Claudia Colesie
Ph.D. Student

Faculty of Biology, Plant Ecology and Systematics
University of Kaiserslautern, Building 13/213
67663 Kaiserslautern
Phone: 0049 (0)631 205 4402
Fax: 0049 (0)631 205 2998
claudia.colesie@biologie.uni-kl.de

RESEARCH | TEACHING | PUBLICATIONS

Research interest

Investigation area

The McMurdo Dry Valleys are amongst the driest regions of the earth. Water availability is limited by very low precipitation, always in the form of snow. Liquid water only occurs with direct sunlight, resulting in melting of snow/ice. However, extremely low relative air humidity and strong, almost permanent winds increase the rapid loss of water by sublimation into air.

Diversity

Antarctic Dry Valleys: Several microbial autotrophic life forms have been found: endolithic biofilms composed of mainly cyanobacteria (17 species), sometimes with additional green algae, and biological soil crusts composed of green algal lichens (4-5 species), few mosses (5 species), intermingled with green algae (5 species) and black fungal hyphae.

Biomass

Biological soil crusts were discovered so far at the Darwin Glacier area and in the Garwood Valley, Antarctica. They reached a biomass of 1.7 g organic carbon/m² (17.9 g total carbon/m²). The chlorophyll_a+b content varied from 120 - 229 mg Chl_a+b/m².

Water

Our investigations clearly showed that condensation of water on rock surfaces via dew point reduction is a frequent and important source of water besides melts water from snowfall for endolithic cyanobacterial communities.

Photosynthesis

First CO₂-gas exchange measurements on biological soil crusts in the field and in the laboratory showed that the crusts need a high amount of water to perform positive net photosynthesis compared with crusts from other geographical regions. They reach their optimum at low temperatures and are active even below zero. Characteristic seems to be a high ratio of net photosynthesis/respiration. 

Biological Soil Crusts as an Ecosystem Component: Ecology and Carbon dynamics of polar soil-crust communities

Diversity and ecology of autotrophic  terrestrial life forms on rock and soil in the Antarctic Dry Valleys.

Facilities

Photosynthesis factor analysis (CMS 400, HCM 1000 (Walz))

Electronmicroscopy and 3-D structure analysis with elemental mapping (ZEISS LT-SEM Supra 55 VP )

Lightmicroscopy

Carbon allocation in lichens

Microclimate measurements