Mohammad Fayaz; Hooshmand Safari; Hasan Yeganeh; Gholam Hosein Rahmani; Hosein Tavakoli; Mohammad Akbarzadeh; Mohammad Ghaytoori; Ahmad Ahmadi
Volume 21, Issue 4 , March 2015, , Pages 731-746
Abstract
Rangelands are one of the major sources of forage production in the country and in addition to its effects on the production of livestock products, a large population is dependent on rangelands because of animal husbandry. Since the government applies management on rangelands through range management ...
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Rangelands are one of the major sources of forage production in the country and in addition to its effects on the production of livestock products, a large population is dependent on rangelands because of animal husbandry. Since the government applies management on rangelands through range management plans, therefore, in this study, direct and indirect effects of management variables on range condition and trend as well as rangeland production were investigated by selecting three range management plans at three levels of successful, moderately successful and unsuccessful in Kerman, Kermanshah, Mazandaran, Khorasan Razavi and West Azarbaijan provinces. Management variables were included as follows: the accuracy of rangeland and livestock data, project compatibility with natural conditions, beneficiaries' conditions, funding and the capabilities of human resources, predicting the executive and beneficiaries' obligations, executive calendar, and active supervisors. According to the results of rank correlation by Spearman, variables of range condition and trend as well as rangeland production had a high rank correlation together.According to the results of path analysis, variables including the accuracy of rangeland data, project compatibility with the capabilities of human resources, predicting the executive obligations, active supervisors, and beneficiaries' obligations were the factors which improved range condition and trend as well as rangeland production. Due to the negative impact of variables including project compatibility with funding, project compatibility with beneficiaries' conditions, and executive calendar on range condition and trend as well as rangeland production, these variables must be revised and their function need be evaluated. In addition, it is emphasized that greater sensitivity is required in planning for the future due to the negative effect of these variables. Other variables had no favorable or negative effect directly; however, they affected range condition and range trend as well as rangeland production indirectly.
Mojtaba Eidi; Ataollah Ebrahimi; Esmaiel Asadi; Hormoz Sohrabi; Hamzehali Shirmardi
Volume 21, Issue 3 , December 2014, , Pages 455-465
Abstract
In this study, the distance methods of density measurementwere compared for four plant species in terms of accuracy, time, and efficiency of the random distribution patterns in Karsanak area, located in the eastern part of Shahrekord in Chaharmahal-va-Bakhtiary province. The study area with 32000m2(160*200) ...
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In this study, the distance methods of density measurementwere compared for four plant species in terms of accuracy, time, and efficiency of the random distribution patterns in Karsanak area, located in the eastern part of Shahrekord in Chaharmahal-va-Bakhtiary province. The study area with 32000m2(160*200) was divided into eight sections of 4000 m2. The total number of each species was counted in each section and considered as the basis for the simulation. Then, eight sections with 4000m2 area were simulated in Stochastic Geometry software, and in each section, a transect of 100m length was established in the center of small side along which 10 points were determined by random systematic method with nine-meter intervals. The distance methods compared included nearest neighbor, closest individual, third closest individual, random pairs, point center quarter, angle order, wandering quarter and variable area transect as well as control group (counting the number of each species in each section). The selected species included Astragalus effuses, Eryngium billardieri, Astragalus rhodosemius and Astragalusverus. The distribution pattern of plant communities was determined by Hopkines and Eberhardt indices. The density estimation error was calculated to evaluate the accuracy. Duncan's test was used to compare the accuracy of methods, and standard deviation and time method were used to compare the efficiency of methods. The results of this study showed that nearest neighbor and closest individual methods (in terms of time), random pairs method (in terms of accuracy) and variable area transect (in terms of precision) could be introduced as the most efficient methods.