Environmental controls on gross primary production and ecosystem respiration in wetlands: a synthesis based on FLUXNET data

Abstract We have initiated an effort to synthesize carbon dioxide (CO2) data from wetland sites within the FLUXNET LaThuile database. FLUXNET is a global network of micro¬meteorological flux measurement sites that monitors the exchange of carbon and energy between land and atmosphere1. Within the LaThuile dataset, major efforts have been made to standardize and gap-fill flux data submitted by site managers. In addition, the net CO2 exchange (NEE) has been partitioned into its components, gross primary production (GPP) and ecosystem respiration (Reco). There are currently 14 wetland sites and 47 site years available, which make up a unique dataset to be used in our synthesis effort. Seven sites are European, and seven are North American. The sites represent a diverse range of wetland types and climatic zones, ranging from ombrotrophic to minerotrophic wetlands, in temperate to arctic climates. The focus of the study will be the CO2 exchange components NEE, GPP and Reco, and which environmental parameters that influence between-site as well as within-site multi¬year variations. The parameters to be used include nutritional status, length of growing season, degree days, the water balance (ET/P), water table depth, temperature, precipitation, radiation, nitrogen deposition, pH, and vegetation indices such as NDVI and LAI etc. The results from these analyses will be discussed at the conference