Tower flux measurements in support of … other tower-flux groups, aircraft teams, chemists, Earth observation scientists, ecologists. - How studying unmanaged forest and managed agroecosystems provide insight on atmospheric biogeosciences

Initiatives such as FIFE and BOREAS helped the micrometeorological community to improve their flux measuring methodology and better understand and interpret their flux measurement datasets. Beyond deploying open-sky laboratories over 100 x100 km study areas, the multidisciplinary teams involved in studying these ecosystems learned from each other’s on how to better integrate their findings. The contributions ranged from improved methodologies and scaling-up techniques, identifying new ecosystems mechanisms, improved emission factors and process-based models, to spatial ecosystem assessment using satellite data and models. A few examples will be presented: How heat stress (T>25oC) increases isoprene emissions in Old Black Spruce as a response to thermoprotection of photosynthesis;new isoprene emission factors based on sound flux measurement approach, better understanding of boreal ecosystem respiration using various techniques (eddy covariance and storage, chambers, nocturnal boundary layer) and models, detecting the contribution of the subcanopy to the net ecosystem exchange, the magnitude of methane emissions at the black spruce site. These ecosystem studies set the stage for the development of new Earth observation descriptors and new techniques to assimilate these descriptors in vegetation models.