Crust sessions at 2012 EGU Assembly

In case you needed an excuse to visit Vienna: two sessions have been organized which will prominently feature biological crusts.

European Geoscience Union General Assembly, Vienna, Austria 22-27.
April 2012.
Biological soil crusts and ecogeomorphological processes

Conveners : Giora J Kidron, Burkhard Büdel, Jayne Belnap, Xin-Rong Li

Situated at the atmosphere-soil boundary, biological soil crust (BSC) plays an important role in the ecology and microbiology of ecosystems. It plays an important role in C and N cycling and plant germination. But it also plays a seminal role in geomorphological processes such as eolian, hydrological, and pedological processes. BSC may effectively impede wind erosion or water flow. Yet, due to hydrophobic properties or extra cellular polysaccharides that act to clog the surface, the crust may also trigger runoff, which may result in nutrient and sediment translocation. The crust may also affect pedological processes either as a result of its organic matter content or due to microorganism-mineral interactions. Focusing on abiotic-biotic relations, this session will examine the abiotic variables responsible for crust establishment and will explore the crust properties and the crust effect on ecogeomorphological and pedological processes responsible for shaping our environment.

Dynamics of soil surface characteristics (including physical and biological soil crusts): consequences on soil functionning and role of climate and land use change

Conveners : O. Cerdan
Co-Conveners : O. Malam Issa, B. Marin, J.L. Rajot


At the interface between the atmosphere and the pedosphere, soil surface characteristics (SSC) have a strong impact on soil functioning. Soil surface characteristics are subjected to changes driven by several interactions between water, air and biotic and abiotic components under the controls of climate and human activity. Illustrative examples of such interactions are provided through crusts formation pattern in arid environments like Sahel where land overuses and drought lead to soil denudation, changes in vegetation pattern and development of physical and biological soil crusts in the plant interspaces. The characteristics and formation of these crusts influence the hydrological balance, control the mass of eroded sediment and influence plant productivity through the modification of nitrogen and carbon cycle. This session provides an opportunity to address recent developments in the comprehension of the environmental importance of soil surface characteristics. The session will focus on changes of soil surface structure due to climate and soil uses and its impact. We are expecting to gather observations from different climatic areas investigating the impact of soil surface characteristics dynamics at small and large temporal and spatial scales. The following questions will be addressed: How climate change and land uses change will affect soil surface characteristics and how this in turn will affect soil properties and functioning? How the structure and composition of communities living at soil surface affects ecosystem processes, functioning and stability of the environment? Contributions dealing with detection and mapping of the spatial distribution of soil surface characteristics are also particularly welcome.