基于“参照系-现状-变化量”的生态系统评估方法

Research on ecosystem assessment method based on Reference-State-Deviation

生态系统评估是开展生态系统管理的重要手段,其评估结果已成为衡量区域生态系统状况优劣的重要依据。由于没有充分考虑生态系统禀赋的区域差异性,缺乏有效区分气候变化和人类活动影响的手段,导致生态系统评估结果的实用性与区域可比性一直存有争议。在生态大数据背景下,基于生态完整性理论,结合长期地面监测数据、野外调查数据、遥感数据等海量数据,耦合生态系统过程模型,构建了基于“参照系-现状-变化量”(RSD)的生态系统评估体系,以受干扰较少接近原生、完整的地带性植被生态系统(完整的生态系统)作为参照系,其表现出来的组成、结构、功能等特征为参照条件,生态系统状况现状与参照条件的偏离程度作为评估生态系统优劣程度的依据,从而将现状评估转变为变化量评估,增强评估结果的时空可比性。并以生态系统过程模型为工具,利用RSD评估方法评估了中国陆地生态系统生产力功能,验证了该方法体系的可行性。评估结果显示,2000—2018年我国植被净初级生产力(NPP)参照值、现实值和变化量均表现为上升趋势,而NPP现实值与变化量的空间分布存在显著差异,基于RSD的评估方法较好地解决了评估结果区域不可比的问题。研究对完善我国生态系统评估体系,推动生态系统评估结果的实用化,支撑我国重点生态功能区县域考核、生态红线监管、自然保护地体系建设等国家需求具有重要意义。

Ecosystem assessment is vital important to carry out ecosystem management, and its results have become a basis to measure the status of regional ecosystem. Due to the insufficient consideration of the regional differences of ecosystem endowments and lack of effective measures to distinguish the impact of climate change and human activities, the practicability and regional comparability of ecosystem assessment results have been controversial. Under the background of ecological big data, this paper combined with long-term ground monitoring data, field investigation data, remote sensing data and other massive data, coupled with the ecosystem process model, and took the less disturbed, nearly native and integral zonal vegetation ecosystem(integral ecosystem) as references based on the ecological integrity theory. The composition, structure and function of the integral ecosystem were defined as the reference conditions. The deviation between the current and reference state of ecosystem was used to evaluate the ecosystem. An ecosystem evaluation method based on “Reference-State-Deviation(RSD)” was then constructed. The RSD evaluation method could transform the assessment of current state into deviation assessment and enhance the temporal and spatial comparability of the assessment results. Taking the self-developed model, CEVAS-RS model and CEVAS-CLI model as tools, the productivity of terrestrial ecosystem in China was evaluated, and the feasibility of the method was verified. This study is of great significance to improve China′s ecosystem assessment system, promote the practicability of ecosystem assessment results, and support the national needs of China′s key ecological function areas and counties assessment, ecological red line supervision, nature reserve system construction and so on.