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Harvard Forest Symposium Abstract 2011

• Title: No effect of temperature on wood decomposition after one year in the "warm ants" chambers
• Primary Author: Emily Austin (University of Tennessee at Knoxville)
• Additional Authors: Aimee Classen (University of Tennessee at Knoxville); Rob Dunn (North Carolina State University at Raleigh); Aaron Ellison (Harvard University); Nathan Sanders (University of Tennessee at Knoxville)
• Abstract:

  Woody debris is an important global carbon (C) pool and decomposition may represent a positive feedback to climate change as respiration generally increases exponentially with temperature (Lloyd and Taylor, 1994). This response could be vital to future carbon cycling as the Intergovernmental Panel on Climate Change (2007) predicts that global temperatures will increase by 1.1- 6.4 °C by 2100. Fungi likely play a large role in C and nutrient cycling in forests as enzymes excreted by fungi allow metabolism of recalcitrant organic substrates, such as lignin and cellulose to which few other organisms have access (Cooke and Rayner, 1984). In total, fungi produce up to 90% of soil respiration (Kirk and Farrell, 1987). I was interested to see how climatic warming may affect the structure and function of wood decomposing fungal communities.
  
  
  
  In 2009, I installed four logs of locally acquired Red Maple (Acer rubrum) in each of twelve 5-m open-top warming chambers (plus three chamber controls) at each of two sites, the Harvard Forest Long Term Ecological Research site, in Petersham, Massachussetts, and the Yates Forest at Duke University. Five living trees were felled from hardwood stands near each site and divided into segments 40-cm long and 20-40cm in diameter. Eight small A. rubrum twigs were placed in separate 6 x18cm decomposition bags in each chamber. The first removal took place during the summer of 2010 (1 year). Mass loss has been assessed on a dry mass basis for these samples. We found no significant trends of mass loss across a regression of temperatures at either site. Wood quality, functional gene copy number, arthropod community structure, and bacteria: fungal abundance will be measured for the first to removals during 2011-2012.
  
  
  
  References:
  
  Cooke, R. C. and A. D. M. Rayner. 1984. Ecology of saprotrophic fungi. Longman, New York.
  
  IPCC. 2007. Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, UK.
  
  Kirk, T. K. and R. L. Farrell. 1987. Enzymatic combustion - the microbial-degradation of lignin. Annual Review of Microbiology 41:465-505.
  
  Kjoller, A. and S. Struwe. 1982. Microfungi in ecosystems - fungal occurrence and activity in litter and soil. Oikos 39:389-&.
  
  Lloyd, J. and J. A. Taylor. 1994. On the temperature-dependence of soil respiration. Functional Ecology 8:315-323.
  
  

• Research Category: Group Projects


• Figures:
austin,ee_HFabstract2011_Fig1.pdf