MITI SMEEB

How do small mammals influence plant biodiversity in the Succulent Karoo, one of the most diverse biodiversity hotspots with a high number of endemic plant species? We have been running a 24‐year long project, monitoring plant and small mammal biodiversity in this vulnerable ecosystem. Our long‐term monitoring provides data and background for a comprehensive understanding of the functioning of this ecosystem. Small mammals can reach high population densities here and are known to positively influence the plant biodiversity. In our study site, bush Karoo rats build extensive stick lodges as a foraging base, reducing the abundance of dominant plant species around lodges and creating space for other species to thrive. Here we seek funding for an interdisciplinary team with INSU (carbon dating and soil chemistry) and INEE (biodiversity) to study the ecology of bush Karoo rat stick lodges, i.e. their construction, function, and their influence on soil dynamics and ultimately ecosystem functioning. We predict that lodges (i) are decades old and used by many generations, (ii) they function as a refuge against cold winter nights with an inbuilt heating system via decomposition of plant material in moist winters, (iii) they have a positive impact on soil composition, locally enriching soils with organic matter (carbon and nitrogen), increasing plant biodiversity and plant biomass.

This project will lead to international and interdisciplinary collaborations opening new avenues of research into socio‐ecology, soil ecology, and ultimately the impact of climate change in a biodiversity hotspot. One aim will be to attract additional researchers that are focussing on topics other than behavioural ecology to this research station, which is the only one in the Succulent Karoo. In the long term, it could then join an international CNRS laboratory in South Africa. This MITI project will contribute important data for future interdisciplinary grants (ANR, ERC etc) that will provide funding to maintain the long‐term monitoring program.

LSCE contribution: LSCE will provide key elements for understanding the impact of the presence and activity of Bush Karoo Rats on soil carbon dynamics.