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Publisher Copyright: © This dataset is made available under the Open Database License (http://opendatacommons.org/licenses/odbl/1.0/). The Open Database License (ODbL) is a license agreement intended to allow users to freely share, modify, and use this Dataset while maintaining this same freedom for others, provided that the original source and author(s) are credited In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, exclusions, and status changes for Italy or for Italian administrative regions. Nomenclatural and distribution updates published elsewhere are provided as Suppl. material 1.

Green alder (Alnus viridis) is a shrub species that has expanded over former pastures in Central Europe due to land abandonment, leading to negative agri-environmental impacts, such as a reduction in forage yield and quality and an increase in nitrate leaching. Robust livestock breeds such as Highland cattle could be used to control A. viridis encroachment. The objectives of this study were to investigate the impact of A. viridis encroachment on plant community composition and diversity and to map the spatial distribution of Highland cattle in A. viridis-encroached pastures. During the summer of 2019, three different Highland cattle herds were placed along an A. viridis encroachment gradient. A total of 58 botanical surveys were carried out before grazing to assess plant community composition, pastoral value, and ecological indicator values. The spatial distribution of cattle was studied during the whole grazing period by monitoring six to eight cows equipped with GPS collars in each herd. Plant species associated with higher pastoral values of the vegetation were found in areas with lower A. viridis cover, while highly encroached areas were dominated by a few nitrophilus and shade-tolerant broad-leaved species and by ferns. Cattle spent more time in areas with higher pastoral value but did not avoid areas with high cover of A. viridis, on steep slopes or far from water. These results show that Highland cattle are able to tolerate harsh environmental conditions and that they can exploit A. viridis-encroached pastures. This suggests that they have a high potential to reduce A. viridis encroachment in the long-term.

In alpine environments, very low and very high amounts of soil nutrients are generally associated to the lowest plant diversity and forage quality levels. Both soil nutrient content and forage quality and productivity of a site can be inferred from plant species lists, by attributing each species a nutrient indicator value (N value) and a quality value, and computing respectively average N Value and Pastoral Value (PV) at site scale. We used a wide dataset of vegetation surveys carried out in the pastures of Western Italian Alps to 1) evaluate if N values, PV, and plant diversity (species richness and Shannon diversity index) change along an elevation gradient, from montane/sub-alpine pastures (i.e. the ones located below treeline) to alpine pastures (above treeline), 2) analyze the relationships between N value and plant diversity indexes and between N value and PV, and 3) evaluate whether the N values associated to the highest plant diversity and PV differ. Plant diversity, PV, and N values were higher in the pastures located at lower elevation. Plant diversity and PV showed a unimodal relation with N values, both in the montane/sub-alpine and alpine belts. Plant diversity indexes peaked at intermediate N indicator values, confirming the Intermediate Disturbance Hypothesis, while PV peaked at higher N values, where higher nutrient availability in the soil increased plant species productivity, growth rate, leaf turnover and nutrient concentration, digestibility, and palatability. The overall shape of the curves as well as the N values at which plant diversity and PV values peaked did not considerably change from montane/sub-alpine to alpine pastures. These results suggest that an extensive pastoral management is recommended when plant diversity conservation is the main goal. Conversely, a more intensive management can produce an overall enhancement of forage quality/productivity of alpine pastures, but only if restricted under certain critical N values.

Throughout the last decades, Calluna vulgaris (L.) Hull heathlands have declined across Europe and nowadays their conservation is particularly challenging at the southern edge of their distribution. In the Nature Reserve of Vauda (north-western Italy), six restoration treatments were applied (extensive annual goat browsing, one-off mowing, annual mowing, one-off fire without and with annual browsing, and annual fire) and their effects on plant diversity and the cover of C. vulgaris, its competitor grass Molinia arundinacea Schrank, woody, and alien species were monitored between 2005 and 2011. In the short-term, most of the treatments changed the vegetation community, reducing C. vulgaris cover according to a gradient of increasing biomass removal. In the mid-term, C. vulgaris, M. arundinacea, woody and alien species cover followed different trajectories according to the treatment and functional group. Annual fire shifted the vegetation towards a M. arundinacea-dominated community, while extensive annual browsing did not affect the heathland community and resulted in the lowest increase in M. arundinacea, which showed a remarkable fitness in these environments. Moreover, annual burning and mowing were effective in reducing woody species encroachment (p < 0.05), and fire treatments triggered a peak in alien species cover (mainly Panicum acuminatum Swartz) in the short-term. Six years after treatment, species richness and Shannon index did not differ between treated and control sites (p > 0.05). In conclusion, these results highlight the need and potential benefit of integrating multiple techniques to preserve C. vulgaris heathlands at their southern edge.

The study of plant phenology has frequently been used to link phenological events to various factors, such as temperature or photoperiod. In the high-alpine environment, proper timing of the phenological cycle has always been crucial to overcome harsh conditions and potential extreme events (i.e. spring frosts) but little is known about the response dynamics of the vegetation, which could shape the alpine landscape in a future of changing climate. Alpine tundra vegetation is composed by an array of species belonging to different phytosociological optima and with various survival strategies, and snowbed communities are a relevant expression of such an extreme-climate adapted flora. We set eight permanent plots with each one in a snowbed located on the Cimalegna plateau in Northwestern Italy and then we selected 10 most recurring species among our plots, all typical of the alpine tundra environment and classified in 3 different pools: snowbed specialists, grassland species and rocky debris species. For 3 years we registered the phenophases of each species during the whole growing season using an adaptation of the BBCH scale. We later focused on the three most biologically relevant phenophases, i.e., flower buds visible, full flowering, and beginning of seed dispersion. Three important season-related variables were chosen to investigate their relationship with the phenological cycle of the studied species: (i) the Day Of Year (DOY), the progressive number of days starting from the 1st of January, used as a proxy of photoperiod, (ii) Days From Snow Melt (DFSM), selected to include the relevance of the snow dynamics, and (iii) Growing Degree Days (GDD), computed as a thermal sum. Our analysis highlighted that phenological development correlated better with DFSM and GDD than with DOY. Indeed, models showed that DOY was always a worse predictor since it failed to overcome interannual variations, while DFSM and marginally GDD were better suited to predict the phenological development of most of the species, despite differences in temperature and snowmelt date among the three years. Even if the response pattern to the three variables was mainly consistent for all the species, the timing of their phenological response was different. Indeed, species such as Salix herbacea and Ranunculus glacialis were always earlier in the achievement of the phenophases, while Agrostis rupestris and Euphrasia minima developed later and the remaining species showed an intermediate behavior. However, we did not detect significant differences among the three functional pools of species.

Understanding the agroecological mechanisms that determine forage yield and quality in intensively managed permanent grasslands is crucial to optimize management and provide environmental and economic benefits to society. In this study, we assessed the relative contribution of climatic, soil and vegetation drivers on forage yield and quality in nine different frequently defoliated and fertilized permanent grasslands used for silage production, that were representative of diverse environmental conditions in Switzerland. Temperature and precipitation, forage yield and quality (i.e., fibers, lignin, carbohydrates, N, P and K contents), relative proportion of plant functional groups, as well as soil nutrient availability and moisture were measured in 2018 (a particularly dry year) during the first three growth cycles. Linear-mixed effect models were performed to test differences among growth cycles on all measured variables and the relationships among them for each cycle. Moreover, a multiple factor analysis (MFA) was performed for each growth cycle to investigate the complex relationships among different sets of variables. Overall, the growth cycle significantly affected all variables, except for forage P content that remained stable over time. Most of the variability in forage yield and quality was explained by climatic conditions and plant functional groups proportion with, however, differences among growth cycles. In the first growth cycle, forage yield and quality were mainly related to the proportion of grasses, precipitation and temperature, then by the proportion of grasses and temperature in the second growth cycle, and finally, by soil nitrogen availability, precipitation and proportion of grasses in the third growth cycle. Overall, in the range of the studied conditions, we found very limited impact of soil nutrient availability on forage yield and quality, except soil N availability during the third growth cycle. Our findings may help prioritize grassland management interventions at specific times during the growing season.

Aims To reverse shrub encroachment and restore grassland vegetation, two pastoral practices were implemented over shrub-encroached areas: the arrangement of temporary night camp areas (TNCA) and the strategic placement of mineral mix supplements (MMS) for cattle. The aim was to assess the effects produced on (1) vegetation structure and (2) botanical composition of both pastoral practices in order to identify their potential to reverse shrub encroachment and restore semi-natural grassland vegetation. Location Shrub-encroached sites in Val Troncea Natural Park, southwest Italian Alps. Methods We measured the effects produced by both practices on vegetation cover and height, cover of species belonging to different vegetation units, biodiversity indices (species richness and Shannon diversity index), forage pastoral value, and average indicator value for soil nutrient content from 2011 to 2014 along permanent linear transects. Data were analysed with GLMMs, multiple response permutational procedure (MRPP) and principal response curve (PRC). Results Both practices were effective in reducing shrub cover and increasing average height of the herbaceous layer, but within TNCA a marked increase in herbaceous cover was also evident. Moreover, the arrangement of TNCA increased the cover of meso-eutrophic grassland and fringe and tall herb species and decreased the cover of boreal-like shrubland and woodland species. The main effect produced by the placement of MMS on botanical composition was an increase in cover of fringe and tall herb species. Plant biodiversity was enhanced by the arrangement of TNCA but not by the placement of MMS, and the implementation of both practices increased forage pastoral value and average indicator value for soil nutrient content. Conclusions The arrangement of TNCA was the most effective pastoral practice to reverse shrub encroachment, restore semi-natural meso-eutrophic grassland vegetation and increase plant diversity, herbage mass and forage quality.

Effects of traditional salt placement (TS) and strategically placed mineral mix supplements (MMS) on cattle distribution were compared in the Italian Alps. Salt was placed within flat and herbaceous sites following the traditional method of farmers, whereas MMS blocks were placed on steep and shrub-encroached sites within three large pastures (44 ha on average). Each TS and MMS site was paired with a control site, and eleven cows were tracked with GPS collars. Within 10 and 50 m of TS and MMS, treatment sites were used more than control sites (P 0·05) in the number of visits by cows within 10 and 50 m of TS and MMS placements. No differences were detected in time spent within 10 m of TS and MMS placements, but cows spent more time (P

Background: Species-rich Nardus stricta grasslands are a priority habitat for conservation in Europe. They typically occur on siliceous substrates and less frequently are found on calcareous bedroc...

Grazing management is an important tool to preserve insect biodiversity. Although literature has discussed the importance of grazing pressure adjustment to support grassland insect communities for the ecosystem services they provide, little has been published on the economic sustainability of such management adjustments to date. This study compared continuous grazing (CG) to an innovative rotational grazing system (the biodiversity-friendly rotation – BR), where a subplot was excluded from grazing for two months during the main flowering period. The effects of grazing two different species (cattle and sheep) within both systems were also evaluated. The aims were to assess the effects on butterfly, bumblebee, and ground beetle assemblages, along with the impact on herbage mass and animal performance. The BR enhanced both the abundance and species richness of flower-visiting insect assemblages and it was observed that cattle provided better results than sheep grazing. A multivariate redundancy analysis highlighted that most of the flower-visiting species (including almost all the endangered and locally rare species) were favoured by BR-cattle treatment, mainly due to the high percentage of flower cover and sward heterogeneity involved in this treatment. However, grazing system and grazer species did not affect ground beetle species richness or abundance. Moreover, herbage mass and animal performance (live weight and body condition score) were comparable between CG and BR throughout the grazing season. The BR could be a useful management system to enhance grassland flower-visiting insect assemblages whilst meeting farm production objectives, especially in protected environments where insect conservation is a major target.

Agro-pastoral decline in European mountain areas has recently caused changes to traditional landscapes with negative consequences on semi-natural grassland conservation and the associated biodiversity and ecosystem services. In the Italian Alps, grassland patches enclosed in a forest matrix are progressively disappearing. Two alpine valleys (Pesio and Pejo), having similar land-use history, were chosen as representative of management conditions of western and eastern Italian Alps, respectively. This study aims at interpreting the effect of abandonment on grassland patch plant diversity, considering land cover changes of the last 60 years, and assessing the role of ecological, topographic, management and landscape configuration on current grassland species richness. The total area of grassland patches has declined by 54 and 91 % at Pesio and at Pejo, respectively. Actual grassland patch species richness was mostly influenced by ecological factors, such as quantity of light, soil moisture and reaction, then by topographic features, especially slope, and finally by management intensity. Landscape factors exerted a slightly significant effect on plant diversity. In the two valleys, differences on management practices were detected. Even though in the western valley the conservation of several grazing activities contributed to slow down the process of patch reduction, many species-rich grasslands were generally under-grazed. Conversely, in the eastern valley, despite a denser road network, the stronger decline of grassland patch extension was linked to the hay making decline. At the same time, overuse of grassland patches near farms reduced plant species richness. As a conclusion, plant species richness was weakly related to the area of grassland patches and current and historical landscape configuration were of relatively lower importance than ecological, topographic and management factors, when evaluated at patch-level.

The decline of agro-pastoral activities has led to a widespread tree and shrub-encroachment of former semi-natural meso-eutrophic grasslands in many European mountain regions. Temporary night camp areas (TNCA) and mineral mix supplements for targeted cattle were arranged over shrub-encroached areas to restore grassland vegetation within the Val Troncea Natural Park (Italy). From 2011 to 2015, their effects on vegetation structure and pastoral value of forage were assessed along permanent transects. Four years after treatments, both practices were effective in reducing the shrub cover and increasing the cover and average height of the herbaceous layer, but changes were more remarkable within TNCA. Moreover, the arrangement of TNCA decreased the cover of nanophanerophytes and increased the cover of graminoids and high quality species, as well as the overall forage pastoral value. In conclusion, TNCA were the most effective pastoral practice to contrast shrub-encroachment and increase herbage mass and forage quality of sub-alpine grasslands.

The interest for goats rearing has increased during last decades on the Italian Alps. However, feeding preferences by grazing goats have not undergone detailed investigation in extensive montane grazing systems. Our study aimed to assess plant species selection by integrating vegetation surveys with animal GPS tracking under two contrasting alpine vegetation communities: a semi-natural grassland (SG) and a grazable forestland (GF). Goats selected a high array of plant species (56 and 47 species in the SG and GF, respectively), but most of their diet was composed by a few species (ten species accounted for 95% and 91% of the total species intake in the SG and GF, respectively). The selection by goats seemed to be more species-dependent rather than functional group-dependent. Goats appeared to be less selective within a homogeneous herbaceous grassland, because they selected plant species proportionally to their abundance (P=0.05). Conversely, in a heterogeneous and stratified grazable forestland they showed a more pronounced preference for most of the browse species, regardless of species abundance. Plant species selection was positively correlated with species height in both vegetation communities (i.e., implementation of different stocking rates and densities) could be an important tool in modifying diet selection, promoting the consumption of particular plant species and thus managing the dynamics of plant communities in alpine environments.

Drought events can strongly affect ecosystem functioning by modifying relationship between plants, microbes and soil chemistry, with consequent impacts on nutrient cycling. However, the potential impacts of a soil moisture reduction on the nitrogen (N) and phosphorus (P) cycling in grasslands remain poorly understood, especially in regard to. forage production., To fill this knowledge gap, a drought experiment was carried out using rainout shelters in two permanent grasslands, characterized by similar vegetation communities but contrasted soil nutrient limitations. Drought treatments were applied during two months, either when plant growth was highest (Early-season drought) or after the peak of biomass production (Late-season drought). Dry matter production, forage N status (NNI) and P content as well as N and P contents in microbial biomass and soil were determined., Both early and late-season drought significantly reduced soil moisture during the vegetation growth period. Forage yield was also reduced by drought, but only when it occurred late in the season. Using a structural equation model, we showed that soil moisture reduction had a direct effect on forage N status, suggesting that water shortage induced lower transpiration and water fluxes. Soil moisture reduction also affected forage P by reducing the availability of soil P. However, other mechanisms played a larger role and were site-specific. At the more fertile site, reduction in soil moisture directly impaired forage P, suggesting that water stress mainly resulted in lower diffusion rates to roots, while at the less fertile site, an indirect reduction of forage P through a pathway implying microbes (decrease in microbial P) was detected., Our results suggest that the two grasslands suffered mainly from water shortage per se, but also from drought induced nutrient deficiency (mainly P), which amplified yield losses and further decreased forage quality. Overall, our findings emphasize the need for further research on the plant-soil-microbe system functioning, in order to secure a sustainable and resilient forage production in the context of climate change.