Influences of Climate on Landscapes of the Southern Colorado Plateau, by Les McFadden

When: Sun, Feb 21 2010 5:30pm

Where: UNM SUB

Thanks to our speaker Les McFadden, Professor of Earth and Planetary Sciences and to Ly Flock and the UNM catering staff.

Les McFadden
Professor of Earth and Planetary Sciences
The University of New Mexico

Relatively small-scale Holocene (the last 10000 years) climate changes have strongly influenced landscape evolution in the dryland areas of the Colorado Plateau. Our geological and biological studies of landscapes, soils and trees in northeastern Arizona on the southern Colorado show that the nature of the rocks in this region plays a heretofore unrecognized, but profound role with respect to how climate and climate changes affects plants and landscapes.

In many areas of the Colorado Plateau, one observes two basic kinds of slopes that reflect their relative exposure to the sun during the day:

1. North-facing hillslopes with soils, relatively low gradients and pinon forests
2. South-facing, generally steeper slopes on bedrock.

We believe that the slopes that face different directions essentially represent transitional regions between these very different slopes and vegetation communities, and that the signatures of very recent climate changes and ongoing global warming can be recognized in these areas.