Analysis of the temporal and spatial dynamics of landscape patterns and hemeroby index of the Ebinur Lake Wetland Nature Reserve, Xinjiang, over the last 40 years

Abstract

Wetlands are an important part of ecological systems. Wetlands not only provide the survival habitats and resources for plants, animals, and human but also are highly beneficial for the environment. In arid zones in particular, wetlands have received considerable scientific attention. The hemeroby index provides a measure of the magnitude to which the vegetation of an ecological environment deviates from the natural state as a consequence of human activities. It is beneficial to manage rationally for economic development in order to protect the ecological environment. The present study fills a gap in our understanding of the sustainable development of the wetland ecosystem in the Ebinur Lake Wetland Nature Reserve, Xinjiang Uyghur Autonomous Region, China. A hemeroby-type classification system for the Ebinur Lake Wetland Reserve was established based on multiple datasets, including Landsat MSS/TM/ETM+/OLI image data obtained in 1972, 1998, 2007, and 2013. The study explored the spatiotemporal dynamics of hemeroby and the landscape pattern response through hemeroby, landscape pattern, spatial patch, and GIS spatial analyses in the study area. The following results were obtained: (1) From 1972 to 2013, the ecological hemeroby degree for the Ebinur Lake wetland showed a relatively stable trend; however, there were marked changes in its spatial distribution. The distribution of the partially disturbed type of wetland has obviously changed. This indicates that the degree of naturalness of wetland vegetation is unstable and susceptible to human interference in this area. There was a high conversion rate of different hemeroby index (HI) types from 1972 to 2013. Dynamic changes in hemeroby degree are more likely to be attributed to natural, human, and policy-driven forces that result in a comprehensive effect. During the period 1972-2013, changes in natural factors (mean annual evaporation, temperature, and precipitation) and human factors (livestock, population, and GDP) led to change in the distribution of vegetation and Ebinur Lake area, which influenced the degree of naturalness of the ecological system. (2) During the period 1972-2013, there were significant increases in four landscape pattern indices, edge density (ED), mean shape index (MSI), area-weighted mean patch fractal dimension index (AWMPFD), and landscape division (DIVISION). However, in 2013, the regional landscape index was relatively stable. (3) High values of ED and AWMPFD were recorded for areas with a high HI. This shows that landscape patch fragmentation and complexity is higher in areas with a high HI, and that the degree of naturalness is unstable. Low values of patch fragmentation and complexity are mainly concentrated in areas with a low HI. This indicates that landscape pattern indices and the HI have good consistency and correlation with regard to spatial distribution. The HI was positively correlated with DIVISION, AWMPFD, MSI, Shannon’s diversity index, patch richness density, and ED, in a decreasing order of influence. Evaluation of the ecological environment of the Ebinur Lake region provides a practical reference for the protection of the natural environment and resources, and will prove beneficial for the coordinated management of the environmental for sustainable development.

Publication Title

Shengtai Xuebao

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