Adriane Aupic-Samain, Virginie Baldy, Ninon Delcourt, Paul Henning Krogh, Thierry Gauquelin, Catherine Fernandez, Mathieu Santonja
With the ongoing climate change, soil biodiversity could be strongly impacted with major consequences for ecosystem processes. Among soil biodiversity, detritivores such as Collembola (springtails) play a major role in plant litter decomposition. Thus, it is of prime interest to improve our knowledge of the impact of climate change (i.e. increasing temperature and decreasing precipitation) on collembolan communities. Under laboratory conditions we applied a decreased level of soil moisture (60% vs. 30% soil water holding capacity) and an increased air temperature (15 °C vs. 25 °C) to a collembolan community consisting of four species (Folsomia candida, Protaphorura fimata, Proisotoma minuta and Mesaphorura macrochaeta) in the presence or absence of a predatory mite (Stratiolaelaps scimitus). The four collembola species exhibited a combination of two distinct functional traits: i) small or large body size and ii) presence or absence of a furca, which is a jumping organ that allows collembola to escape predators. After two months, lower soil moisture altered the composition of the collembolan community due to species-specific responses to hydric stress. In addition, the impact of predation on the collembolan community was amplified under low soil moisture. While total collembola abundance was higher with increasing temperature under optimal soil moisture, decreasing soil moisture suppressed this positive warming effect.
Our findings are highly important since a strengthening of predation impact on Collembola prey could have major consequences for the whole soil food web, leading to a slowdown of key ecosystem processes they drive (e.g., litter decomposition and nutrient recycling). Finally, our findings highlight the need for scientists to study distinct soil-dwelling species, their morphological traits and their prey-predator relationships to better predict ecosystem responses to ongoing climate change.