Format: ORAL

Vanessa Lozano1,2, Maria Teresa Tiloca1, Giuseppe Brundu1,2, Luigi Ledda3

1 Department of Agricultural Sciences, University of Sassari, Sassari, Italy 2 National Biodiversity Future Center (NBFC), Palermo 90133, Italy 3 Department of Agricultural, Food and Environmental Sciences, Marche Polytechnic University, Ancona, Italy

Segetal flora refers to the set of spontaneous plant species, almost exclusively annual, that grow in agroecosystems, within crops, and whose composition and biomass depend on habitat conditions and management adopted. Plant communities in conventional intensive cropping systems often include a limited number of species, with dense covering, which may represent a limiting factor as their presence affects crop yield. On the contrary, a more diverse segetal flora considerably increases the whole biodiversity of agroecosystems, supporting pollinators and other beneficial insects. The study was carried out in Sardinia (Italy) during 2019-2021 to assess the dynamics of species richnessof the segetal flora in globe artichoke (Cynara cardunculus L. s.l.) cropping system. The data was collected in Sardinian fields of globe artichoke through random located georeferenced plots (11 m). Two different cropping systems were analyzed: conventional and organic. Based on floristic surveys, it was possible to make an inventory of 115 plant species classified as native or non-native (neophytes and archaeophytes). The most frequent and often also the most abundant species were three natives (Calendula arvensis (Vaill.) L., Convolvulus arvensis L., Lolium rigidum Gaudin), one archaeophyte (Avena fatua L. s.l.), and three neophytes (Glebionis coronaria (L.) Spach, Oxalis pes-caprae L., Veronica persica Poir). Our results showed that organic farming often has positive effects on species richness, improving the diversity of plant communities, reconciling the sustainability of agricultural systems and the provision of ecosystem services. However, a higher coverage of plant species was observed in the conventional systems compared to the organic. In the conventional systems the composition of the segetal flora is shaped by high nutrient availability, herbicide resistance and biogeographic origin. Such traits are often linked to species that are highly competitive and difficult to control.