The extinction of some of medical plants is not only due to the overuse of them and the grazing pressure but also their incorrect exploitation methods. Ferula assafoetida is one of the most important medical plants in Iranian rangelands, which is gradually disappeared from its habitats due to destructive traditional exploitations. Therefore, in order to determine how different incision techniques (exploitation methods) affect F. assafoetida properties, a study was carried out in the research field of Agricultural and Natural Resources Research Center in Mashad, Iran from 2009 to 2010. F. assafoetida plants were five years olds. The plants were cultivated in four densities in the field (25×50, 40×50, 55×50, and 70×50 cm) and four incision treatments as horizontal cutting (traditional), 45-degree cutting, concave cutting and non-incision (control) using a split plot design based on the completely randomized block design with three replications. In each plot, three plants were selected and leaf area, number of leaves, basal diameter, dry matter of post-harvest leaves and survival rate were measured. Analysis of variance of data was conducted and means comparisons were made using Duncan methods. The results showed the significant effects of incision on all the F. assafoetida traits (P<0.05). The effects of density and interactions of density by incision were not significant for all the traits. Results showed that the plants with a traditional incision had the lowest properties. It was concluded that the traditional incision method is fatal for plants and it is suggested to be replaced with 45-degree cutting method in plant density of 70×50 cm. تفاصيل المقالة

Biodiversity plays a crucial role in stability and productivity of natural ecosystem. The main goal of this research was to classify ecological groups in steppe rangeland and investigate their relationships with plant diversity indices. Therefore, fifty different Land Unit Tracts (LUT) were identified in Khod-Neuk basin, Yazd province, Iran, in 2010. Vegetation and soil samples were taken in the LUT’s representative stands. Two way indicator species analysis (TWINSPAN) method were used to identify ecological groups on the basis of presence-absence and canopy cover of plant species. The diversity indices including species richness, Shannon-Wiener evenness index, Simpsons’ dominance index, Shannon-Wiener diversity index and Simpsons’ diversity index were analyzed in vascular plants based on species canopy cover data. Then the relationship between land unit distribution and diversity indices was assessed using Canonical Correspondence Analysis (CCA). Results showed that ecological groups were quite different in terms of species composition and plant diversity indices. So that, ecological group 2 had the lowest dominance index and the highest scores of other indices and ecological groups 1 and 5 had the lowest richness and along with ecological group 3 had the lowest species evenness values. Ecological group 5 had the lowest and the highest scores of Shannon-Weiner diversity index and Simpsons’ dominance index respectively. The second group located in the mid altitudes with high saturation percentage and low Na, lime and Sodium Adsorption Ratio (SAR) had the highest diversity indices. Therefore, these groups are enough to delineate rangeland into ecological units which could be used for management purposes. تفاصيل المقالة

Economic valuation of rangelands is one of the best methods for conservation goals. A study was conducted to assess the economic value of forage loss under the two main forms of traditional pastoralism i.e. sedentary pastoralism and nomadism in historic grazing semiarid rangelands in Khabr National Park, Kerman province, Iran in 2019. Forage production was measured by clip-and-weigh method and forage quality was assessed using Crude Protein (CP) and Acid Detergent Fibre (ADF) indices. The replacement cost method was used for forage valuation and Total Digestible Nutrients (TDN) was used as the principal character of forage value. Forage production was decreased by 65% and 78% under nomadism and sedentary pastoralism respectively as compared to exclosure. Assessing species distribution along grazing gradient, using Detrended Correspondence Analysis (DCA), showed that forage quality decreased as grazing intensity increased due to plant composition change. Lathyrus annuus and annual grasses were the highest and lowest value forage, respectively. The forage values for exclosure area, near exclosure area and near village and pastoral tent were 75 $, 20-25 $ and 6-10 $.ha-1.year-1, respectively, indicating 65 to 92% reduction in the forage value in traditional pastoralism forms than to exclosure area. Therefore, there was priority to perform appropriate grazing systems such as rest rotational grazing to improve the condition of historic grazing lands and pastoral’s income. تفاصيل المقالة

Forage is one of the main products of rangeland ecosystems, which is threatened by different anthropogenic disturbances. This study was conducted to assess the impact of urbanization, rural development, agriculture extension, road construction and industry on forage production in an arid and semiarid rangeland using InVEST habitat quality model in spring 2018. In 14 rangeland types, thirty 2×1m quadrats were randomly located to measure forage production using double sampling method. Habitat quality was mapped based on the relative impact of each threat, the relative sensitivity of each rangeland type to each threat and the distance between the habitats and threats. The results showed that there is a significant relationship between rangeland condition and habitat quality (p<0.01). Habitat quality varied between 0 and 0.77 across the study region. Habitats with low quality comprised half of the total area (51%) where anthropogenic factors were concentrated. Habitat quality was significantly correlated with forage production (p<0.01). The dominant species Artemisia sieberi was replaced by invasive species Salsola brachiata and forage production was decreased to the minimum 21 kg ha-1 in habitats with low quality. Rangelands with medium habitat quality produced two and a half times more forage than the ones with low habitat quality and half of the ones with high habitat quality. Astragalus gossypinus and Artemisia aucheri in high habitat quality areas supplied the highest forage production (216 kg ha-1). Since the large areas of agricultural lands are in the low quality habitats, agriculture can be considered as the main threat of forage production. Hence, the extension of agricultural lands with short-term benefits should be controlled in order to improve ecosystem services which have long-term benefits in sustainable development. تفاصيل المقالة

In arid and semi-arid rangelands, grazing as one of the natural or human induced processes has direct and indirect effects on structure and dynamics of plant community and ecosystems. A study was done to analyze the effects of grazing on plant species diversity and Plant Functional Types‘ (PFTs) diversity of arid and semi-arid rangelands. We analyzed plant richness and diversity data from 75 sampling plots located in five bioclimatic zones of Khabr National Park containing a total of 73 plant species. Ward's hierarchical clustering was then used to cluster all plant species into eight PFTs according to the chosen traits. For each site, grazing intensity was estimated in three classes (low grazing, medium and high grazing intensities). We found that as grazing intensity increased, total species richness and diversity were decreased. Considering PFTs as total showed the same pattern for species; however, each PFT diversity and richness didn‘t display a significant different response to grazing. Looking at each PFT relative cover change in different grazing intensities showed that PFT1 and PFT8 were grazing sensitivities while PFT6 and PFT7 benefited from grazing and their relative cover increased consistently in response to the increased grazing intensity. PFT3 and PFT4 had the highest relative cover rates in moderately grazed areas. PFT2 and PFT5 had a complicated response to grazing and their relative cover was the minimum at moderately grazed sits. This finding may imply that grazing has completely negative impacts on the community structure and it seems that it reduces plant species and functional types‘ diversity and richness. It can be also concluded that the analyses on PFTs level possibly give more insight into the grazing response of plant community in arid and semi-arid rangelands than those on species level but there is a need for further studies. تفاصيل المقالة

Renewable natural resources are the wealth that not only belongs to the currentgeneration but also to future generations. Diversity in rangeland user viewpoints and policymakers has caused these lands to face some damages. This study was conducted to compareviewpoints of ordinary members as rangeland users, and board of directors as executives ofmanagement plans. Statistical population of the study involved ordinary members and boardof directorsof 28 range management cooperatives in Golestan province. According to theKrejsi- Morgan Table, 308 and 78 individuals were randomly selected for ordinary membersand board of directorsas sample size, respectively. Main material of this study is based onutilizing question naires that their validity and reliability were checked based on a guide study.To analyze data, qualitative methods, descriptive statistics and T-test were used. The resultsshowed that there was a significant disagreement between ordinary members and board ofdirectors about effective social-economic factors on range management cooperatives success.Based on the results, providing loans to the cooperative members with low interest and longterm payback and betters cheming for more attraction of members participation in decisionmakingand cooperatives plansare recommended. تفاصيل المقالة