Ecology of Iranian Forest

Extended Abstract

Background: Using landscape metrics allows researchers to quantify spatial patterns of environmental elements and analyze changes in their extent across various scales. This quantitative approach is essential for understanding how landscapes evolve over time, which is crucial for sustainable management and planning practices. The significance of this topic cannot be overstated, as effective landscape management can help mitigate the adverse effects of human activities on natural ecosystems. Therefore, the primary objective of this study is to employ remote sensing techniques to evaluate the efficiency of landscape metrics in analyzing changes in forest areas and land cover within parts of the Northern Zagros forest region. The Northern Zagros region is characterized by its rich biodiversity and ecological significance, making it a vital area for conservation efforts. However, this region has also faced increasing pressures from urbanization, agricultural expansion, and other anthropogenic activities. By employing landscape metrics, this study aims to provide a comprehensive assessment of how these pressures have affected forest cover and land use patterns over time. Understanding these dynamics will facilitate better decision-making in land-use planning and contribute to the preservation of this important ecological zone.
Methods: To analyze land cover changes over time, land cover maps for the years 1998, 2009, and 2020 were created through a combination of supervised classification of satellite imagery, visual interpretation of Google Earth images, and field surveys. The process began with the acquisition of high-resolution satellite images, which were then classified using supervised methods to ensure accuracy. The visual interpretation of Google Earth images complemented this analysis, allowing for ground-truthing and validation of the classified data. The ArcGIS Patch Analyst extension and FRAGSTAT software were utilized to monitor and evaluate various landscape metrics. Nine landscape metrics were selected for this study, including four metrics at the class level: the number of patches (NP), patch density (PD), percentage of each class (PLAND), and area of each class (CA). Additionally, five metrics were calculated at the landscape level: the number of patches (NP), Mean Patch Size (MPS), Shannon Diversity Index (SHDI), Largest Patch Index (LPI), and Continuity (contag). These metrics provide a comprehensive view of landscape structure, diversity, and fragmentation, enabling a detailed analysis of changes over the specified time periods. The data were analyzed to identify trends in land cover changes, focusing on the dynamics of forest areas relative to residential and agricultural land uses. By examining these metrics over time, the study aimed to uncover patterns that indicate the extent of landscape fragmentation and the overall health of the ecosystem in the Northern Zagros region.
Results: The results of the analysis revealed significant changes in land cover over the study period. At the class level, measurements of area and percentage for each land cover type indicated a marked decline in forest area, juxtaposed with an increase in residential and agricultural coverage. Specifically, forest cover decreased from 78.82% in 1998 to 77.36% in 2020, reflecting an annual reduction of approximately 0.066% over the 22-year span. This decline in forest cover highlights the urgent need for effective conservation strategies in the region. During the same period, the data showed an increase in the number of residential patches, rising from 13 to 17, and agricultural patches surged from 19 to 42. In contrast, the number of forest patches decreased from 21 to 18, indicating a trend toward fragmentation of forested areas. The patch density metric further illustrated these trends, showing an increase across all land cover types except for forests, which experienced a decline. Moreover, the survey results indicated an increase in both the number of patches and the Shannon Diversity Index, suggesting greater landscape complexity and diversity. However, there was a concurrent decrease in the Continuity Index, Mean Patch Size, and Largest Patch Size metrics, pointing to increased fragmentation and reduced connectivity among forest patches. These findings underscore the impact of human activities on the landscape, leading to a more fragmented and less cohesive ecological structure.
Conclusion: The findings of this study clearly illustrate the expansion of residential and agricultural areas at the expense of forest cover, indicating a concerning trend in the Northern Zagros region. The reduction of forest areas signifies a loss of ecological integrity, primarily driven by the proliferation of man-made land uses. As urbanization and agriculture continue to encroach upon natural habitats, the fragmentation of landscapes poses significant challenges for biodiversity conservation and ecosystem health. This study emphasizes the importance of utilizing landscape metrics as a tool for monitoring environmental changes and guiding sustainable land-use practices. Future research should focus on developing strategies to mitigate these impacts, promote the restoration of forest ecosystems, and ensure that development efforts are balanced with environmental conservation. By prioritizing sustainable management practices, it is possible to preserve the ecological integrity of the Northern Zagros region while accommodating necessary human activities.