Authors: Nina Hewitt*, University of British Columbia
Topics: Biogeography, Earth Science, Anthropocene
Keywords: plant dispersal, species migration, range shifts, climate change, alpine species, ecosystem fragmentation
Session Type: Paper
Start / End Time: 8:00 AM / 9:15 AM
Room: Virtual Track 11
Presentation File: No File Uploaded
Climate change is expected to rapidly alter the distribution and quality of plant species’ suitable habitat, and to force upslope and poleward range shifts to occur at unprecedented rates. Conditions will vary between mountainous and “flat”, continental, landscapes. In alpine areas, upslope shifts in habitable ranges will occur over potentially short distances, but will move species toward “habitat-end”, the mountain tops. In flat landscapes, migration will need to occur across extensive distances in order to track shifting habitat, presenting major dispersal barriers. This study compared these constraints on climate change-induced plant migration in 1) high alpine ecosystems of the Central Karakoram-Himalaya in Pakistan and 2) Eastern Deciduous Forests in Southern Ontario, drawing on our own field and modelling data in these ecosystems. My team found that alpine species’ ranges were organized into narrow elevation zones, suggesting that upper alpine species will experience a compression and local disappearance of habitat as upslope migration occurs. Additionally, evidence suggested that upper alpine species were also regionally rare, and therefore risk extinction as their local habitat disappears. Meanwhile, in Eastern Forests we found that many tree species had strong dispersal and migration limitations over landscape scales. These species face the combined risks of migration over long distances required to relocate ranges under rapid climate change scenarios, and across intensively human-settled and fragmented continental landscapes. I consider implications for climate change adaptation policy, including policy of assisted migration, in response to these variable constraints.