Search

Alpine bluegrass ( Poa alpina L.) is common in mountain areas, where it represents a valuable forage resource and is widely used for ecological restoration of disturbed landscapes. This study assessed the variation of germplasm from the Rhaetian Alps, Italy. Both seed production and morphology were examined for potential use in restoration projects and for conservation and selection purposes of local genetic resources. The effects of the ex situ growing site were also assessed in two altitude-contrasting sites. Individual populations harboured great phenotypic diversity for all traits, including seed yield, while variation among valleys of origin was less manifest. Noticeable site-specific population yield responses were observed, suggesting that the environment adopted for seed production may steer the choice of materials to be multiplied. The longer vegetative period in the lowland site, combined with environment-tailored agronomic practices, contributed to better plant growth, seed yield and survival compared to the mountain site, suggesting that seed production of this Alpine species could be feasible in a lowland environment when adequate inputs were provided. One valley ( Valchiavenna) displayed high average levels of seed yield and plant vigour across growing sites, indicating its possible value as a source of germplasm suitable for resowing at high altitude. [ABSTRACT FROM AUTHOR]

Due to decades of loss of grassland diversity across Europe, there is a need to identify factors affecting species composition and diversity in managed meadows. The aim of the current study was to assess how ecological, landscape and management factors may affect plant species composition, biodiversity and forage value in Alpine hay meadows. Species composition, Shannon index and forage value were obtained from phytosociological relevés. Twenty explanatory variables were selected from a set of ecological, landscape and management factors. Their effects on plant species composition, Shannon index and forage value were analysed by applying the variation partitioning approach. Plant species composition was related to sixteen factors, explaining 35·6% of the variability. Shannon index and forage value were related to eleven factors, explaining 47·8 and 40·8% of their total variation respectively. Ecological factors were the main set explaining species composition and diversity, whereas none of the three individual groups of factors (ecological, landscape, management) significantly explained variability within forage value. Overall, the effects of the three groups of factors accounted for 70% of the total variability in plant species composition, but less than half that of Shannon index and of forage value. [ABSTRACT FROM AUTHOR]

In Europe, the decline in agriculture in traditional mountain farming areas has caused abandonment, or irregular grazing, of less accessible pastures. In the Italian Alps, we studied plant diversity, forage value and trophic traits in six large-scale heterogeneously grazed Nardus pastures, in their central and peripheral parts, and across the montane, lower and upper subalpine zones. Seventy cover-abundance floristic relevés were performed in randomly located permanent plots, half at the pasture edge (M-plots) and half in their central part (C-plots). Plant diversity varied significantly with respect to the distance from the edge, being higher in M-plots because of shrub invasion as a consequence of reduced cattle pressure. Nardus cover was slightly higher in C-plots and negatively related to plant diversity. Forage value was lower in M-plots and negatively correlated with the cover of Nardus and woody species, implying that different grazing pressure was negatively influencing sward productivity. Differences in trophic traits of swards between C- and M-plots existed mostly as trends. Forage value significantly decreased in the lower subalpine and montane pastures, which are further grazed in late summer. Heterogeneous grazing management was therefore exerting positive effects on plant diversity and negative effects on forage value. Results are discussed in the context of future management recommendations. [ABSTRACT FROM AUTHOR]