Effective and feasible mechanisms to support native invertebrate pollinators in agricultural landscapes: A meta‐analysis

AbstractPollinator declines have emerged as a major conservation concern across a wide diversity of systems and taxa worldwide. In response to these concerns, active efforts to conserve pollinators are increasingly considered in agricultural landscape design and management, natural area management, and public land decision‐making. An important conservation challenge is translating these efforts to feasible recommendations that agriculturalists across a diversity of systems and contexts can employ to support pollinator communities. In order to develop such a toolbox for agriculturalists, we conducted a meta‐analysis to examine feasible management practices, tools, or decisions, employed in agricultural landscapes, that directly impact pollinator forage and nest site resources. Our search terms netted a total of 743 unique references; from this, we developed a dataset of 209 unique records, derived from 89 unique references, for inclusion in our meta‐analysis. We found that across all treatments aimed at boosting pollinators, there were significant increases in bee abundance, bee species richness, and overall pollinator abundance and visitation rate. We also found specifically that across all study types, the following practices resulted in positive changes in pollinator community responses: reduced distance to natural areas, reduced regional intensity of human modification, increased quantity and quality of pollinator resources within a focal system, plantings adjacent to agricultural areas, and the use of nonconventional agricultural practices. The most consistent pollinator response to treatments was bee species richness, which was significantly increased by plantings adjacent to agricultural areas, distance from natural areas, and quantity and diversity of pollinator resources. Bee species richness also decreased with intensity of human modification. These findings are presented in a toolbox for agriculturalists, containing evidence‐based actions and outcomes to assist practitioners in decision‐making specific to pollinator habitat improvement that could be actionable in the near term.