Semi-natural habitats and their contribution to crop productivity through pollination and pest control: a systematic review

Abstract

Context: Semi-natural habitats (SNHs) play a vital role in delivering key ecosystem services, such as crop pollination and biological pest control, which are essential to support agricultural productivity. However, the evidence of the economic benefits of SNHs is scattered, and their impacts on productivity in agricultural landscapes are not well understood, limiting their adoption and integration into farming practices and agricultural policies. Objectives: In this study, we qualitatively assess the benefits of SNHs for pollination and biological pest control, as well as their translation into economic outcomes. Our objective is to determine whether the spatial scale of the study and the type of metrics used influence the relationship between SNHs and productivity. Methods: We conducted a systematic review and identified 68 peer-reviewed studies from which we extracted 355 relationships that evaluated the effects of SNHs on productivity. For each relationship, we identified the spatial scale (local or landscape) and the metrics used to measure productivity, pollination or pest control. We conducted a qualitative analysis of the relationships and categorized them as positive, negative, or no evidence for a relationship based on the results reported in the primary studies. Results: We found that SNHs typically enhance pollination and pest control, with 70% of studies reporting a benefit for diversity of pollinators, flower visitation rates and pest predation. However, the link between SNHs and ecosystem services did not consistently translate into increased productivity. Increase in pollination supply translated into higher productivity when indirect metrics (e.g., flower visitation rate) were measured. In contrast, pest control benefits were largely confined to reductions in pest pressure, with limited evidence of increases in productivity. Importantly, the economic benefits and costs of reallocating land for SNHs remain underexplored, with only 15% of relationships addressing these aspects. Conclusions: Understanding ecosystem service provision and productivity is challenged by the variability in measures used, mismatches in scale across studies that limit the comparability, and a limited availability of economic data. Advancing this field will require the development of standardized measures that effectively connect biodiversity enhancements with economic outcomes, facilitating quantitative analysis to improve policymaking and the integration of SNHs into sustainable agricultural practices.