Growth dynamics of a laminated microbial mat in response to
Details of Research
TitleGrowth dynamics of a laminated microbial mat in response to variable irradiance in an Antarctic lakeAbstractLaminated microbial mats are important ecosystem components of perennially ice-covered Antarctic dry valley lakes. In order to understand better their response to changing environment, we made observations and carried out a manipulation experiment to determine their response to variations in irradiance in Lake Hoare (77°38′ S, 162°53′ E). Ice transparency was the most variable parameter that affected benthic light dose, both spatially and between years. Patterns of lamina accrual corresponded to irradiance history, with laminae that were initiated in high transmission years thicker than those from low transmission years. A shading experiment confirmed that accrual of lamina thickness, calcite precipitation and ash-free dry mass were determined by irradiance, but photosynthetic biomass and phototrophic species composition were less affected. Buried laminae decomposed only slowly over time, with potentially viable phototrophs many laminae down into the microbial mat. Decay rate increased only slightly with shading. We conclude that the microbial mats in Lake Hoare are characterised by remarkable stability, with slow accumulation rates and turnover of biomass over time. Photosynthetic biomass and species composition appeared to be stable across long time periods, with interannual variation in lamination pattern due to differential accumulation of extracellular polysaccharide and representing the visible expression of annual growth conditions. Copyright 2016 John Wiley and Sons Ltd.AcknowledgementsFunding for this long research came from the U.S. National Science Foundation via the MCM-LTER grant numbers, 0832755, 0096250, 1041742 and 1115245 and from the New Zealand Ministry of Research, Science and Technology through grant CO1605. Logistic supportwas from the U.S. Antarctic Program and Antarctica New Zealand. We thank the many colleagues who have assisted with this research over many years, particularly the diver support from the McMurdo Station Dive Locker, Robin Ellwood, Richard Costello, Tyler Mackey and Aslan Wright-Stow. LTER colleagues, particularly Dr John Priscu, made long-term monitoring data available and consistently supported this research. We are particularly grateful to the efforts of the editorial teamand to two anonymous reviewers whose thoughtful suggestions greatly enhanced the article.
1st AuthorHawes, I.AuthorHawes, I.Jungblut, A.Obryk, M.Doran, P.Year2016JournalFreshwater BiologyVolume61Number4Pages396-410DOI10.1111/fwb.12715URLhttps://www.scopus.com/inward/recor.....2b06480bc2aab50329e460eb6Keywordsrank5Author Keywords16S rRNA geneBenthicCyanobacteriaEnvironmental changeLake FryxellProgrammeK081 - Aquatic Ecosystems
TypeArticleCitationHawes, I., Jungblut, A., Obryk, M. and Doran, P. (2016). Growth dynamics of a laminated microbial mat in response to variable irradiance in an Antarctic lake. Freshwater Biology, 61(4): 396-410
Antarctica NZ (29th Nov 2018). Growth dynamics of a laminated microbial mat in response to . In Website Antarctica NZ. Retrieved 28th Nov 2020 14:14, from https://adam.antarcticanz.govt.nz/nodes/view/63545