The Botanical Recovery of Glen Canyon
By Kendra Babitz, MPP, Policy Coordinator and Blake Wellard, MS, Botanical Consultant
GCI Staff note: In the spring of 2019 we conducted an “expert BioBlitz” with Sage Land Collaborative in the Escalante region of Glen Canyon. Below is a report from two botanist that joined the BioBlitz. With trips planned for this spring, we look forward to expanding this work in 2022.
The botanical experience on the Glen Canyon Bioblitz was enlightening and thrilling, between compiling a dream team of scientists to bounce ideas across, and a fascinating area to explore that has changed so much in a short amount of time. Botany in the canyon above the high water mark was in excellent condition considering that some of the areas above the canyons still showed evidence of recovery from early grazing. The climax communities above the high waterline were well established with abundance of oak, indigo bush, sage brush, rabbit brush, and netleaf hackberry, and the ecosystem was well balanced with species diversity and dispersion. The deeper into the canyon we descended, the better the botany and ecosystems appeared with fewer and fewer weeds that came along with more difficult terrain for grazing animals to access.
The botany did not change starkly until we descended below the high water mark. The most glaring contrast was the disappearance of almost all of the shrub and tree species that were so prevalent in defining the ecosystem just 20 meters higher in the canyon. These community species were replaced by invasive species like cheat grass and tamarisk. Even 25 years after the Lake Powell water line receded, very few community level plants had returned, most likely due to resource competition. However, roughly 20 native species were observed. Those were species with higher reproduction rates and broader ranges of habitat adaptation. Plants like desert trumpet and James’ galleta grass were making their way back into establishment in the ecosystem.
Why were key community level plants not getting established like indigo bush, netleaf hackberry, oak, even after so many years? One idea is that there simply was not room in a plant community that was dominated by tamarisk and other invasive species immediately following the drop in lake level. This drastically limited the number of native plants, soil microbiome species, and biocrust species like lichen and moss that could get established. Native plants’ seeds continue to land in the space formerly occupied by the lake and some get established year after year but with an established invasive plant community, reestablishment of a community resembling the rest of the canyon has been slowed. Yet, many native plants have become established and some of these species include: globemallow, wirelettuce, scorpion weed, sacred Datura, four wing salt bush, matted crinkle mat, wooly plantain, Jone’s blue star, woody aster, desert trumpet, milkvetch, sticky brittle bush, purple three awn, common pepperweed, threadleaf sunflower, Indian rice grass, sand sage, and prickly pear cactus. The bright side to this is that these plants are the beginnings of desert ecosystem restoration.
Another exciting find was the establishment of native plants in many of the wet areas of the canyon bottoms and seepy cliffs such as stream orchid, which was very well established below high waterline. Stream orchid requires very specific ecosystem requirements for it to exist and thrive, much of which concern mycorrhizal fungi. Mycorrhizal fungi are needed to promote seed germination and subsequent development of seedlings. As a result, the availability of suitable mycorrhizal fungi and the level of specialization between orchids and mycorrhizal fungi can have broad implications for the distribution and fitness of future orchid populations. With our understanding of the base level of the ecosystem in Glen Canyon, the soil microbiome is intact enough to host a species like an orchid. Maiden Hair Fern is another exciting wind dispersed pioneer species. When both these species are present, it shows the beginnings of a healthy canyon seep community.
However, our observations were limited to one canyon of data collection above and below the high water mark. It would be helpful to hike down additional borderline canyons surrounding Lake Powell to gather data above and beneath the high water mark to see if this example holds true for other areas in Glen Canyon.
