Distribution and Occurrence Regularity of an Invasive Alien Plant, Flaveria bidentis (L.) Kuntze in Cities of Anyang and Hebi in Northern Henan Province

PurposeTo elucidate the distribution and occurrence regularity of Flaveria bidentis (L.) Kuntze in northern Henan Province, providing guideline for developing early control and prevention measures.

MethodsThe distribution of invaded sites, occurrence habitat, phenological period and reproductive characteristics of F. bidentis were obtained through field monitoring and investigations. The spatial distribution pattern and aggregation area of invaded sites were analyzed by geostatistical method to determine the main diffusion routes and paths.

ResultsA total of 93 invasion sites were detected by 2020, mainly distributed in 45 towns of Anyang and Hebi cities in northern Henan Province. 95% of the earliest sites were located within 5 km of the road, and the frequency of occurrence decreased with the increase of distance. The distribution points of F. bidentis showed spatial discontinuous aggregation distribution, and the aggregation areas were mainly concentrated in the roadsides where human activities were frequent. Field investigations showed that all the invaded populations could complete their life cycles and produce seeds once a year. The maximum number of seeds per plant could reach 110 000.

ConclusionThe potential for further dispersal in this region is enormous. Human activity is the main driving factor that promoting the invasion and spread of F. bidentis from Hebei to this region. The results of this study are of great significance for the development of monitoring and early warning and monitoring measures to prevent and control new invasions of F. bidentis.