山西省自然保护区生态系统格局及稳定性变化趋势研究

掌握自然保护区生态系统格局信息,对于摸清生态环境现状,评估保护成效,进而提出保护对策具有重要的意义。论文以2000和2010年为时间点,利用生态系统转移矩阵和正向逆向转换指数（Positive and Negative Transformation Index,PNTI）模型分析山西省自然保护区生态系统格局转换趋势,并运用Shannon-Wiener多样性指数和净初级生产力（Net Primary Productivity,NPP）分级标准分析生态系统稳定性变化特征。结果表明：山西省自然保护区以森林生态系统为主,其次为草地生态系统和耕地生态系统;2000—2010年间,保护区生态系统格局朝着有利的方向发展,生态系统阻抗稳定性和恢复稳定性也呈增强趋势;保护区植被生长状况得到了较好的改善,且森林生态系统保护区的保护作用最为突出,其他保护区生态系统稳定性较弱,尤其需加强对野生动物保护区的管理与修复。

Study on the Change Trend of Ecosystem Pattern and Stability of Nature Reserves in Shanxi Province

Knowing the ecosystem pattern of nature reserves is of great significance to the understanding of the status of the ecological environment, the valuation of the protection effect, and the proposal of protective measures. In this paper, the transition trend of ecosystem pattern of nature reserves in Shanxi during 2000-2010 was analyzed with ecosystem transfer matrix and the Positive and Negative Transformation Index (PNTI) model, and the stability of ecosystem was analyzed with Shannon-Wiener diversity index and Net Primary Productivity (NPP) grading standard. The results showed that: 1) Forest ecosystem was the main ecosystem in the nature reserves in Shanxi, followed by grassland ecosystem and farmland ecosystem. From 2000 to 2010, the area of forest ecosystem increased, while the area of grassland ecosystem and farmland ecosystem decreased. 2) During the ten years, the grassland ecosystem had the largest area that transformed into forest ecosystem, which was 1 117.21 km². It was the result of the natural forest protection project, Taihang Mountain greening project and plain greening project in Shanxi. In addition, 49.1 km² farmland ecosystem transformed into forest ecosystem, which indicated that the vegetation was restored and the ecological environment was improved during the ten years. However, due to human disturbance, 466.72 km² forest ecosystem degenerated into grassland, 3.63 km² forest ecosystem and 5.92 km² grassland ecosystem transformed into farmland ecosystem, and 4.18 km² grassland ecosystem became construction land, which indicated that the management and rehabilitation of relevant nature reserves need to be strengthened. 3) The positive conversion rate of nature reserves was higher than the reverse conversion rate, and the ecological system pattern was developing in a favorable direction. The net conversion rate of the grassland meadow reserves, forest ecosystem reserves and wild plant reserves was 29.47%, 8% and 4.04%-7.32%, respectively. However, the net conversion rate of wildlife reserves was less than 1.1%, and the protective effect in wildlife reserves was weak. 4) The diversity index of nature reserves showed an increasing trend, and the stability of ecosystems enhanced. The total amount of NPP in the nature reserves increased from 2.51×10⁷ g C to 2.59×10⁷ g C. In general, the vegetation growth status of the nature reserves improved during the ten years. The average NPP of nature reserves was between 50-100 g C·m^-2·a^-1, belonging to the third-class vegetation NPP according to the NPP classification standard of China, which indicated that the ecosystem restoration stability of the nature reserves was strong. However, the NPP of the wildlife reserves, the wild plant reserves and the grassland meadow reserves decreased, and the stability of restoration in these areas became weak. In summary, the ecosystem structure of the nature reserves in Shanxi Province was developing in a favorable direction, the impedance stability and the restoration stability of the ecosystem were increasing, and the growth of vegetation was improved. The protection of forest ecosystem reserves was the most prominent, while the ecosystem stability of other reserves was weak, especially wildlife reserves, such as Lingqiu Black Stork Nature Reserve and Zezhou Monkey Nature Reserve, where there exited degradation phenomenon of forest and grassland. The management and reparation of wildlife reserves need to be strenghened.