Mendel University in Brno

Functional traits can vary in response to tree species mixing, which in turn might influence biomass production and, consequently, carbon (C) sequestration in diverse forests. However, evidence for consistent broad-scale patterns in tree trait responses, particularly regarding trait identity and their contribution to above-ground biomass outcomes, remains limited. Using data from even-aged forest stands in 11 tree diversity experiments in Europe and Brazil, encompassing 40 tree species, we estimated the influence of species mixing on above-ground biomass components (woody, litterfall and understory biomass), as well as effects of mixing on plasticity-driven changes in species- and community-level functional traits. At the community level, specific leaf area (SLA) and leaf area index (LAI) were higher in mixtures than expected values based on monocultures, while leaf nitrogen per area decreased, and leaf nitrogen per mass remained stable. SLA increases were primarily due to the response of less dominant tree species. Woody and litterfall biomass increased in mixtures, whereas understory biomass remained unchanged. At the species level, diversity-driven plastic changes were observed in multiple traits, but only SLA showed a consistent shift across species. Tree diversity effects on above-ground biomass were influenced by both functional diversity and diversity-driven trait shifts, where increased SLA and LAI enhanced woody biomass accumulation, while higher LAI in diverse stands reduced understory biomass. Together, these results show that tree species mixing alters canopy structure and light-related traits, with shifts in SLA and LAI constituting key pathways through which mixed forests accumulate more woody biomass.Read the free for this article on the Journal blog.

In this work, we developed biodegradable cellulose acetate (CA) fibers infiltrated with ZnO nanocrystals for the Acne vulgaris (AV) treatment. The antibacterial effect (through Zn2+ release) was activated upon oxygen plasma treatment. CA fibers (fiber diameter ≈ 2 µm) were produced via centrifugal spinning, followed by ZnO infiltration (up to 8 wt% of Zn content) using Vapor Phase Infiltration (VPI) with varying deposition cycles. As CA fibers are naturally hydrophobic, oxygen plasma treatment was applied to turn them hydrophilic and to improve skin wetting. The combination of these steps is presented for the first time. Plasma treatment introduced oxygen-containing functional groups on the CA surface, significantly improving wettability. Scanning electron microscopy analyses of treated fibers showed no morphological damage. Detailed characterization (using X-ray photoelectron spectroscopy, Raman spectroscopy, energy dispersive X-ray fluorescence, X-ray diffraction, tranmission electron microscopy) focused on fibers with 32 and 128 VPI cycles, revealed that plasma partially oxidized and etched the surface, affecting the ZnO distribution. Plasma-modified fibers, unlike untreated ones, exhibited antibacterial activity against AV-causing bacteria (Cutibacterium acnes and Staphylococcus epidermidis), creating significant inhibition zones (up to 5 mm), demonstrating their potential as promising therapeutic modality. Overall, plasma treatment enabled effective surface functionalization, producing antibacterial fibers with enhanced surface properties suitable for application in AV management.

Forestry, nursery, and planting tasks involve repetitive trunk flexion, squatting, and kneeling, as well as manual handling, increasing musculoskeletal load, and the need for mobility-related safety measures. Passive exoskeletons could mitigate postural exposure and reduce the overall body workload. We conducted a preliminary study (n = 14) to test the feasibility of a protocol and estimated model- and task-specific trends during standardized simulated nursery activities in a laboratory setting. Participants simulated planting and seeding tasks (loads of 0.5-2 kg) and material handling and preparation tasks (loads of 5-15 kg) without an exoskeleton (No-EXO) and with three passive models (EXO 1-EXO 3). EXO 3 was excluded from the planting tasks for feasibility reasons. Whole-body kinematics were recorded using an IMU-based motion capture system and converted into time-based ergonomic exposure outcomes (OWAS and RULA). Physiological load was monitored via heart-rate (HR) measurements. Compared to the No-EXO condition, exoskeleton use shifted posture exposure towards lower-risk categories. The largest improvements were observed with EXO 2 and EXO 3 during material handling (OWAS: -18%/-20%; RULA action-level reduction: -25%/-39%) and with EXO 2 during planting/seeding (OWAS: -15%; RULA: -26%). HRmax did not increase across tasks or conditions and HR tended not to rise with higher workload when exoskeletons were used. Overall, the results suggest positive ergonomic and workload trends related to the model and tasks. Field validation on uneven terrain with full personal protective equipment and harness integration is needed to confirm usability and support and to define implementation requirements (fit, compatibility with PPE, and safe-use conditions).

The purpose of this study was to evaluate the risk of the spore germination and subsequent multiplication of Clostridium perfringens during the distribution of hot ready-to-eat (RTE) meals by the courier services. This evaluation was based on the ability of C. perfringens vegetative cells growth in the model RTE meals (minced chicken meat, minced pork, and minced beef) and on determination of the rate of internal temperature decrease in identical meals during a simulated distribution. After 4 h of incubation at 40 degrees C and 50 degrees C, C. perfringens NCTC 8798 counts reached 3.54 and 4.45 log CFU/g, respectively. No significant differences (P > 0.05) in C. perfringens NCTC 8798 counts were observed among the tested meals after 4 and 6 h of incubation at 40 degrees C, 50 degrees C, or 60 degrees C. It was concluded that an average time interval of the internal dish temperature decline to the hazardous zone between 40 degrees C and 50 degrees C was 60-90 min, which corresponded to a negligible growth of C. perfringens during this time. Even a 4-h delay in meal delivery did not increase C. perfringens counts above 5 log CFU/g which thus remained below the threshold for causing gastrointestinal illness (with limit of detection 1.7 log CFU/g).

Abstract Background Urban trees play a vital role in supporting biodiversity, enhancing human well-being, and promoting climate resilience. However, they are increasingly threatened by invasive insect pests. These pests belong to different feeding guilds, such as leaf-miners and sap-suckers, which may respond differently to the tree spatial arrangement and health of trees. Understanding how specific strategies of these pest groups interact with tree spatial arrangement, tree health, tree size, levels of defoliation, and the proportion of neighboring conspecific trees is crucial for explaining how infestations develop in urban areas. This study investigated how these factors influence infestations by three invasive pests: the horse-chestnut leaf miner (Cameraria ohridella), the plane leaf miner (Phyllonorycter platani), and the sycamore lace bug (Corythucha ciliata). Results Infestation intensity increased across all species as summer progressed (p < 0.001 for all species). C. ohridella reached the highest levels on solitary horse chestnuts, while P. platani was more abundant on plane trees growing in stands or groups. Proximity to conspecific trees reduced C. ohridella infestation, whereas healthier plane trees exhibited lower C. ciliata abundance. Tree size had no consistent effect, and defoliation did not reduce infestation in any species, despite significantly higher defoliation in horse chestnut compared to plane trees (p = 0.002). Leaf-mining and sap-sucking guilds differed in their spatial responses. Conclusions Fine-scale tree spatial arrangement and host condition are associated with variation in invasive pest dynamics in urban environments. Guild-specific differences in spatial responses and the finding that defoliation did not reduce infestation highlight the importance of local tree context for understanding infestation patterns of multivoltine pests. These insights may support the design of more resilient urban plantings, particularly through strategic arrangement of host trees and maintaining host vitality. Graphical abstract