Professor of Biological Sciences Brock University St. Catharines, Ontario, Canada
Although the creation and use of landfill sites necessitates considerable environmental damage, habitat restoration and naturalization of closed landfills has the potential to provide protected habitat for bees and other organisms for the foreseeable future. The Brock Bee Lab has monitored bee abundance at three landfill sites, one restored in 2003 and two restored in 2011, mainly using pan traps to mitigate variation in collection effort that would produce biased estimates of annual variation in abundance. Following closure and initial landscape naturalization, bees, in particular ground-nesting species, rapidly repopulated restored landfill sites, with bee abundance in restored sites surpassing abundance in control sites within three years. Over the longer term (12-20 years), abundance trends at widely separated sites converged to similar patterns, suggesting that regional weather and climate patterns are a major regulator of abundance in the ground-nesting bee assemblage. This suggests that restored landfill sites can become important refuges for native bee species, preserving bee diversity even landscapes highly impacted by anthropogenic activities.