Title Synergistic effects of iron and temperature on Antarctic phytoplankton and microzooplankton assemblages
Author Rose, J.M.; Feng, Y.; DiTullio, G.R.; Dunbar, R.B.; Hare, C.E.; Lee, P.A.; Lohan, M.; Long, M.; Smith, W.O.; Sohst, B.; Tozzi, S.; Zhang, Y.; Hutchins, D.A.
Author Affil Rose, J.M., Woods Hole Oceanographic Institution, Biology Department, Woods Hole, MA. Other: University of Southern California; College of Charleston; Stanford University; University of Delaware; University of Plymouth, United Kingdom; College of William and Mary; Old Dominion University
Source Biogeosciences, 6(12), p.3131-3147, . Publisher: Copernicus GmbH on behalf of the European Union, Katlenburg-Lindau, International. ISSN: 1726- 4170
Publication Date 2009
Notes In English. Part of special issue no. 46, Iron biogeochemistry across marine systems at changing times, edited by Turner, D., Hunter, K. and Riebesell, U., http://www.biogeosciences.net/special_issue46.h tml; published in Biogeosciences Discussions: 19 June 2009, http://www.biogeosciences- discuss.net/6/5849/2009/bgd-6-5849-2009.html; accessed in March, 2011; abstract: doi: 10.5194/bg-6-3131-2009. 96 refs. Ant. Acc. No: 91582. GeoRef Acc. No: 310489
Index Terms algae; animals; chlorophylls; climatic change; ecosystems; global change; global warming; ice; melting; metals; plankton; statistical analysis; temperature; Antarctica; Southern Ocean--Ross Sea; algal blooms; assemblages; biota; carbon; chlorophyll; climate change; diatoms; iron; multivariate analysis; nitrogen; nutrients; organic compounds; Phaeocystis antarctica; phosphorus; photochemistry; phytoplankton; pigments; Plantae; porphyrins; productivity; Ross Sea; sea ice; seasonal variations; silica; Southern Ocean; sulfur; zooplankton
Abstract Iron availability and temperature are important limiting factors for the biota in many areas of the world ocean, and both have been predicted to change in future climate scenarios. However, the impacts of combined changes in these two key factors on microbial trophic dynamics and nutrient cycling are unknown. We examined the relative effects of iron addition (+1 nM) and increased temperature (+4C) on plankton assemblages of the Ross Sea, Antarctica, a region characterized by annual algal blooms and an active microbial community. Increased iron and temperature individually had consistently significant but relatively minor positive effects on total phytoplankton abundance, phytoplankton and microzooplankton community composition, as well as photosynthetic parameters and nutrient drawdown. Unexpectedly, increased iron had a consistently negative impact on microzooplankton abundance, most likely a secondary response to changes in phytoplankton community composition. When iron and temperature were increased in concert, the resulting interactive effects were greatly magnified. This synergy between iron and temperature increases would not have been predictable by examining the effects of each variable individually. Our results suggest the possibility that if iron availability increases under future climate regimes, the impacts of predicted temperature increases on plankton assemblages in polar regions could be significantly enhanced. Such synergistic and antagonistic interactions between individual climate change variables highlight the importance of multivariate studies for marine global change experiments.
URL http://www.biogeosciences.net/6/3131/2009/bg-6-3131-2009.pdf
Publication Type journal article
Record ID 65007112