Open Access. Powered by Scholars. Published by Universities.®
- Discipline
Articles 1 - 3 of 3
Full-Text Articles in Life Sciences
Exploring Post-Fire Recovery Of Biocrusts And Desert Ecosystem Services, Jason R. Bahr
Exploring Post-Fire Recovery Of Biocrusts And Desert Ecosystem Services, Jason R. Bahr
Theses and Dissertations
Biocrusts and the ecosystem services they provide are becoming more susceptible to fire as exotic annual grass invasions facilitate the spread of desert wildfires. Further, precipitation patterns across the western United States are predicted to change over the next century, and have the potential to dramatically influence fire regimes and the recovery of burned biocrusts. Despite these changes to desert fire and precipitation cycles, our understanding of post-fire biocrust recovery is limited, especially regarding the first two years after fire. To investigate biocrust recovery, we created burn manipulations (i.e., unburned and burned) and tracked crust form and function over two …
Resource Legacies And Priming Regulate Microbial Communities In Antarctica's Dry Valleys, Sabrina Deni Saurey
Resource Legacies And Priming Regulate Microbial Communities In Antarctica's Dry Valleys, Sabrina Deni Saurey
Theses and Dissertations
Multiple mechanisms control bacterial community structure but two in particular, the "legacy" of past environmental conditions, and the "priming" of bacteria to respond to seasonal or reoccurring fluctuations in resources, have the potential to determine both bacterial communities, as well as, temporal shifts in active bacterial taxa. To begin to evaluate the legacy effects of resources on microbial communities, we added four limiting resources annually (i.e., water only; C-mannitol + water; N-NH4NO3 + water; and C, N + water) and measured shifts in bacterial community composition after seven years in a cold desert ecosystem in the McMurdo Dry Valleys, Antarctica. …
Hypersaline Lake Environments Exhibit Reduced Microbial Dormancy, Joshua Christopher Vert
Hypersaline Lake Environments Exhibit Reduced Microbial Dormancy, Joshua Christopher Vert
Theses and Dissertations
From acid seeps and deep-sea thermal vents to glacial ice and hypersaline lakes, extreme environments contain relatively simplified communities consisting of extremophiles that have evolved to survive and thrive under adverse abiotic conditions. In more neutral environments, microorganisms use dormancy as a common life history strategy to weather temporal fluctuations of resources or stresses until more 'optimal' conditions are present. It is unclear if dormancy is an essential survival mechanism for microorganisms in extreme environments; however, recent studies suggest that extreme environments may create stable conditions for extremophiles to the extent that dormancy is of less ecological importance. Using lake …