جستجوی مقالات مرتبط با کلیدواژه "بوم سازگان" در نشریات گروه "آبخیزداری، بیابان، محیط زیست، مرتع"

Reduced rainfall and inappropriate temporal distribution are one of the problems and issues in the natural resources of our country. The aforementioned factors limit the conditions for the establishment and growth of various rangeland and forest species, especially in arid and semi-arid regions. In order to deal with this problem, in addition to implementing improvement and restoration operations in rangeland ecosystems in arid and semi-arid regions, along with cultivating plant species compatible with the climatic conditions of the region, management and collection of runoff from atmospheric precipitation is necessary (12). Management and collection of surface runoff is possible through various biomechanical and structural methods. Crescent catchment, as one of the types of biomechanical methods for managing and collecting atmospheric precipitation with the aim of improving and restoring rangelands in arid and semi-arid regions, has become common in Iran in recent years (3). Water catchment crescents are considered structural operations due to their construction, but because they are usually accompanied by planting, they can be considered a biomechanical method (15). Water catchment crescents are actually short horizontal banks that are built in an arc or arc shape to create micro-watersheds (16). The most important and prominent goals of constructing water catchment crescents include controlling and storing surface water runoff, increasing water infiltration in the soil, controlling erosion and preventing soil loss, creating a suitable microclimate for plant growth, and finally creating a suitable ground for implementing rangeland improvement and restoration projects (15). The effective factors and appropriate levels for constructing and implementing water catchment crescents include rainfall, slope, canopy cover, cover condition, soil depth, soil texture, and the amount of rock and gravel (Table 1). Some of the research conducted on the performance and effectiveness of crescent catchment systems are as follows. In the Kumiran rangelands of Qain County, South Khorasan Province, the effect of holes and their location in the rangelands, as well as the best place to plant shrubs inside the crescent-shaped hole, has been investigated (10). A study in Sarbisheh County, South Khorasan Province, examined the impact of the crescent-shaped water intake system on changes in rangeland plant production, soil moisture, and texture in dry and steppe rangelands. Based on this study, it was determined that rangeland plant production has more than doubled in the project implementation area (12). In a study conducted in the rangelands of Narun region of Khash County, Sistan and Baluchestan province, a comparison of diversity and species richness indices using parametric and nonparametric methods was conducted in the improved area under the influence of crescentic water intake operations and the control area. According to the results of this study, the implementation of crescentic water intake has resulted in a uniform vegetation cover in the area, which has resulted in better plant diversity and greater ecosystem stability (6). In the Zirkuh region of South Khorasan province, the effect of the crescent catchment system on vegetation cover and soil moisture levels under wet and drought conditions has been investigated and compared. The results showed that the implementation of the crescent catchment plan in the region has increased vegetation cover compared to the control region (19). In addition, in some studies, the effectiveness of crescent catchment systems on increasing agricultural production has been reported (2, 7, and 11). According to previous studies, the role of crescent catchment systems in managing and collecting runoff in the region and comparing the performance of these systems with mortar rock dams has been less studied. The present study investigates the role of crescent catchment systems in managing and collecting runoff in the region and comparing the performance of these systems with mortar rock dams in the Chadaroyeh watershed of Jahrom County, Fars province. The present study investigated the role of crescent catchment systems in managing and collecting runoff in the region and compared the performance of these systems with mortar rock dams. The Chadaroyeh watershed in Jahrom County, Fars Province is the study area of ​​this study. With this study, the performance of crescent catchment systems with mortar rock dams has been compared.

Accordingly, an area of 1796.76 hectares, equivalent to 23.93% of the total area of ​​the Chadarviyeh watershed, has been designated for the construction of crescent-shaped water intake systems with seeding (Table 2 and Fig. 2, 3 and 4). In addition, three mortar rock weirs and five dry-fill weirs have been designed at the outlet of the basin, considering the annual inflow and morphology of the main waterway, and two mortar rock weirs have been designed at the outlet of sub-basins CH1 and CH2 to control sediment and protect soil in the upstream of the basin. In addition, five dry-fill weirs were designed around the aforementioned structures and in second- and third-grade waterways. The SCS method has been used to determine the flood volume in different return periods (Tables 3 and 4).

The results of estimating the water intake volume in the intake crescents showed that by implementing this method on 1796.76 hectares of the Chedarviyeh watershed, 2454515.79 m3 of surface runoff will be stored annually (Tables 5,6 and 7). Considering the flood volume in different return periods for the Chedarviyeh watershed, the total storage volume of the three rock-mortar dam structures was estimated to be 88,000 m3 with a 25-year return period, which only extracts and manages 11.9% of the total 25-year flood volume (Table 8). In total, these structures manage and store 75.3% and 25.8% of the total flood volume generated in the Chedarviyeh watershed for 2- and 5 year return periods, respectively (Table 8).

Considering the performance of crescent catchment systems in extracting and managing surface runoff up to the level of extracting 100% of the runoff generated in the Chedarviyeh watershed during different return periods, the high effectiveness of this method in extracting and managing runoff and floods is determined (Table 9). This advantage, along with other advantages of this method, including low implementation cost, maximum compatibility with natural resources and the environment, simplicity of implementation, speed of implementation, the possibility of planting seedlings and seeds in the system environment, moistening the topsoil in a wide area of the watershed, creating a place to provide water for livestock and wildlife in the watershed, with the occurrence of strengthening and revitalizing pastures, preventing soil erosion, transferring watershed management activities from the waterways to the slopes, and the health and stability of the watershed and its relative superiority over mortar stone structures in extracting a larger volume of surface runoff, the importance and efficiency of this method for extracting runoff and floods are increasingly proven.

Analyzing changes in land use/cover and identifying their drivers is essential for developing sustainable land management approaches that restore ecosystem resources and services. This research analyzes land use/land cover changes in the Fandoghlo region in Ardabil province in the last two decades based on Landsat 8 (OLI/TIRS L1TP) satellite images and investigates governance and socio-economic drivers based on household surveys and key informants interviews. The results recorded a negative net change in forest (187.5 ha) and rangeland (662.5 ha) ecosystems and a positive net change in agriculture (587.1 ha) and man-made (267.6 ha). Analysis of the 20-year (2003-2023) change detection matrix showed that about 26% of the study area experienced a transition. Based on the results of the investigation of 11 governance and socio-economic drivers, the observed change in ecosystems caused by the expansion of agriculture (91%), poverty (71%), livestock pressure (68%), weak law enforcement (65%), wood smuggling (62%), increasing demand for firewood (60%), population growth (44%), fires (41%), incompatible forms of tourism (40%), distance to the road (36%), and mining (11%). These socio-economic drivers have a significant impact on the availability of ecosystem services, community welfare, biodiversity, and climate. Therefore, this study recommends coordinated efforts by stakeholders to develop participatory ecosystem management and public awareness on the coexistence of nature conservation and sustainable livelihoods. In order to protect ecosystems in this region, it is crucial to empower local communities, understand the dynamics of agricultural lands, and manage the causes and consequences of recent demographic changes.

It is necessary to predict the influencing parameters on homogeneous watersheds for the future in order to make decision and correct management. In this research, 19 bioclimatic variables extracted from the ESM4-GFDL general circulation model based on ssp126 scenario and then were clustered in two statistical periods, including the years average of 1981-2010 and the average of 2041-2070, and also homogeneous watersheds were identified for two statistical periods. Also, the intensity of utility in homogeneous watersheds was investigated. The results showed that the homogeneous watersheds located in cluster 4, will be involved with the highest changes in increasing temperature and decreasing precipitation and it will cover about 16% of the area of Chaharmahal va Bakhtiari province. On the other hand, in all homogeneous watersheds, the seasonal changes in precipitation and average air temperatures of the wettest quarter have an increasing trend, which shows the disproportionate temporal distribution of precipitation will be occurred, then the problems lead to destructive floods, the reduction of plants and agricultural productions and destruction of native habitats of the regions. In this regard, Kohrang city has been studied as the most critical city and has the least desirable area, 23.38 and 22.35 in two periods, respectively.

The sudden increase in population growth, followed by the restriction and scarcity of the world's supply of freshwater resources, has created new conditions for countries in the arid and semi-arid belts. To conserve, enhance and make the best use of these valuable resources, several projects have been implemented, including irrigation and drainage, flood control and dam construction. Meanwhile, dams are a very important tool to manage the river water for socio-economic development and also to improve the deteriorated ecological status of the river system and its services. Depending on place and time, dams play both negative and positive roles in environmental flows, with significant environmental costs. According to the results of the documents and reports, the construction of the dam has brought about environmental changes from various aspects of invasion and increase in invasive species to improving access to spawning habitats for migratory fish. The challenge for managers and scientists today is to better understand and manage the consequences of dam decommissioning. For this reason, the purpose of this study is to present the approaches of removing the dam on ecological changes. The results of this research can provide stakeholders in the responsible departments with valuable information about the changes in the behavior of dams on the environmental properties.

Lack of rainfall and its high temporal and spatial variation are the main problems of vegetation restoration in Iran.  Rainfall harvesting methods can play an effective role in improving soil moisture. Rainfall harvesting operations have a great impact on the structure and function of ecosystems. Therefore, the present study investigates the changes of soil properties as a result of implementing two rainfall harvesting methods (water spreading system and micro-catchment) in arid rangelands of Hormozgan province. First, 45 soil samples were taken from control, micro-catchment and water spreading system sites and their physical and chemical properties were measured in the soil laboratory. One-way analysis of variance was used to compare the different sites in terms of soil properties. The rate of change index was used in order to assess the performance of soil properties and the overall performance of each of the rainfall harvesting methods compared to the control. Synergy and trade-off relations between soil properties were investigated using Pearson correlation coefficient. The results showed that except EC, pH, TNV, water spreading system had a significant effect on soil properties. EC, pH, TNV, calcium, magnesium, nitrogen and sand had negative performance in the water spreading system, and the rest of the soil properties had positive performance. The overall performance of soil properties was 31 and 11% in the micro-catchment, and 52 and 25% in the water spreading system. Sand had a significant trade-off relationship with most soil chemical properties. The highest trade-off was observed between sand and silt (p <0.01, R2 = -0.99). The highest synergy was observed between silt and phosphorus (p <0.01, R2 =+0.87), and next phosphorus and OC (p <0.01, R2= +0.72). In general, the positive impact of water spreading system on the soil properties of arid rangelands was greater than the micro-catchment in this region.

Increased concentration of atmospheric carbon dioxide due to human activities has resulted in accelerated global warming process. Forestation is the most effective way to absorb atmospheric carbon dioxide and store it in terrestrial ecosystems in order to reduce and mitigate global warming. This study aimed to investigate the comparison of soil carbon sequestration in various stands in ​​Kuhdasht Aquifer and to present the best regression model for carbon sequestration based on all soil characteristics. In each stand (20-year old) of Ficus carica, Punica granatum, Pistacia vera, Amygdalus lycioides and Cupressus arizonica species as well as control rangeland, a number of 10 sample plots (5×5 m) were randomly selected and soil samples were taken in each plot at 0-10, 10-30 and 30-50 cm depths. All soil samples were transferred to the laboratory in order to measure soil characteristics including soil texture, organic carbon, bulk density, electrical conductivity, lime percentage and soil acidity. The results showed that the highest value of carbon sequestration in soil of Pistacia vera stand (54.94 tha-1) significantly (P <%1) higher compared to other stands, followed by Ficus carica (50.23 tha-1), Amygdalus lycioides (31.53 tha-1), Punica granatum (27.09 tha-1), Cupressus arizonica (24.17 tha-1) and control rangeland (9.01 tha-1) stands. Results also showed significant differences (P <%1) between the studied stands in terms of soil texture, acidity, organic carbon, electrical conductivity and soil bulk density. Also, the result of stepwise regression indicated that soil texture and acidity were the most important components affecting soil carbon sequestration, respectively.

as healthy watersheds provide many ecosystem services in various fields such as social and economic welfare, some methods need to be developed for measuring the extent of watershedschr('39') health and sustainability. Sustainable development is a comprehensive approach to improving human life quality by providing the economic, social, and environmental well-being of human settlements. Therefore, it is achieved if there is an overlap between the ecological, economic, and social layers. The purpose of this study was to compare two methods of HLEP and the organization of forests, rangelands, and watershed management in assessing the sustainability of the Bakhtegan watershed in Fars province.

The first Method used the guidelines for monitoring and evaluating natural resource management and watershed management plans prepared by the Vice President for Strategic Planning and the Organization of Forests, Rangelands, and Watershed Management for Iran. In this method, the watershed was divided into five ecosystems: forest, desert, rangeland, aquatic environment, and economic and social issues. Different criteria and indicators were defined, determined, and measured for each of these ecosystems. Each variable was divided into different classes numerically, and each class was given a score (from high to low). The second method for analyzing and measuring stability in the field was the HELP that was based on four categories of hydrology (quantitative and qualitative), environment, watershed life, and policy-making. Moreover, three parameters of pressure, status, and reaction were used under the title of Basin Stability Index (WSI) to study basin stability at three levels: low, medium, and high.

as for the first method, the scores were added up to create a class, and according to the study area, three criteria, nine indicators, and 14 variables were selected and measured based on the rangeland and desert ecologistschr('39') section. In the ecologistschr('39') section, five criteria and 16 indicators (the indicators themselves act as variables) were selected and measured. The final scores for rangeland and desert ecologists and the economic and social issues were reported as 45 and 32, respectively, putting both in the middle class. The watershedchr('39')s sustainability status was also determined using the score estimation matrix and watershed assessment table. Taking the Bakhtegan watershedchr('39')s total points into account, it could be said that it is in a weak position in terms of stability. The results of the application of the HELP method showed that the pressure parameter with a score of 0.75 and the response parameter with a score of 0.45 had the highest and lowest scores for assessing the sustainability of the Bakhtegan watershed, respectively, indicating an appropriate response to reduce the pressure on the ecosystem. The results also suggested that quantitative hydrological sub-indices with a score of 0.25 and environment with a score of one had the highest and lowest priority for watershed management (especially management and protection of existing water resources), respectively. The level of watershed stability was assessed with a mean downward score of 0.61 in the study period, indicating that improving the regionchr('39')s level of sustainability requires more attention.

This studychr('39')s results in terms of selected criteria and indicators concerning the quality and quantity of information and accuracy of the data could be generalized to other parts of Iran (although similar to the field). To achieve acceptable sustainability, the area must be developed in terms of ecosystem, economic, and social issues and surpass the current equilibrium state. These conditions are made possible by protecting the ecosystem and providing a decent life for watershed dwellers. Considering the watershed management operations carried out in the basin, it is expected that the ecosystem sector will reach the desired level of stability. Moreover, for the basin to be sustainable, the economic and social sectors must get involved, conducting some measures to improve peoplechr('39')s living standards. Naturally, ecosystemschr('39') substantive and functional value in the formation and sustainability of watersheds are not the same; Therefore, according to the consensus of experts, aquatic ecosystems have the highest value, and desert ecosystems have the lowest value in the evaluation of a watershed. Thus, in the process of determining the sustainability of the watershed, the essential value of the composition of the ecosystems and the surface of the watershed that are covered must be taken into consideration.

The natural ecosystems of Iran are the most important origins of speciation in the world and protecting this diversity is of great importance. Sumac species in Bideskan habitat is considered as one of the most important rangeland sub-products that in addition to regional economic prosperity, it provides sustainable employment for villagers and is considered as an important species for soil conservation. Therefore, by studying the environmental conditions and the needs of the Sumac species, it would be possible to judge about its geographic distribution, density and activity in different environments.
Material and The habitat of Bideskan with an area of 3685 hectares is considered as one of the sub basins of the Lut Desert great basin in Iran. During May 2016, through the field visit, vegetation information and environmental factors were monitored. The area was divided into two parts of the natural Sumac beds and the control area, however with the same geological formation. In each section, 15 plots (total of 30 plots and soil samples) were taken by a random-systematic approach. A size of 10 × 10 m for the sampled plot was considered according to the type of plants and their distribution in the area. Within each plot, information related to the plants, including number and type, were recorded. During sampling, it was determined that the rootage direction of the Rhus coriaria L. followed the longitudinal growth in the soil and moved in the direction of the gradient, as a result, soil samples were taken from a depth of 0-30 cm. In the next step, taken soil samples were dried and in order to prepare for soil tests, they were passed through a 2 mm sieve. Subsequently, the parameters soil texture, saturation moisture content, pH, EC, OM, lime, Na, K, Ca, Mg, cation exchange capacity (CEC), and total nitrogen (N) were determined in laboratory. To determine the diversity and species richness, the number of species was counted in each plot within the two habitats of Sumac and control. Shannon-Weiner Species Diversity Index, Simpson and Fisher Alpha were calculated based on the frequency of plant species using the EstimateS win 9.1. The independent t-test was used in Statistical Package for Social Sciences (SPSS) software to compare the measured variables in two areas of Sumac habitat and control.
In total 24 species belong to 14 families were identified in area. The most dominted familiy was Asteraceae having 8 species of total number of species, followed by Apiaceae, Geraniaceae, Poaceae with 2 species each. Hemicryptophytes were the most important biological form with 14 species (54.16%), the Trophites with 7 species (33.33%), Geophytes with 2 species (8.33%) and Phanerophytes with 1 species (4.16%) were measured. Asteraceae species had a better adaptation to climatic conditions than other families. This could be due to a better compatibility of this family with climatic harsh conditions, which gives them a high potential of distribution. The presence of 58.33% Hemicryptophyte can be attributed to the dry-cold climate and mountainous topographic conditions. Furthermore, the abundance of Therophyte (33%) revealed low rainfall, recent droughts, unfavorable conditions of the enclosure and grazing and, consequently, the degradation caused by the impact of the pressures from these factors, are among the reasons that affect annual plants.According to the Shannon-Weiner index, the Sumac habitat with the index of 1.942 is more diverse than the control area (with an index of 1.667). The higher the evenness index, the distribution of species within the plot or a range is more uniform; therefore, the Sumac habitat with uniformity equal to 0.717 has more uniform distribution compared to the control area. According to the Shannon-Weiner and Simpson diversity indices, the Sumac habitat is more diverse, although its number of species (15 species) is less than the number of species in the control area (17 species). The student's t-test of independent samples on soil data showed that the soil fctors EC, ECe, Ca, OM, TNV, pH, K and silt content had significant differences in two regions. Moreover, four factors of EC, K, OM and TNV in the Sumac habitat showed a significant increase compared to the control area. The falling of shoot organs on the soil surface could be the main reason for the increase of K and OM under the stratum of the Sumac plant. The increase in the content of litters causes the increase of soil porosity, the decrease of bulk density and thus the soil gets better permeability conditions. The results confirm the significant role of Rhus coriaria in soil conservation planning. Therefore, it is necessary to encourage local farmers to preserve this species.
Awareness of the relationship between soil characteristics and the distribution of plant species is vital for the sustainable use of rangelands. Therefore, this study was aimed to determine the effect of soil characteristics in the distribution of vegetation cover, especially Rhus coriaria L. in Bideskan habitat. The sampling results indicated that the most important vegetative form of the region, is Hemicryptophytes, 58.35% of the species population of the area, followed by Throphytes with 33% . The student's t-test of independent samples on soil data showed that the soil properties EC, ECe, Ca, OM, TNV, pH, K and silt content had significant differences in two regions. Moreover, four factors of EC, K, OM and TNV in the Sumac habitat showed a significant increase compared to the control area. According to the results of this research, it can be stated that it is possible to establish Sumac (Rhus coriaria L.) as a species compatible with arid areas (calcareous soils with higher EC) to control erosion and sedimentation and improve revival of green spaces in mountainous regions of arid and semi arid areas, especially in Khorasan province and others areas with similar ecological conditions.

Sustainability is a concept that emphasizes substantially on investments conservation (natural, social and economic) toward intra-generation equity. When sustainable development is achieved an overlapping is created between ecological, economic and social classes. The goal of this study is to measure and evaluate watershed sustainability. In order to evaluate sustainability in Zidasht basin 1, an ecosystem approach has been used to create balance between three categories of economic, social and ecosystem. Selective variables were obtained by common assessment methods. The IUCN method was used to analysis and evaluate the sustainability of the study basin. By and large, two subjects of human welfare and ecosystem sustainability are dealt with within IUCN approach. Two criteria, six indices and 28 variables were measured in human welfare section and also four criteria and 10 indices and 35 variables were evaluated in ecosystem sustainability section. Above mentioned indices measurement using software Wellbeing Score has scored based on intervals 0-100.finall indices and criteria Arithmetic Mean method integration was completed and map was developed in GIS. Final scores for ecosystem and social and economic issues were derived equal to 51 and 49, respectively. Final results of this study based on the Barometer of Sustainability showed that sustainability of Zidasht 1 basin is moderate. This situation can be improved by ecosystem conservation and people life style quality enhancement.

The fire as one of the ecological factor has positive or negative effects on ecosystems components. Therefore, this study was evaluated the effect of fire on some soil physico-chemical properties in winter rangelands of Behshahr. So that two burned sites were selected in rangelands and changed rangelands to wheat and barley with two control areas (unburned) in each of them. The soil sampling was done by three transects (100m) with ten sample points in random-systematic method (total 30 samples in each area). Soil samples were taken in 0-15cm depth. The soil physico-chemical properties such as bulk density, moisture, texture, potassium, phosphorus, nitrogen, calcium carbonate, organic carbon, acidity and electrical conductivity were measured in lab. Finally, the data was analyzed by paired t-Test in SPSS19 Software. The results showed that the fire in rangelands had significant effect on moisture (P≤ 0.01) and organic carbon (P≤ 0.05) reduction but P (P≤ 0.01), K, EC and pH (P≤ 0.05) have been increased. While K had significant increase (P≤ 0.05) and moisture had reduction (P≤ 0.01) in changed rangelands. Generally the results showed that soil chemical characteristics in natural ecosystems had clear and more specific reaction against the fire in comparison to changed rangelands. Also according to the results, it is necessary to manage intensity and time of fire to control the fire next effects.

Sustainable development is a comprehensive approach to improve Human life quality to meet economical, social and environmental needs of anthropological residents. When sustainable development is achieved an overlapping is created between ecological, economical and social classes. The most principle goal for this research is to determine sustainability criteria and indices and to measure sustainability. The first approach was obtained from, watershed and range management projects monitoring and evaluation monitoring instructions provided by president strategically supervising planning assistant and range and watershed management, forest organization for Iran. As a whole in rangeland ecological section, three criteria, nine indices and fourteen variables were evaluated. In economical and social issues section 5 criteria and 16 indices were evaluated (indices served as variables by themselves) in respect to total Zeidasht watershed score, this watershed is categorized in too poor sustainability class. The second method to analysis and evaluate sustainability in interested basin has been IUCN. This method simultaneously considers ecosystem and anthropological issues. Two criteria, six indices and 28 variables were measured in human welfare section. In ecosystems sustainability four criteria and ten indices and 35 variables were evaluated. Final indices and criteria integration was completed and map was developed in GIS. Final score for ecosystem and social and economical issues were 51 and 49 respectively. Final results the Barometer of Sustainability showed that Zeidasht 1 basin sustainability is moderate. This situation can be improved by ecosystem conservation and people life style quality enhancement.