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借助风力传播连萼瘦果,是菊科入侵种最普遍的自然扩散方式,而其适应风力传播的特性与入侵性关系的研究还未得到足够的重视。阐明种子本身的风力传播特性与入侵潜力间的关系,可以为深入理解外来入侵种的入侵机制以及入侵种的控制提供理论依据。该研究以10种菊科入侵种为研究对象,测量其连萼瘦果的形态特征,测定它们在静止空气中的垂直沉降速度和模拟风力条件下的水平扩散距离,分析比较连萼瘦果的形态性状与沉降速度、水平扩散距离以及这些菊科入侵种在国内入侵范围的相关性。结果表明,根据连萼瘦果的形态特征,将这10个入侵种分为强、中和弱风传播3类;连萼瘦果的重量和冠毛特征对垂直沉降速度和水平扩散距离均有显著影响,对垂直沉降速度影响最大的因素是冠毛长度和冠毛上的小刺对数,对水平扩散距离影响最大的因素是连萼瘦果的重量和冠毛长度。在垂直沉降速度和水平扩散距离间存在极显著负相关性(r=-0.806,p=0.005),表明沉降速度越慢,借风力水平移动的距离越远。这些入侵种的发生程度与沉降速度间存在显著负相关性(r=-0.721,p=0.019),而与水平扩散距离之间存在着极显著正相关性(r=0.927,p=0.000),说明水平扩散距离比垂直沉降速度更适合作为评估菊科入侵种入侵能力的指标。根据上述研究结果,提出了南京市需重点防范胜红蓟(Agratum conyzoides)和牛膝菊(Galinsoga parviflora)等菊科入侵种的建议。
The propagation of Calyx acuminatum by wind is the most common natural diffusion method of Asteraceae invasive species. However, its research on the relationship between wind propagation and invasiveness has not been given sufficient attention. The elucidation of the relationship between the seed’s wind propagation characteristics and invasion potential can provide a theoretical basis for understanding the invasion mechanism of invasive alien species and the control of invasive species. In this study, 10 species of Asteraceae invaders were selected as the research object to measure the morphological characteristics of Achene anserine, to measure their vertical sedimentation velocity in still air and to simulate the horizontal diffusion distance under wind conditions. And sedimentation rate, horizontal diffusion distance and the invasiveness of these Asteraceae in the scope of the domestic invasion. The results showed that the 10 invasive species were divided into three groups according to their morphological characteristics: Acanthopanax senticosus, Acanthopanax senticosus and Acanthopanax senticosus, respectively. , The most influential factor on the vertical settlement velocity is the length of pappus and the number of small thorns on the pappus. The most important factor affecting horizontal spreading distance is the weight of the callus and the length of the pappus. There was a significant negative correlation (r = -0.806, p = 0.005) between the vertical sedimentation velocity and the horizontal diffusion distance, indicating that the slower the sedimentation velocity, the farther the distance moves by the wind force. There was a significant negative correlation between the occurrence of these invasive species and the sedimentation rate (r = -0.721, p = 0.019), but there was a significant positive correlation with horizontal diffusion distance (r = 0.927, p = 0.000) It shows that the horizontal diffusion distance is more suitable than the vertical sedimentation rate as an indicator to evaluate the invasion ability of Asteraceae invasive species. Based on the above research results, this paper proposed that Nanjing should pay special attention to the prevention of invasive species such as Agratum conyzoides and Galinsoga parviflora.