基于“目标-成本-效益”协同优化的山水林田湖草沙一体化生态保护与修复格局

当前以“山水林田湖草沙一体化保护与修复”为代表的国土空间生态修复工程已在全国范围内陆续开展,但相关规划的理论和方法支撑仍较为薄弱,如何确定合理的保护修复目标,并对生态保护与修复格局进行整合优化,是实现山水林田湖草沙一体化保护与修复规划需要解决的关键问题。基于系统保护规划理论和方法,初步构建了基于“目标-成本-效益”协同优化的一体化保护修复规划构架,以大兴安岭中段嫩江-哈拉哈河源头区为例,依托空间优化模型(Marxan)对一体化保护修复格局进行了优化模拟,结果表明：(1)绰尔河流域的生态系统保护优先级最高,其次是哈拉哈河流域和洮儿河流域,最后是霍林河流域。当预算不足时,优先保护绰尔河流域可以最大限度的提升研究区内的生态系统服务功能;(2)当优化目标低于50%,优化格局中以林地保护和草地保护为主,需要修复格局规模较小,当优化目标比例超过50%,需要采取生态修复的面积明显增加。随着优化目标比例的提升,优化格局所需面积越来越大,优化后区域中各类生态系统服务功能均有所提高;(3)依据目标-成本-效益曲线,60%的保护修复水平(即1980—2020年退化损失的生态系统服务的60%)为最高效的保护修...

Optimization of integrated ecological conservation and restoration pattern by trading off the targets, costs, and ecological benefits

Although Terrestrial Ecological Restoration (TER) projects have been advocated and carried out across the China''s mainland in recent years, the underlying scientific theory and methodology are still urgently needed to reduce uncertainties in target setting, site selection for conservation & restoration, and cost-benefit evaluation. How to determine reasonable conservation and restoration objectives and to integrate and optimise ecological conservation and restoration patterns are key issues that need to be addressed in order to achieve Terrestrial Ecological Restoration.This paper initially attempted to develop a theoretic and methodological TER framework for integrating conservation and restoration pattern based on the principle of Systematic Conservation Planning, demonstrating by a case study in the central part of the Great Xing''an Mountains. The results show that: (1) The Chao''er River Basin exhibited the highest conservation priority, followed by the Halaha and Taoer river basins, hence prioritizing conservation of Chao''er River Basin could maximize ecosystem services in case of insufficient budget. (2) When the target setting was below 50% (i.e., mitigating 50% of the loss in total ecosystem service during 1980-2020), the prioritized pattern would mainly focus on forestland & grassland ecosystem conservation with a small-scale restoration pattern. With the target level exceeding 50%, the area needed to be restored would increase significantly. With the proportion of targets for optimisation increased, the area required to optimise the pattern became larger, and ecosystem services were improved in the optimised area compared to the current situation.(3) According to the target-cost-benefit curve, the optimized target level was identified at 60% for the ecosystem conservation and restoration in the central part of the Great Xing''an Mountains (i.e., making up 60% of the total ecosystem service lost during 1980-2020). (4) Under the target level of 60%, the cost of conservation and restoration was 5.06 billion yuan, and the ecological benefits generated were 6.64 billion yuan. The prioritized area of forestland, grassland and wetland to be conserved were identified at 20400.27 km², 11919.45 km², and 25.23 km². The prioritized area of forestland, grassland, and wetland to be restored were identified at 272.18 km²,1695.23 km², and 3.71 km², accounting for 40.9%, 23.5%, and 6.3% of potential restorable forestland, grassland and riverine & lacustrine wetlands (i.e., areal loss between 19802020), respectively. Based on trading off "target-cost-benefit", this integrated conservation and restoration planning provides an operational framework to measure priorities between conservation and restoration actions, and highlights the necessity to optimize allocation of limited resources by integrating the two approaches cost-efficiently.