28 Jun The Greater Yellowstone Inventory and Monitoring Network: Upland Vegetation Surveys at Bighorn Canyon National Recreation Area
Thanks to the Greater Yellowstone Inventory and Monitoring Network, I learned how to accurately record and spatially asses upland vegetation quadrats. In order to properly asses these quadrats, we began by estimating the percent of total quadrat area associated with bare ground, cryptobiotic crust (made from microscopic organisms living on top of the soil), prickly pear cactus, litter, trees, shrubs, and grasses. The genus and/or species of various trees, shrubs, native grasses, and invasive grasses were tied to their relative percent cover. Examples of the identified vegetation include Mountain Mahogany, Utah Juniper, Rocky Mountain Juniper, Snakeweed, Threeawn, Bluebunch, Poa, Carex, and Cheatgrass.
A short summary of the implications associated with each measurement is as follows:
Bare ground: more bare ground implies that the soil is eroding at a faster rate. Soil erosion may affect the ability of the soil to store water and nutrients, which ultimately impacts plant and animal communities.
Cryptobiotic crust: this crust shields the soil beneath it from erosion and provides Nitrogen for plants. Thus, cryptobiotic crust helps maintain the composition of the soil while adding nutrients to it.
Prickly pear cactus: a sub-shrub that is an important food source for some animals.
Litter: not including what is found in shaded parts of the quadrat, examples of litter are dead leaves, uprooted branches, and animal waste. Decomposition of litter can provide nutrients to the surrounding plants.
Trees and shrubs: the trees and shrubs found in this desert environment tend to grow slowly, are sensitive to changes in the amounts of water and nutrients, provide shelter, are food for animals, and are slow to recover when damaged.
Native and invasive grasses: ideally, we want to be seeing more native than invasive grasses. Invasive grasses, such as cheatgrass, may not have the same natural enemies and could have a higher tolerance to arid environments, ultimately displacing native grasses.
We also took specific photo points of the sites in each cardinal direction; we did this so that pictures from this year can be compared to those taken in the past and those that will be taken in the future. While taking photos in the same frame year after year can help us determine if there are any changes in landscape, they are not indicative of a specific causative agent. For instance, tent caterpillars create nests and demolish Mountain Mahogany. Even if we see an old or new tent caterpillar nest on the branches of a damaged Mountain Mahogany tree, we cannot say with complete certainty that animals or bad weather were not contributing factors. Knowing how upland vegetation is changing allows scientists to communicate their findings to park management, as the goal of the National Park Service is to “conserve, unimpaired, the natural and cultural resources and values of the national park system for the enjoyment of this and future generations” (source: https://www.nps.gov/aboutus/index.htm).
Speaking of enjoyment, we saw bighorn sheep and wild horses as we were performing fieldwork and making our way to field sites. Accidentally startling bighorn sheep in their natural habitat revealed just how agile and adept they are to scaling the sides of rocky cliffs! To my surprise, the wild horses did not look like a typical domesticated horse – they had zebra-like striped markings behind their legs. What is fascinating about Bighorn Canyon is that the horses have a designated range to which they can freely roam; through our research, we can compare quadrat surveys between the horse range and non-horse range sites and see what we learn.
Highlights of this hitch include tasting a wild onion, hiking the Upper Layout Creek trail, stumbling upon the skull of a bighorn sheep, seeing different color variations of the Indian Paintbrush flower, and witnessing countless breathtaking views.