灾后生态恢复评价研究进展

Research advances and prospects of post-disaster ecological restoration assessment

灾后生态恢复评价是恢复生态学重要研究方向之一,从20世纪90年代开始,随着研究手段和防灾减灾意识的提高逐渐成为研究的热点。灾害生态恢复评价以森林火灾、地震及地质灾害、旱灾、采矿及地面沉降、火山喷发、飓风6大灾害为主要研究领域,以不同时间序列生态系统演替、不同条件下受灾生态系统恢复效果差异性和相关性分析以及受灾生态系统生态恢复趋势预测为研究内容,针对退化生态系统的结构、功能、过程进行评估和鉴定。当前,灾害生态恢复评价采用的指标包括遥感和地面两大类,方法分为单因子对比法、综合指数法、模拟预测法、反推法。针对灾后生态恢复评价指标缺乏系统性、参照系过于单一性以及对灾区后续恢复指导性不强等问题,未来应在技术框架流程、指标体系分类归纳、生态恢复标准阈值制定、以及生态恢复评价应用等方面加强研究,以体现灾后生态恢复评价评估结果的科学性、客观性以及对生态系统管理的作用。

Post-disaster ecological restoration assessment as one of the key research directions of restoration ecology assumes, with reference to specific goals and systems, the role of assessing and appraising the change of structure, function, quality, health and safety of damaged or degraded ecosystem during the restoration succession, after an interval of certain time following natural or induced disaster. It is inevitably the requirement for determining the degree of ecosystem restoration, testing the effect of restoration pattern and screening out the feasible ecological restoration project. Ever since the 90s of the last century, it has by no means halted at any occasions in enticing the attention more than ever from the research fellows, in parallel with the improvement of research methods and hiked public awareness of necessity of disaster prevention and mitigation. Post-disaster ecological restoration assessment is conducted mainly towards highly frequent disaster with severe ecological damage, covering six major types of disasters, namely forest fire, earthquake and geological disaster, drought, mining and ground subsidence, volcanic eruption and hurricane. Research content extends to three aspects, i.e. ecological succession under various time series, differentiation and correlation analysis on restoration effect of the affected ecosystems under various conditions and trend prediction of the ecological restoration of the affectedecosystems. Based on various indices of the reference systems, the assessment indices could be categorized as two parts ： 1 ） the remote sensing indices based on pre-disaster reference systems, such as NDVI, vegetation coverage, leaf area index, land use type and landscape pattern indices, etc. ; 2） ground indices based on unaffected reference systems or on restoration property, such as species composition, biomass, species richness, thickness of trees and shrubs, tree height and DBH, and soilindices in terms of soil moisture, pure soil composition, organic carbon and nutrient （N. P, Ca and K）content, etc. Presently there are four key assessment methods, which are single factor comparison method （ comparison of time series between vegetation and soil factors）, comprehensive index method （ comparison of ecological safety, health and stability before and after disaster）, simulation method （cellular automata model and Markov chain intended to simulate and predict dynamic changes of damaged ecosystem） and inverse method （ assessment of the effect of disaster prevention and mitigation intended to reconstruct the ecological restoration condition）. In wake of the problems like absence of overly unitary reference system and inefficacy in guiding the subsequent restoration of the disaster systematic feature, areas, prospective researches on technical framework process, classification and induction of index system, formulation of the ecological restoration standard threshold and application of ecological restoration assessment should be revved up for the good of showcasing the scientific and objective features of the assessment conclusions and of rendering the boost to the ecosystem management.