IS THE OVERSPREADING OF PAEDERIA SCANDENS IN HIGHLY DISTURBED AREAS JUST OCCASIONAL?

Abstract

Paederia scandens, a native weedy vine, is a common species in China, however in recent years, it has spread extensively. Though research focused on this vine has increased, still ecological information concerning it is rare. We hypothesized that the overspreading of this weedy vine in highly disturbed area was not an occasional case. In order to test this hypothesis, field observations were carried out in Shenzhen, China. Records showed that P. scandens was distributed sporadically before in most of the ecosystems in Shenzhen, but it was densely distributed in 8 areas now where the ecosystems were disturbed and quite vulnerable. The current coverage area is about 24-5000 times that of the past and the total coverage area has reached 8.8 hm2 . More than 29 plant families, 39 genera and 45 species have been impacted by this weedy vine. The average growth rate was 1.3cm/d in the rapid growing period, and the maximum growth rate was 1.9cm/d. The simple community of P. scandens had a lower number of species and abundance than the control. Results suggested that the distribution pattern of P. scandens had changed from sporadic to dense in the highly disturbed areas. P. scandens had the potential to overspread in highly disturbed areas and the community with simple configuration offered more opportunities for it to overspread. Integrating the present investigations and studies, we conclude that the overspreading of P. scandens in highly disturbed areas is not just an occasional case.