Short- and long-term conditioning of a temperate marine diatom community to acidification and warming

• Published in: Philosophical Transactions of the Royal Society B: Biological Sciences
• Main Authors: Tatters, AO, Roleda, MY, Schnetzera, A, Fu, F, Hurd, CL, Boyd, PW, Caron, DA, Lie, AAY, Hoffman, LJ, Hutchins, DA
• Format: Article in Journal/Newspaper
• Language: English
• Published: The Royal Society Publishing 2013
• Subjects: Environmental Sciences; Ecological Applications; Ecological Impacts of Climate Change; Ocean acidification
• Online Access: https://doi.org/10.1098/rstb.2012.0437; http://www.ncbi.nlm.nih.gov/pubmed/23980240; http://ecite.utas.edu.au/89042

Ocean acidification and greenhouse warming will interactively influencecompetitive success of key phytoplankton groups such as diatoms, buthow long-term responses to global change will affect community structureis unknown. We incubated a mixed natural diatom community from coastalNew Zealand waters in a short-term (two-week) incubation experimentusing a factorial matrix of warming and/or elevated pCO2 and measuredeffects on community structure. We then isolated the dominant diatoms inclonal cultures and conditioned them for 1 year under the same temperatureand pCO2 conditions from which they were isolated, in order to allow forextended selection or acclimation by these abiotic environmental change factorsin the absence of interspecific interactions. These conditioned isolateswere then recombined into artificial communities modelled after the originalnatural assemblage and allowed to compete under conditions identical tothose in the short-term natural community experiment. In general, the resultingstructure of both the unconditioned natural community and conditionedartificial community experiments was similar, despite differences such asthe loss of two species in the latter. pCO2 and temperature had both individualand interactive effects on community structure, but temperature was moreinfluential, as warming significantly reduced species richness. In this case,our short-term manipulative experiment with a mixed natural assemblagespanning weeks served as a reasonable proxy to predict the effects of globalchange forcing on diatom community structure after the component specieswere conditioned in isolation over an extended timescale. Future studies willbe required to assess whether or not this is also the case for other types ofalgal communities from other marine regimes.