Field Work in WP3
Work Package III focuses on leaf, plant and ecosystem gas exchange; growth, biomass stocks, and water use efficiency; trace gas emissions; and the biodiversity of insects, invasive weeds and bird populations as influenced by climate gradients, soil characteristics and nutrient availability, and landscape structure. Ecosystem types under study at multiple sites within the landscape include oak dominated deciduous forest, dryland agricultural crops (beans, potatoes, radish, cabbage, Codonopsis and ginseng), and rice paddies. The gas exchange capacity of crop plants as well as invasive weeds is linked via chamber measurements to changing “ecosystem structure”, growth and production.
The information from process studies, along with information from eddy covariance measurements of ecosystem latent heat and CO2 exchange, and information from sapflow and forest canopy conductance studies, will be used to extend and parameterize the PIXGRO landscape production model with respect to management methods and fertilization regimes. With PIXGRO, carbon balance and emission of trace gases by the landscape as dependent on climate, land use, and landscape planning are quantified along with water use by vegetation.
Biodiversity studies, in the context of an organic versus conventional farming comparison, examine the relationships between landscape structure, weed invasions, insect biodiversity, and herbivory in conjunction with fertilizer and pesticide applications. Landscape structure influences on pollination and on bird species distributions are being quantified. In the case of organic rice farming, specialized management of weeds by introduction of snail browsers is examined in detail. Our goal, based on these observations, is to develop statistical models where empirical data on biodiversity and ecosystem services are related to topography, climate, soil parameters and land use pattern. Additional experimental and modelling studies will be carried out to link predictions of plant growth in PIXGRO to these selected biodiversity factors.
