Nasim Kheirkhah Ghehi; Bahram Malek Mohammadi; Hamidreza Jafari
Abstract
Introduction: Landscape connectivity plays an essential role in the conservation of protected areas. The Alborz wild sheep (Ovis orientalis × Ovis vignei) is the dominant species in Varjin Protected Area. The population of the species has been decreased during the last 20 years due to habitat loss ...
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Introduction: Landscape connectivity plays an essential role in the conservation of protected areas. The Alborz wild sheep (Ovis orientalis × Ovis vignei) is the dominant species in Varjin Protected Area. The population of the species has been decreased during the last 20 years due to habitat loss and fragmentation. So far, many studies have been done on the environmental impact assessment of urban area developments on the protected area, but there is still a lack of habitat connectivity and quality analysis in the area. Based on the spatial location of Varjin Protected Area, connectivity analysis can help conservation planners to identify key patches and corridors that more than others, contribute to upholding species dispersal. The aim of this research is to prioritize habitat patches for conservation by analyzing the connectivity of the habitat patches and considering habitat quality as the second important factor in species distribution. Applying this method could lead to better conservation prioritization between habitat patches.Material and methods: Landsat 7 and 8 satellite images have been used as inputs for the Habitat Quality model and Connectivity analysis. The connectivity metric was analyzed by calculating the probability of connectivity (dPC) and betweenness centrality (dBC) at different spatial scales of landscape and patch. All the analyses have been done in Graphab open-source software using graph theory and applying network analysis containing nodes and edges. The threshold was pre-defined for the species, and all the calculations were based on Euclidian distance. This research used the InVEST Habitat Quality model to analyze the spatial status of habitat quality. Finally, spatial analysis was performed by ArcGIS 10.4 and the maps were classified based on natural breaks.Results and discussion: Results demonstrated that the value of dPC was between 0 to 0.796, and the value of dBC varied from 0 to 7.58E+11. Different importance values have been obtained for all 23 patches. This suggested that patches 1 and 4 showed the highest dBC and dPC metric values. The values of InVEST habitat quality decreased in the south and northeast of the area, respectively, due to proximity to urban areas and other threats. Patches with good performance in improving connectivity and higher habitat quality values were identified. By overlaying the output values of the maps, prioritized patches were recognized and suggested to be placed under protection.Conclusion: Patches with a high level of connectivity and habitat quality were located in the east and southeast of the region. This research has taken a novel step toward conservation by using connectivity analysis and habitat quality as an ecosystem service in protected areas. Landscape and patch scales as two spatial indices can be used in other regions and for other essential species. As the Varjin Protected Area is located between two important ecological areas, Lar National Park and the Central Alborz Protected Area, the priority of patches would be changed by a great extent when taking those areas under consideration.
Leila Rahimi Blouchi; Bahram Malekmohammadi
Volume 11, Issue 2 , July 2013
Abstract
This study has been done to provide a method for vulnerability assessment of wetland ecosystems based on their ecological and hydrological values and threatening factors. At first, wetland values and their threatening factors have been reviewed and rated. Next, the relations between wetland values and ...
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This study has been done to provide a method for vulnerability assessment of wetland ecosystems based on their ecological and hydrological values and threatening factors. At first, wetland values and their threatening factors have been reviewed and rated. Next, the relations between wetland values and their threats have been assessed. By multiplying the scores achieved by all factors studied, the vulnerability of wetland values are calculated, and finally management strategies to deal with the most important threats are presented. Shadegan international wetland, which is located in Khuzestan Province, was chosen as a case study and according to the proposed method was assessed. According to the results of this study, ecological values such as aquatic fauna, aquatic flora, ecologically sensitive areas, wetland biodiversity, and hydrological values such as hydrological stability, storing the overflow water and preventing from flooding are the most important wetland values that are exposed to threats such as variation of hydrological regime due to upstream activities, inflow industrial contaminants to the wetland, indiscriminate exploitation of the vegetation and aquatic resource of the wetland and land use change in wetland habitats to agricultural land. By developing vulnerability assessment for Shadegan Wetland, the most effective strategies in the ecosystem approach for the best management were presented.
