Flanagan, Patrick Hilton. Limited responses of benthic marine communities to local temperature changes. Retrieved from https://doi.org/doi:10.7282/T3JM2D3B
DescriptionAs global climate change and variability drive changes in regional and local temperatures, species’ distributions are shifting, leading to changes in ecological communities. One approach to the problem of anticipating community change has been to characterize communities by a collective thermal preference, or community temperature index (CTI), and then to compare changes in CTI with changes in temperature. However, this method has been tested in only a few ecosystems, and it carries untested assumptions about the responsiveness of communities to changes in their local thermal environments. We used CTI to analyze changes in benthic marine communities along the continental shelf of the Northeast United States. We found that, while community composition was associated with bottom temperature, communities responded much more strongly to interannual variation than to long-term trends in temperature, and a mixed-effects model found that for every 1 oC increase in bottom temperature, CTI increased by 0.38 oC. We also showed that nonlinear species’ responses to temperature scale up to nonlinear community responses to temperature change. Future research into community change with increasing global temperatures should take into account these nonlinear responses, as well as examine the relative importance of interannual fluctuations and decadal trends.