Thermal Diversity: the importance of a community perspective

In a Figure that Jon Shik says used a “shocking” color choice–but that the lead author (who is color blind) finds pleasant and peaceful–we plot the distribution of thermal maxima (or, CTmax, or “death temp”) of an assemblage of 87 ants from a Panama forest. Towards the left are  two measures of environmental temperature–“air temperature”, and the temperature the ants actually experience, that is,  the surfaces ants crawl upon. Note the differences in the distribution of thermal maxima for understory species versus those in the hot canopy. Finally, compare those distributions from a single tropical forest to those from Diamond’s excellent meta-analysis for ants from all around the world, and the best collection from those model organisms: lizards and fruit flies. 

Our takehome?  Tiny organisms experience superheated environments (think the steering wheel of your car on a hot day); ecological communities that experience change have a lot of thermal niches to shuffle; and the more we study the niches in a given community, and the environmental gradients they are adapted to, the more we need to deeply grok the biogeography of communities, not just populations, if we want to predict the ecological future of our planet. Oh, one more thing. Procyptocerus and Pseudomyrmex are high temperature champions; Cyphomyrmex and Strumigenys…not so much.

4 ants from BCI


Kaspari, M, NA Clay, J Lucas, SP Yanoviak, A Kay. (2015) Thermal adaptation generates a diversity of thermal limits in a rainforest ant community. Global Change Biology.

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