Carbon dioxide exchange of a pepperweed infestation

Sonnentag, O., M. Detto, B. Runkle, Y. Teh, W. Silver, M. Kelly, and D. D. Baldocchi. 2011. Carbon dioxide exchange of a pepperweed (Lepidium latifolium L.) infestation: how do flowering and mowing affect canopy photosynthesis and autotrophic respiration? J. Geophys. Res., 116, G01021, doi:10.1029/2010JG001522

The net ecosystem carbon dioxide (CO2) exchange of invasive plant infestations, such as perennial pepperweed (Lepidium latifolium L.), is not well understood. Little is known about how pepperweed flowering and control measures such as mowing affect canopy photosynthesis and autotrophic respiration (FAR) and thus ecosystem respiration. To examine this question we analyzed CO2 flux measurements made with eddy covariance over a pepperweed infestation in California, covering three growing seasons. We found that unmowed pepperweed caused the site to be almost CO2 neutral or a net source, and mowing during early flowering caused the site to act as a net CO2 sink. Our results highlight the tight link between pepperweed’s prominent key phenological phase and applied control measures, which together exert dominant control over the infestation’s CO2 source-sink strength. Journal Link. Pdf download.

Keywords: Invasive plants . Perennial pepperweed . Flowering . Net ecosystem carbon dioxide exchange . Non-linear mixed-effects models