Evaluation of forest ecosystem health in the Iril Watershed, Ardabil Province

Jafari, Aniss and Keivan Behjou, Farshad and Mostafazadeh, Raoof (2017) Evaluation of forest ecosystem health in the Iril Watershed, Ardabil Province. Masters thesis, University of Mohaghegh Ardabili.

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Text (ارزیابی وضعیت سلامت اکوسیستم جنگل در حوزه آبخیز ایریل، استان اردبیل) Aniss Jafari.pdf Download (499kB) | Preview

Abstract

Assessing ecosystem health to monitor the degradation of natural resources and exploring the causes of degradation is considered as an effective step in management and utilization of ecosystems. Recently, the need to provide comprehensive indicators for assessing the current status of ecosystem and predicting future scenarios has become especially important. In this regard, the ecosystem health index is presented to evaluate ecosystem health. In this study, the ecosystem health index was calculated by considering vigor, organization and resilience criteria in sub-watersheds of Iril watershed in Ardebil province. The aim of this study was to evaluate the factors affecting the health of ecosystems comprehensively, considering three main landscape characteristics including: vigor, structure, and resilience in the iril watershed, Ardebil province. In this regard, the values of vigor (NDVI, erosion and runoff), were quantified. The TerSet software was used to obtain the NDVI values through band combinations, and the EPM and SCS models were used to erosion and runoff estimation. The landscape structure (continuity, degree of division, patch density and density edge) and resilience (different landuse classes, the largest patch index and aggregation index) were quantified using the Fragstats Software. The results were compared using radar charts among different multidimensional components through sub-watershed of study area. The ecosystem health index was then evaluated using different weightING approaches. In the next step, different sub-watersheds were prioritized according to different weights to each criterion. According to the results of vigor component, the S8 and S1 sub-watersheds had the highest 0.89 and 0.13 scores, respectively. The S7, S2 and S3 sub-watersheds had a favorable condition in terms of structure, having 0.73, 0.63, and 0.63 scores, while the other sub-watersheds had not a good condition. The resilience index values of S1, S3 and S8 sub-watersheds are more than other parts of the study area. In summary, the results showed that the highest variability is related to resilience component over the study area. Based on the results, the average value of the vigor, structure, and resilience components were calculated to be 0.40, 0.55, and 0.55, respectively, and the S1 sub-watershed had the highest average value of calculation indices in the study area. The results also showed that the ecosystem health index varies in different weighting approaches in range of 0.32 to 0.79 in the studied sub-watersheds. Based on the equal weighting to the ecosystem health index, the S5 sub-watershed with the value of 0.34 had the lower health status and S1 sub-watershed with a value of 0.77 had the higher health status than the other sub-watersheds in the Irish watershed. The average value of the ecosystem health index over all sub-watersheds was 0.50, which is relatively undesirable according to the classifications of ecosystem health status. Considering the multidimensional nature of the ecosystem health index and taking into account all the factors affecting ecosystem restoration or destruction as well as economic and social characteristics, it can be a useful tool in prioritizing critical areas as an effective step in ecosystem management. The ecosystem health index indicates the combined effect of factors affecting ecosystem degradation and regeneration, which allows the prioritization and compilation of management decisions for different regions. In codusion, the ecosystem health degree of the Iril watershed was assessed as undesirable (exept the forested sub watershed according to the used indices).

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