Food Chain Restoration for Pollinators: Regional Habitat Recovery Strategies Involving Protected Areas of the Southwest

Abstract

The steep declines over the last quarter century of wild pollinators in the Southwest among native bees, monarch butterflies (Danaus plexippus L.), hummingbirds, and nectar-feeding bats have come during a time of accelerated climate change, and are likely due to a variety of stresses interacting with climatic shifts. Nevertheless, there is mounting evidence that declining availability and altered timing of floral resources along “nectar corridors” accessible to pollinators involves climatic shifts as a serious stressor that had been previously underestimated. Longitudinal studies from both urban heat islands and rural habitats in Southwestern North America suggest peak flowering of many wildflowers serving as floral resources for pollinators is occurring three to five weeks earlier in spring than a century ago, leaving “phenological gaps” in nectar resource availability for certain pollinators. To avoid the threat of what A. Dobson (Professor of Ecology and Evolutionary Biology, Princeton University) and others have termed “food web collapse,” a range of groups have initiated ecological restoration efforts in semi-arid zones that attempt to (a) assemble more resilient plant-pollinator food chains, and (b) hydrologically restore watercourses to ensure water scarcity will be less likely to disrupt re-assembled food chains in the face of droughts, catastrophic floods, and other correlates of global climate change. We recommend “bottom-up food chain restoration” strategies for restoring nectar corridors in protected areas on or near geopolitical and land management boundaries in all regions, but particularly in the Southwest or US-Mexico desert border states. We highlight binational and multicultural workshops facilitated to communicate about, and initiate restoration of, mutualistic relationships among plants, pollinators, and people to protected area managers on both sides of the border.