While the overall species diversity of boreal biomes is lower than found in most, if not all, temperate, subtropical and tropical regions, these biomes contain numerous species that are adapted to the region's harsh environment. In addition, the low abundance of predators combined with a high level of insect species whose life cycles are suited to the short, intense summers have resulted in the large numbers of a variety of bird species that migrate to this region each summer. This region is also unique in that a significant portion of Native Peoples who live in small villages scattered throughout the North American boreal region still employ traditional subsistence harvesting and hunting practices, and therefore depend on many of the services that the wildlife and ecosystems provide.
Given the recent rates of change to the sub-arctic climate and the boreal forest, and the projections for continuing or accelerated warming throughout the 21st century, there is little doubt that the ecosystems of this region will undergo dramatic changes. Based on dynamic global vegetation models, there is a consensus that there will be a northward shift in the extent of the boreal forest, with the northern boundary extending into areas currently occupied by tundra and the southern boreal forest being replaced by temperate forests or steppe/ grasslands (Cramer et al, 2001). However, while such models present a broad overview of the patterns of vegetation cover change, they are problematic in terms of predicting specific changes at regional scales. These models predict changes of plant functional types based on assuming equilibrium states that are only achieved over longer time scales, and may not accurately predict the time it takes for species migration to occur. In addition, most models do not have realistic representations of permafrost dynamics and the impacts of and interactions between disturbance by insects, disease and fire. While modeling studies indicate there will be a continuing increase in the annual burned area across the North American boreal forest (Flannigan et al, 2005), particular attention needs to be paid to future changes in the frequency of large fire years at regional scales, seasonal patterns of burning, and variations in fire severity, including shifts between surface and crown fires and the depth of burning in ecosystems with deep organic layers.
In summary, while most scientists and resource managers accept the fact that dramatic changes are going to take place throughout the boreal region, given the complexity of processes that control ecosystem processes, the need for continuing research and monitoring is imperative. There is little doubt, however, that over the next few decades, there will be a continuing period of discovery as research and observations begin to answer some of the many unanswered questions that we now face.
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