Aim: The regional co-occurrence of contrasting bioclimatic elements (warm-temperate, continental, boreal, arctic-alpine) may be shaped by the distribution of their glacial or post-glacial refugia. We tested this hypothesis using pollen proxies in a region where such refugia are expected, but not unequivocally demonstrated.Location: East-Central Europe (Western Carpathians and adjacent regions). Methods:We compiled pollen spectra from 112 sites distributed across various landscapes for six time-periods from the Late Glacial to the present. Compositional patterns were assessed by principal coordinates analyses (PCoA) with a sensitivity analysis based on a bootstrap technique. Site PCoA scores were interpolated geographically and correlated with palaeoclimatic models.Results: Consistently over the last 15,000 years, the first ordination axis sorted samples according to the proportion of deciduous temperate trees, while the second axis consistently followed an altitudinal gradient that coincided with temperature.The principal gradient was more important than the altitudinal gradient except for the Late Glacial and Bronze & Iron Ages, when both gradients were of similar importance. The fine-grained pattern in the present mountain landscape was formed as late as during early modern colonization.Main conclusions: Since the Late Glacial, the landscape has been differentiated into temperate, continental and cold regions. This finding supports the hypothesis that refugia are a key factor for understanding current biogeography in Central Europe.The Late Glacial occurrence of temperate trees is unlikely to be explained only by gradual migrations from southern Europe. Humid but relatively warm mountains hence might have acted as glacial refugia of temperate forest species, while lowlands and leeward basins might have acted as post-glacial refugia of steppe grasslands. The strong contrast between forested (temperate) and more open continental landscapes during the Early Holocene seems to correspond with recent diversity patterns. Our results highlight the relevance of integrating past landscape trajectories into modern biogeographical models.
The samples of two technogenic sediments (MOS, coal ash sediment; MOD, a mixture of ash and natural soil) and two natural soils (MOM, meadow; MOF—forest; both Cambisol Dystric) in the vicinage of the coal ash basin were studied. We evaluated risk element concentrations and select-ed chemical and microbiological parameters to determine their influence on the community structure of Oribatida. High concentrations of various toxic elements, alkaline pH, and low hu-midity negatively affected the abundance of oribatid mites. The microbial indicator values showed that the soil microbial community formed in technogenic sediments could effectively use organic carbon. However, considering the wide C/N ratio of the substrates, the process of soil organic matter (SOM) decomposition was slowed down, and thus nutrients were less available for the mites, which could be among the reasons why we did not find any individual of oribatid mite in MOS. In MOD, however, we found representatives of three species, but only Tectocepheus velatus sarekensis established an abundant community at the highly contaminated site. Anthropogenic pressure resulted in the selection of r-strategists, which became dominant and reduced the whole community’s species’ diversity. Therefore, we consider it a suitable indicator of improper human intervention in the ecosystem.
Hilly regions along the Western Carpathian–Pannonian border are phytogeographically important, but their vegetation history remains largely unknown. We analysed two peat cores of Late Glacial origin from a bog woodland in the Malé Karpaty Mts (SW Slovakia) using plant macrofossil, pollen, peat chemistry and charcoal analyses to trace local successional patterns, regional vegetation development and occurrence of rare species. The small distance between the two profiles situated within homogeneous vegetation enabled us to explore small-scale differences in local vegetation history. The sediment started to accumulate at the end of the Allerød (ca. 12950 cal. yr BP), when a shallow oligotrophic/mesotrophic lake with macrophytes developed. Open pine-birch forests dominated in the landscape. During the early Holocene, the lake was infilled, mire vegetation appeared and broad-leaved forests spread in the surroundings. Two fire events indicated by increases in number of macroscopic charcoal particles were recorded. The first one, which occurred at the end of the Late Glacial, was found only in one of the profiles, while the second one affected entire mire and probably caused a hiatus spanning the middle and late Holocene. Fagus started to spread no later than 5800 cal. yr BP. Open mire vegetation reappeared after the fire (ca. 400 cal. yr BP). During the 19th century, the mire was overgrown by a birch bog woodland. The two profiles showed basically the same successional patterns, but some local events and occurrences of rare species ( Potamogeton alpinus, Potamogeton praelongus, Scorpidium scorpioides and Pleurospermum austriacum) were traced only in one of them.
Question: Which vegetation and soil parameters limit species establishment in restored grasslands? Do these parameters operate predominantly on a fine or a community scale?Location: White Carpathian Mountains, SE Czech Republic. Methods:We compared 16 grasslands restored on former arable land with 9 wellpreserved reference grasslands. We sampled cover of plant species in plots of 2 m × 2 m (community scale) in which four 20 cm × 20 cm subplots (fine scale) were nested. We quantified fine-scale heterogeneity as the mean Sørensen dissimilarity index among the species composition of the subplots. To characterize site conditions, we analyzed soil properties, above-ground plant biomass and its nutrient content. Results:Restored grasslands had a lower number of plant species at both the community and fine scales. Species number at the community scale was positively associated with the species number at the fine scale (irrespective of grassland type), but was not associated with fine-scale heterogeneity. This indicates the importance of fine-scale biotic interactions for overall species diversity. In support of this, in both grassland types, the species number was negatively associated with the cover of grasses, but only at the fine scale. Total cover (but not the biomass) was lower in restored grasslands, and was positively related with species number, particularly in restored grasslands. This indicates that the lower species number in the restored grasslands mainly resulted from deteriorated abiotic conditions. Such deterioration of the plant environment can be attributed particularly to the soil of the restored, formerly plowed grasslands. They had a lower soil organic matter content and a higher proportion of fine soil particles (silt and clay), indicating reduced soil water availability. The lower soil N content of restored grasslands was also reflected in the nutrient content of plant biomass, where lower N:P and N:K ratios indicated a limitation of plant growth by N-supply. Conclusion:The species number was generally driven by fine-scale biotic interactions, which operated similarly in both grassland types. The reduced number of plant
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.