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Project 5 (phase I):

Structure and function of biocrusts in weathering, soil formation and erosion processes (CRUSTWEATHERING)

 

Investigator Names and Contact Info:

  • Ulf Karsten (Ecophysiology). Applied Ecology & Phycology, Institute of Biological Sciences, University of Rostock, Germany
  • Burkhard Büdel (Geoecology). Institute of Biology, Department Plant Ecology and Systematics, Technical University of Kaiserslautern, Germany
  • Peter Leinweber (Soil Science). Faculty of Agricultural and Environmental Sciences, University of Rostock, Germany
  • Jörg Bendix (Geography). Institute of Geography, Department of Climatology and Remote Sensing, University of Marburg, Germany

 

Chilean Collaborators Involved:

  • Pablo Osses (Physical Geography). Centro del Desierto de Atacama & Pontifical Catholic University of Chile, Chile

 

 

 

Project 5a:

Physiological, biochemical and molecular-taxonomical studies on biocrust organisms with a main focus on microorganisms and bioweathering mechanisms to address structure and function.

Supervisor: Prof. Ulf Karsten, Co-supervisor: Prof. Burkhard Büdel

 

 

Ökophysiologische Reaktion der weit verbreiteten terrestrischen Alge Klebsormidium isoliert aus verschiedenen Klimazonen.

BSc-Student:

 

Supervisor: Prof. Ulf Karsten, Co-supervisor: Dr. Karin Glaser

 

Project 5b:

Geoecological, ecophysiological and taxonomical studies on biocrust lichens and mosses to address areal coverage and saisonal photosynthetic activity.

 

PhD-student:

Supervisor: Prof. Burkhard Büdel, Co-supervisor: Prof. Jörg Bendix

 

 

Ecophysiology and Structure of crustose versus epiphytic chlorolichens of the Atacama Desert.

 

MSc-student:

  • Dina Emrich. University of Kaiserslautern, Germany

Supervisor: Prof. Burkhard Büdel

 

 

 

A comparative study about photosynthetic reactivation of epiphytic fruticose chlorolichens by air humidity: their ecophysiological performance, morphology and photobiont-phylogeny.

 

MSc-student:

  • Lena Weber. University of Kaiserslautern, Germany

Supervisor: Prof. Burkhard Büdel

 

Project 5c:

Chemical analyses of proxies for the weathering intensity, characterisation of organic matter fractions/dynamics, and investigation of the role of biocrusts in the P cycling from single grain- up to soil profile/slope/catchment-scale.

 

Postdoc:

Supervisor: Prof. Peter Leinweber, Co-supervisor: Prof. Ulf Karsten

 

Project 5d:

Climatic control of biocrusts, and multi-/hyperspectral detection of crusts as well as related weathering and soil formation processes by remote sensing for selected catchments.

 

Postdoc:

Supervisor: Prof. Jörg Bendix, Co-supervisor: Prof. Burkhard Büdel

 

Hyperspectral remote sensing of biological soil crusts in the Atacama Desert.

 

MSc-student:

  • Jakob Schmidt. University of Marburg, Germany

Supervisor: Prof. Jörg Bendix, Co-supervisor: Prof. Burkhard Büdel

 

Project Summary:

On a global scale, biological soil crusts (biocrusts) form the most productive microbial biomass in arid regions. Biocrusts are formed by living organisms such as heterotrophic bacteria, fungi, lichens, bryophytes, cyanobacteria and algae and their by-products, creating a top-soil layer of inorganic particles bound together by organic materials. They can be characterized as “ecosystem-engineers” forming water-stable, aggregated surface layers that have important multi-functional ecological roles in primary production, mineralization, bioweathering, dust trapping, and the stabilization of soils, slopes and entire landscapes, thereby affecting the nutrient and hydrological cycles across scales. Intensive literature reviews made us aware that these communities are almost unstudied in South America, although highly abundant in the study areas of the Priority Programme. Therefore, the objectives of this interdisciplinary proposal are to 1) evaluate the almost unknown community structure of Chilean biocrust types using a combination of field and laboratory methods to address the relative abundance of the full spectrum of biocrust organisms, particularly with regard to their role in weathering and landscape forming processes (who is doing what?); 2) disclose which of the abundant organisms contribute by which biochemical processes to bioweathering, and quantify the reaction rates in relation to community structure and environmental conditions; 3) uncover the function of biocrusts in the coupled biogeochemical cycling of P- (particular emphasis!), C- and N-compounds across spatial scales from the atomic/molecular-, the single mineral grain-, biocrust patch- and soil profile- up to the slope/catchment-scale, the latter with the help of remotely sensed spectral data and jointly developed transfer functions; 4) understand how microclimatic conditions and water availability determine the biocrust community structure and activity, coverage and their functioning in the arid ecosystems. 5) Upscaling of 1-4 with remote sensing data to catchments of the PP. The expected results will not only disclose presently unknown biocrust organisms and their physiological and ecological functioning but also enlighten their contribution to bioweathering and fundamental Earth-shaping processes, and provide overall knowledge and data background for regional or global-scale geosystem models.