مجله مرتع
سال دهم شماره 3 (پیاپی 39، پاییز 1395)

This study investigated the effects of seasonal changes and different soil conditions on proline, soluble sugars, and ion content of Hammada salicornica in Bafgh area, Yazd province. Three Hammada salicornica habitats with various environmental conditions were selected. The first habitat had salty soil and hardpan (Hamada habitat), the second habitat located next to playa with saline soil and high groundwater table, and the third habitat characterized by sandy soil. The plant samples were collected in four seasons with five replications. The highest Proline content in the species was observed (2.5 mg/gwt) in autumn in sandy habitat and its lowest value was found (1 mg/gwt) in Hamadat habitat. The highest amounts of soluble sugar (2.5 mg/gwt) were measured in summer in sandy and playa habitats and its lowest amount (0.87 mg/gwt) was observed in winter in sandy habitat. The highest amounts of sodium content (42 Meq/l) measured in winter in Hamada habitat and its lowest amount (.64 Meq/l) found in winter in sandy habitat. The highest amounts of potasium (31 Meq/l) were measured in winter in Hamada and sandy habitats and its lowest amount (0.6 Meq/l) were found in all habitats in winter. The highest amounts of nitrogen content (2.6 percent) were measured in Hamada habitat and its lowest amount (1.1 percent) was also found in winter in Hamada habitat. It is concluded that hammada salicornica can adjust its osmotic potential with absorbing and increasing its sodium and potassium content. This study showed that physiological responses of hammada salicornica to environmental conditions depend mostly on plant phenology and the kind of stress as well as their interactions.

Phonological and morphological responses of three rangeland grasses Stipa turkestanica, Melica persica and Elymus elongantus were studied to the understory soil moisture reduction and temperature increase, within a growth season in Dehbar rangelands, Binalud, northeast Iran. Phenological events were recorded by doing field visits every 10-14 days. Soil moisture and temperature, leaf moisture and air temperature were measured under canopy of the grass species, five times during the growing season. Native species M. persica and S. turkestanica started their flowering in Mid-May and finished the seed ripening stage at Mid-June. Introduced E. elongatus started its flowering stage from early May and finished the seed ripening stage at mid-July. The C4 photosynthetic pathway and fewer leaf and stems led to a lower reduction in leaf moisture of M. persica. In contrast, a dense canopy for E. elongatus led to soil moisture conservation. From beginning till the end of growth season, 90 and 7 percent moisture reductions were respectively found in leaves and understory soil of the studied species. For the same time, 10 and 15 percent increases were respectively found in the understory soil and air temperatures. Under the intense summer drought, higher reduction in leaf length and number was found for M. persica (40%) but lower value (12%) for E. elongatus. According to our findings, the introduced grass E. elongatus can be a suitable species for Dehbar rangelands both in terms of forage production and drought resistance. Proper time for livestock grazing from all three species in Dehbar ragelands is suggested from late May till early July.

The present study was conducted to study the response curves of Aeluropus lagopoides and Salsola turcomanica along some environmental gradient using HOF function in Inchehboroun rangelands in Golestan province. A randomized-systematic method was used to collect the species occurrence data in four hundred quadrates with size of 4m2, placed along a gradient from watering point. Soil samples were collected from 0-20 cm in all quadrates and their bulk density, soil moisture, pH, N, EC, P, organic carbon, sand, silt and clay content were measured. HOF model with binomial distribution function was used to explore response curves of the species to these soil variables. The data were analyzed by R ver.3.0.2 computer programmer. Results revealed that ecological amplitudes of A. lagopoides and S. turcomanic differ considerably. According to the results, the occurrence range and optimum condition for A. lagopoides were 320-1000m and 874m from watering point respectively. The occurrence range and optimum condition for S. turcomanica occurrence was 200-1000m and 845 m from watering point respectively. A. lagopoides and S. turcomanica response curves to watering point distance and pH gradient had increasing and decreasing monotonically trend respectively. The ecological optimums along the pH gradient were 7.5 and 7.7 for A. lagopoides and S. turcomanica respectively.

This study aimed to investigate effects of grazing on forage quality and quantity of Artemisia sieberi in two rangelands of Semnan province. Three sites with different grazing intensities including reference, key and critical areas were selected in each rangeland. Plant shoots were collected from 15 plant individuals and 90 plant samples were collected for chemical analysis. The results showed that heavy grazing in Goosheh had significant effects on protein, P, metabolizable energy, DMD, ADF and production of the plant species. Although moderate grazing in key areas had no significant impact on plant production per hectare and leaf to stem ratio, heavy grazing reduced the production (75%), canopy cover (72%) and leaf to stem ratio (55%). Protein content was identified as the most sensitive parameter to grazing, as it was declined 20 and 44 percent under moderate and heavy grazing, respectively. Moderate grazing had no significant effect on the measured parameters in Lookeh rangeland but the species protein content declined significantly (50%) under heavy grazing pressure. Although dry matter digestibility and metabolizable energy of the species reduced 28 and 21 % respectively under heavy grazing, its ADF was increased by 21 %. Canopy cover percentage, leaf to stem ratio and A. sieberi production also were reduced by 60, 43 and 56 percent respectively under heavy grazing pressure. The results showed that although the quantity and quality of A. sieberi decreased significantly under heavy grazing, no evidence of these negative impacts were found under moderate grazing condition.

Range managers try to maintain good conditions and restore degraded rangelands to increase forage production. Twenty plant individuals of Tanacetum polycephalum with similar size were selected in three growth stages for 4 years to evaluate the effects of different clipping intensities on some vegetative and reproductive characteristics of the species. Five plant individuals with no harvesting were considered as control and 25%, 50% and 75% clipping were applied in various plant growth stages in May, Jun and July for 4 years on each five plant species. Harvested forages were air dried separately and analyzed. A split plot based on a completely randomized design was used to analyze the data. Analysis of variance showed that species production did not differ significantly between various clipping treatments. The production of the species over the studied years varied significantly (P

This study aimed to evaluate the effects of environmental factors on plant species production in some range sites in Isfahan province. Systematic randomized sampling was performed during 10 years (1377-1387). Four and six parallel transects with 400 and 200 meters lengths were established in each of Steppe and semi Steppe sites respectively. Fifteen 1 by 2 meters plots and ten plots with size of 1 by 1 meter were established along each transect in Steppe and semi Steppe regions respectively. The production of plant species were recorded in each plot using double sampling method. Grid layers of bioclimatic and topographic variables were prepared in ArcGIS 10.1 and values for each range site were extracted. Soil samples were collected from range sites and some physical and chemical properties of the collected samples were measured. Canonical Correspondence Analysis (CCA) was used to evaluate the relationships between environmental factors with the plant species production. Cluster analysis was also used to group the studied range sites based on environmental factors. According to the results, minimum temperature of coldest month, annual mean temperature, electrical conductivity, calcium carbonate and sand percentage in steppe region and precipitation of wettest month, annual precipitation, elevation, organic matter and potassium in semi Steppe region were identified as the most important ecological factors affecting plant species production. Maximum of mean plant species production in Steppe was 64.4kg/ha and semi Steppe 144.1kg/ha. Sixty Steppe was from shrub species while grasses composed 56 percent of production in semi Steppe region.

This study investigated the effects of seasonal changes and different soil conditions on proline, soluble sugars, and ion content of Hammada salicornica in Bafgh area, Yazd province. Three Hammada salicornica habitats with various environmental conditions were selected. The first habitat had salty soil and hardpan (Hamada habitat), the second habitat located next to playa with saline soil and high groundwater table, and the third habitat characterized by sandy soil. The plant samples were collected in four seasons with five replications. The highest Proline content in the species was observed (2.5 mg/gwt) in autumn in sandy habitat and its lowest value was found (1 mg/gwt) in Hamadat habitat. The highest amounts of soluble sugar (2.5 mg/gwt) were measured in summer in sandy and playa habitats and its lowest amount (0.87 mg/gwt) was observed in winter in sandy habitat. The highest amounts of sodium content (42 Meq/l) measured in winter in Hamada habitat and its lowest amount (.64 Meq/l) found in winter in sandy habitat. The highest amounts of potasium (31 Meq/l) were measured in winter in Hamada and sandy habitats and its lowest amount (0.6 Meq/l) were found in all habitats in winter. The highest amounts of nitrogen content (2.6 percent) were measured in Hamada habitat and its lowest amount (1.1 percent) was also found in winter in Hamada habitat. It is concluded that hammada salicornica can adjust its osmotic potential with absorbing and increasing its sodium and potassium content. This study showed that physiological responses of hammada salicornica to environmental conditions depend mostly on plant phenology and the kind of stress as well as their interactions.

Determining the recreational appropriatness of rangeands based on their ecological potentials is vital for ecotourism management. Ecological potentials should be evaluated to achieve an appropriate ecotorism planning. This study aimed to provid a model for evaluating ecotourim suitability using GIS in Venae basin, Boroujerd County, Lorestan province, Iran. The effective sub-criteria on ecotorism suitability were identified using literature review, questioners from exporters and tourists. Analytical Hierarchy Process (AHP) was used to weight and evaluate these factors or sub-criteria on rangeland recreational appropriateness. Expret Choice software was used to conduct AHP. Digital information map, slope, aspect, satellite map and so on were overlaid by ArcGIS© software. The ecotourism suitability sub-criteria were categorized into two main physical and biotic criteria. Twenty two sub-criteria were evaluated based on the specific ecotourism type, and their spatial maps were produced and combined. According to the AHP synthesis, sensitivity to soil erosion was identified as the most important sub-criteria (with relative weight of 0.431) from physical criteria for ecotourism suitability and distance from city and camping were not identified as important sub-criteria with relative weight as low as 0.028. Security and residents charcteristics were also identified as the most and least important sub-criteria for ecotourism suitability among biotic criteria with relative weight of 0.56 and 0.33 respectively. Results indicated that 1457 hectares (24.85 percent) of the study area was classified as highly suitable for eotourism (S1), 1751 hectares (29.86 percent) classified as S2, 1200 hectares (20.46 percent) classified as S3 and 1456 hectares (24.85 percent) were classified as unsuitable (N) for ecotourism purposes. In summary, the physiographic condition of the study area such as high slope and mountainous land units were identified as the most limiting factors of ecotourim suitability. Specific landscape, high mountain peaks, plant diversity, gardens, orchards and plantation were aslo identified as sub-criteria that improve ecotourim suitability in the study area. The limitation of slope sub-criteria for ecotourism suitability can be decreased by providing walking trails appropriate for tourists in the area.

Vulnerability assessment of ecosystems is required to achieve sustainable management of ecosystems and to identify the best management strategies to minimize damaging effects caused by traumatic factors. This study aimed to assess socio-economic vulnerability in highland rangelands of Natanz County. The most important socio-economic indices were identified using literature review, accordingly. The sample size was calculated based on Cochran’s formula. Data were collected using a researcher-made questionnaire. The content validity and reliability of the produced questionnaire were approved using expert reviews and Cronbach’s alpha coefficient (0.861) respectively. Me-Bar and Valdez's vulnerability formula were used to assess the socio-economic vulnerability. According to the results, “local problems and the collapse of past utilization systems”, “number of rangeland user” and “utilization pattern” were identified as the most important indices influencing social vulnerability. Findings further indicated that “livestock number of rangeland users”, “life expenses of rangeland users” and “economic status of rangeland users”, were the most important indices affecting economic vulnerability. The results also identified that more accuracy can be obtained to assess rangelands vulnerability by integrating social and economic factors at local scale. Therefore, identification and classification of rangeland vulnerability can be facilitated by considering and integrating socioeconomic factors.

Participation is a multi-dimensional phenomenon, heavily depending on various variables each with its own relative weight. Carried out in 2016, this study strives for critical understanding of the inhibiting parameters in public participation, as a social phenomenon, for developing of livestock drinking water in Yazd Province's rangelands. In this study, effective parameters were determined using the Delphi technique in three rounds through filling questionnaires. To elicit knowledge a group of experts consisting of 15 members of academic scholars, officials from Natural Resources and Watershed Management Office in Yazd province and some selected people from local communities were participated. Consensus among the experts on the influential parameters has been achieved after three rounds, entailing three criteria including: a least agreement of 75%, average, score of 4 out of 5, and Kruskal-Wallis statistical test. In this research, a total of 15 parameters from social, economic and climatic criteria were determined on the basis of the standpoint of the expert group. Analysis suggests that lack of inclusive rural cooperatives (weak role of NGOs), reduced rainfall and looming droughts, jointly have major impact on the social participation, by a score of 4.53 and 90.7% consensus. Meanwhile, low income and financial dependence of ranchers on the government subsidies and loans respectively by 85.3 and 82.7 percent of specialist group consensus were identified as the important economic factors. This research assists policy makers and managers of natural resources in removing the obstacles of the pathway of participation and improving public participation for livestock drinking water management in the rangelands of Yazd Province.