1 minute, 16 seconds

Dr. Andrea Lloyd says:

We're standing right now at the upper edge of our lower transect which is what we're calling treeline. So this is pretty much the limit of continuous forest and what we're going to do is walk uphill from here, um, across the treeline ecotone. And as we're walking uphill through willow and shrub birch and all these other smaller blueberries and little shrubs, we're finding trees are getting sparser and sparser and eventually we'll reach a point where there aren't any trees at all. And that gradient from continuous forest to the place at which there aren't any trees at all is what we are interested in studying.

What we're trying to study is whether or not the position of that ecotone, that boundary between forest and tundra, has changed in the last several decades. It's gotten warmer throughout Alaska in the last several decades and it seems reasonable to suppose that as it's gotten warmer, places that used to be too cold for spruce are now warm enough to support spruce.

And, what we're going to be looking for is whether the spruce up here are younger, so if the forest limit is advancing, as we expect that it might be, than we should find that as we go up in elevation, spruce get younger and younger.