What is the use of volunteer data?

Modelling invasive species in the Costa Brava for rapid management

Volunteer data are a key element in the fight against invasive alien plant species on the Costa Brava. Through collaborative work between science and the public, valuable information can be obtained to predict and manage the spread of these species, with the aim of protecting the natural ecosystems of the Costa Brava.

Volunteers of the the LIFE medCLIFFS volunteer network.


The use of risk assessment maps is essential to anticipate the possible spread, establishment and persistence of invasive plant species in the environment. This proactive approach identifies priority areas with high invasion risks, helping land management to implement more informed strategies for prevention, early eradication or containment measures.

Within the framework of the LIFE medCLIFFS project, we use a tool called “Riskmapr” (Rapid spatial risk modelling for management of early weed invasions: Balancing ecological complexity and operational needs) developed by Australian researchers Jens G. Froese, Alan R. Pearse and Grant Hamilton. This tool, specifically designed to assess the risk of invasion by non-native species, facilitates decision-making for rapid response to plant invasions. It outperforms conventional models that do not consider the biology and dispersal capacity of individual species and populations, ensuring more accurate risk assessments and facilitating appropriate management strategies for invasive species control.

The resulting risk maps, generated using the “Riskmapr” tool, serve several purposes: to identify areas susceptible and resistant to invasions by different species, to detect the distribution areas of endemic and endangered species or other sensitive natural areas, and to determine the most problematic species with the highest probability of invasion.

Distribution maps (publicly available) of endemic species (Limonium tremolsi, and Seseli farrenyi), and areas of susceptibility of invasion.


In this aspect, the data collected by the LIFE medCLIFFS volunteer network is of indisputable value. The active participation of the public provides up-to-date and accurate abundance data, as the volunteers have been specifically trained to identify the invasive plants under study. Therefore, in order to give priority to volunteer data, we excluded all data from the LIFE medCLIFFS observer network in areas around the transects monitored during the year prior to modelling. Only volunteer data in these areas are taken into consideration. For areas outside the transects or in non-monitored transects, data from the LIFE medCLIFFS observer network from the last year or the last two years are used, depending on the biology of the species studied. This ensures the reliability and representativeness of the data used in the modelling, thus optimising the project results.

The first results of the rapid risk assessment exemplify how collaboration between science and volunteers is fundamental for the effective management of invasive alien plant species on the Costa Brava. Through this synergy, information that contributes to the conservation of local ecosystems and the preservation of biodiversity can be obtained.

Text: Arnau Bosch