西北干旱荒漠区排矸平台不同配置与保育模式重建植被生态能值分析

Ecological emergy analysis of vegetation reconstruction based on different configuration and conservation models of waste dump platform in arid desert area of northwest China

通过多维度探索排矸平台区植被恢复与重建初期植物群落稳定性、系统自组织能力、环境承载力及可持续发展能力,为构建费省效宏的西北干旱荒漠区排矸平台植被配置与保育模式提供技术支撑。以排矸场平台区4种植被配置与保育模式(乔灌草(M1)、灌草(M2)、观赏型灌草(M3)和灌木林(M4))为研究对象,以人工播种(柠条、沙蒿、苜蓿)后未采取任何保育措施的近自然恢复模式(CK)为对照,利用普通生态学方法分析不同植被配置与保育模式的群落组成、物种重要值、物种多样性的变化,分析恢复初期植被群落结构特征,利用能值法分析各配置与保育模式的系统环境经济效益。结果表明:(1)4种植物配置与保育模式植物种类组成均增加,表现出较高的物种多样性。其中,M3>M1>M2>M4>CK;(2)购买能值在能值投入结构中占主导地位,4种模式的可更新资源利用程度均低于CK(99.86%);M1的不可更新资源利用率最高,为29.52%;(3)不同植被配置与保育模式能值指标相比,M1的净能值产出率(EYR)和能值自给率(ESR)高于其他模式,在生产效率方面具有最大优势,独自发展能力较强。M3的能值投资率(EIR)和系统可持续发展指标(EISD)高于其他模式,环境负载率(ELR)低于其他模式,表明M3的经济发展水平较高,对环境的依赖程度低,产生的压力较小,具有一定的可持续发展潜力;(4)从群落特征结构、系统经济发展水平、对环境产生的依赖程度和可持续发展能力方面考虑,M3为最优模式;从对生产效率、独自发展能力方面考虑,M1为最优模式。

Nowadays, coal mining activities remain of great environmental concern because of several negative impacts on soil ecosystems. At the same time vegetation restoration in coal mining area is getting more and more concern in China. This study aimed at building a cost-saving and effective gangue platform vegetation allocation and conservation mode in the northwest arid desert area of China, plant community stability, system self-organization capacity, environmental carrying capacity and sustainable development capacity in the initial stage of vegetation restoration of gangue platform area were explored multi-dimensionally. Four types of vegetation allocation and conservation mode including arbor shrub grass(M1), shrub grass(M2), ornamental shrub grass(M3), and shrub forest(M4) in the gangue platform area were taken as the study objects. Artificial seeding of Caragana korshinskii, Artemisia sphaerocephala and Medicago sativa in the gangue platform without taking any conservation measures pattern was the near-natural restoration mode(CK, control). The community composition, species importance value, and species diversity changes of different vegetation disposition and conservation modes were analyzed using common ecological methods. The characteristics of vegetation community structure at the initial stage of restoration were also analyzed. The environmental and economic benefits of each mode system were calculated by emergy method. The results showed that:(1) The plant species composition of the four plant disposition and conservation modes increased, presenting a high species diversity. Species diversity followed the order as M3>M1>M2>M4>CK.(2) Purchased emergy dominated the emergy input structure. The utilization of renewable resources of the four modes was lower than that of CK(99.86%) and the utilization of non-renewable resources of M1 was the highest(29.52%).(3) Compared with the emergy indicators of different vegetation configurations and conservation modes, M1′s net emergy yield rate(EYR) and emergy self-sufficiency rate(ESR) were higher than others, which had the greatest advantage in production efficiency and a strong independent development ability. The emergy investment rate(EIR) and system sustainability index(EISD) of M3 were higher than other modes, and the environmental load rate(ELR) was lower than other modes, indicating that M3 had a high level of economic development and low dependence on the environment. The pressure generated was small and had a certain potential for sustainable development.(4) M3 was the best mode in terms of community characteristic structure, system economic development level, dependence on the environment and sustainable development ability. M1 was the optimal mode in terms of production efficiency and independent development ability.