Last Saturday, May 11, a trip was made with volunteers to transects CS_07 and CS_06, in the northern area of Sant Feliu de Guíxols. The objective was to explain how to upload data to iNaturalist and how to fill in the survey form of the populations to the new volunteers, and also to see which species appeared on the route. Sara Barceló, European auditor of the project for the company ELMEN, also attended this trip.

The itinerary began in Sa Caleta, at the beginning of the CS_07 transect and advanced south. The first thing we found was a large population of Lonicera japonica, which occupied the entire cliff to the left of the coastal path. We explained how to monitor these large populations, it should always note the species at a central point of the population. We also advised to always visit the place in similar dates, to write down the plants in a similar phenological state. It was discussed with Sara Barceló that in the case of this species it is difficult to say which individuals are breeders, which vegetative and which juvenile (seedlings), since at the time of observation it was not yet in bloom, and in this case, if we are not sure, that it is better to put only vegetatives.

Volunteers observing the Lonicera japonica population.

The walk reached almost as far as the CS_06 section, and during the tour we found Agave americana (century plant), Ailanthus altissima (tree of heaven), Arundo donax (giant cane), Cenchrus longisetus (feathertop ), Dimorphoteca ecklonis (cape marguerite) and Opuntia ficus-indica (prickly pear, infected by cochineal insect), among others. We made a special mention of the pitosporum, Pittosporum tobira, from which we found numerous specimens, which we clearly saw that had been scattered from a house next to the coastal path, probably due to the dispersion of seeds through birds.

We also found quite a few populations of Chenopodium nutans, a species that goes unnoticed by the network of observers, but which, on the other hand, is observed by the network of volunteers. Probably because it is a small plant that is difficult to see. However, since the volunteers have taken the course of identification of invasive plants for the project, they know how to locate it more easily than the observers.

Analyzing the populations of Ailanthus altissima (left) and differentiating between populations of cultivated plants and spontaneous plants (right).

It was also discussed the importance of differentiating between cultivated plants and spontaneous plants, as we found a terrace of cultivated plants from a house next to the coastal path. In this case, the populations should not be monitored, but they can be put as specific appointments in the network of iNaturalist observers to have evidence in case they escape in the future.

Throughout the journey, Sara Barceló was informed about how volunteers are taught to take data, and what the two volunteer networks are like. It was also explained the importance of the data provided by the volunteers for the project technicians to be able to make the risk maps of the most invasive species. The information about presence of reproductive and juvenile individuals is also useful to see if the population is increasing and if can be dangerous in the future.

Once the activity was over, and as usual, a snack was made, where the anniversary of Javier Martínez, the volunteer who had just sponsored this transect, was celebrated. It was recalled that the next field trip will be on Saturday, June 1, in Roses, and that it will be the last one before the summer stop.

Final group photo with the new T-shirts for the volunteers.