As one of the key tools for regulating human-ecosystem relations, environmental conservation policies can promote ecological rehabilitation across a variety of spatiotemporal scales. However, quantifying the ecological effects of such policies at the regional level is difficult. A case study was conducted at the regional level in the ecologically vulnerable region of the Loess Plateau, China, through the use of several methods including the Universal Soil Loss Equation (USLE), hydrological modeling and multivariate analysis. An assessment of the changes over the period of 2000–2008 in four key ecosystem services was undertaken to determine the effects of the Chinese government's ecological rehabilitation initiatives implemented in 1999. These ecosystem services included water regulation, soil conservation, carbon sequestration and grain production. Significant conversions of farmland to woodland and grassland were found to have resulted in enhanced soil conservation and carbon sequestration, but decreased regional water yield under a warming and drying climate trend. The total grain production increased in spite of a significant decline in farmland acreage. These trends have been attributed to the strong socioeconomic incentives embedded in the ecological rehabilitation policy. Although some positive policy results have been achieved over the last decade, large uncertainty remains regarding long-term policy effects on the sustainability of ecological rehabilitation performance and ecosystem service enhancement. To reduce such uncertainty, this study calls for an adaptive management approach to regional ecological rehabilitation policy to be adopted, with a focus on the dynamic interactions between people and their environments in a changing world.
Restoring disturbed and over-exploited ecosystems is important to mitigate human pressures on natural ecosystems. China has launched an ambitious national ecosystem restoration program called Grain to Green Program (GTGP) over the last decade. By using remote sensing techniques and ecosystem modelling, we quantitatively evaluated the changes in ecosystem carbon sequestration since China's GTGP program during period of 2000–2008. It was found the NPP and NEP in this region had steadily increased after the initiative of the GTGP program, and a total of 96.1 Tg of additional carbon had been sequestered during that period. Changes in soil carbon storage were lagged behind and thus insignificant over the period, but was expected to follow in the coming decades. As a result, the Loess Plateau ecosystem had shifted from a net carbon source in 2000 to a net carbon sink in 2008. The carbon sequestration efficiency was constrained by precipitation, and appropriate choices of restoration types (trees, shrubs, and grasses) in accordance to local climate are critical for achieving the best benefit/cost efficiency.
Facing the need for transdisciplinary research to promote ecological restoration that achieves both social and ecological benefits, research on past restoration efforts that have directly or indirectly contributed to regional or national sustainable development warrants reassessment. Using China as an example, in this review, we address three basic research questions that can be summarized as follows: ecological restoration—of what, for whom and to what purpose? Accordingly, a ‘landscape pattern—ecosystem service—sustainable development’ co-evolutionary framework is proposed here to describe landscape-scale ecological restoration and its impact on landscape patterns and ecological processes, ecosystem services for human well-being, sustainable livelihoods and socioeconomic development. From the strategic pattern of national ecological security to the pattern of major projects to protect and restore major national ecosystems, the spatial pattern of China's ecological restoration is more geographically integrative. From major function-oriented zoning to systematic ecological protection and restoration, and for the purpose of achieving the Beautiful China Initiative, there are three stages of ecosystem services management: classification, synergy and integration, respectively. The difference in geographic processes should be considered in the key requirements of ecological restoration for China's five national strategies for regional sustainable-development strategies. Deepening understanding of the relationship between humans and nature in different geographical contexts is a scientific prerequisite to support policymaking related to ecological restoration. To promote greater harmony between humans and nature, we propose four important research directions: (i) understanding coupling processes among key components, (ii) identifying ecosystem service flows, (iii) evaluating social-ecological benefits and (iv) supporting adaptive management for regional sustainable development.