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A boreal ecosystem is an ecosystem with a subarctic climate located in the Northern Hemisphere, approximately between 50° and 70°N latitude. These ecosystems are commonly known as taiga and are located in parts of North America, Europe, and Asia. The ecosystems that lie immediately to the south of boreal zones are often called hemiboreal. There are a variety of processes and species that occur in these areas as well.
The Köppen symbols of boreal ecosystems are Dfc, Dwc, Dfd, and Dwd.
Boreal ecosystems are some of the most vulnerable to climate change. Both loss of permafrost, reductions in cold weather and increases in summer heat cause significant changes to ecosystems, displacing cold-adapted species, increasing forest fires, and making ecosystems vulnerable to changing to other ecosystem types. These changes can cause Climate change feedback cycles, where thawing permafrost and changing ecosystems release more greenhouse gas emissions into the atmosphere causing more climate change.
However, despite not being as biodiverse as tropical systems, this area has a variety of species. Boreal ecosystems are filled with a multitude of flora species from Picea mariana and Picea glauca, to , , and alders. Caribou, although not there year round, come down and into these regions during the winter to forage for lichen. A few fish species include salmonids, smelts, , lamprey and . For salmon these systems are vital: relying on the riparian systems within boreal ecosystems for multiple life stages in both the beginning and the end of their life cycle, Sockeye salmon rely on the provided freshwater environments as eggs, fry and adult stages.
In terms of boreal trees, the poleward limit for any given species is most likely defined by the temperature, whereas the equatorward limit is generally defined by competitive exclusion. As changes in climate occur, change in the corresponding weather variables follows,Woodward, F.I. 1987. Climate and plant distribution. Cambridge University Press, Cambridge, UK. 188 pp. and ecosystem alterations involving timing for migration, mating, and plant blooming can occur. This can lead to the transition into a different type of ecosystem as the northward shift of plant and animal species has already been observed. Trees may expand towards the tundra; however, they may not survive due to various temperature or precipitation stressors. The rate depends on growth and reproductive rate, and adaptability of the vegetation. In addition, the migration of flora may lag behind warming for a few decades to a century, and in most cases warming happens faster than plants can keep up.
Due to permafrost thaw and disturbance alterations such as fire and insect outbreaks, certain models have suggested that boreal forests have developed into a net carbon source instead of a net carbon sink. Although the trees in the boreal are aging, they continue to accumulate carbon into their biomass. However, if disturbed, higher than normal amounts of carbon will be lost to the atmosphere.
In some areas, boreal ecosystems are located on a layer of permafrost, which is a layer of permanently frozen soil. The underground root of boreal trees are stabilized by permafrost, a process which permits the deeper trapping of soil carbon and aids in the regulation of hydrology.Ashton, M. S., M. L. Tyrrell, D. Spalding, and B. Gentry. (2012). Managing Forest Carbon in a Changing Climate. New York: Springer.Bonan, G. B. (2008). Forests and Climate Change: Forcings, Feedbacks, and the Climate Benefits of Forests. Science 320: 1444–1449. Permafrost is able to store double the amount of current atmospheric carbon that can be mobilized and released to the atmosphere as greenhouse gases when thawed under a warming climate feedback.Loranty, M. M., Abbott, B. W., Blok, D., Douglas, T. A., Epstein, H. E., Forbes, B. C., . . . Walker, D. A. (2018). Reviews and syntheses: Changing ecosystem influences on soil thermal regimes in northern high-latitude permafrost regions. Biogeosciences, 15(17), 5287-5313. Boreal ecosystems contain approximately 338 Pg (petagrams) of soil carbon, this is comparable to the amount which is stored in biomass in tropical ecosystems.Lal, R. (2004). Soil carbon sequestration to mitigate climate change. Geoderma, 123(1-2), 1-22.
Ecosystem services
In boreal ecosystems, Carbon cycle is a major producer of ecosystem services especially timber production and climate regulation. The boreal ecosystem in Canada is one of the largest carbon reservoirs in the world.IPCC (Intergovernmental Panel on Climate Change). 2001. Chapter 1: Global perspectives. In: R.T. Watson, I.R. Nobel, B. Bolin, N.H. Ravindranath, D.J. Verardo, and D.J. Dokken. Eds. Land use, land-use change and forestry. Cambridge: Cambridge University Press. 550 p. Moreover, these boreal ecosystems in Canada possess high Hydroelectricity potential and are thus able to contribute to the resource-based economy.Pasher, J., Seed, E., & Duffe, J. (2013). “Development of boreal ecosystem anthropogenic disturbance layers for Canada based on 2008 to 2010 Landsat imagery.” Canadian Journal of Remote Sensing, 39(1), 42-58. Through ecosystem assessment, inventory data, and modeling, scientists are able to determine the relationships between ecosystem services and biodiversity and human influence.Akujärvi, Anu, et al. “Ecosystem Services of Boreal Forests – Carbon Budget Mapping at High Resolution.” Journal of Environmental Management, vol. 181, 1 Oct. 2016, pp. 498–514. ScienceDirect, Elsevier, .
/ref> Within the past decade, the number of studies focusing on the relationships between ecosystem services has been increasing.Bennett, Elena M., et al. “ Understanding Relationships among Multiple Ecosystem Services.” Ecology Letters, vol. 12, no. 12, 21 Nov. 2009, pp. 1394–1404. Wiley Online Library, . This is due to the rise of human management of ecosystems through the manipulation of one ecosystem service to utilize its maximum productivity. Ultimately, this results in the supply decline of other ecosystem services.
See also
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