Ten years of citizen science data collection of wetland plants in an urban protected area

Floodplain landscape is the result of man's presence over a long period of time. This has caused the degradation, or even loss, of several habitats, especially wetlands, which frequently preserve rare biodiversity, even though they are subjected to intense human presence. Human activities can be of value, but can also cause problems in species preservation. The protected area Ansa e Valli del Mincio (northern Italy) is an outstanding case study in this respect: it is located in a densely urbanized context, but has great value from a conservation standpoint. This paper presents the results of 10 years of monitoring (2003-2012) of the spatial distribution of two native species (Trapa natans and Nymphaea alba) and the invasive Nelumbo nucifera. Data collected by volunteers from the protected area were processed in GIS and analysed using a number of configurational landscape metrics. Nymphaea alba and N. nucifera became more widespread; T. natans underwent a serious decline, mostly due to the interference of N. nucifera. An oscillating trend of this species is visible until 2008, followed by substantial stability. Furthermore, the potential area of each species was calculated. On the whole, citizen science is a valuable tool to enhance biodiversity knowledge and safeguarding, especially in wetlands that are used for tourism and surrounded by residential areas. As in other contexts, the volunteer contribution was particularly helpful in data collection on a local scale, over a considerable time span.