IMIS - Marine Onderzoeksgroepen

The central goal of nzTABS is to determine the primary abiotic drivers of biodiversity in the Dry Valleys, one of few ecosystems where such undertaking can be achieved. With the aid of a comprehensive GIS framework, we are on track to achieve this goal by examining community microbial sequence data in conjunction with a broad range of physicochemical parameters. This project currently involves over 29 senior investigators from 9 countries that encompass disciplines from geochemistry and geomorphology to population genetics and microbial ecology.
Initially a 220 km2 study area, consisting of Miers, Marshall, and Garwood Valleys as well as Shangri-La, was divided into more than 600 geographically and geologically distinct ice-free sectors (hereinafter “tiles”) using remote-sensing data and published soil maps. Tile boundaries were delineated where the combination of geographical and geological variables changed, and on-the-ground assessments were carried out in November 2008 to confirm the reliability of delineations. 554 tiles were chosen for sampling to encompass the entire range of geographical and geological heterogeneity. Sampling of soils and biological communities was carried out over two successive austral summers (January 2009 and January 2010). Surveys were conducted for vegetation (i.e., mosses, lichens, algal and cyanobacterial mats), lithic microbial communities, and invertebrates at each sampling site (verified by GPS to be inside its respective tile), followed by collection of bulk soil samples for additional analyses, including molecular analyses of bacteria (total and cyanobacteria-only) and fungi. In addition, a number of key variables were derived from satellite imagery, including surface soil temperature, a topographically derived ‘wetness index’, and distance to the coast. After quality control, data for 490 samples were included in the analysis.
All samples were collected on foot by hand from each location. All samples were collected during the month of January in each sampling year.
All samples were collected using sterile techniques and transferred frozen to the laboratory for continued analysis.