مجله بوم شناسی کاربردی
پیاپی 28 (تابستان 1398)

Currently, conservation planning based on the future distribution of species is among the most important adaptive conservation approaches to reduce the  negative impacts of climate change on species. In this study, by adapting an ensemble modelling approach, scenarios of RCP 2.6 and RCP 8.5 and five global circulation models,  the distribution of Goitered gazelle (Gazellea subgutturosa) under climate change was predicted in the central Iran (Isfahan, Semnan, Markazi, Fars and Yazd provinces). In addition, by comparing the current and future distributions, suitable habitats that would remain so in the future with the potential to function as climatic refugia were identified. The results revealed that by 2070, Goitered gazelle will have lost 46% and 70% of its habitats based on RCP 2.6 and RCP 8.5, respectively. Across central Iran, only proportions of habitats in Isfahan and Semnan at higher latitudes were predicted to function as the climatic refugia. Based on RCP 8.5, however, all refugia in Isfahan, except for those in Mooteh Wildlife Refuge, were projected to disappear. According to the findings of this study, expanding the protected network and increasing connectivity in the areas where refugia are distributed, and enhancing the protection status of key no-hunting areas and wildlife refugees are recommended as the management approaches for the effective conservation of this species against climate change.

Spiny and aromatic species in rangelands can play important role in the conservation of plant species in rangelands; however, few studies  have been done on the role of these plants under different levels of livestock grazing. In this research, the facilitation effects of spiny (Astragalus chrysostachys Boiss) and aromatic (Artemisia kopetdaghensis (Poljakov) Y.R.Ling) shrubs were studied on species diversity along a grazing gradient. In 2017, five sites were selected in Baharkish rangelands, Quchan, where the livestock grazing varied from low to very intense. In each site, 30 twin plots were established under a canopy of the nurse shrubs and their nearby open spaces. Density, frequency and canopy cover of all plants were measured within the plots. Species diversity were reduced by increasing the grazing intensity, but it was consistently higher under canopy. In the highest grazing intensities, species diversity was higher under the canopy of Artemisia than Astragalus; however, opposite results were found under the high grazing intensity. In conclusion, in the areas of high grazing (livestock rest points), the aromatic species (Artemisia) may not be protected against livestock grazing, and spiny shrubs (Astregalus and Acantholimon) may still maintain their nursing effects.

Haftad-Gholleh Area has recently encountered many changes. In this study, by using landsat images of the years 1996 and 2016, landuse maps were classified into four classes including: agriculture, rangeland, residential areas, and rocks. Land Change Modeler (LCM) and Habitat and Biodiversity Modeler (HBM) modules in the Idrisi GIS software were used to analyze the land use changes and habitat evaluation for the prediction of  the land uses status in 2016, based on the Artificial Neural Network (ANN), Markov Chain analysis and logistic regression. The results showed that most of the changes in the landscape of the region between 1996 and 2016 were related, respectively, to attrition, aggregation and creation indicators; between the years 2016 to 2041, they can be related, respectively, to the creation and dissection indicators. The habitat evaluation showed that 4.5% of the habitat was decreased in 2016, as compared to 1996. With the continuation of this trend, 6.5% of the habitat will fall in 2041, as compared to 2016. Receiver Operating Characteridtic (ROC) of the model also specified that the desirability model validity was equal to 0.9558, showing the excellent performance of logistic regression method. In general, this can be an important principle approach preventing from changes in the habitat of wild sheep to other land uses.

Today’s situation in cities requires that planned parks be set up to create ecological equilibrium. The current study was  aimed to identify suitable zones for establishing ecoparks in the central region of Isfahan province; this was done using seven effective criteria including topography, landscape, climate, rock and soil, water resources, environmental sensitivity, and accessibility. The weights of the criteria and the subcriteria were obtained using the  analytic hierarchy process (AHP) with expert opinions. All layers were combined using weighted linear combination (WLC) and the land suitability maps for ecoparks were produced. After evaluating and prioritizing suitable zones, finally, the zone with an area of 85.2 hectares, which was located in the Bag Bahadoran district and adjacent to the Zayanderood River, was selected as the most suitable one  due to its larger area, more access to the welfare facilities, and higher ecological potentials. Also, the results obtained from overlaying the ecopark’s land suitability map and the map of existing parks in the region suggested that Sararud coastal park, in Mobarakeh, and the  coastal park, in Zarrin Shahr, can be  suitable places for establishing ecopark in the region.

Changes in the geographical distribution of plants are one of the major impacts of the climate change. This study was aimed to predict the potential changes in the distribution of Artemisia aucheri Boiss in Isfahan rangelands. Therefore, six bioclimatic variables and two physiographic variables were used under the Generalized Linear Model (GLM), Flexible Denotative Analysis (FDA), Surface Range Envelope (SRE), Random Forest (RF), and Multivariate Adaptive Regression Spline (MARS), as well as in an ensemble model framework. Among the environmental factors, the mean temperature of the coldest quarter and the mean annual precipitation played the most important role or exhibited relative importance in model fitting. Based on the model evaluation, the ensemble model and then MARS presented the most accurate prediction in the determination of the climatic habitat. There was also a significant difference between area under curve (AUC) of the SRE model with a good performance and other models with a high performance. The maximum presence of the species occurred at the 2000-3000 m elevation and the 100-250 mm annual precipitation. In both CCSM4 and MPI-ESM-LR climatic models, the highest amount of habitat displacement is likely to happen under the RCP8.5 scenario in 2070, while the lowest amount may happen under the RCP2.6 scenario in 2050. Also, the habitat of species will be displaced more in 2070 than in 2050. The results of this study can be used to prioritize conservation measures or species introduction into areas with similar ecological conditions.

Selecting the appropriate rangeland improvement method is a challenging task for range managers because it requires consideration of  various criteria. This study was  aimed to evaluate various restoration and reclamation practices in the rangelands of Semirom-Isfahan using Multi-Criteria Decision Making (MCDM) methods. Grazing management, water point development, pit seeding, exclosure, water harvesting and planting almond, fertilization and direct cropping of forage were compared using various social, economic, managerial and environmental criteria. These criteria included cost, local conflict, response time, applicability of method, employment, forage production and their effectiveness. The criteria were weighted from 0 to 1 for all rangeland improvement alternatives based on the  results obtained from 30 questionnaires from experts in universities, Isfahan Research and Education Center for Agriculture and Natural Resources, and Natural Resources and Watershed Management Organization of Isfahan. The criteria were ranked based on the Likert method and rangeland improvement alternatives were compared using the MDCM approach and the  Facilitator software. According to the results, grazing management and pit seeding were identified as the best rangeland improvement alternatives, with favorability ranges of 0.54-0.98 and 0.6-0.95 respectively Water resource development had a lower risk of failure with the favorability ranges of 0.55-0.76, as compared to the other alternatives. The results, therefore, indicated that performing water harvesting along with planting almond in this area could be an inappropriate rangeland improvement alternative with the  favorability of less than 0.5, so it should not be implemented in this area.