Biotic interactions are an unexpected yet critical control on the complexity of an abiotically driven polar ecosystem

• Published in: Communications Biology
• Main Authors: Lee, Charles K., Laughlin, Daniel C., Bottos, Eric M., Caruso, Tancredi, Joy, Kurt, Barrett, John E., Brabyn, Lars, Nielsen, Uffe N., Adams, Byron J., Wall, Diana H., Hopkins, David W., Pointing, Stephen B., McDonald, Ian R., Cowan, Don A., Banks, Jonathan C., Stichbury, Glen A., Jones, Irfon, Zawar-Reza, Peyman, Katurji, Marwan, Hogg, Ian D., Sparrow, Ashley D., Storey, Bryan C., Green, T. G. Allan, Cary, S. Craig
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Research 2019
• Subjects: Ecosystem; Biodiversity; Abiotic control; Biotic control; Biotic interaction; Antarctic; The Antarctic; New Zealand; Marsden; Antarc*
• Online Access: http://hdl.handle.net/2263/75433; https://doi.org/10.1038/s42003-018-0274-5

Abiotic and biotic factors control ecosystem biodiversity, but their relative contributions remain unclear. The ultraoligotrophic ecosystem of the Antarctic Dry Valleys, a simple yet highly heterogeneous ecosystem, is a natural laboratory well-suited for resolving the abiotic and biotic controls of community structure. We undertook a multidisciplinary investigation to capture ecologically relevant biotic and abiotic attributes of more than 500 sites in the Dry Valleys, encompassing observed landscape heterogeneities across more than 200 km2. Using richness of autotrophic and heterotrophic taxa as a proxy for functional complexity, we linked measured variables in a parsimonious yet comprehensive structural equation model that explained significant variations in biological complexity and identified landscape-scale and fine-scale abiotic factors as the primary drivers of diversity. However, the inclusion of linkages among functional groups was essential for constructing the best-fitting model. Our findings support the notion that biotic interactions make crucial contributions even in an extremely simple ecosystem. The New Zealand Foundation for Research, Science and Technology; the New Zealand Marsden Fund; the New Zealand Ministry of Business, Innovation and Employment; the United States National Science Foundation; and the UK Natural Environment Research Council, the Royal Society of London, and the Carnegie Trust for the Universities of Scotland. https://www.nature.com/commsbio am2020 Biochemistry Genetics Microbiology and Plant Pathology