At limits of life: multidisciplinary insights reveal environmental constraints on biotic diversity in continental Antarctica

PLoS One. 2012;7(9):e44578. doi: 10.1371/journal.pone.0044578. Epub 2012 Sep 19.

Abstract

Multitrophic communities that maintain the functionality of the extreme Antarctic terrestrial ecosystems, while the simplest of any natural community, are still challenging our knowledge about the limits to life on earth. In this study, we describe and interpret the linkage between the diversity of different trophic level communities to the geological morphology and soil geochemistry in the remote Transantarctic Mountains (Darwin Mountains, 80°S). We examined the distribution and diversity of biota (bacteria, cyanobacteria, lichens, algae, invertebrates) with respect to elevation, age of glacial drift sheets, and soil physicochemistry. Results showed an abiotic spatial gradient with respect to the diversity of the organisms across different trophic levels. More complex communities, in terms of trophic level diversity, were related to the weakly developed younger drifts (Hatherton and Britannia) with higher soil C/N ratio and lower total soluble salts content (thus lower conductivity). Our results indicate that an increase of ion concentration from younger to older drift regions drives a succession of complex to more simple communities, in terms of number of trophic levels and diversity within each group of organisms analysed. This study revealed that integrating diversity across multi-trophic levels of biotic communities with abiotic spatial heterogeneity and geological history is fundamental to understand environmental constraints influencing biological distribution in Antarctic soil ecosystems.

MeSH terms

  • Antarctic Regions
  • Biodiversity*
  • Ecosystem
  • Soil / analysis

Substances

  • Soil

Grants and funding

This study was conducted as part of the New Zealand Latitudinal Gradient Project (LGP), in connection with the New Zealand Terrestrial Antarctic Biocomplexity Survey (NZTABS) - a New Zealand International Polar Year program - supported through a grant from the Foundation for Research in Science and Technology, New Zealand to SCC, BCS and MIS. The study was also supported, by a grant from Australian Antarctic Division (project 2355 to MIS) and grants from the US National Science Foundation to SCC (OPP-0739648), and to RAV and DHW (MCM LTER OPP-0423595 and OPP-1115245). This study was partial funded by FCT through a Postdoctoral fellowship and a grant to CM (SFRH/BPD/76989/2011; PTDC/MAR/112723/2009) and by University of Porto and Santander Totta through a grant to CM. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.