Biology subjects

Ciach, M.

Publications and source records attributed to Ciach, M..

5 recordsLinked to original sources

bioRxiv2025

Urban green infrastructure fails to mitigate exposure to mercury with increasing pollution levels: evidence from corvids

The urban landscape acts as a novel habitat providing opportunities for certain species. However, populations of these so-called urban winners are constantly exposed to environmental contaminants, among which mercury (Hg) is perceived as a significant health concern for both wildlife and humans. While absorption of Hg is primarily related to its environmental level, it could be theoretically mitigated by near-natural habitats that have persisted within the urban landscape. Here, we investigated this hypothesis using three sympatric corvids as a model - Magpie Pica pica, Jackdaw Corvus monedula and Rook Corvus frugilegus. Total Hg concentrations were identified in the feathers (in the shafts and barbs separately) of each species collected in their breeding territories located along the urbanization gradient of Krakow (Poland). These concentrations were then correlated with particulate matter emissions (PM10) and habitat features (green and grey infrastructure) measured in the territories where the feathers had been collected. We expected that Hg concentrations in feathers would increase with increasing local pollutant emissions but decrease with increasing areas of green infrastructure, i.e. natural or semi-natural vegetation. Mean Hg concentrations in both feather shafts and barbs differed between the species. Magpie showed the highest concentrations (0.621 {+/-}0.442 SD {micro}g/g in barbs), followed by Jackdaw (0.441 {+/-}0.272 {micro}g/g) and Rook (0.296 {+/-}0.134 {micro}g/g). A generalized linear model yielded a correlation between habitat composition and Hg concentration only for Jackdaw feather shafts. A generalized additive model, however, revealed a non-linear relationship between PM10 emissions and Hg concentrations in feather barbs and/or shafts of Jackdaw and Magpie (but not Rook). Hg concentrations initially increased, but then fell with increasing PM10 emissions; these relationships were not influenced by habitat features. In conclusion, we found no evidence that Hg contamination was mitigated by urban green infrastructure. HighlightsO_LIUrban birds are exposed to environmental contaminants, including mercury (Hg) C_LIO_LIHg concentrations in feather shafts and barbs differed between the species C_LIO_LIHg concentrations non-linearly correlated with particulate matter emissions C_LIO_LIHg contaminations not mitigated by urban green infrastructure C_LI

ecology↗

bioRxiv2025

Bark beetles as ecosystem engineers: triggered tree mortality rearranges the assemblage of Tree-related Microhabitats in old-growth coniferous forest

Although species with ecosystem engineering capabilities like woodpeckers, ungulates or saproxylic insects may initiate the formation of Tree-related Microhabitats (TreMs), their overall impact on TreM assemblages remains unexplored. Bark beetle activity can increase tree mortality, accelerating the emergence of canopy gaps with altered tree species composition, stand structure and deadwood resources, all of which can influence TreM profiles and cascade on biodiversity. We investigated the TreM assemblage in a strictly-protected old-growth Norway spruce Picea abies forest in the Tatra Mountains (Carpathians, S Poland), comparing bark beetle-induced canopy gaps with undisturbed closed-canopy reference sites. Although TreM richness, density and diversity did not differ between the canopy gaps and reference sites, the frequency and density of woodpecker cavities, splintered stems, cracks, bark pockets, bark shelters, fruiting bodies of polypore fungi and epiphytic ferns was higher in the canopy gap TreM assemblage. In contrast, the frequency and density of exposed sapwood, shaded dead branches, dead tree tops, coarse bark, root buttress cavities, cankers, resin runs and microsoil in the tree crown or bark were higher in the reference sites. TreM richness, density and diversity were correlated with the density of living or dead standing trees and tree species richness, all related to previous bark beetle activity. Bark beetle-induced canopy gaps did not increase the total TreM abundance or diversity, but by hosting more saproxylic TreMs, locally altered the TreM composition. Our study underlines the importance of ecosystem engineering by bark beetles as drivers of the heterogeneity of temperate coniferous montane forests. HighlightsO_LITreMs in coniferous forests are abundant but less diverse than in deciduous ones C_LIO_LICanopy gaps have a distinct TreM profile compared to intact old-growth forest C_LIO_LICanopy gaps are hot-spots of certain TreMs in coniferous forests C_LIO_LISaproxylic TreMs are 3-9 times more abundant in canopy gaps than in intact forests C_LIO_LITree mortality triggered by bark beetles increases habitat heterogeneity C_LI

ecology↗

bioRxiv2024

Ecosystem engineers cause biodiversity spill-over: beavers affect breeding bird assemblages on both wetlands and adjacent terrestrial habitats

The influence of ecosystem engineers on habitats and communities is commonly acknowledged in a site-bounded context, i.e. in places directly affected by the presence of the focal species. However, the spatial extent of the effects of such engineering is poorly understood, raising the question as to what impact they have on ecosystems situated beyond the species direct influence. Beavers Castor spp., iconic ecosystem engineers, are capable of significantly transforming aquatic ecosystems. Their presence boosts biodiversity in near-water habitats, but as a result of cascading processes, beavers may affect terrestrial habitats situated beyond the range of their immediate activity. Our study investigates the breeding bird assemblage along a spatial gradient from the water to the forest interior on central European watercourses modified and unmodified by beavers. The results show that beaver sites are characterized by a higher species richness and abundance of breeding birds than unmodified watercourses. Such sites also host a different species pool, as 27% of the recorded bird species occurred exclusively on the beaver sites. The effect of the beavers presence on the bird assemblage caused this to spill over from the wetlands to adjacent terrestrial habitats located up to 100 m from the waters edge, where the species richness and abundance was higher and the species composition was substantially modified. We also found a positive correlation between the total area of beaver wetland and the numbers of bird species and individuals recorded. Our study indicates that beaver activity has major consequences for ecosystem functioning that extend beyond the wetland, spilling over on to adjacent terrestrial ecosystems. These findings add to the general understanding of the spatial context of the ecosystem engineering concept, as the changes brought about by engineers have an influence beyond the area of their immediate occurrence. Our work also has implications for landscape planning and management, where existing beaver sites with terrestrial buffer zones may constitute a network of biodiversity hot-spots. Highlights* Beavers create hot-spots of bird richness and abundance in temperate forests * The beavers impact spills over beyond wetlands on to terrestrial ecosystems * Bird richness, number and composition is changed up to 100 m from beaver sites * The area of a beaver wetland positively correlates with bird richness and numbers * The beaver is an umbrella species for the riparian forest bird community

ecology↗

bioRxiv2024

Spatial distribution of Tree-related Microhabitats in a primeval mountain forest: from natural patterns to landscape planning and forest management recommendations

Tree-related Microhabitats (TreMs) are essential for sustaining forest biodiversity. Although TreMs represent ephemeral resources that are spread across the landscape, their spatial distribution within temperate forests remains poorly understood. To address this knowledge gap, we conducted a study on 90 sample plots (0.05 ha each) located in a primeval mountain European beech Fagus sylvatica-dominated forest (Bieszczady Mountains, Carpathians). We explored the TreM profile with its link to habitat characteristics and described the spatial distribution of TreM indices. We identified 61 TreM types, with a mean richness of 19.7 {+/-}4.9 SD TreM types per plot, a mean density of 740.7 {+/-}292.5 SD TreM-bearing trees ha-1 and a mean TreM diversity of 1.2 {+/-}0.1 SD. The diameter and living status of trees (living vs dead standing tree) were correlated with TreM richness on an individual tree. The stand structure, i.e. density and/or basal area of living and/or dead standing trees, and topographic conditions, i.e. slope exposure, were correlated with the TreM richness, density and diversity recorded on a study plot. We found no relationship between TreM richness, density and diversity and the presence of canopy gaps, which indicates that the influence of small-scale disturbances on the TreM profile is limited. However, our analysis revealed a clustered spatial pattern of TreM indices, with TreM-rich habitat patches (hot-spots) covering [~]20% of the forest. A moderate TreM richness, density and diversity dominated [~]60% of the forest, while TreM-poor habitat patches (cold-spots) covered [~]20%. Based on our findings, we advise the transfer of knowledge on the spatial distribution of TreMs from primeval to managed forests and advocate the 2:6:2 triad rule: to allocate 20% of forests as strictly protected areas, to dedicate 60% to low-intensity forest management with the retention of large living trees and all dead standing trees, and to use the remaining 20% for intensive timber production. To ensure the continuance of the majority of TreM types, [≥] 55 living trees ha-1 > 60 cm in diameter should be retained. Such an approach will maintain a rich and diverse TreM assemblage across a broad spatial scale, which in turn will support biodiversity conservation and ecosystem restoration in secondary or managed forests. HighlightsO_LIPrimeval mountain beech forest hosts rich and abundant TreM assemblage C_LIO_LIStand structure, slope exposure, but not canopy gaps mould TreM profiles C_LIO_LIHabitat patches with high/low TreM indices are spatially clustered C_LIO_LIHot- and cold-spots each make up 20% of TreM richness, density and diversity C_LIO_LI2:6:2 - the protected: managed forest ratio for maintaining the TreM assemblage C_LI

ecology↗

bioRxiv2024

To be browsed or not to be browsed: differences in nutritional characteristics of blackthorn Prunus spinosa subject to the long-term pressure of herbivores

The impact of ungulates on temperate forest vegetation has been investigated for a long time. Numerous studies on food selection have identified the palatable plant species preferred by large European herbivores. However, intra-specific food selection and the question why particular plants of a given species are ignored during foraging have been neglected in the literature. In central Europe, Blackthorns Prunus spinosa growing in abandoned pastures are an important component of the red deers Cervus elaphus diet. In areas densely populated by deer, annual shoot browsing produces dwarf shrubby forms of blackthorns. However, some blackthorns are not browsed by ungulates and tend to adopt a tree-like form. The existence of distinct, browsing-dependent growth forms of blackthorns raises the question of inter-individual differences in the nutritional composition of plants. Based on factor analysis, we discovered differences in nutritional composition between browsed and unbrowsed blackthorns that might explain the individual plant-related drivers of red deer food preferences. The leaves of browsed blackthorns contained higher concentrations of C, N, P and Cu but lower levels of Ca and Mg than unbrowsed ones. Moreover, browsed blackthorns had a higher water content and higher concentrations of insoluble proteins, chlorophylls and carotenoids. We highlight the fact that the nutritional characteristics of an individual plant may explain the observed food selection pattern, leading to the unhindered growth of a fraction of the blackthorn population, in spite of severe pressure on the part of ungulate herbivores. The results of this study underline the important role of herbivores in the dynamics of plant communities, in which ungulates may mediate the persistence of certain individuals of a given species. HighlightsO_LIBrowsing by ungulates leads to the formation of dwarf shrubby forms in blackthorns C_LIO_LISome blackthorns are unbrowsed and adopt a tree-like form C_LIO_LIBrowsed blackthorns differ in chemical composition from unbrowsed ones C_LIO_LIThe nutritional profile of a given plant may influence food selection by ungulates C_LI

ecology↗