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

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.

High Phenotypic Plasticity in a Prominent Plant Invader along Altitudinal and Temperature Gradients.

Studies on plant growth and trait variation along environmental gradients can provide important information for identifying drivers of plant invasions and for deriving management strategies. We used seeds of the annual plant invader Ambrosia artemisiifolia L. (common ragweed) collected from an agricultural site in Northern Italy (226 m. a.s.l; Mean Annual Air Temperature: 12.9 °C; precipitations: 930 mm) to determine variation in growth trajectories and plant traits when grown along a 1000-m altitudinal gradient in Northern Italy, and under different temperature conditions in the growth chamber (from 14/18 °C to 26/30 °C, night/day), using a non-liner modeling approach. Under field conditions, traits related to plant height (maximum height, stem height, number of internodes) followed a three-parameter logistic curve. In contrast, leaf traits (lateral spread, number of leaves, leaf length and width) followed non-monotonic double-Richards curves that captured the decline patterns evident in the data. Plants grew faster, reaching a higher maximum plant height, and produced more biomass when grown at intermediate elevations. Under laboratory conditions, plants exhibited the same general growth trajectory of field conditions. However, leaf width did not show the recession after the maximum value shown by plants grown in the field, although the growth trajectories of some individuals, particularly those grown at 18 °C, showed a decline at late times. In addition, the plants grown at lower temperatures exhibited the highest value of biomass and preserved reproductive performances (e.g., amount of male inflorescence, pollen weight). From our findings, common ragweed exhibits a high phenotypic plasticity of vegetative and reproductive traits in response to different altitudes and temperature conditions. Under climate warming, this plasticity may facilitate the shift of the species towards higher elevation, but also the in situ resistance and (pre)adaptation of populations currently abundant at low elevations in the invasive European range. Such results may be also relevant for projecting the species management such as the impact by possible biocontrol agents.

Seeding and Overseeding Native Hayseed Support Plant and Soil Arthropod Communities in Agriculture Areas.

Using native seed mixtures to create or recover grassland habitats in rotation to crops or in strips surrounding fields is considered a cost-effective practice to enhance ecosystem resilience and agro-biodiversity. The aim of this research was to assess the effects of native hayseed mixtures on plant and microarthropod communities in an agricultural area of Northern Italy. Three different experimental treatments were set up. The first was a control (C) (i.e., non-seeded plots left to spontaneous vegetation succession after ploughing no deeper than 15 cm). The second, hayseed seeded (Hs) after ploughing no deeper than 15 cm. The third experimental treatment was hayseed overseeded (Ov) on the resident plant community after only a superficial harrowing. Ov plots exhibited the preeminent positive effects on the total productivity and quality of the grassland in terms of total vegetation cover, cover and richness of typical grassland species (i.e., Molinio-Arrhenatheretea species), and cover of legumes, grasses and perennial species. Moreover, Ov sites exhibited the highest abundance of microarthropod taxa and soil biological quality (QBS-ar) but only in spring, when the disturbance of ploughing negatively affected Hs and C plots. On the other hand, Hs sites showed a great reduction of invasive alien (i.e., Ambrosia artemisiifolia and Artemisia verlotiorum) and segetal weed species (i.e., Capsella bursa-pastoris and Spergula arvensis) in terms of cover. This study provides valuable indication on using hayseed mixtures to create grassland habitats as reservoir of native flora and soil biodiversity in agriculture areas.

Ground beetles (Coleoptera: Carabidae) of rice field banks and restored habitats in an agricultural area of the Po Plain (Lombardy, Italy).

An entomological investigation was carried out in an agricultural area, mainly rice fields, of the Po river plain, located in the municipalities of Lacchiarella (MI) and Giussago (PV) (Lombardy, Italy). In 2009 and 2010, ground beetles (Coleoptera: Carabidae) were sampled along rice field banks and in restored habitats, by means of pitfall traps. The area appeared as species-rich, compared to other anthropogenic habitats in the Po river pain. Most of the collected Carabids were species with a wide distribution in the Paleartic region, eurytopic and common in European agroecosystems. The assemblages were dominated by small-medium, macropterous species, with summer larvae. No endemic species were found. Species with southern distribution, rarely found north of the Po river, were also sampled. Amaralittorea is recorded for the first time in Italy.