Submitted to: Environment Control in Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/19/2010
Publication Date: 10/1/2011
Citation: Runion, G.B., Finegan, H., Prior, S.A., Rogers Jr, H.H., Gjerstad, D. 2011. Effects of elevated atmospheric CO2 on non-native plants: comparison of two important Southeastern ornamentals. Environment Control in Biology. 49(3):107-117.
Interpretive Summary: Some of the plants intentionally introduced to the U.S. for use as ornamentals have become serious invasive weeds. Understanding how the rising levels of CO2 in the atmosphere will change the establishment and spread of these plants is crucial to future efforts to control them. We studies how elevated CO2 would effect growth of two non-native plants (Lantana and Vinca) commonly used as ornamentals in the southeastern U.S. Lantana had a much greater response to elevated CO2, especially in its roots, than did Vinca. This suggests that Vinca probably won’t be a problem as atmospheric CO2 continues to rise, but Lantana could become a serious invasive weed.
Technical Abstract: Some of the plants intentionally introduced to the U.S. for use as horticultural crops have become serious invasive weeds. Understanding how the increasing level of CO2 in the atmosphere will effect landscape plants will aid future selection and management of useful ornamentals and may help predict which might become serious weed pests. Further, understanding how rising levels of CO2 may alter establishment, spread, and control of invasive weeds will be crucial to future management strategies. This study was conducted to determine the effects of elevated CO2 on growth of two non-native plants commonly used as ornamentals in the southeastern U.S. Lantana (Lantana camara) and Vinca (Catharanthus roseus), growing in 10.65 L containers, were placed in open top field chambers and grown at either 375 µmol mol-1 (ambient) or 575 µmol mol-1 (elevated) CO2. Measurements of plant morphology, biomass, and plant tissue carbon and nitrogen were assessed for both species. Lantana growth was more responsive to elevated CO2 than was Vinca; root and total plant dry weights were increased by 31 and 19 %, respectively, in Lantana but only by 9 % each in Vinca. Root length was increased by 46 % in Lantana when grown under high CO2, while it was unaffected in Vinca. This study suggests that the rising level of atmospheric CO2 will have little impact on Vinca as either an ornamental or as a potential invasive weed. Lantana’s value as an ornamental may increase due to its abundant growth under elevated CO2; its greater root growth may also increase its drought tolerance, adding to its ornamental potential. However, the factors which may make it a more desirable ornamental under future higher CO2 conditions also increase its ability to become a serious invasive weed in the southeastern U.S.