Commonwealth Forests

Chapter 1: The Forest Resource

BOX 1.2 Two climatic extremes - mangroves and boreal forest

Mangrove forests are essential for coastal protection from storms and tidal surges and provide a wide range of products.  The most reliable recent estimate provided by countries in a recent FAO study showed that there are 15.7 million ha of mangroves world-wide, of which Commonwealth countries account for 6.1 million ha, or 39% of the world’s total.

Most reliable recent estimate ha  x1000.  Main countries in regions

The many wood products obtained from mangroves range from timber, poles and posts to firewood, charcoal and tannin, while non-wood products include thatch, honey, wildlife, fish, fodder and medicine. Unfortunately, many mangrove forests have been converted to salt pans, aquaculture ponds or agriculture.

Commonwealth countries possess a significant part of the world’s mangrove forests, and they form an important resource for the livelihoods of coastal people.

Canada’s boreal forest covers 310 million ha, or 77% of Canada’s total forest area and nearly one third of this forest type in the world.  The boreal coniferous forest occurs in a mainly continental climate.  There are large areas of closed stands of conifers composed of white and black spruces Picea glauca and P. mariana, balsam fir Abies balsamea, and tamarack Larix laricina, but there are also deciduous species such as white birch Betula papyrifera, trembling aspen Populus tremuloides and balsam poplar P. balsamifera.  The boreal tundra woodland is influenced by cold arctic air and are more open.  The better-drained sites support black spruce and tamarack and some white spruce, with balsam poplar, white birch and alder (Alnus incana) along rivers.

While there have been small losses of Canada’s boreal forest in the recent past due to man’s activities (agricultural clearing, hydro-electric development, oil and gas exploration etc) the greatest threat now comes from climate change.  Global warming may shift the geographic range of many of the boreal forest species northwards by 300 to 500 km, replacing them with species of temperate forest.  At the same time the occurrence of natural disturbances such as fire, insect and disease infestations and extreme weather events may increase.  The consequence of global warming on the boreal forest will be reduction in area, or even loss, of some of the boreal forest and the release of greenhouse gases.  Carbon, presently locked in permafrost forest soils, may not be released but accumulate as organic matter in melted bogs.  Methane, on the other hand, a greenhouse gas with a global warming potential more than 20 times greater than carbon dioxide, may be emitted from the bogs, compounding the accumulation of greenhouse gases.

Sources:

• Mangroves: FAO, 2003 and 2006(a)

• Boreal: FAO, 2002

• The State of Canada’s Forests 2004-2005.  Canadian Forest Service, Natural Resources, Canada.  Web site: http://www.cfs.nrcan.gc.ca