Search Results (110)

Forests in the Eastern and Midwestern U.S. have been profoundly affected by human use over the last 150 years, with few old growth forests remaining. Such mature forests may harbor distinct communities and high biodiversity, particularly detritivores and their associated food webs. These communities, however, have been surveyed only rarely in comparisons of diversity and community composition between old and young forests. Here, we compare the mycophilous beetle communities of young and old deciduous forest stands in Southwestern Ohio (U.S.A.). We assess how the abundance and diversity of beetles associated with fungal sporocarps varies with forest age, downed woody debris, and invasive honeysuckle density. We surveyed fungus-associated beetles with baited traps at eight wooded parklands centered around Dayton, Ohio, conducting sampling three times over a growing season. In contrast to expectation, we found no clear effect of forest age on mycophilous beetle communities, but infestation by invasive honeysuckle (Lonicera maackii) negatively affected beetle abundance and diversity. Beetle abundance, richness, and community composition also strongly varied across seasonal sampling periods. Our surveys of mycophilous beetles in a Midwestern U.S. forest represent an initial step toward understanding how these communities are shaped by forest age and invasive species. Such information is crucial in managing forests to preserve biodiversity and ecosystem services. Full article

Sustainable Forest Management (SFM) requires the building of relationships among diameter increment, shape, and size (ISS), and increment–age variables to identify critical changes in forest structure and dynamics. This understanding is essential for maintaining forest productivity, structural and species diversity, stability, and sustainability. This study focused on measuring, reporting, and modeling these relationships for Araucaria angustifolia (Bertol.) Kuntze, across various diameters and three stands, located at different rural properties in southern Brazil. A random sample of 186 individual trees was acquired; the trees were measured for multiple dendrometric variables, and several morphometric indices were calculated. Additionally, two cores were extracted from each tree using an increment borer, enabling the measurement of growth rings and annual diameter increments. These were modeled using generalized linear models to assess the relationships among them and to quantify changes in forest structure and dynamics. The results revealed the dominance of A. angustifolia and a decline in the increment rate with increasing age, shape, and size in both old and young trees, indicating potential risks to the structure and dynamics of these unmanaged forests. Therefore, the models constructed in this study can guide conservation-by-use efforts and ensure the long-term continuity and productivity of forest remnants at selected rural properties, where A. angustifolia trees are predominant. Full article

Selection forestry sustains timber production and stand structural complexity via partial harvesting. However, regeneration initiated by harvesting may function as fuel ladders, providing pathways for fire to reach the forest canopy. We sought potential mitigation approaches by simulating stand growth and potential wildfire behavior over a century in stands dominated by coast redwood (Sequoia sempervirens (Lamb. ex. D. Don) Endl.) on California’s north coast. We used the fire and fuels extension to the forest vegetation simulator (FFE-FVS) to compare group selection (GS) to single-tree selection silviculture with either low-density (LD) or high-density (HD) retention on a 20-year harvest return interval. These three approaches were paired with six options involving vegetation management (i.e., hardwood control or pre-commercial thinning (PCT)) with and without fuels treatments (i.e., prescribed fire or pile burning), or no subsequent vegetation or fuel treatment applied after GS, HD, or LD silviculture. Fuel treatment involving prescribed fire reduced hazardous fuel loading but lowered stand density and hence productivity. Hardwood control followed by prescribed fire mitigated potential wildfire behavior and promoted dominance of merchantable conifers. PCT of small young trees regenerating after selection harvests, followed by piling and burning of these cut trees, sustained timber production while reducing potential wildfire behavior by approximately 40% relative to selection silviculture without vegetation/fuel management, which exhibited the worst potential wildfire behavior. Full article

Water use strategies reflect the ability of plants to adapt to drought caused by climate change. However, how these strategies change with stand development and seasonal drought is not fully understood. This study used stable isotope techniques (δD, δ¹⁸O, and δ¹³C) combined with the MixSIAR model to quantify the seasonal changes in water use sources and water use efficiency (WUE) of Eucalyptus urophylla S.T.Blake × E. grandis (E. urophylla × E. grandis) at four stand ages (2-, 4-, 9- and 14-year-old) and to identify their influencing factors. Our results showed that the young (2-year-old) and middle-aged (4-year-old) stands primarily relied on shallow soil water throughout the growing season due to the limitations of a shallow root system. In contrast, the mature (9-year-old) and overmature (14-year-old) stands, influenced by the synergistic effects of larger and deeper root systems and relative extractable water (REW), exhibited more flexibility in water use, mainly relying on shallow soil water in wet months, but shifting to using middle and deep soil layer water in dry months, and quickly returning to mainly using shallow soil water in the episodic wet month of the dry season. The WUE of E. urophylla × E. grandis was affected by the combined effect of air temperature (T), vapor pressure deficit (VPD), and REW. WUE was consistent across the stand ages in the wet season but decreased significantly with stand age in the dry season. This suggests that mature and overmature stands depend more on shifting their water source, while young and middle-aged stands rely more on enhanced WUE to cope with seasonal drought stress, resulting in young and middle-aged stands being more vulnerable to drought stress. These findings offer valuable insights for managing water resources in eucalyptus plantations, particularly as drought frequency and intensity continue to rise. Full article

Michelia macclurei, a valuable native broad-leaved species with good ecological and economic benefits and a key afforestation tree in South China, is facing progressive stand degradation and soil fertility decline with age. To investigate age-dependent dynamics of stand structure and soil properties, this study examined five stands (5, 10, 15, 20, and 42 a) in Yunfu City, Guangdong Province. The results revealed that (1) spatial distribution shifted from aggregated in young stands (5–10 a) to random in mature stands (42 a), with diameter and height class distributions becoming more diverse with age. Notably, topsoil (0–20 cm) in near-mature stands (15–20 a) exhibited not only significantly higher capillary porosity, non-capillary porosity, and water-holding capacity compared to young stands but also increased bulk density, indicating soil physical degradation. (2) Soil nutrient decline was observed in over-mature stands (42 a), characterized by a reduction in soil total nitrogen to 1.08 ± 0.06 g·kg⁻¹ and total phosphorus to 0.16 ± 0.02 g·kg⁻¹ in the topsoil (0–20 cm layer), suggesting age-related soil nutrient degradation. (3) Correlation analysis revealed a significant negative correlation between total potassium content and crown uniformity indices (p < 0.01), while available phosphorus was significantly positively correlated with crown and tree growth (p < 0.05). These findings provide critical insights for developing stage-specific management strategies in Michelia macclurei plantations. Full article

With the intensification of global climate change and human activities, coniferous species as the main components of natural forests in the Altay Mountains are facing the challenges of aging and regeneration. This study systematically analyzed structural heterogeneity and regeneration of three coniferous stand groups, Larix sibirica Ledeb. stand group, Abies sibirica Ledeb.-Picea obovata Ledeb.-Larix sibirica mixed stand group, and Picea obovata stand group, respectively, across western, central, and eastern forest areas of the Altay Mountains in Northwest China based on field surveys in 2023. Methodologically, we integrated Kruskal–Wallis/Dunn’s post hoc tests, nonlinear power-law modeling (diameter at breast height (DBH)–age relationships, validated via R², root mean square error (RMSE), and F-tests), static life tables (age class mortality and survival curves), and dynamic indices. Key findings revealed structural divergence: the L. sibirica stand group exhibited dominance of large-diameter trees (>30 cm DBH) with sparse seedlings/saplings and limited regeneration; the mixed stand group was dominated by small DBH individuals (<10 cm), showing young age structures and vigorous regeneration; while the P. obovata stand group displayed uniform DBH/height distributions and slow regeneration capacity. Radial growth rates differed significantly—highest in the mixed stand group (average of 0.315 cm/a), intermediate in the P. obovata stand group (0.216 cm/a), and lowest in the L. sibirica stand group (0.180 cm/a). Age–density trends varied among stand groups: unimodal in the L. sibirica and P. obovata stand groups while declining in the mixed stand group. All stand groups followed a Deevey-II survival curve (constant mortality across ages). The mixed stand group showed the highest growth potential but maximum disturbance risk, the L. sibirica stand group exhibited complex variation with lowest risk probability, while the P. obovata stand group had weaker adaptive capacity. These results underscore the need for differentiated management: promoting L. sibirica regeneration via gap-based interventions, enhancing disturbance resistance in the mixed stand group through structural diversification, and prioritizing P. obovata conservation to maintain ecosystem stability. This multi-method framework bridges stand-scale heterogeneity with demographic mechanisms, offering actionable insights for climate-resilient forestry. Full article

Given the high postural control demands of sport Jiu-Jitsu, prolonged training in this discipline may result in sport-specific adaptations, particularly in positions closely related to combat scenarios. This study aimed to evaluate the differences in reaction time and postural control between elite Jiu-Jitsu athletes and untrained individuals, highlighting the potential influence of specialized training on these critical performance attributes. This study was conducted on thirty-one young participants (fifteen Brazilian Jiu-Jitsu athletes and sixteen non-athletes). Reaction time was measured using the Fit Light Trainer system in two positions. Postural control was assessed during 30 s bipedal and single-leg standing, both with and without a dual task involving tracking a randomly moving point on a screen. Results indicated that athletes demonstrated significantly faster reaction times (p = 0.0242) and greater complexity in postural control mechanisms, as evidenced by higher fractal dimension values during single-leg standing with dual tasks in the anterior–posterior direction (p = 0.0011). These findings suggest that Brazilian Jiu-Jitsu athletes possess enhanced neuromuscular and cognitive–motor integration, crucial for managing the complex demands of martial arts. This study highlights the importance of incorporating dual-task scenarios in training to optimize athletic performance and postural control in high-demand sport contexts. Full article

Young forest stands from natural regeneration are characterized by high competitive pressure and dynamic changes over time, especially in the initial growth stages. Despite their increasing area in the temperate zone, they have received significantly less scientific attention than old forest stands. Therefore, our research was conducted on young, over-dense European beech (Fagus sylvatica L.) forest originating from natural regeneration, grown in central Slovakia, Western Carpathians. Repeated measurements of tree height and stem diameter measured on the base within a beech stand revealed significant temporal changes in their relationship. Over 16 years, height increased more than stem diameter. Both Lorey’s height and mean diameter d₀ showed continuous growth, with Lorey’s height increasing 3.5-fold and mean diameter increasing 2.8-fold. The height-to-diameter ratio increased until stand age 15, then briefly declined before rising again. Stand density decreased over time, with the sharpest decline occurring between ages 15 and 16 (dropping from 843 to 599 trees per 100 m²). Mortality rates peaked at age 16, with an average annual rate of 9.4% over the entire observation period (2008–2023). Specific leaf area (SLA) was negatively related to tree size, and its value was smaller in 10- than in 20-year-old stands. The increase in SLA was driven by greater leaf area relative to leaf weight. Additionally, allometric relationships showed that branch and leaf contributions to aboveground biomass decreased with tree size within the stand but were greater in the older stand than in the younger growth stage. Estimated aboveground biomass was 667 ± 175 kg per 100 m² in the 10-year-old stand and 1574 ± 382 kg per 100 m² in the 20-year-old stand, with stems contributing the majority of biomass. Leaf Area Index (LAI) remained similar across both stand ages, while the Leaf Area Ratio (LAR) was nearly twice as high in the younger stand. These findings highlight dynamic shifts in beech stand structure, biomass allocation, and leaf traits over time, reflecting growth patterns and competition effects. The outputs indicate that competition in young forest stands is a dominant force in tree mortality. Understanding key interactions in young stands is crucial for sustainable forest management, as these interactions influence long-term stand stability and ecosystem functions. Full article

Improved forage and living conditions in certain parts of Europe over the past few decades have led to alarming levels of ungulate densities. Consequently, the overabundance of red deer, roe deer, and fallow deer in the Western Plains of Romania has begun to generate issues in the development of young oak stands. In addition to causing damage to the agricultural sector and increasing the risk of vehicle collisions, ungulates are increasing pressure on the forestry sector, mainly through the browsing of young saplings. This study quantifies the levels of ungulate browsing in oak stands using a permanent sample grid of 42 plots in both natural and artificial regeneration areas. A total of 3223 individual saplings were measured, revealing browsing intensities of 49.65% in clearcut systems and 12.8% in continuous forest cover systems. With high ungulate densities identified as the main cause, the Sustainable Population Threshold was calculated using a complex set of indices and compared to the actual numbers of ungulates, both of which were translated into stock unit equivalents. A logistic regression model was developed based on silvicultural and wildlife indices to identify other factors influencing browsing occurrence. The findings indicate that the proportion of forested areas in the hunting ground and the type of silvicultural system are significant factors in the occurrence of browsing. The problem of ungulate overabundance clearly influences forest development, and new solutions should be identified in terms of both forestry and wildlife management. Full article

Employability has been widely studied from various theoretical and methodological perspectives. However, certain dimensions of the determinants of employability remain underexplored, particularly in the context of a rapidly evolving labor market shaped by digital transformation and artificial intelligence and socio-economic contextual factors. The aim of this study is to analyze the dimensions influencing the employability of young Moroccans through an exploratory qualitative approach, based on structured roundtable discussions organized at the Careers and Skills Centre of Laâyoune. The findings identify eight key pillars of employability, aligned with the current labor market demands, encompassing educational and training opportunities, hard and soft skills, geographical mobility, entrepreneurial and project management skills, adaptation to emerging professions, regional economic infrastructure, and state support. These insights provide a comprehensive framework for understanding employability dynamics, offering actionable recommendations for educators, policymakers, and employers. This research stands out by integrating a contextualized approach to employability, bridging global labor market trends with region-specific socio-economic realities. Full article

Intensive forest management has promoted an increase in deer (Cervidae) population density. Various silvicultural activities, such as pre-commercial thinning, can change the feeding conditions for deer species, therefore impacting browsing pressure on target tree species. In this study, we analyzed how several factors, including the density of the main tree species, admixture, undergrowth, and forest type, affect deer damage intensity in pine stands, considering deer densities and regional aspects in hemiboreal Latvia. GLMM analysis, based on data from 1238 sample plots, showed that the probability of browsing damage decreases with an increase in the density of undergrowth in young (<20 years) pine stands with a dominant height below 3 m. Also, the probability of pines being damaged by deer was significantly (p = 0.001) higher in stands with fresh pre-commercial thinning than in those with no thinning. However, differences in deer density between regions also determined browsing pressure. Results indicated that undergrowth density, pre-commercial thinning, and deer density may be important drivers of damage levels, especially in the winter browsing of young pine stands on wet mineral soils. Therefore, future research should continue to evaluate applied forest management strategies in hemiboreal forests that provide additional natural food base in the form of woody plants and shrubs in winter forage to ensure more deer-adapted practices. Full article

Soil fauna is integral to facilitating material cycles, energy flows, and the conservation of biodiversity in terrestrial ecosystems. However, the impacts of forest development on the compositions and structures of soil invertebrates remain uncertain. Here, we assessed the dynamics in abundance and diversity of soil invertebrates across eight successional age stages of Metasequoia glyptostroboides tree plantations (7-, 16-, 21-, 26-, 31-, 36-, 41-, 46-year-old stands) in a reclaimed coastal land in China. We used pitfall traps to collect soil invertebrates and analyzed key soil and litter properties to understand their relationships with the faunal communities. The results revealed that the total abundance of soil invertebrates initially decreased during the young to near-mature stand period (7- to 31-year-old stands), whereas it increased along the age series, from the near-mature to overmature stand period (31- to 46-year-old stands). Specifically, the dynamics showed a U-shaped curve with stand development. Further, there was a significantly negative correlation between the Shannon–Wiener diversity index and the total abundance of soil invertebrates across this plantation chronosequence. The variations in abundance of detritivores were consistent with the total abundance of soil invertebrates during stand development. The abundance and diversity of the soil invertebrates were strongly correlated with the soil environment (e.g., soil organic carbon, litter biomass, and microbial biomass nitrogen). These findings highlight that the compositions and structures of soil invertebrates were significantly altered with M. glyptostroboides stand development. Thus, the management of plantations should consider the abundance and diversity of soil invertebrates and functional groups for improving soil structure and fertility. This provides important insights for studying the interconnection of above- and below-ground plantation ecosystems toward their optimal management. Full article

Background/Objectives: Overall priorities of the international pediatric-onset spinal cord injury (SCI) population are unknown. The purpose was to describe and compare Life and Health (L&H) domain overall priorities of European youth with SCI and their parents and caregivers (P&C). Methods: A survey with a cross-sectional design, prepared by the PEPSCI Collaboration, was conducted in six European countries. In total, 202 participants, including youth with SCI (n = 101) and their P&C (n = 101), were included. Overall priorities were calculated based on unhappiness, importance, and research. Results: The sample included youth aged 8–12 years (30.7%) and 13–25 years (69.3%; 38.6% 13–17-year-olds and 30.7% youth aged 18–25 years), in addition to their P&C. The top three L&H priorities highlighted by P&C of the youth aged 8–12 years were “bladder” function (78%), “leg/foot movement” (77%), or “bowel” function (74%), compared with “leg/foot movement” (79%), “sit-to-stand” (76%), or “walking/ability to move” (75%) reported by P&C of the youth aged 13–25 years. The youth aged 13–25 years considered “leg/foot movement” (68%), “bowel” (66%), or “bladder” function (65%) as priorities. The top 10 priorities highlighted by the youth aged 13–25 years compared to the top 10 priorities rated by P&C were issues related to “personal needs”. Nevertheless, “pressure injuries”, “pain”, “bowel function”, or “mobility in the community” were highlighted as top preferences of priorities for the youth aged 13–25 years compared to their P&C. Conclusions: Adolescents/young adults highlighted health domain priorities compared with their P&C, who equally considered L&H domains. Life domains, which were previously unaddressed, were highlighted by P&C, including “adulthood expectations” and “parenthood expectations”. This survey will promote the involvement of stakeholders for comprehensive rehabilitation management for this population. Full article

Introduction: Cardiovascular diseases are the leading cause of mortality worldwide, with a significant impact on socioeconomic aspects. Various biomarkers have been studied in relation to the diagnosis, progression, and prognosis of atherosclerotic disease, with lipoprotein (a) [Lp (a)] standing out as an important predictor of cardiovascular risk. This observational study aimed to clarify the association between Lp (a) levels and the severity of significant multivessel coronary lesions in acute myocardial infarction (AMI) patients. Materials and Methods: Conducted at the Clinical Emergency County Hospital of Craiova, Romania, the study involved 256 young patients divided into two groups based on Lp (a) levels: Group A (Lp (a) < 30 mg/dL) and Group B (Lp (a) ≥ 30 mg/dL). Patients included young adults up to 55 years for males and 60 years for females, excluding those with familial hypercholesterolemia. Results: The study revealed a significant association between elevated Lp (a) levels and the presence of multivessel coronary lesions. Patients with Lp (a) concentrations ≥ 30 mg/dL exhibited a higher prevalence of multivessel disease compared to those with lower levels. Discussion: The findings suggest that elevated Lp (a) levels are a crucial biomarker for the risk of coronary artery disease, particularly in young patients with AMI. The study emphasizes the need for aggressive lipid management strategies and personalized treatment approaches, considering the significant role of Lp (a) in atherosclerosis and AMI. Conclusions: Lipoprotein A levels above 30 mg/dL are associated with a higher prevalence of multivessel coronary lesions. Multivariate analysis revealed that higher Lp (a) levels and lower HDL levels are linked to an increased risk of multivessel coronary lesions. Full article

Immunosenescence, the gradual deterioration of immune function with age, holds profound implications for our understanding and management of multiple sclerosis (MS), a chronic autoimmune disease affecting the central nervous system. Traditionally diagnosed in young adults, advancements in disease-modifying therapies and increased life expectancy have led to a growing number of older individuals with MS. This demographic shift underscores the need for a deeper investigation into how age-related alterations in immune function shape the course of MS, influencing disease progression, treatment effectiveness, and overall patient outcomes. Age-related immunosenescence involves changes such as shifts in cytokine profiles, the accumulation of senescent immune cells, and compromised immune surveillance, collectively contributing to a state known as “inflammaging”. In the context of MS, these immunological changes disturb the intricate balance between inflammatory and regulatory responses, thereby impacting mechanisms of central immune tolerance and peripheral regulation. This paper stands out by combining the most recent advancements in immunosenescence with both pathophysiological and treatment perspectives on multiple sclerosis, offering a cohesive and accessible discussion that bridges theory and practice, while also introducing novel insights into underexplored concepts such as therapy discontinuation and the latest senolytic, neuroprotective, and remyelination therapies. Enhancing our understanding of these complexities will guide tailored approaches to MS management, ultimately improving clinical outcomes for affected individuals. Full article