alga
; bacterium
; bedrock
; carbon fixation
; geomicrobiology
; glacial environment
; microbial community
; nitrogen cycle
; nutrient dynamics
; phosphate
; photoautotrophy
; photosynthesis
; primary production
; snow
; solar radiation
; stratovolcano
; Cascade Range
; Pacific Northwest
; United States
; algae
; algal DNA
; ribosome DNA
; RNA 16S
; RNA 18S
; snow
; bacterium
; biota
; carbon cycle
; chemistry
; classification
; cluster analysis
; DNA sequence
; genetics
; metabolism
; microalga
; microbiology
; phylogeny
; United States
; Bacteria
; Biota
; Carbon Cycle
; Cluster Analysis
; DNA, Algal
; DNA, Ribosomal
; Microalgae
; Northwestern United States
; Phylogeny
; RNA, Ribosomal, 16S
; RNA, Ribosomal, 18S
; Sequence Analysis, DNA
; Snow
Scopus学科分类:
Earth and Planetary Sciences: General Earth and Planetary Sciences
; Environmental Science: General Environmental Science
; Agricultural and Biological Sciences: Ecology, Evolution, Behavior and Systematic
英文摘要:
The majority of geomicrobiological research conducted on glacial systems to date has focused on glaciers that override primarily carbonate or granitic bedrock types, with little known of the processes that support microbial life in glacial systems overriding volcanic terrains (e.g., basalt or andesite). To better constrain the role of the supraglacial ecosystems in the carbon and nitrogen cycles, to gain insight into microbiome composition and function in alpine glacial systems overriding volcanic terrains, and to constrain potential elemental sequestration or release through weathering processes associated with snow algae communities, we examined the microbial community structure and primary productivity of snow algae communities on stratovolcanoes in the Cascade Range of the Pacific Northwest. Here, we present the first published values for carbon fixation rates of snow algae communities on glaciers in the Pacific Northwest. We observed varying levels of light-dependent carbon fixation on supraglacial and periglacial snowfields at Mt. Hood, Mt. Adams, and North Sister. Recovery of abundant 18S rRNA transcripts affiliated with photoautotrophs and 16S rRNA transcripts affiliated with heterotrophic bacteria is consistent with previous studies indicating the majority of primary productivity on snow and ice can be attributed to photoautotrophs. In contrast to previous observations of glacial ecosystems, our geochemical, isotopic, and microcosm data suggest these assemblages are not limited by phosphorus or fixed nitrogen availability. Furthermore, our data indicate these snow algae communities actively sequester Fe, Mn, and P leached from minerals sourced from the local rocks. Our observations of light-dependent primary productivity on snow are consistent with similar studies in polar ecosystems; however, our data may suggest that DIC may be a limiting nutrient in contrast to phosphorus or fixed nitrogen as has been observed in other glacial ecosystems. Our data underscore the need for similar studies on glacier surfaces and seasonal snowfields to better constrain the role of local bedrock and nutrient delivery on carbon fixation and biogeochemical cycling in these ecosystems. � 2016 The Authors. Geobiology Published by John Wiley & Sons Ltd
Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, United States; Department of Geology, University of Cincinnati, Cincinnati, OH, United States
Recommended Citation:
Hamilton T.L.,Havig J.. Primary productivity of snow algae communities on stratovolcanoes of the Pacific Northwest[J]. Geobiology,2017-01-01,15(2)