Species at Risk: Our Trees Weren’t Made for Walking
As dire predictions about global warming continue to mount, climate change is already having profound effects in British Columbia's wild places. Our majestic forests – the trademark of our province, both culturally and economically, have not only been ravaged by mountain pine beetle, a blight connected to warmer average temperatures, but also, with less than one degree of global warming, our province’s yellow-cedar populations are declining.
Warmer temperatures produce more rain and less snow during the winter months in British Columbia. Without protective ground snow cover, frost damages the roots of yellow-cedars impairing their ability to absorb water. In a province experiencing more rain than ever, our yellow-cedars are dying of thirst.
As temperatures continue to increase and precipitation levels continue to change, how will the yellow-cedar fare, or other species like the coastal, western red cedar? Will our tree species be able to migrate to more suitable, northern climates or will they be faced with extinction?
Trees are naturally slow travellers due to the amount of time it takes for trees to grow to seed-bearing age, and then to prepare and disperse seeds. Trees migrate through their seeds and the average distance a seed moves is a few hundred meters per year. While that is an impressive distance for a little seed, in the urgent context of climate change, it is not nearly far enough. In order to keep up with the rapid rate of global temperature increase, seeds need to move several thousand meters per year. In addition to their naturally slow migration speed, tree species face unsuitable soil conditions, urban development barriers, and competition from local plant residents in their new environments.
To learn more about mycorrhizal networks, watch this video featuring UBC forester Suzanne Simard.
Another uncertain factor in the successful migration of tree species is the vital role of mycorrhizal networks. Beneath the ground of every forest, and linked to every root system, is a complex network of life-giving fungi – and it is yet to be determined if those fungi networks are up for a move. Connecting every tree in a forest, webs of mycorrhizal (“fungus roots”) supply trees with nitrogen, phosphorus, and water in exchange for carbon from photosynthesis. Without this essential network of mycorrhizal, trees would be unable to survive in their native habitat, let alone in a new environment.
Climate change is set to radically alter the landscape of British Columbia. We need look no further than our declining yellow-cedar populations to understand the damage that has already been done. There has never been a more urgent time for British Columbian’s to join the fight against climate change and protect our legendary forests. In British Columbia, our history can be told through our trees - they are now telling us the future, and we must listen carefully.