Assisted Migration and Plant Invasion: Importance of Belowground Ecology in Conifer Forest Tree Ecosystems

This paper reviews and discusses the main features of biological invasion by plants and the assisted migration theory referencing a critical common factor —belowground ecology. The risk of a plant becoming invasive, and the potential failure of assisted migration programs depend on the presence or absence of soil microorganisms that regulate key ecosystem processes and mitigate adverse environmental conditions. This biotic interaction should be considered in the selection of sites for afforestation programs since it is as important as temperature and precipitation in decisions regarding conservation and assisted migration practices in response to climate change. Fungal species should be determined and included in climate change mitigation programs to avoid disease outbreaks and ensure the presence of beneficial mutualistic species in sites selected for assisted migration. Plants considered for assisted migration should pose a low risk of becoming invasive for having establishment difficulties per se. However, the real threat is that they may displace other species, introduce pathogens, or trigger disease outbreaks in introduction sites that nullify assisted migration efforts.