Old forests are losing ground, there are changes in river flows at critical times of the year, and wildlife habitat is losing out to agricultural landscapes in many cases, a comprehensive report ever on the state of Canada's biodiversity has revealed.
Canadian Biodiversity: Ecosystem Status and Trends 2010, the first assessment of the country's biodiversity from an ecosystem perspective that presents 22 key findings, has also voiced concern over declines in certain bird populations, increases in wildfire, and significant shifts in marine, freshwater, and terrestrial food webs.
"Plant communities and animal populations are responding to climate change. Temperature increases, shifting seasons, and changes in precipitation, ice cover, snowpack, and frozen ground are interacting to alter ecosystems, sometimes in unpredictable ways," the report said.
Published by the federal, provincial and territorial working group on biodiversity, [Link] that much of Canada’s natural endowment remains healthy, including large tracts of undisturbed wilderness, internationally significant wetlands, and thriving estuaries, particularly in sparsely populated or less accessible areas.
The report was posted on the official website on Friday ahead of the the Tenth Meeting of the Conference of Parties to the Convention on Biological Diversity (COP-10) which began Monday in Japan, [Link] Montreal Gazette.
Over 500 experts participated in the preparation of the technical reports. The 22 key findings have been classified under four interrelated themes: biomes; human/ecosystem interactions; habitat, wildlife, and ecosystem processes; and science/policy interface.
Among its key findings:
- Forests: At a national level, the extent of forests has changed little since 1990; at a regional level, loss of forest extent is significant in some places. The structure of some Canadian forests, including species composition, age classes, and size of intact patches of forest, has changed over longer time frames.
- Grasslands: Native grasslands have been reduced to a fraction of their original extent. Although at a slower pace, declines continue in some areas. The health of many existing grasslands has also been compromised by a variety of stressors.
- Wetlands: High loss of wetlands has occurred in southern Canada; loss and degradation continue due to a wide range of stressors. Some wetlands have been or are being restored.
- Lakes and Rivers: Trends over the past 40 years influencing biodiversity in lakes and rivers include seasonal changes in magnitude of stream flows, increases in river and lake temperatures, decreases in lake levels, and habitat loss and fragmentation.
- Coastal: Coastal ecosystems, such as estuaries, salt marshes, and mud flats, are believed to be healthy in less-developed coastal areas, although there are exceptions. In developed areas, extent and quality of coastal ecosystems are declining as a result of habitat modification, erosion, and sea-level rise.
- Contaminants: Concentrations of legacy contaminants in terrestrial, freshwater, and marine systems have generally declined over the past 10 to 40 years. Concentrations of many emerging contaminants are increasing in wildlife; mercury is increasing in some wildlife in some areas.
- Agricultural Landscapes as Habitat: The potential capacity of agricultural landscapes to support wildlife in Canada has declined over the past 20 years, largely due to the intensification of agriculture and the loss of natural and semi-natural land cover.
- Food Webs and Population Cycles: Fundamental changes in relationships among species have been observed in marine, freshwater, and terrestrial environments. The loss or reduction of important components of food webs has greatly altered some ecosystems.
