The project investigates the amount of carbon lost from agricultural crops as volatile organic compounds (VOCs). These compounds are emitted from plants in response to environmental conditions, i.e. to temperature, air chemical composition and physical stress. VOCs are essential for plant-plant or plant-insect communication, protect plants from oxidative damage, and are important reaction partners in photochemistry, i.e. regarding ozone formation.
The emission of VOCs depends on the species involved and on environmental conditions. Both are subject to change. On the one hand, bioenergy production increases in Germany and many of the respective plant species are known to differ in their emission behavior from conventional crops. On the other hand, climate change is going to increase temperature and drought stress, and emission control strategies will alter air chemistry composition. It is thus important to find mechanistic descriptions of VOC emission and introduce them into models that can be applied regionally.
Maize field with hut including the observation devices (PTR-MS, LGR-GGA) and one of the two automatic chambers in open position at the field experiment site in Dedelow, Brandenburg, Germany, 11th August 2015.
To provide such knowledge, VOC measurements will be conducted for various agricultural crops under natural conditions at two agricultural sites in Brandenburg (Dedelow, Uckermark) which differ in their susceptibility to drought stress. The experiment is part of the CarboZALF program which investigates the carbon cycle for several crop species throughout a couple of rotation periods. Highly sensitive instruments provided by the Helmholtz Zentrum München, will monitor more than 50 different VOCs during several measurement campaigns in each of three investigation years. Measurements of other environmental conditions are available from the CarboZALF infrastructure.
Hourly mean emission rates for three days in August 2015
Based on these data, leaf-scale models will be revised, parameterized, and evaluated which describe VOC emissions in dependence on a multitude of environmental conditions. These models will then be implemented into a regional agricultural model which will be additionally complemented to reflect growth and carbon balance of short-rotation cropping (e.g. poplar plantations). The new model will be used to 1) determine the carbon loss by VOCs for North-East Germany and 2) produce VOC emission inventories based on different land-use change scenarios. The results will close a gap in current carbon balance research and provide new input for air pollution simulations.
The project is funded by BMEL (Gefördert durch das BMEL aufgrund eines Beschlusses des Deutschen Bundestages)
Contact: Rüdiger Grote