The impact of salvage logging on herb layer species composition and plant community recovery in Białowieża Forest

Białowieża Forest is one of the closest to pristine forest ecosystems in temperate vegetation zone in European Lowland, which is still being transformed by forest management. We investigated the effects of salvage logging of spruce stands killed by bark beetle on the recovery process and the biodiversity of the herb layer in the early stages of vegetation development after felling, on the habitat of mixed deciduous, oak-lime-hornbeam forest (Tilio-Carpinetum). We tested: (i) to what extent salvage logging modifies the plant species richness and diversity compared to sites left intact; (ii) whether clear-felling leads to an increase in diversity of vascular plants; and (iii) which ecological groups of plants benefit, and which are hindered by disturbance, depending on age and size of the clear-felled site. Salvage harvesting executed between 2012 and 2016 led to an increase in overall plant diversity. However, the winners were the species of open habitats, promoted by soil disturbance, whereas the number and cover of ancient forest indicator species decreased in comparison to unlogged forests. Both trends were significantly related to the increasing size of clear-felled sites, and developed right after logging. A comparison of the species composition of the disturbed (logged and unlogged) sites with undisturbed forest with stands unaffected by infestation, treated as control plots revealed the great potential of the affected sites for spontaneous recovery towards the oak-lime-hornbeam forest community, despite 50–90 years of spruce-dominated stand cover. We conclude that continuous deterioration of the forest habitats via clearcutting of stands affected by insect outbreak, followed by tree planting, substantially reduces the chances of successful, natural regeneration towards deciduous, structurally complex and diverse forests

Fungal disease incidence along tree diversity gradients depends on latitude in European forests

European forests host a diversity of tree species that are increasingly threatened by fungal pathogens, which may have cascading consequences for forest ecosystems and their functioning. Previous experimental studies suggest that foliar and root pathogen abundance and disease severity decrease with increasing tree species diversity, but evidences from natural forests are rare. Here, we tested whether foliar fungal disease incidence was negatively affected by tree species diversity in different forest types across Europe. We measured the foliar fungal disease incidence on 16 different tree species in 209 plots in six European countries, representing a forest-type gradient from the Mediterranean to boreal forests. Forest plots of single species (monoculture plots) and those with different combinations of two to five tree species (mixed species plots) were compared. Specifically, we analyzed the influence of tree species richness, functional type (conifer vs. broadleaved) and phylogenetic diversity on overall fungal disease incidence. The effect of tree species richness on disease incidence varied with latitude and functional type. Disease incidence tended to increase with tree diversity, in particular in northern latitudes. Disease incidence decreased with tree species richness in conifers, but not in broadleaved trees. However, for specific damage symptoms, no tree species richness effects were observed. Although the patterns were weak, susceptibility of forests to disease appears to depend on the forest site and tree type

BFKL at Next-to-Next-to-Leading Order

We determine an approximate expression for the O(alpha_s^3) contribution chi_2 to the kernel of the BFKL equation, which includes all collinear and anticollinear singular contributions. This is derived using recent results on the relation between the GLAP and BFKL kernels (including running-coupling effects to all orders) and on small-x factorization schemes. We present the result in various schemes, relevant both for applications to the BFKL equation and to small-x evolution of parton distributions.Comment: 34 pages, 6 figures, TeX with harvmac. Various small typos corrects, in particular first term in eq D.3. Final version to be published in Nucl. Phys.

Tree identity rather than tree diversity drives earthworm communities in European forests

Given the key role of belowground biota on forest ecosystem functioning, it is important to identify the factors that influence their abundance and composition. However, the understanding of the ecological linkage between tree diversity and belowground biota is still insufficient. Here we investigated the influence of tree diversity (richness, True Shannon diversity index, functional diversity) and identity (proportion of evergreen leaf litter and leaf litter quality) on earthworm species richness and biomass at a continental and regional scale, using data from a Europe-wide forest research platform (FunDivEUROPE) spanning six major forest types. We found a marked tree identity effect at the continental scale, with proportion of evergreen leaf litter negatively affecting total earthworm biomass and species richness, as well as their biomass per functional group. Furthermore, there were clear litter quality effects with a latitudinal variation in trait-specific responses. In north and central Europe, earthworm biomass and species richness clearly increased with increasing litter nutrient concentrations (decreasing C:N ratio and increasing calcium concentration), whereas this influence of litter nutrients was absent or even reversed in southern Europe. In addition, although earthworms were unaffected by the number of tree species, tree diversity positively affected earthworm biomass at the continental scale through functional diversity of the leaf litter. By focusing on tree leaf litter traits, this study advanced our understanding of the mechanisms driving tree identity effects and supported previous findings that litter quality, as a proxy of tree identity, was a stronger driver of earthworm species richness and biomass than tree diversit

Seasonal drivers of understorey temperature buffering in temperate deciduous forests across Europe.

Aim:Forest understorey microclimates are often buffered against extreme heat or cold, with important implications for the organisms living in these environments. We quantified seasonal effects of understorey microclimate predictors describing canopy structure, canopy composition and topography (i.e., local factors) and the forest patch size and distance to the coast (i.e., landscape factors). Location:Temperate forests in Europe. Time period:2017-2018. Major taxa studied:Woody plants. Methods:We combined data from a microclimate sensor network with weather-station records to calculate the difference, or offset, between temperatures measured inside and outside forests. We used regression analysis to study the effects of local and landscape factors on the seasonal offset of minimum, mean and maximum temperatures. Results:The maximum temperature during the summer was on average cooler by 2.1 °C inside than outside forests, and the minimum temperatures during the winter and spring were 0.4 and 0.9 °C warmer. The local canopy cover was a strong nonlinear driver of the maximum temperature offset during summer, and we found increased cooling beneath tree species that cast the deepest shade. Seasonal offsets of minimum temperature were mainly regulated by landscape and topographic features, such as the distance to the coast and topographic position. Main conclusions:Forest organisms experience less severe temperature extremes than suggested by currently available macroclimate data; therefore, climate-species relationships and the responses of species to anthropogenic global warming cannot be modelled accurately in forests using macroclimate data alone. Changes in canopy cover and composition will strongly modulate the warming of maximum temperatures in forest understories, with important implications for understanding the responses of forest biodiversity and functioning to the combined threats of land-use change and climate change. Our predictive models are generally applicable across lowland temperate deciduous forests, providing ecologically important microclimate data for forest understories

Strengthening a One Health approach to emerging zoonoses

Given the enormous global impact of the COVID-19 pandemic, outbreaks of highly pathogenic avian influenza in Canada, and manifold other zoonotic pathogen activity, there is a pressing need for a deeper understanding of the human-animal-environment interface and the intersecting biological, ecological, and societal factors contributing to the emergence, spread, and impact of zoonotic diseases. We aim to apply a One Health approach to pressing issues related to emerging zoonoses, and propose a functional framework of interconnected but distinct groups of recommendations around strategy and governance, technical leadership (operations), equity, education and research for a One Health approach and Action Plan for Canada. Change is desperately needed, beginning by reorienting our approach to health and recalibrating our perspectives to restore balance with the natural world in a rapid and sustainable fashion. In Canada, a major paradigm shift in how we think about health is required. All of society must recognize the intrinsic value of all living species and the importance of the health of humans, other animals, and ecosystems to health for all

Puszcza Białowieska : miniprzewodnik naukowy

"Dzisiejsza roślinność Puszczy jest wynikiem procesów ekologicznych, które kształtowały ją od schyłku ostatniego zlodowacenia, kiedy ocieplenie klimatu umożliwiło rozwój ekosystemów leśnych na tym terenie. Około 12 tysięcy lat temu rozprzestrzeniły się tu lasy sosnowo-brzozowe, a następnie kolejno przybywały inne gatunki drzew, które wędrowały z cieplejszych rejonów Europy, gdzie przetrwały okres zlodowacenia. Stopniowo wzbogacały one tutejsze lasy i powodowały ich zróżnicowanie w zależności od warunków siedliskowych. Do pierwszych przybyszów, po sośnie i brzozie, należały wiąz i leszczyna, a między ok. 9300 a 3800 lat temu miał miejsce najbujniejszy rozwój wielogatunkowych, mieszanych lasów liściastych." (fragm.