Background
There is a long-term trend towards the abandonment of agro-pastoral activities in the mountain areas of Europe: the following encroachment process of semi-natural grasslands by shrubs is ...one of the main severe threats to the conservation of biodiversity in mountain environments. To better understand the impact of land abandonment, we analysed the reliability of plant functional groups, ant traits, and ant functional groups as indicators of land use changes. We carried out the research in Italy at four sites along a latitudinal/altitudinal gradient in three biogeographic regions (Mediterranean, Continental, Alpine). We identified three stages of a chronosequence at each site as representative of the plant succession in response to pastoral land-use abandonment.
Results
As expected, both the plant and ant assemblages considerably differed across sites at the species level and, within each site, among the three stages. This trend was found also using ant traits, functional groups of ants, and plant functional groups. Ant and plant communities were related in terms of composition and functionality. Harvester ants and ants with collective foraging strategy were associated with annual legumes and grasses (Therophytes); ants with a strictly individual foraging strategy with Phanerophytes. Ant traits and plant functional groups indicated significant differences among the three stages of the chronosequence. However, ant functional groups could not discriminate between the stages represented by secondary grasslands currently grazed and shrub-encroached grasslands ungrazed.
Conclusion
Despite some limitations of ant functional groups in explaining the succession stages of land abandonment, our results suggest that ants are a good surrogate taxon and might be used as bioindicators of land-use changes and ecosystem functioning. Furthermore, our findings indicate that the functional group approach should be applied to other European ecosystems. Finally, reducing the taxonomic complexity could contribute to developing predictive models to detect early environmental changes and biodiversity loss in mountain habitats.
Alnus viridis is a pioneer species that has expanded in Central Europe in the last decades, causing a series of negative agro-environmental impacts. Robust livestock grazing could be used as a ...targeted tool to reduce its encroachment, but more information is needed to find the best approach to achieve this goal. In this study, we assessed the potential of molasses-based blocks (MB) to lure Highland cattle into
A. viridis
-encroached areas and monitored impacts on the vegetation after grazing. In 2019 and 2020, two Highland cattle herds equipped with GPS collars were placed in three paddocks in the Swiss and Italian Alps, differing in the degree of
A. viridis
encroachment. In 2020, MB were added to highly encroached areas within each paddock to attract the herds to feed on
A. viridis
. Botanical surveys were carried out before and after grazing, around MB and control areas. Highland cattle grazed significantly more around MB (up to 50 m from the MB) compared to the previous year (i.e., same area without MB) and compared to control areas. The increased targeted grazing around MB led to a significant decrease in herbaceous cover and an increase in bare soil compared to control areas. Livestock grazing and trampling significantly reduced the cover of ferns, tall herbs, medium and small herbs, and woody species around MB compared to control areas.
A. viridis
leaves and branches were significantly removed and damaged up to 10 m from the MB, due to the more intense livestock grazing. Such results highlight the potential of this management regime to effectively reduce
A. viridis
encroachment in montane grasslands.
Land abandonment represents a major threat to the conservation of European semi-natural dry grasslands. To ensure biodiversity and habitat conservation, in this study, sheep grazing was reintroduced ...in abandoned Festuco-Brometea dry grasslands of a western Italian alpine valley. The experimental design included three treatments, along a gradient of increasing disturbance: (i) not-grazed, (ii) grazed, and (iii) penning areas. Unexpectedly, two years after grazing reintroduction, a wildfire hit the study area. To investigate the short-term effects of grazing and wildfire disturbances on vegetation, 62 permanent transects were monitored from 2014 to 2018. Vegetation cover, plant diversity, and richness and abundance of three functional groups of species were analyzed through generalized linear mixed models. Grazing caused little changes in vegetation, with the greatest effects observed in penning areas: the pioneer xerothermic species group, including many rare plant species, benefited from the reduction in the litter layer and the opening of gaps in the sward induced by trampling. The wildfire led to an increase in plant diversity and to changes in plant composition: dry grassland species decreased, while pioneer xerothermic and ruderal species increased their abundance. Short-term results suggest that both disturbances may foster the conservation of alpine dry grasslands.
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 this contribution, new data concerning the distribution of native vascular flora in Italy are presented. It includes new records, confirmations, and exclusions to the Italian administrative ...regions for taxa in the genera Anacyclus , Anthyllis , Bolboschoenus , Catapodium , Festuca , Hordeum , Lavandula , Ophrys , Pseudopodospermum , Rosa , Sorbus and Spergula . Nomenclatural and distribution updates, published elsewhere, and corrigenda are provided as Suppl. material 1.
Livestock site use intensity can vary widely across a grazing area due to several factors such as topography and distance from sheds and water sources. However, an accurate approximation of animal ...site use should be assessed for each part of the grazing area to apply effective management strategies. In the Alps, shepherds manage sheep through lenient supervision during the day and confining the animals in temporary night penning areas (TNPA) at night. In our case study, we assessed sheep site use over the grazing area with global positioning system (GPS) collars and calculated the sums of inverse distances from all TNPA (unweighted and weighted on the number of penning nights) and from all water sources, as well as the slope, on 118 sample points. We assessed the relative importance of these variables in affecting site use intensity by animals using different sets of models. Both the unweighted and weighted distances from TNPA were found to be the most important factors. The best fitting model accounted for the weighted distance from TNPA and the distance from water, but the latter showed a lower relative importance. Our study suggests that using the distance from TNPA, preferably weighted on the number of penning nights, is an effective proxy to estimate the spatial variability of sheep stocking rate during grazing in the Alps.
In this contribution, new data concerning the distribution of native vascular flora in Italy are presented. It includes new records, confirmations, and exclusions to the Italian administrative ...regions. Nomenclatural and distribution updates, published elsewhere, and corrigenda are provided as supplementary material.
In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records and status changes from casual to naturalized for Italy or for ...Italian administrative regions. Nomenclatural and distribution updates, published elsewhere, and corrections are provided as supplementary material.
In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, exclusions for Italy or for Italian administrative ...regions. Nomenclatural and distribution updates, published elsewhere, and corrections are provided as Suppl. material 1.
Alnus viridis is a shrub species that has been increasing in many European mountains over the past decades, leading to a loss of agricultural areas and several negative environmental impacts. ...Recently, targeted livestock management systems have been investigated to reduce its encroachment. This study aims to provide an exhaustive assessment of A. viridis leaf composition and its temporal variation across the grazing season. A. viridis leaves were collected throughout the summers of 2020 and 2021 in four encroached sites across the Swiss and Italian Alps, characterized by different pedo-climatic conditions. Based on the data collected by meteorological stations, the growing degree days (GDD) were calculated for each site and year. The leaf functional traits (i.e., Leaf Dry Matter Content – LDMC – and Specific Leaf Area – SLA), chemical composition (macro- and micro-elements and fibre content), phenolic content, in vitro organic matter digestibility (IVOMD), and related gas production (CO2 and CH4) were assessed. The LDMC significantly increased throughout the season, whereas the SLA decreased. All macro- and micro-elements significantly varied during the season, with leaf nitrogen (N) and phosphorus (P) decreasing. In contrast, leaf fibre contents significantly increased as the season advanced. There was a significant increase in condensed tannin content during the summer season. Finally, adding A. viridis leaves (20% of diet on a dry matter basis) to cattle diets significantly reduced IVOMD, methane produced per digested organic matter (CH4/dOM) and CO2/dOM, compared to a 100% hay diet. Moreover, CH4/dOM and CH4/CO2 ratio increased during the summer season. These results highlight the potential of A. viridis leaves as a valuable forage resource, especially at the beginning of the summer. Such information could be used to optimize grazing of robust livestock in A. viridis-encroached alpine pastures in order to reduce its invasion and minimize greenhouse gases production at the same time.
•viridis leaves have higher LDMC and lower SLA as the season advances.•viridis leaves become more fibrous at the end of the summer season.•viridis leaves have high crude protein and phenolic concentrations.•Diet composed of A. viridis leaves reduced in vitro methane emissions.•viridis is a valuable resource for robust livestock, above all in early summer..
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