Land-use change and forest programs in low- and middle-income countries: updating the evidence gap map (Evidence gap map report 29 January 2024) – World
In the context of increasing global greenhouse gas emissions, agriculture, forestry and other land use sectors continue to contribute a significant proportion of these emissions, mainly due to deforestation. International coordination and financing efforts continue to develop mitigation and adaptation strategies to climate change. To inform policy makers of the latest evidence on the impacts of programs and policies that address land use change and forests, this informal plenary meeting updated the evidence in the Evidence Gap Map (EGM) 3ie published in 2016. Seven years later, the evidence base in this The area has increased significantly, especially in light of the enhanced investments in this sector and the urgent need to find solutions to reduce emissions and reduce deforestation.
By mapping the evidence published since the original EGM, we aimed to identify lessons learned in sector effectiveness, highlight areas of land use and forestry that remain or have become understudied, and facilitate critical thinking about assessment methods used in the field. We have updated the EGM by reiterating the range of interventions used in the original map, which aims to identify programs and policies that are likely to have an impact on greenhouse gas emissions. These interventions are grouped into five categories: area protection and management; law and policy relating to forests and other lands; incentives; training, education and information to promote sustainable practices and technology; And infrastructure. We focused on the average, environmental and human well-being outcomes reported in these studies.
We conducted the search in February 2023 and identified 176,240 records from seven databases and nine gray literature sources. After using machine learning to prioritize screening of these records, we ultimately included 557 impact evaluations and 39 systematic reviews. The volume of evidence has increased significantly since the original map: 63% of the studies in the map were identified in the update search, highlighting the interest in understanding land use and forestry challenges.
Key trends from the original map remain: 85% of studies remain focused in sub-Saharan Africa, Latin America and the Caribbean, and East Asia and the Pacific. Likewise, there are still few studies evaluating interventions in the MENA region. The countries with the largest number of studies are China, Brazil, Ethiopia and Indonesia. Protected areas, community-based/decentralized forest management, payment for environmental services, agricultural extension and training remain the most common interventions, covering 58% of the evidence. Likewise, forest coverage, income and household expenditure remain the most common metrics, accounting for 49% of the results in the map.
The body of evidence still relies heavily on the use of quasi-experimental designs, especially matching techniques. More than half of the random evaluations focused on subsidies, grants, concessions, agricultural extension and training. A third of the studies relied on the use of geospatial data, and their publications were concentrated in the last five years.
Systematic reviews have nearly doubled in this period; However, 72% of reviews were rated as having low confidence, meaning their findings were likely to have a high risk of bias. Some key lessons learned from high- or medium-confidence reviews include that small-scale, short-term agricultural field schools can be effective in promoting sustainable management practices but may not be appropriate for large-scale contexts; The transition from extended fallow tillage to other land uses can have negative impacts on farmers and ecosystem services; Providing land titling for smallholders can increase investment, agricultural productivity and farmers’ income, especially in Latin America and Asia; Protected areas can be effective in conserving tropical forests, but evidence is insufficient to generalize policy recommendations to other regions.
The lack of high-quality tuning is one of the main consequences of this EGM update. Increased production of primary evidence should be accompanied by synthesis efforts that follow standards for conducting and reporting reviews. These systematic reviews have emphasized the need to incorporate rigorous evaluation into the program design phase and coordinate efforts to produce high-quality, comparable studies, including testing different versions of programs, using common outcome measures, and adhering to reporting standards.