China’s conversion of cropland to forest program: a systematic review of the environmental and socioeconomic effects
Farming on sloping lands has historically led to forest loss and degradation in China, which coupled with unsustainable timber extraction activities, was deemed responsible for catastrophic flooding events in the late 1990s. These events led to the introduction of forest policies targeting ecological conservation and rural development in China, a process epitomized by the launch of the conversion of cropland to forest program (CCFP) in 1999. This systematic review responds to the question: What are the environmental and socioeconomic effects of China’s Conversion of Cropland to Forest Program after the first 15 years of implementation?
Based on the published protocol, we searched for English language studies published between 1999 and 2014, and screened them for relevance and eligibility in two stages (titles and abstracts followed by full texts), after which they were further assessed for potential sources of bias before data extraction and analyses. Following initial screening of 879 titles and abstracts, 169 studies underwent full text screening, followed by 61 studies being subjected to quality assessment. Eighteen papers did not meet minimum quality criteria, while the remaining 43 papers were eligible and underwent data extraction and subsequent analyses. Among the final set of 43 studies were four national-level studies, seven regional-level studies, and 32 county-level (or below) studies. The majority of studies were published after 2009 and evaluated impacts within the first 5 years of CCFP implementation, such that the long-term impacts of the program remain open for further investigation.
A skewed temporal and geographic distribution of the examined studies limits the generalizability of the results, though the evidence base confirms a substantial increase in forest cover and associated carbon stocks linked to reallocation of sloping agricultural land to forest. To some degree, soil erosion has been controlled and flood risk reduced at local scales. Meanwhile household incomes have increased and rural employment has readjusted towards off-farm sectors. However, some studies also indicate instances of diminished food security and increasing social inequality. Finally, several studies indicate suboptimal regional or localized trade-offs among specific ecosystem services, including carbon sequestration vs. water discharge rates, flood control vs. riparian soil replacement, and forest productivity vs. biodiversity.
Additional research on long-term environmental impacts and program effects in under-studied regions, particularly southern and western provinces, is necessary. In terms of recommendations for future research on the CCFP, there is a significant need to examine confounding factors, ideally through the selection of matching control groups to CCFP participants, and to ensure that sampling methodologies are more representative of selected study sites and the overall targeted area. There remain many opportunities to assess specific socioecological effects, upon which to base future policy decisions and more broadly inform ecological restoration and eco-compensation in both theory and practice.
Conversion of cropland to forest program, Sloping land conversion program, Grain for green, Upland conversion program, Payments for ecosystem services, Afforestation, Soil erosion, Flooding, Poverty alleviation
Agricultural activities on sloping lands have historically led to forest loss and degradation in China which, coupled with industrial pressures on the environment, were deemed responsible for catastrophic flooding events in the late 1990s. After these events, China’s forest policy underwent a significant reorientation towards ecological conservation and rural development, a process epitomized by the Conversion of Cropland to Forest Program (CCFP). Launched in 1999, the CCFP integrates both socioeconomic and environmental objectives with the aim of reforesting smallholder cropland on sloping lands, while compensating farmers with payments for their lost income. Following 15 years of implementation, it is timely to conduct a comprehensive assessment of the state of knowledge about the CCFP’s impacts on human populations and the environment.
The primary research question asks “What socioeconomic and environmental effects has the Conversion of Cropland to Forest Program had on human populations and land resources during its first 15 years in China?” We use a theory of change and a Population-Intervention-Comparator-Outcome (PICO) framework to structure our systematic review, where populations of interest consist of both human populations and land resources targeted by the program, while the intervention of interest is the CCFP as defined by its component activities, including compensatory subsidies, skill-training, and enforcement with field checks. Outcomes are defined as both the socioeconomic and environmental impacts of the program. We will conduct a search for relevant English and Chinese language literature on Scopus, Web of Science, CAB Abstracts, AGRIS (FAO), and the China National Knowledge Infrastructure. Search results will be screened for relevance in a two stage process (titles and abstracts, followed by full texts) based on predefined eligibility criteria, and then further assessed for potential sources of bias. Extraction of data from those studies that have passed full-text screening will follow a coding protocol based on the PICO framework, and quantitative and qualitative analyses of the extracted data will be conducted and synthesized. Finally, a narrative report will present the findings of the review, alongside a geographic map illustrating the coverage of included studies compared with the actual implementation area of the CCFP.