Monday, November 30, 2009

Invasive species: Already in an ecosystem near you

While nearly everyone is familiar with the concept of climate change, very few people feel any urgency about it. When you're thinking on a human timescale (and being human, that's the natural thing to do) it's hard to get concerned about the poles melting in 50 years. Or even in 20. But ecosystems don't change in predictable ways. Natural systems have checks and balances that are sometimes very resilient and durable. But small changes in climate can produce big changes in how an ecosystem functions. Almost every ecosystem in North America is undergoing some kind of shift that's directly attributable to invasive species or to endemic species that are rushing in to fill some kind of void as the climate shifts. I've been researching shifts in the nation's forests specifically.
Mountain pine beetle, an endemic species, wiping out mature lodgepoles in the Rockies, for instance. A massive change in the mountain landscape has already happened. Entire mountain valleys have turned rust red as the pines die. Forestry officials and scientists say almost all mature lodgepoles from the Rockies west will be gone within 5 years. That's fast, and understandable on human timescales. Scientists believe warmer winters, combined with drought and a human-controlled fire regime have allowed the pine beetles free reign. I'm not familiar with the Sonoran desert, but this article in the Tucson Weekly caught my eye. I wonder if and how climate change has a role in the spread of buffelgrass?