Grassland management and wild bee biodiversity: conservation lessons from native and non-native systems in southern Ontario

Pollinator declines are occurring globally, threatening wild bee species critical to the pollination of crops and wild plants. In North America, grasslands have historically supported species rich and diverse pollinator communities, but widespread habitat loss and degradation have greatly diminished their extent in the landscape. Managing remaining grasslands, including both native prairies and non-native pastures, offers opportunities to support pollinator biodiversity within agricultural landscapes. This literature review explores how grassland habitat type and management practices influence wild bee biodiversity, using Southern Ontario as a case study. Here, we examine regional grassland change, explore the effects of grazing and restoration practices on pollinator biodiversity, and highlight conservation programs (such as the Alternative Land Use Services and Grasslands Stewardship Initiative) that promote pollinator-supportive landscapes. The review synthesizes evidence from global and local sources to assess the ecological trade-offs and conservation potential of native and non-native grasslands. We emphasize the importance of integrating incentive-based management and targeted restoration across working lands to enhance habitat availability. Finally, we outline key research needs for advancing pollinator conservation and supporting sustainable agricultural systems in Ontario and beyond.