An introduction to Canada’s boreal zone: ecosystem processes,health, sustainability, and environmental issues

摘要

The boreal zone and its ecosystems provide numerous provisioning, regulating, cultural, and supporting services.Because of its resources and its hydroelectric potential, Canada’s boreal zone is important to the country’s resource-basedeconomy. The region presently occupied by Canada’s boreal zone has experienced dramatic changes during the past3 million years as the climate cooled and repeated glaciations affected both the biota and the landscape. For about the past7000 years, climate, fire, insects, diseases, and their interactions have been the most important natural drivers of borealecosystem dynamics, including rejuvenation, biogeochemical cycling, maintenance of productivity, and landscape variability.Layered upon natural drivers are changes increasingly caused by people and development and those related tohuman-caused climate change. Effects of these agents vary spatially and temporally, and, as global population increases,the demands and impacts on ecosystems will likely increase. Understanding how humans directly affect terrestrial andaquatic ecosystems in Canada’s boreal zone and how these effects and actions interact with natural disturbance agents isa prerequisite for informed and adaptive decisions about management of natural resources, while maintaining the economyand environment upon which humans depend. This paper reports on the genesis and present condition of the borealzone and its ecosystems and sets the context for a detailed scientific investigation in subsequent papers published in thisjournal on several key aspects: carbon in boreal forests; climate change consequences, adaptation, and mitigation; nutrientand elemental cycling; protected areas; status, impacts, and risks of non-native species; factors affecting sustainable timberharvest levels; terrestrial and aquatic biodiversity; and water and wetland resources.