Bachelor of Arts
Biological and Physical Sciences
Program or Major
In the desert ecosystem, the ground is covered with soil crusts. Several organisms exist here, such as cyanobacteria, lichens, mosses, fungi, bacteria, and green algae. This most superficial layer of the soil contains several primary producers of the food web in this ecosystem, which stabilize the soil, facilitate plant growth, protect from water and wind erosion, and provide water filtration and nitrogen fixation. Researching the biodiversity of green algae in the soil crusts can provide more context about the importance of the soil crusts. Little is known about the species of green algae that live there, and through DNA-based phylogeny and microscopy, more can be understood. In this study, DNA was extracted from algal cultures newly isolated from desert soil crusts in New Mexico and California. Through PCR reactions, the 18S and rbcL genes were amplified and sequenced for analysis. A phylogenetic tree was constructed to observe biodiversity in the collection site and genetic relatedness to previously collected soil algae from New Hampshire. The analyzed strains belong to the classes Chlorophyceae and Trebouxiophyceae, representing several genera and potentially novel species. These results show that biodiversity of soil crusts, both desert and temperate, is still in need of further study and may yield new discoveries in the future.
Williamson, Victoria, "Biodiversity of Microscopic Green Algae from Desert Soil Crusts" (2020). Honors Theses. 69.