Multifaceted Roles of Management on Land-Atmosphere Interactions

Abstract:

To the first degree the exchange of mass and energy between vegetated canopies and the atmosphere are driven by environmental factors. But when one compares fluxes of a mesoscale network of flux towers in a common climate area, the impacts of management emerge. In this talk we will develop a vocabulary for evaluating the roles of management on fluxes, as it remains lacking in the assessment of data in the literature. Examples, will be drawn from our work across a network of agricultural and wetland sites in the Sacramento and San Joaquin Delta and from examples drawn from the AmeriFlux and FluxNet networks. Planting date, type of irrigation, burning, grazing, plowing/discing/no till, herbicide application and harvesting will be some of the management practices discussed. In sum, different management practices affect timing of phenology, the state of leaf area index and the activity of soil reservoirs. These factors modulate photosynthesis, and in turn can perturb ecosystem respiration and methane production. With regards of mass and energy exchange, different management practices can affect the state of the atmosphere and its feedback on surface fluxes.