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Methane and nitrous oxide fluxes from the tropical Andes

12 November 2013, 11am: Free
at the James Hutton Institute, Aberdeen AB15 8QH
for scientists, students and other interested parties
Yit Arn Teh

This seminar entitled "Methane and nitrous oxide fluxes from the tropical Andes" will be given by Dr Yit Arn Teh of the University of Aberdeen at the James Hutton Institute in Aberdeen. It will be broadcast live to the Dundee site.


Remote sensing and inverse modelling studies indicate that the tropics emit more methane (CH4) and nitrous oxide (N2O) than predicted by bottom-up emissions inventories, suggesting that terrestrial sources are stronger than previously thought. Tropical uplands are a potentially large and important source of CH4 and N2O but have often been overlooked by past empirical and modelling studies. We investigated spatial, temporal and environmental trends in CH4 and N2O fluxes across a long elevation gradient in the Kosñipata Valley, in the southern Peruvian Andes.

Ecosystems across this altitudinal gradient were both atmospheric sources and sinks of CH4 on an annual basis. Montane grasslands were strong atmospheric sources; upper montane forest and lower montane forest were net atmospheric sinks; while premontane forests fluctuated between source or sink, depending on the season.

Ecosystems across the region were net atmospheric N2O sources. N2O fluxes declined with increasing elevation though N2O fluxes from premontane and lower montane forests exceeded prior model predictions. Comprehensive investigation of field and laboratory data suggest that N2O fluxes were primarily driven by denitrification and that nitrate availability was the principal constraint on N2O fluxes. Any current and future changes in N management or anthropogenic N deposition may cause shifts in net N2O fluxes from these tropical montane ecosystems, further enhancing this emission source.


I study ecosystem C and nutrient dynamics, biosphere-atmosphere exchange and land-use change. My work spans diverse environments, including tropical forests, wetlands (tropical, temperate, arctic), arid and semiarid grasslands, and savannahs. My research explores biogeochemical processes at multiple spatial and temporal scales, ranging from soil aggregate-level studies of C metabolism to ecosystem-scale investigations of biogeochemistry using micrometeorological and airborne techniques. I currently maintain active research programmes in Borneo, the Andes, western Amazon, coastal UK wetlands (salt marshes, mudflats), and managed peatlands in Scotland. The core focus of my research is on understanding the impacts of land-use change and biodiversity loss on C, N and trace gas fluxes in tropical ecosystems.

The seminar is being hosted by Dr Steve Chapman.

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The James Hutton Research Institute is the result of the merger in April 2011 of MLURI and SCRI. This merger formed a new powerhouse for research into food, land use, and climate change.