Chin J Plant Ecol ›› 2010, Vol. 34 ›› Issue (8): 957-965.DOI: 10.3773/j.issn.1005-264x.2010.08.008

Special Issue: 入侵生态学

• Research Articles • Previous Articles     Next Articles

Wind-dispersed traits of cypselas in ten Asteraceae alien invasive species

HAO Jian-Hua1,2, QIANG Sheng1,*(), Du Kang-Ning2, GAO Yuan-Xing3   

  1. 1Weed Research Laboratory, Nanjing Agricultural University, Nanjing 210095, China
    2College of Biology and Food Engineering, Changshu Institute of Technology, Changshu, Jiangsu 215500, China
    3College of Mathematics and Statistics, Changshu Institute of Technology, Changshu, Jiangsu 215500, China
  • Received:2009-03-24 Accepted:2010-04-21 Online:2010-03-24 Published:2010-09-28
  • Contact: QIANG Sheng


Aims Wind dispersal of cypsela is the prevailing natural dispersal pattern in Asteraceae alien invasive species, but few studies have addressed the relationship between the characteristics of cypsela adapted to wind-dispersal and invasiveness. Our objective is to study the relationship between wind-dispersal traits and invasiveness to provide insight into invasion mechanisms and control of alien invasive species.

Methods We selected ten wind-dispersed Asteraceae invasive species with cypselas, observed morphological traits of cypsela such as pappus number, pappus length, barb number on pappus and 1000-grain weight of cypsela and measured vertical settlement velocity in still air and horizontal dispersal distance in moving air. Correlations between morphological traits of cypsela and settlement velocity and horizontal dispersal distance were analyzed in relation to invasive range.

Important findings We categorized the ten Asteraceae invasive species into three classes with strong, medium and weak dispersal-wind potential according to morphological traits of cypsela. Correlation analysis showed that pappus traits and weight of cypsela significantly affected both the settlement velocity and the horizontal dispersal distance. The settlement velocity was significantly affected by both pappus length (r = -0.483, p < 0.001) and barb numbers on pappus (r = -0.282, p = 0.002). Factors most affecting horizontal dispersal distance were cypsela weight and pappus length. Settlement velocity and horizontal dispersal distance were negatively correlated (r = -0.806, p = 0.005). The occurrence of these Asteraceae invasive species was significantly negatively correlated with settlement velocity (r = -0.721, p = 0.019) and significantly positively correlated with horizontal dispersal distance (r = 0.927, p = 0.000), suggesting that the horizontal dispersal distance better reflected invasiveness. Agratum conyzoides and Galinsoga parviflora with high invasiveness should be primary targets for invasive species management in Nanjing, China based on our results.

Key words: Asteraceae, cypsela, dispersal potential, horizontal dispersal distance, invasive species, pappus, settlement velocity