XIVth International Colloquium on Soil Zoology and Ecology

Soils provide humans with a whole range of irreplaceable ecosystem services the production and maintenance of which are largely dependent on the actions of the animal communities which inhabit them. Apart from the substantial agricultural production made necessary by humanity’s demand for food, soils filter and store water, holding back erosion and flooding. They provide a large proportion of the nutrients necessary for plant growth and for maintaining biodiversity, and at the same time limit greenhouse-gas emissions by storing organic matter. They are a rich harbour of biodiversity. But their associated processes are barely understood.

Soil quality is often overlooked in farming practice. Yet it is one of the key factors for rendering ecosystem services. Soils become depleted by intensive cultivation, erosion, deforestation or pollution. Subsurface fauna communities, which play a prime role in the preservation and maintenance of this quality, are often largely eliminated by farming procedures in which they are not taken into account. Burrowing animals create soil structure which limits the impact of erosion and provides zones underground where water can accumulate. This underground activity also offers prospects for atmospheric detoxification by means of carbon sequestration, and control of methane production or of oxidising agents such as nitric oxide. Earthworms, termites and ants –known indeed as soil or ecosystem engineers- regulate the activity of smaller organisms, thereby controlling the various stages of soil biogeochemical cycles. They stimulate the auxiliary micro-organisms of plants while limiting the impact of parasites, for example extremely harmful soil nematodes. The presence and diversity of these animals is naturally an indicator of the “good health” of the land they inhabit.

Research on these aspects is vital at a time when the preoccupation of those in soil management is no longer solely straightforward agricultural production. These practitioners are concerned about farming’s negative effects on other ecosystem services this medium performs. The pieces of research presented will draw a picture of the range of influences the fauna exerts and set out for soil managers alternative methods and indices potentially useful for evaluation and adjustment of soil management practices and policies.

The symposium will be opened jointly by Mr Jean-Louis Buër, Director of the Ministerial Office of the French Secretary of State for Agriculture, Food, Fisheries and Rural Affairs, Mr Patrice Cayré, Director of Department Living resources of the Institut de recherche pour le développement and Mr Jean-Luc Nahel, president of the University of Rouen, demonstrating the interest in soil fauna research shared by the agricultural and scientific worlds.

This symposium is organised by the IRD UMR (mixed research unit) “Biodiversité et Fonctionnement du Sol” and the University of Rouen. Other partners have lent their support to this event: ADEME, Universities Paris VI and Paris XII, the French Ministry for Foreign Affairs and the CTA. Conservation of diversity in soils and development of new methods suitable for sustainable development are two necessities that were expressed at the 1992 Rio Earth Summit Conference.

The research work of UMR “Biodiversité et Fonctionnement du Sol”, headed by Patrick Lavelle, professor at University of Paris VI, responds to this dual requirement. In fact, this UMR is tackling these two objectives together, with the conviction that they are intimately bound together and cannot be achieved separately.

The importance of preserving biodiversity needs no further demonstration, but it is not always compatible with human activity and its impact on the environment. At the meeting point of two scientific worlds where there has been little exchange, the objective of the UMR “Biodiversité et Fonctionnement du Sol ” research team is to generate a truly cross-disciplinary approach which uses the concepts and tools from the two communities, soil scientists and ecologists.