Showing posts with label ecosystem. Show all posts
Showing posts with label ecosystem. Show all posts

Sunday, 8 January 2012

Wrapping up (2)

This is the penultimate post! (please, don't cheer too loudly). For the second half of the review (click here for the first part), I'm going to briefly consider some of the more tricky questions about the Arctic about the future. Of course, any answers are only based on past experience. It's impossible to tell what path environmental change in the Arctic will take, especially with the added complication of people who are even more unpredictable than the environment. So, here goes...

What is the likely impact of future human activity on aquatic and terrestrial arctic ecosystems?

It's only possible to extrapolate from what we know, meaning it's likely the changes seen in the past few decades are likely to continue. Also, natural systems exhibit lagged responses, especially when organisms take decades to grow. For example, shifts seen in aquatic ecosystems are very significant as they respond quickly to temperatures. Alterations to terrestrial vegetation, on the other hand, are slow, meaning the small changes evident in the past few years are probably responses to warming a few decades ago. Therefore, it's likely that aquatic communities will continue to shift with changing patterns of ice cover and benthic vegetation, woody (and perhaps even large vascular plants) will expand in extent, permafrost will melt and temperate organisms will begin to move north.

This is also a good point to bring up all the papers which I haven't had time to bring up, but indicate the potential for future changes in the Arctic as extrapolated from that seen in recent decades. In a great review article, Post et al. (2009) provided a short account of ecological responses to Climate Change in the Arctic. Changes with significant potential include range shifts (seen in moths), invasive species and phenology (see graph below).
Earlier flowering in Greenland (direct from Post et al., 2009)
Such movements in seasonality become problematic when there's a mismatch between producers and consumers. For example, a growing difference was observed between peak Caribou births and peak productivity of