Dr Ed Tanner, Senior Lecturer
Tropical Ecology
We have several current projects in the New World Tropics. Our main project is a study of the effects of litter removal and litter addition on: tree growth, soil and tree nutrient concentrations, and soil carbon dynamics in semi-deciduous forest at Barro Colorado Nature Monument in Panama. Six years of litter removal and addition, have had marked effects on soil respiration, soil nutrients, leaf and litter nutrients, and significant effects on litterfall in the wet season (but not over the whole year), but no significant effects on tree growth. Our most interesting findings are 1) that the extra soil respiration in L+ plots is more than the decrease in the L- plots (Sayer at al 2007); which, because tropical soils store almost 30% of global soil carbon, means that any increase in soil respiration as a result of increased litterfall (for example caused by climate change) could cause a large change in atmospheric carbon dioxide. 2) We have had more effect on nitrogen than on phosphorus, for example leaf N is significantly higher in litter addition plots, leaf P is not higher (Sayer & Tanner 2010 Journal of Ecology, in press) 3) we have discovered a much faster way of estimating root respiration (Sayer & Tanner 2010).
In a separate study in Panama on the role of roots and mycorrhizas in 'soil' respiration we have discovered that mycorrhizas account for 14% of total soil respiration and 26% of 'root derived' respiration (Nottingham et al 2010); thus mycorrhizas are significant players in the global carbon cycle.
We also have a long term research in the Blue Mountains of Jamaica, where we are studying forest dynamics. We discovered that Hurricane Gilbert (in 1988) increased tree growth and increased tree diversity (Tanner and Bellingham 2006). In a much wider ranging study Shauna Chai (Chai et al. 2009) has shown that rates of deforestation in the Blue mountains National Park were not different in the decade before and the decade after the park was created, this (and other research in S E Asia) shows that simply creating parks is not going to conserve forests.
- Quick Links:
- PhD Studentships
- In the UK:
- Oxford Forestry Institute
- Royal Botanic Gardens, Kew
- Outside the UK:
- Smithsonian Tropical Research Institute (Panama)
- Tropical Forestry Research Centre (Australia)
- Contact us:
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Department of Plant Sciences
University of Cambridge
Downing Site Downing Street
CAMBRIDGE CB2 3EA
Email: evt1@cam.ac.uk
Office +44 (0)1223 333912
Litter removal plot in the litter manipulation experiment at BCNM Panama with Emma Sayer and the soil IRGA