Quantifying effects of legal and non-legal designations of alien plant species on their control and profile

Abstract

Invasive alien species (IAS) pose serious threats to native ecosystems worldwide. In some regions, laws and/or lists related to alien species have been made, but their effects on actual measures against alien species have been little studied. In Japan the IAS act, which came into force in 2005, lists many harmful species under the heading “Designated IAS”. The importation, domestication, sale or release of these species is tightly regulated. In addition, other species are named as alerted alien species (AASs) on the “alien species alert list” to raise public awareness. In this paper we examined the situation in Japan as case study that is exposed to threats from alien species under such laws in recent year to evaluate the effects of that for public interesting. We conducted a survey of the effects of the legal designation and other classification of alien plant species, examining a number of aspects, including research publications, eradications and public awareness. In our analysis, the degree of harmfulness of IASs was considered on the basis of weed risk assessment (WRA). The results show that legal classification of IASs has led to increases in research focused on the designated species, eradication efforts and public awareness. Similar results were also apparent for some AASs, but there was a great deal of variability among the many sub-categories of AASs. This may be partly because AAS sub-categories are based on different premises, and partly because the identification of AASs is not necessarily linked to legal controls that affect the behavior of individuals.