Search Results (7)

European semi-dry grasslands are habitats of high conservation value. Therefore, research into the mechanisms of community assembly is important for their effective management. Using data from 76 vegetation plots of calcareous and acidic semi-dry grasslands in continental Slovenia, the author analysed the composition of plant traits, focusing on less studied belowground traits. Community-weighted means were calculated for nine plant functional traits: life form, growth form, clonal growth organ (CGO) type, persistence of connection in CGO, number of clonal offspring shoots, lateral spreading distance, role of CGO, bud bank, CSR strategy. The results showed that both grassland communities were characterized by high local persistence (perennial plants with long-lived connections between ramets). Acidic grasslands had more species with rosettes, rhizomes and stress-tolerators, indicating more stressful conditions, probably due to low pH. Mesic grassland species with numerous stolons and longer lateral spread were also characteristic of acidic grasslands. Calcareous grasslands hosted more competitors, plants with leafy stems and plants with perennial main roots. This study contributes to a deeper understanding of grassland processes and provides a basis for future investigations of belowground plant traits and their function. Full article

Due of the potential of species to determine ecosystem properties, it is important to understand how species abundance influences community assembly. Using vegetation surveys on 35 dry grasslands in north-east Slovenia, we defined dominant (8) and subordinate (61) plant species. They were compared on 14 traits to test for differences in community-weighted mean (CWM) and functional diversity (FD). We found that dominants and subordinates differed strongly in their functional traits. Dominants showed higher leaf dry matter content and a more pronounced stress tolerance strategy and were all clonal with a large proportion of species with rhizomes and a rich bud bank, while other species showed a higher specific leaf area, a longer flowering period and more ruderals. For most traits, FD was higher in subordinates. Our results suggest that dominants drive community structure by limited susceptibility to non-competitive processes. Dominants may have positive effects on subordinates by mitigating environmental stressors. Subordinates are able to assemble together by being dissimilar and use different fine-scale niches that are engineered and homogenised by dominants. Our results show that there are fundamental differences in the relative importance of ecological processes between dominant and subordinate plants in species-rich grasslands, which is also important for their conservational management. Full article

The calcareous xerothermic grasslands of the Festuco-Brometea class are among the most endangered Natura 2000 sites in Europe. The greatest threats include a lack of grazing, secondary succession, and invasive alien and expansive native species. The abandonment of such grasslands is caused by the low nutritional value of biomass, as well as by difficult habitat conditions. The aim of this study was to assess the physiological responses of native sheep breeds to hard environmental conditions when grazing in Natura 2000 habitats and to confirm the hypothesis that native sheep of the Świniarka and Uhruska breeds can be used to protect valuable natural habitats. The analysed grasslands were characterised by very difficult climatic and edaphic conditions and a low fodder value for sheep. Grazing in environmentally valuable areas, sometimes poor in fodder, did not adversely affect the welfare of grazed sheep. In both the Uhruska and Świniarka breeds, there were no indicators for heat or nutritional stress, but physiological changes were observed in the animals’ adaptation to new environmental conditions. Despite poor fodder positions, Świniarka sheep improved their condition and body weight. Fluctuations in indicators showing an adaptation process were also visible. Full article

The thousands of kilometers of forest steppes in Eurasia belong to the most threatened ecosystems thanks to habitat loss. We have limited knowledge on the recolonization ability of forest steppe species to date, which is the reason we examined the textural and structural changes in these species during secondary succession in areas of different former land use. The species number, cover, and diversity of forest steppe species, especially those of the Festuco-Brometea group, became significant for all three types in the oldest fallows. The number and proportion of forest steppe species have been steadily increasing in abandoned vineyards and arable land, indicating that forest steppe species are able to rapidly recolonize. The increase in the number and cover of forest steppe species in abandoned grasslands reveals that the replacement of the species pool of these grasslands is not necessarily accompanied by degradation, but also by the appearance and spread of valuable natural species if the habitat is sufficiently patchy. The proportions of habitat categories level off in abandoned vineyards and arable land as abandonment progresses. The cover rates of disturbed habitats species were negligible for all three types for the third decade after abandonment, indicating a change in the quality of the species pool. Full article

This work represents the first study of the floristic diversity on Bulgaria’s ancient mounds. The objective of this research was to assess the importance of the mounds for the preservation of the native vascular and cryptogam flora. Our sampling design included 111 ancient mounds distributed throughout the country. We recorded a total of 1059 vascular plants, 58 bryophytes and 61 lichen taxa. Despite their small area, the mounds were shown to preserve nearly a quarter of the Bulgarian flora. The vegetation cover on the mounds included 61% perennials indicating a long-term persistence and stability. The majority (98%) of the established vascular plants were native species. Although the conservation significance of the vascular plant species were not common, we recorded 2 critically endangered, 9 endangered and 14 Balkan endemics during the present study. The lichen Arthopyrenia salicis was recorded for the first time in Bulgaria and a new locality of the rare bryophyte Ceratodon conicus was discovered. The established compositional difference between plots from the northern and southern slopes of the mounds (88.95%) is a testament to the high local habitat diversity. The prevalence of species characteristic for Festuco-Brometea suggests that the mounds preserve fragments of native grasslands and steppes. The variation in cover of agricultural and other human modified areas in the mounds’ immediate surroundings did not substantially affect their species richness. We argue that the ancient mounds should be taken into consideration in future green space planning. Full article

Rock outcrops have promoted a high level of species diversity and provided a stable microclimate for long time periods. The present study is devoted to plant diversity of natural Quaternary outcrops of basaltic rocks. Chorological and ecological investigations were carried out at 35 such outcrops, located within five physiogeographic units of the Sudetes Mountains. The focus was on 120 xerothermic taxa of vascular plants: 62 strictly xerothermic (steppe) taxa of the Festuco valesiacae-Brometea erecti class, and 58 thermophilous taxa representing classes Trifolio medii-Geranietea sanguinei and Quercetea pubescentis. Limited geographical ranges of these plants are manifested by variable frequency of their occurrence. Species distribution is determined by natural factors, like surface area of the outcrop, the type of basaltic rock and the type of plant communities developed. Basaltic outcrops in the Sudetes meet the criterion of habitat islands (inselbergs), serve as regional centers of vascular flora, and are refugia for marginal populations of relict species. Full article

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. Full article