Saturday, November 6, 2010

The Big Picture

Sunday is lab tour day here in McMurdo. Folks from all over the station come in to the Crary lab to find out what the scientists are up to. As I was telling folks here about what it is that I do, I realized that I haven't really given a big picture explanation of what my research is all about. Most folks know that I disappear to Antarctica once a year or so--here's why!

As I mentioned earlier, I'm working with a project called the McMurdo Dry Valleys Long Term Ecological Research project (MCM-LTER). The LTER is actually part of a much larger network of scientists who are trying to understand how climate change affects ecosystems. You hear the word "ecosystem" a lot, but all it means is the relationships between living things (like trees or fish) and their physical habitat (soil, air, water, etc.) .LTER wants to know how those relationships are changing in a changing world.

The McMurdo LTER has it easy. We study one of the simplest ecosystems on the planet, the Dry Valleys I've been writing about. In Taylor Valley, sunlight, water, and soil are used by microbes and algae and moss to make food and energy (they're called "primary producers" and are the core of the food web). Some microbes eat algae or other microbes, which are all food for some tiny, microscopic invertebrates (things like rotifers and tardigrades) I think tardigrades look pretty alien:

The top predator in the Taylor Valley ecosystem is the fearsome nematode . This microscopic worm is only about 1 mm long (so about 100 of them could party on your pinky nail). And that's just about it.

So why is it important to understand the relationships between these simple living things and their environment, and how it is changing as the Antarctic climate changes? Because, like it or not, we live in an ecosystem of our own (they say up in Alaska, "Step out of the car, and into the food chain"). More broadly, we depend on clean air, soil, and water to grow crops. We depend on microbes in the soil to make it fertile, and on bees and other bugs to pollinate our plants. We depend on rivers and lakes for water, and on the very complex ecosystem of the ocean for food--and more importantly, for algae and plankton, that make most of the oxygen we breath every day through photosynthesis.

Learning about how a simple ecosystem is changing gives us a model for how more complicated ecosystems change as the air and soil warm. What will happen in Taylor Valley over the next few years to decades? Will the microbes that pry minerals from the soil suffer from warming dirt, cutting off the base of the food supply? Will the nematodes, feeling fast and feisty in the warm temperatures over-hunt and exhaust their food supply? Will the glaciers that ring the valley melt, flooding out organisms that cannot find dry habitats fast enough? These are the kinds of questions that the LTER is trying to answer (and many others, of course!). The answers to these questions will help us predict how the ecosystem that we inhabit will change as the physical world changes around us.

Time to head back to lab work. I'll be heading back out to the field tomorrow if the weather holds, and will write about what I've been up to on station.  

No comments:

Post a Comment