Contribution to the knowledge of the arthropods community inhabiting the winter-flooded meadows (marcite) of northern Italy

Abstract

Background: Flooded semi-natural grasslands are endangered ecosystems throughout Europe. In Italy, amongst flooded meadows, one special type called "marcita" is strongly threatened. It is a stable flooded grassland used to produce green forage even during winter months due to the thermal properties of water coming from springs and fountains that prevent the soil from freezing. To date, some research has been carried out to investigate the role of the marcita for ornithological and herpetological communities. However, no comprehensive data on invertebrates inhabiting this particular biotope available. The aim of this study was to characterise the terrestrial entomological community of these typical winter-flooded meadows in northern Italy and, in particular, in six marcita fields located in the Ticino Valley Regional Park. We collected data on species richness and diversity of Carabidae, Staphylinidae, Araneae, Lepidoptera and Orthoptera inhabiting marcita during the summers of 2014 and 2015 and data on overwintering Coleoptera during the winter of 2014-2015. Amongst the collected species, we identified those highly linked to this habitat.

New information: We found a total of 47 ground beetle species, 35 rove beetle species, 29 spider species, one Lucanidae, 16 butterfly species and 24 grasshopper and cricket species. Most of the species were collected during the summers of 2014 and 2015, while some others were also, or exclusively, overwintering (17 ground beetles, four rove beetles and one Lucanidae) and were collected during the winter of 2014-2015.Marcita fields hosted specialised species and species typical of hygrophilous habitats, amongst which are included the butterfly Lycaena dispar, the ground beetle Dolichus halensis and the grasshopper Chrysochraon dispar. This study represents the first contribution to the knowledge of terrestrial arthropod communities associated with this particular type of winter-irrigated meadow in Europe and confirms the importance of this biotope for invertebrate conservation in agricultural landscapes.

Keywords: Chrysochraon dispar; Dolichus halensis; Lycaena dispar; arthropods community; threatened habitat.

Figure 1.

The six marcita fields in north-western Italy. In grey, the boundaries of the Ticino Valley Regional Park (Lombardy area) and, in black, the Ticino River.

Figure 2.

Rarefaction curves showing the diversity of a) ground beetles; b) spiders; c) rove beetles, in the three marcita fields when the order q was set at q = 0 (species richness), q=1 (exponential Shannon index) and q=2 (Simpson index).

Figure 3.

Distance-based redundancy analysis (dbRDA) ordination plot of ground beetle, spiders and rove beetle assemblages in the three marcita fields (Casterno: triangle; Tre Colombaie: inverted triangle; Sforzesca: square)