Monday, February 25, 2008

Buffelgrass invasion increases geologic hazards

Saturday, March 1 is Buffelgrass Eradication Day in Pima County. Most of the attention being paid to this invasive species centers on its crowding out of native species and the fact it burns so hot it can destroy saguaro, something that normally doesn't happen in the Sonoran ecosystem. Also, the spread of buffelgrass will convert our desert into a savannah-like environment much more prone to repeated wildfires.

And the problem with extensive wildfires is that they clear the land, and especially hillsides of the vegetation that holds the soils in place. All over the West, one the first things land managers do after a wildfire is to reseed quickly, so as to reduce the mudslides and debris flows that come with the subsequent rains.

If buffelgrass continues its expansion in the Catalina and Tucson mountains, expect to more debris flows like the ones that so damanged Sabino Canyon in 2006 and expect mudslides coming into our neighborhoods.

[left: this debris flow triggered on hillslopes burned by the South Canyon fire of 1994 crossed four lanes of Interstate 70, and nearly dammed the Colorado River. Photograph by Jim Scheidt, BLM]

There are also serious threats to water quality in post-fire situations.

No comments:

Post a Comment