Document Type
Article
Department/Program
Virginia Institute of Marine Science
Publication Date
2009
Journal
Biogeosciences
Volume
6
Issue
12
First Page
3131
Last Page
3147
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 (+4 degrees C) 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.
DOI
10.5194/bg-6-3131-2009
Keywords
Euphausia-superba Dana; Ross Sea; Southern-Ocean; Community Structure
Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.
Recommended Citation
Rose, J. M.; Feng, Y.; al, et; Smith, Walker O. Jr.; Sigist, B.; Tozzi, S.; and al, et, Synergistic effects of iron and temperature on Antarctic phytoplankton and microzooplankton assemblages (2009). Biogeosciences, 6(12), 3131-3147.
10.5194/bg-6-3131-2009
