Rapid Ecosystem Changes in Arctic Associated with Climate Change May Foreshadow Global Environment of the Future
The rapid recent climate change in the Arctic has “severely perturbed” Arctic ecosystems and the trophic relationships that structure them, according to a paper published 11 September in the journal Science by an international team of 25 scientists. They wrote to take stock of the region at the close of the Fourth International Polar Year.
These rapid changes may be a bellwether of changes to come at lower latitudes and have the potential to affect ecosystem services related to natural resources, food production, climate regulation, and cultural integrity.—Post et al. 2009
Results of studies noted in the paper indicate that the Arctic ecosystem has experienced immense changes in the last twenty years. At many levels, the changes impact the ecosystem services that the environment provides for people; the effects extend to the adequacy of natural resources, food production, climate temperature, and result in changes to the landscape.
The results show that spring begins considerably sooner than before. The blossoming and pollination period of plants starts as much as twenty days sooner in comparison to the situation ten years ago. Predators are in trouble because nutrition is now available too soon in relation to the otherwise favorable nesting period. The distribution of many insects has moved further north. European winter moths, for example, have destroyed extensive birch areas in Lapland after moving north. Species invading new areas might supersede the original species in the area—this is already happening to Arctic foxes, which are currently being overrun by red foxes.
Ivory gulls, ringed seals, polar bears and narwhals are examples of species with a small distribution and specialized habitats, and such species will be the first ones to suffer from the changes.
After reviewing the numerous sudden direct, indirect, and reciprocal changes across the Arctic region associated with climate change, the authors highlighted areas of research they said required immediate emphasis:
Conservation. Low-diversity ecosystems like the Arctic warrant greater conservation attention, as there is little functional redundancy among species.
Therefore, extirpation or range shifts in the Arctic may precipitate larger and more fundamental changes in ecosystem dynamics compared to those within more speciose ecosystems where loss of individual species may have less immediate consequence for ecosystem processes.—Post et al. 2009
Dynamics outside the growing season. Winter conditions are likely of key importance to the annual Arctic cycle, they noted, and may exert cascading effects throughout the growing season.
Trophic interactions. Trophic interactions—i.e., the interaction between organisms at different levels in the food chain—modulate ecosystem responses to climate change in the Arctic.
We urge more studies of the role of climate warming in trophic dynamics, and of species interactions in response to climate change at different trophic levels, especially in aquatic systems, soils, and sediments.—Post et al. 2009
Heterogeneity as a buffer against climate change in the Arctic.
The scale dependence of climate responses.
Extreme events, tipping points, and resilience. Stochastic events such as insect outbreaks, sudden and transient temperature changes, rapid retreat of sea- and lake ice, bouts of abnormally high precipitation or extended droughts, wildfires, the sudden release of water from melting glaciers, and slumping of permafrost may have disproportionately large effects on ecological dynamics, they noted.
Such processes, and ecological responses to them, may be nonlinear and difficult to predict. We urge research aimed specifically at understanding the role of extreme events in ecological dynamics in the Arctic, in particular with regard to the build-up of tipping points in ecological systems.—Post et al. 2009
Baseline studies in anticipation of predicted changes.
Post et al. (2009) Ecological Dynamics Across the Arctic Associated with Recent Climate Change. Science. Vol. 325. no. 5946, pp. 1355 - 1358 doi: 10.1126/science.1173113