Sightings Map of Invasive Plants in Portugal

Registers are occasional, whenever submitted by users.

The dataset includes Portuguese mainland and Archipelagos of Madeira and Azores. First record is from 2002 and there are some records from following years, but most sightings are after March 2013, when the citizen science platform INVASORAS.PT was made available online.

Dataset is obtained directly from the web application that results from the submitted sightings; later it is Darwin Core transformed. Data submitted is from the responsibility of the users registered in the platform. The scientific team of the platform validate the sightings based only on photographs submitted along with the sighting; whenever there is doubt about the identification of the species, the user is contacted and the sighting is only validated if another photo or explanation allows verifying the species identification. However, in such a citizen science platform is not possible to be 100% sure of the reliability of the data. Nevertheless, as stated previously, the users that are more active in the platform (more than 80% of the sightings) have expertise in plant identification. For some species, namely Arundo donax, Opuntia maxima, Conyza bonariensis, Conyza canadensis, Conyza sumatrensis, Agave americana and Pittosporum undulatum, identification to species level is rather difficult when photographs are not very detailed; as such, use of data of these species should take this warning into consideration (they are most probably correctly identified to genus level and most often to species level, but some records may be similar species). For some species, phenology data may be uncertain, e.g., Cortaderia selloana keeps the lush “inflorescence” long after the flowering season and as such users may record them as “in flower”, but in fact they have seeds or the seeds may have already been dispersed even though they keep the apparent inflorescence.
All sightings are georeferenced, but locating errors associated with GPS and other devices used for georeferencing are possible. Source of geolocation can be “Web”, “Android (gps)”, “Android (network)” – error associated with the last option can be sometimes bigger than the two other options. Another possibility is that some of the invasive plants that were recorded have been meanwhile controlled and removed from the sighting place.