Camille D Hervilly

I am a soil ecologist, and focus on soil macrofauna (it includes earthworms but also some large arthropods such as millipedes and woodlice). I particularly study how soil fauna affects the decomposition process. Decomposition involves all the changes that affect the dead organic matter, ultimately leading to the release of carbon as CO2 (mineralization). If mineralization is mostly performed by soil microorganisms, soil fauna plays a major role in the process by regulating the availability of the organic matter to microorganisms. My work aims at understanding the mechanisms involved in the decomposition process in the presence of macrofauna. I investigate where and under which forms the organic matter is stored in the soil, the carbon and nutrient dynamics associated with decomposition and the impact on microbial communities. This involves at the present time experiments in pots and mesocosms, manipulating the macrofaunal community.

In some ecosystems, macrofauna is absent, and these provide an ideal situation to investigate their impact. This is for example the case in artic tundra and boreal forests, where earthworms disappeared after the last glaciation. These ecosystems store a huge part of the global carbon pool in their soil, what has been mostly attributed to the low temperatures. However, climate change and increased dispersal of earthworms due to human activity could lead to an invasion of these ecosystems by non-native earthworms. This could induce substantial changes, as suggested by studies of invaded forests in North America. It could particularly lead to the release of a huge portion of the carbon stored in the soil as CO2, switching these ecosystems from carbon sinks to carbon sources. The final effect of earthworms is however more complex than that, as they have antagonist effects on the fate of carbon in the soil, and as decomposition is a complex process involving interaction between many organisms including microorganisms and plants. My work at EMG will be directed towards the dynamics of the soil organic matter in these particular ecosystems, on which I am working in the terrestrial ecology group (with Gesche Blume-Werry, and Eva Krab from SLU).

I am also investigating these processes in post mining sites, which are another type of earthworm-deprived ecosystem, following a postdoc at the Institute for Environmental Studies of The Charles University in Prague (Czech Republic). Some of my previous work (at INRAE Montpellier, France) also focused on the spatial heterogeneity of soil macrofauna and soil organic matter distribution in alley cropping agroforestry systems, which have been suggested as a more sustainable way to produce crops.