Microclimates mitigate against hot temperatures in dryland ecosystems: termite mounds as an example

Termite mounds have recently been shown to protect against drought by providing refuges for plants and foci for revegetation, but whether mounds modulate temperature remains untested. Organisms tend to experience climate at finer scales than those captured by models predicting how distributions alter with global change, so microclimates represent important "climate refuges." Using data we collected from African savanna sites, generalized linear mixed-effects models and linear quantile regression analysis confirm for the first time that the woody species associated with large termite mounds establish microclimates that are significantly cooler than surrounding savannas, a cooling effect that is even greater at warmer extremes. As air temperatures approached 40 degrees C, a cooling effect of up to 4 degrees C occurred, representing a doubling from that observed at 34 degrees C. African savannas encompass 10 million km(2), and much of this harbors evenly dispersed termitaria. The temperature-modulating effect of mounds facilitates agricultural and conservation decision-making as global change begins to impact the integrity of both human well-being and ecological processes.