangeland hence it is required to investigate the positive and negative consequences of suchchanges The aim of this study was to investigate the effects of small crescent pond or small micro catchment semi circular bunds on functional characteristics of soil surface including soil stability infiltration and nutrient cycling model and the soil seed bank of Naroon rangelands located inSistan Baluchistan province The length and width of all patches inter patch lengths wererecorded along the 10 established 50 meters transects in treated and reference sites Eleven soilsurface indicators with three replications were measured in each patch and inter patch area tocalculate the stability infiltration and nutrient cycling of the studied sites A systematic randomsampling method was used to establish ten 150 meters transects in the treated and control sites 5transects in each site and ten 2m 2m Sampling plots were established along each transectrandomly and the vegetation attributes including plant density and species richness were recorded Abundance distribution models including geometric series log series broken stick and log normalmodels were fitted using PAST program The soil samples from the area under the effects of tensemi circular bunds and also ten samples from the bare soils understory of Artemisia sieberi andZygoghyllum atriplicoides 40 samples in total were collected To compare the effects of thismanagement option on soil seed bank soil samples from 6o semi circular bunds bare soils understory of Artemisia sieberi and Zygoghyllum atriplicoides 300 soil samples in total werecollected randomly from 0 10 cm of soil surface Seed content of the collected soil samples wasassessed in a greenhouse germination experiment over a period of 6 months According to theresults all structural and functional indices in treated and control sites varied significantly 5 Results indicated that the diversity indices between treated and control sites varied significantly 5 but the richness indices did not varied statistically Log normal model was the best fittedparametric model among the species abundance models for the study area The result confirmedthat the vegetation community has high stability in the study area because plant species withmoderate to high frequency are dominant Using semi circular bunds in the study area resulteddensity richness and diversity were measured in understory of Zygoghyllum atriplicoides whichsignificantly differs with other patches 5 This study indicated that although semi circularbunds can improve the structural and functional status of rangeland by improving the hydrologicalcondition of the study areas sediments logged in the semi circular bunds had some negativeimpacts on soil surface infiltration Given the facts that there are rich seed bank in understory ofnative vegetation biological restoration with endemic shrub and woody species along withconstructing semi circular bunds is recommended to improve rangeland ecological condition Keywords Semi circular bunds Landscape function analysis Diversity indices Abundancedistribution models Stability Infiltration Soil seed bank

دلاوري، عبدالواحد

بررسي تاثير هلالي هاي آبگير بر خاك و پوشش مراتع منطقه نارون خاش

تحليل عملكرد چشم انداز , شاخص هاي تنوع و مدل وفور رتبه اي , پايداري , نفوذپذيري و بانك بذر خاك