|Thornby, David - UC DAVIS|
|Hanan, Jim - U QUEENSLAND, AUSTRALIA|
Submitted to: Aquatic Botany
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 1, 2007
Publication Date: November 1, 2007
Citation: Spencer, D.F., Thornby, D., Hanan, J. 2007. L-Donax, a growth model of the invasive weed species, Arundo donax L. Aquatic Botany. 87(4):275-284. Interpretive Summary: Arundo donax L. is a tall perennial reed that has invaded riparian zones where it changes important ecosystem properties. In order to better predict important life stages in the plant’s development, we constructed a three dimensional growth model of this species. The model produced a realistic number of plant components from a single rhizome segment over the course of the first year of growth, using data from outdoor experiments. Biomass production was simulated through the use of equations relating shoot height to weight. The model confirms that control of A. donax clumps is likely to require more than mechanical biomass removal, due to the ability of remaining rhizome or stem segments to produce large clumps quickly. The model extrapolates to several years of growth beyond the first. This tool will aid Arundo management by better defining thresholds through simulation of interactions between Arundo architecture and management techniques. It will improve biological control efforts by identifying combinations of Arundo architecture and damage caused by insects and pathogens that interact effectively to limit Arundo populations.
Technical Abstract: A structural model of Arundo donax L., an invasive weed in North America, was constructed using LStudio, a computer-based implementation of L-system modelling. The model produces a realistic number of plant components from a single rhizome segment over the course of the first year of growth, using empirical relationships derived from outdoor experiments. Biomass production is also simulated, through the use of relationships found between aerial plant portion sizes and masses. The model demonstrates that control of A. donax clumps is likely to require more than mechanical biomass removal, due to the ability of remaining rhizome or stem segments to produce large clumps quickly. The model extrapolates to years of growth beyond the first, but is found to require some re-parameterisation to improve accuracy.