Secondary invasion refers to the proliferation of non-target invaders following efforts to suppress or control dominant target invaders. It is common in invasive plant management in ecosystems that harbor multiple non-native species. To date, secondary invasion has become a serious obstacle to ecosystem recovery. However, little is known about the dynamics and potential mechanisms of secondary invasion.
Researchers from the Wuhan Botanical Garden of the Chinese Academy of Sciences have evaluated the secondary invasion and the invasiveness of 14 non-target invaders after control of dominant target invader Ambrosia artemisiifolia by biocontrol agent Ophraella communa in two consecutive years.
Their study was published in New Phytologist on March 14. It was supported by the National Natural Science Foundation of China and the Natural Science Foundation of Hubei Province.
The results showed that secondary invasion occurred for all tested non-target invaders, but their abilities to invade (secondary invasiveness) differed among non-target invaders and varied with time since management.
The researchers found that important drivers of secondary invasiveness were phylogenetic relatedness between the target invader that was managed by biocontrol and the non-target invaders, as well as the non-target invaders' functional traits with competitive advantages. However, the importance of these two drivers also varied with time since management.
This study is the first to apply the theories of phylogenetic relatedness and functional traits to investigate secondary invasiveness following management of the dominant invader. It provides valuable insights to predict and manage secondary invasions to restore native communities more effectively.
