Harnessing community science and open research-based data to track distributions of invasive species in Japan

At the forefront of invasive alien species (IAS) control, information gaps about the latest IAS distribution can hinder the required actions of local governments. In Japan, many prefectural governments still lack a list of invasive species despite the request stipulated in the Action Plan for Prevention of Damage from Alien Species enacted in 2015. Here, we examined to what extent open research-based data deposited by museums and herbaria (ORD) and community science data by volunteers (CSD) can fill the gaps. We focused on 145 plant and 38 insect species and updated their distribution maps using ORD and CSD. We identified new distributions of 106 plant invasive species among 145, and 16 insect invasive species among 38, by combining data from ORD and CSD. We also found both complementarity and shared limitations between ORD and CSD. While taxonomic biases were less pronounced in ORD, CSD provided broader prefectural coverage. However, some important taxa—particularly small insect pests—were rarely captured by either ORD or CSD, indicating a common gap. Based on these findings, we recommend mobilizing diverse data sources, promoting community science, conducting taxon-specific expert surveillance, and building local capacity to better utilize ORD and CSD in local governments.