A Greener World May Hold Red Flags for Woodland Caribou

Authors
Kurt Illerbrun
Date:
2021

A recent publication in Proceedings of the Royal Society: B shows that species like Woodland  Caribou (Rangifer tarandus caribou) are not expected to do well in a “greener” world. Globally, climate change and habitat alteration are increasing primary productivity - an increase in vegetation in this context - in a process that is often termed “global greening.” While these changes may benefit some species, they can harm others. Researchers from across western Canada, led by a team from the Alberta Biodiversity Monitoring Institute’s Caribou Monitoring Unit, studied links between habitat alteration (e.g., forest harvesting), primary productivity, moose, wolves, and caribou across the Canadian boreal forest. While other studies have looked at subsets of these factors, this one is unique in its attempt to tackle them together. The result is a study that considered multiple levels of the food web, from plants to herbivores to carnivores, across 600,000 km2 of British Columbia, Alberta, Saskatchewan, and the Northwest Territories. 

Of all the relationships the researchers tested between factors, the most supported findings were:
●    habitat alteration such as forestry leads to higher primary productivity (that is, more shrubby vegetation);
●    increased vegetation increases moose densities because their preferred food is more available;
●    increased moose density supports a greater density of predators such as wolves in the area; and
●    more wolves leads to declining caribou populations.