My internship has been extended, and I have just about finished the first of two extra months working for the BLM in Alturas, California. Fall has arrived. Although the days are still getting surprisingly hot, the nights are getting cold, with the first frost predicted for tonight. The hay has been baled, the cows are back on their home ranges, and thousands of ducks, geese, and sandhill cranes are passing through on their way South.
My field partner Jaycee and I have shifted our focus from seed collecting to other projects. The biggest of these is a mapping project on the Likely Tablelands, a piece of BLM land about 45,000 acres large just Southeast of Alturas. It is a flat volcanic plateau that has been carved by the Pit river and other creeks from the Warner mountains watershed. We are mapping lines around areas of a species of sagebrush called Wyoming Big Sage, Artemesia tridentata ssp. wyomingensis. These lines, or “greenstrips”, will be installed around patches of sagebrush, and seeded with fire resistant plants. The purpose of this is to protect the sagebrush from burning, and from being converted to Medusahead, Taeniatherum caput-meduasae (an exotic annual grass), which is what most of the rest of the Tablelands is composed of. Medusahead is particularly good at coming back after fires, and it outcompetes the native bunch grasses. Wyoming big sage is of special concern because it takes as long as 100 years to fully recover after a fire whereas other species of sagebrush take about 20 years.
The Likely Tablelands. A volcanic plateau surrounded by a highway, agricultural fields, creeks and a mountain range.
At first this project seemed incredibly daunting. Mapping sagebrush in the high desert sounded like mapping grains of sand at the beach. It was first introduced to me in early May and I had no idea where to start and quickly abandoned it in favor of more interesting, accesible projects. It is a sign of how much I have learned about navigation, map reading, and ArcGIS that this project is even possible for me to work on . It is still quite a challenge figuring out how to best solve the spatial problem of representing sagebrush and medusahead. It is a lot easier than it sounds because the majority of the Tablelands is extensive, contiguous medusahead monoculture, which means fewer lines need to be mapped than I initially thought. I’m not sure how relieved I am by that.
Another component of the mapping is finding out where different types of sagebrush grow. Besides visual ID, there is a really cool way to tell them apart. You take a few leaves, crush them, and put them in some water in a glass. Then you shine a blacklight on it (our office has a blacklight kit for this purpose that is probably protected under the antiquities act) and depending on the species they will flouresce different shades of blue or not flouresce at all. This is due to a chemical compound that some produce and some don’t.
SCIENCE!
All this mapping and seeing so much medusahead has me wondering why it is there in the first place. The tablelands were grazed by sheep up until the 1960’s, when medusahead first showed up, and overgrazing may have dealt the first blow to the sagebrush and bunch grasses. Past fires have also spread it around. It is no doubt ultimately due to the productive capacity of the land being compromised in some way, leaving medusahead and other weedy forbs as the only plants that can grow. This greenbelt project is interesting, but is inherently a defensive act that will not reverse this process. I am curious as to what methods could be employed to restore the land in a lasting way that would promote more desirable species for use by wildlife and humans.
Joe Broberg
Botany Intern
Alturas BLM Field Office