|LIU, DASHENG - Shandong Institute|
|HU, J.. - South China Agricultural University|
|ZHANG, X. - Shandong University|
|BIAN, X. - Shandong Institute|
|CHANG, G. - Shandong University|
|SUN, X. - Shandong University|
|TIAN, J. - China Institute Of Water Resources|
Submitted to: Journal of Aquatic Plant Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/4/2012
Publication Date: 3/1/2012
Citation: Liu, D., Hu, J.F., Horvath, D.P., Zhang, X.J., Bian, X.Y., Chang, G.L., Sun, X.H., Tian, J. 2012. Invasions and impacts of alligatorweed in the upper Xiaoqing River basin of northern China. Journal of Aquatic Plant Management. 50:19-24.
Interpretive Summary: Alligator weed is an invasive weed in many parts of the world and can negatively impact navigation and flooding potential in the waterways it infests. Previous climactic models had predicted the northern limits of the spread of this weed. However, recently, alligator weed was found nearly 5 degrees in latitude north of its predicted northern limit in China. A survey of alligator weed presence and density in the upper Xiaoqing River in northern China indicated not only the presence of alligator weed well outside its predicted range, but also determined that water quality did not significantly impact its ability to become established and that local farmers had not yet recognized this weed as a threat in the new areas where it is growing.
Technical Abstract: Alligatorweed (Alternanthera philoxeroides (Mart.) Griseb), is a problematic and difficult to manage invasive weed. The recent invasion in the upper Xiaoqing River, northern China extends its range northwards through almost five degrees latitude and 500 km from the northern limit and main invasion area of the weed in China. The length of main branches of the weed in Jinan ranges from 198 cm to 382 cm, with an average value of 266.67±24.01 cm. The average number of nodes and adventitious roots on the main branches are 27.01±2.25 and 17.11±0.84, respectively. The number of main branches per linear meter transect is 376-511, with an average of 436.52±55.33. The main impact of alligatorweed is that it chokes the flood flow of the local river in rainy seasons, but was not found to cause obvious damage to agricultural production in the area covered by this study. However, the presence of this weed in northern China highlights its potential future risk, and questions the previous models used to predict the spread and distribution of this weed.