Ecology of Terrestrial Hot Springs
High temperature affects ecosystem functions in ways that are very important but poorly understood. For example, above 73°C, photosynthesis cannot operate so organisms must gain energy by catalyzing oxidation-reduction reactions involving inorganic compounds, a process called chemolithotrophy. Major goals in the Hedlund lab include definition the upper temperature limits of various ecosystem processes, identification of organisms that carry out ecosystem processes at or near these limits, and elucidation of how these limits affect the biogeochemical cycles of geothermal environments.
For these studies, our research is primarily in hot springs in the U.S. Great Basin and in the Tengchong region of Yunnan Province, China. By studying at least two geologically and geographically distinct geothermal regions we hope to begin to identify common themes in terrestrial geothermal biology and to disentangle the roles of geological setting and geographic location in defining microbial community structure and function. These studies involve, careful study of the chemistry and mineralogy of geothermal springs, measurement of microbial activities in situ, identification and enumeration of microorganisms of interest in geothermal ecosystems, microbial cultivation, and various genomic approaches, including metagenomics, single-cell genomics, and genomics of microbial isolates of interest.
This research is made possible through many strong collaborations, particularly with the Tengchong PIRE team, and generous funding from the National Science Foundation (NSF) and the Department of Energy (DOE).
This work will allow us to better understand the foundations of life in hot springs and expand our knowledge of the diversity of life on Earth.
How Does Temperature Affect Biogeochemical Cycles?
Looking into Smith Creek Hot Spring, Nevada.