Search Results (319)

This study was carried out to investigate stand structure, growth dynamics, and carbon fluxes in Pinus rigida plantations of varying ages in South Korea. Field measurements across four mountain sites quantified diameter-class distributions, net primary productivity (NPP), soil respiration, and net ecosystem production (NEP). P. rigida exhibited normally distributed diameter structures in larger classes, whereas Quercus spp. showed reverse J-shaped patterns, indicating active regeneration and ongoing succession toward mixed broadleaved stands. Individual NPP was highest in P. densiflora (4.77 kg yr⁻¹) and P. rigida (4.31 kg yr⁻¹), while Quercus spp. displayed lower growth due to light limitation. Stand-level NPP peaked in 20–40-year-old stands (4.27–4.88 ton C ha⁻¹ yr⁻¹) and declined with age (2.30 ton C ha⁻¹ yr⁻¹). Soil respiration averaged 1.0 ton C ha⁻¹ yr⁻¹ and was strongly temperature dependent (R² = 0.56; Q₁₀ = 2.70). NEP on Mt. Galmi reached 4.38 ton C ha⁻¹ yr⁻¹, demonstrating substantial carbon sink capacity. These findings indicate that aging P. rigida plantations maintain ecosystem-level carbon uptake through successional compensation. Policy efforts should prioritize adaptive thinning, assisted natural regeneration, and long-term monitoring frameworks to accelerate the transition toward climate-resilient mixed forests and to strengthen national forest carbon neutrality strategies. Future research should integrate long-term carbon flux observations, species interaction modeling, and assessments of climate-driven disturbance regimes to refine management pathways for resilient mixed-forest landscapes. Full article

Soil fungi play an indispensable role in maintaining soil ecosystem functions. However, how forest succession and soil depth interactively shape fungal community composition and diversity remains poorly understood. To address this, we investigated fungal communities across four successional stages and two soil depths (0–10 cm and 40–60 cm) in a subalpine forest on the eastern Qinghai–Tibetan Plateau using Illumina high-throughput sequencing. Results showed that the soil fungal community composition of different trophic modes varied significantly with both succession and soil depth. The α-diversity of symbiotic and saprotrophic fungi responded to succession in a depth-dependent manner, while β-diversity across all trophic modes was primarily driven by species turnover. Soil properties and vegetation factors collectively explained 69.85–82.91% of the variation in soil fungal community composition, with their effects being dependent on both soil depth and trophic mode. Specifically, in topsoil, the β-diversity of symbiotic fungi was influenced only by soil property heterogeneity, whereas that of saprotrophic and pathogenic fungi was shaped by both vegetation and soil property heterogeneity. In subsoil, symbiotic fungal β-diversity was co-regulated by vegetation and soil properties heterogeneity, while saprotrophic fungal β-diversity was driven solely by soil properties heterogeneity. This study demonstrates that soil depth modulates the successional dynamics of soil fungal communities and highlights the trophic-dependent drivers of fungal assembly in forest soils. Full article

Artificial hybrid pine (Pinus × rigitaeda) plantations, widely established in Northeast Asia for reforestation and timber production, have reached maturity, necessitating an evaluation of their ecological sustainability and successional dynamics. Although numerous studies have examined succession in pure Pinus rigida or Pinus densiflora stands, the long-term structural transition and regeneration potential of hybrid P. × rigitaeda plantations remain poorly understood. This study quantitatively assessed the successional stage and potential transition pathways of P. × rigitaeda stands using an integrated analytical framework combining vegetation classification (TWINSPAN), ordination (NMDS), successional index, survival analysis (Weibull model), and growth–environment modeling (GAM). Multi-layer vegetation data were analyzed to evaluate compositional changes, structural attributes, and nonlinear environmental responses. The results revealed that the dominance of P. × rigitaeda declined markedly while native deciduous species increased in lower strata. The Weibull survival model (k = 1.3) indicated accelerating mortality with stand aging, and the successional index showed the highest value (0.4) for Castanea crenata, followed by other Quercus species, confirming an ongoing shift toward hardwood dominance. GAM analysis confirmed that growth stability was influenced by stand age and precipitation. These findings demonstrate that P. × rigitaeda plantations are not merely artificial production forests but function as self-organizing systems facilitating natural forest recovery. In this respect, the hybrid pine plantation can be interpreted as a spontaneous ecological experiment, highlighting the restoration value of artificial hybrids as transitional stages bridging artificial afforestation and natural forest succession in temperate monsoon regions. Full article

Bioindication is a key tool for monitoring habitat quality and ecosystem dynamics under increasing anthropogenic pressure. Among model organisms, ground beetles (Coleoptera: Carabidae) play a particularly important role, and one of the widely applied functional indicators describing their assemblage structure is the Mean Individual Biomass (MIB). Introduced in the 1980s, this index reflects the average body mass of Carabidae and allows assessment of successional stages. Its computational simplicity and intuitive interpretation have led to its application in forests, agricultural landscapes, post-industrial areas, and glacier forelands. This paper synthesizes the development and applications of the MIB, highlighting both its advantages and methodological limitations (including variability of length–mass models, seasonal activity patterns, and dependence on sampling methods). Particular attention is given to the potential of the MIB in the context of global environmental change, including its role as an indicator of ecosystem responses to climate change and processes related to soil carbon sequestration. Based on a literature review, future research directions are identified, encompassing methodological standardization, integration of MIB with other ecological and molecular indicators, and expansion of analyses to regions beyond Europe. By linking classical bioindication with ecosystem functioning studies, the MIB may serve as a universal tool for environmental monitoring and the assessment of ecosystem services under accelerated global change. Full article

Spatial pattern analysis is essential for understanding forest structure and successional dynamics. Focusing on natural secondary forests in the subalpine region of western Sichuan, China, we established two 1-hectare permanent plots to investigate the spatial distribution of dominant tree species and assess the soil’s water-holding properties, aiming to clarify the relationship between species spatial patterns and edaphic conditions. The pioneer species Betula albosinensis exhibited a unimodal diameter distribution with scarce seedling presence, indicating limited regeneration. In contrast, Abies fargesii var. faxoniana showed a typical inverse J-shaped diameter distribution, suggesting stable population recruitment. At fine spatial scales, dominant species generally exhibited aggregated distributions, with A. fargesii var. faxoniana seedlings showing the strongest clumping; however, as the spatial scale increased, distributions tended toward randomness, likely due to self-thinning and density-dependent interactions. Bivariate spatial association analysis revealed that B. albosinensis was positively associated with A. fargesii var. faxoniana and Picea asperata at small scales, suggesting a potential facilitative effect of B. albosinensis on Pinaceae species. Moreover, capillary water-holding capacity was significantly higher in areas with greater conifer dominance, underscoring the strong environmental filtering effect of microhabitat moisture on community spatial structure. Collectively, our results suggest an ongoing mid- to late-successional shift from pioneer broadleaved to shade-tolerant conifer dominance, with concurrent changes in species composition and soil conditions. This study provides empirical insight into spatial successional processes and highlights their ecological implications for hydrological regulation in subalpine secondary forests. Full article

Fungal communities inhabiting leaves are key players in ecosystem processes but remain largely unexplored in Southern Hemisphere temperate forests. We characterized the foliar mycobiota of Nothofagus pumilio, a dominant deciduous tree in Patagonian forests, using ITS1 metabarcoding across seasons and tree health conditions. We detected 426 fungal taxa, including a 40-Amplicon Sequence Variant (ASV) core mycobiome persisting year-round. Fungal richness and biomass increased significantly in autumn, coinciding with leaf senescence, and community composition shifted markedly between seasons. Spring leaves were enriched in pathogens and basidiomycetous yeasts, while autumn leaves hosted more saprotrophs, ascomycetous yeasts, and lichen-associated fungi. Tree health had limited influence on overall community structure, but symptomatic trees showed higher ASV richness and specific indicator taxa, including the pathogen Trichosporiella multisporum and members of the Taphrinaceae and Saccotheciaceae families. Despite taxonomic turnover, ecological guilds remained relatively stable, suggesting functional redundancy. These findings reveal a seasonal successional trajectory in the foliar mycobiota of N. pumilio, from early-colonizing endophytes in spring to diverse decomposer assemblages in autumn. This study provides the first high-throughput insight into the structure and dynamics of foliar fungal communities in Southern Hemisphere temperate forests, offering a baseline for understanding microbial roles in forest health and resilience. Full article

Understory vegetation diversity is the key indicator of ecological outcomes in the close-to-nature transformation of plantations, with its composition revealing successional dynamics and ecosystem functionality. In response to China’s “Green and Beautiful Guangdong” Initiative, enhancing the ecological quality of plantations has been established as a critical objective for sustainable forest management. This study assessed the understory vegetation in four representative transformed plantations in Guangdong Province, China, using Multi-Response Permutation Procedure (MRPP), Indicator Species Analysis (ISA), Detrended Correspondence Analysis (DCA), and Redundancy Analysis (RDA). The results showed that: (1) Species richness was highest in the Eucalyptus L’Hér plantation (102 species), followed by Pinus massoniana Lamb (94), Acacia mangium Willd (92), and Litchi chinensis Soon plantations (85). (2) MRPP analysis revealed significant differences in species composition among plantation types (A = 0.149, p < 0.001). ISA identified 5, 7, 3, and 5 indicator species for each type, respectively, predominantly light-demanding pioneers such as Dicranopteris dichotoma (Thunb.) Bernh and Microstegium vagans (Nees ex Steud.) A. Camus. (3) DCA ordination showed clear compositional segregation among the understory communities of Eucalyptus, Pinus massoniana, and Acacia mangium plantations, whereas the Litchi chinensis plantation exhibited substantial overlap with others. RDA further demonstrated a significant negative correlation between mean diameter at breast height (DBH) and understory diversity (p < 0.01) across all plantations except Litchi chinensis. These findings offer a quantitative basis for tailored management strategies. We recommend structural adjustments through target-tree thinning to optimize light availability by regulating DBH, combined with interplanting native understory species. This integrated approach can enhance structural heterogeneity and promote more effective and sustainable plantation restoration. Full article

Understanding the mechanisms that assemble diverse forest communities is a central goal in ecology. Phylogenetic analyses based on DNA barcodes have advanced this field, but their use of sequences evolving at constant rates may not capture adaptations to specific environmental drivers. Light is a critical factor shaping forest structure, particularly in the vertical dimension. This study introduces a novel phylogenetic approach using the blue-light receptor gene, cryptochrome (Cry), which is directly involved in plant light perception and adaptation. We reconstructed a Cry-based phylogeny for 96 tree species in a 20 ha subtropical forest dynamics plot and analyzed community structure using the net relatedness index (NRI) and nearest taxon index (NTI) across horizontal habitats, successional stages, and vertical canopy layers. Compared to traditional DNA barcoding, the Cry phylogeny revealed distinct patterns, showing consistent phylogenetic structure across different habitats—a finding indicative of convergent evolution in light-sensing systems. Furthermore, the Cry-based analysis demonstrated a stronger and more consistent signal in the forest’s vertical structure, with significant phylogenetic clustering in upper canopy layers, directly linking light adaptation to community stratification. Over time, both NRI and NTI values increased, suggesting succession leads to greater phylogenetic overdispersion and highlighting an increased role for environmental filtering among closely related taxa. Our results validate Cry as a powerful functional gene marker for phylogenetics, providing unique insights into how light environment filters species and shapes the vertical assembly of forest communities. Full article

A previous study demonstrated that spontaneous forest recovery can result in the development of functional mixed forests in post-mining areas. A critical step in this process is the establishment of climax woody species in the understory of pioneer trees. In this case study, we utilise repeated sampling to evaluate the establishment, initial survival, and growth of pedunculate oak (Quercus robur) and European beech (Fagus sylvatica) seedlings, and to newly assess Norway spruce (Picea abies) during unassisted forest recovery on a post-mining site after coal mining near Sokolov in North Bohemia. Detailed mapping of beech and oak seedlings was conducted in 2009 and 2012 (i.e., 14 and 11 years after the site was reclaimed). Now, we have resurveyed these seedlings, which has allowed us to evaluate their survival and growth. We have also mapped spruce seedlings and estimated their age from annual branch whorls. In the original study, most seedlings were found on the northern site near the edge of the post-mining area and the surrounding landscape, which serve as seed sources. Beech shows the best survival and growth on the northern site, where the greatest number of new seedlings also appear. In contrast, oaks demonstrate much higher mortality than beech overall, with the highest mortality observed on the northern site and the highest survival on the southern site, where most of the new seedlings also appeared. Interestingly, however, surviving oaks grew faster on the northern site. Across microtopography, seedlings of all three tree species were most frequent on the slopes of micro-undulations. Beech individuals were taller in depressions, whereas oaks did not consistently demonstrate a size advantage across microhabitats. Spruce colonised vigorously and was the most abundant of the three species across microhabitats. Age-frequency analyses suggest an annual mortality rate of 3%–9%. Browsing damage was observed on 19% of beech seedlings and 9% of oak seedlings. The study shows that pioneer tree stands are suitable nursing sites for studied climax tree species, which can colonise these sites several kilometres away from mature trees, and their establishment involves a complex interplay between distance to seed source and local microclimatic conditions. Our resurvey indicates that later successional stages may increasingly be shaped by shade-tolerant beech and spruce under the developing canopy. Full article

Ecological restoration of mine wastelands is central to biodiversity conservation and ecosystem recovery worldwide. However, the long-term ecological consequences of active restoration versus natural regeneration remain debated, particularly in mountainous karst landscapes. Using a space-for-time substitution, we established a five-stage chronosequence—recently abandoned, 10 years, 20 years, 30 years, and a late-successional forest (>35 years)—in a typical underground coal-mine wasteland in eastern Yunnan, southwest China. Each age class contained paired active restoration and natural regeneration sites; the late-successional forest served as a reference. We surveyed nested vegetation plots (20 × 20 m with shrub and herb subplots) in summer and autumn, recorded vertebrate species with camera traps, and quantified α-diversity (species richness, Shannon–Wiener diversity, Simpson’s diversity, Pielou’s evenness) and β-diversity (Bray–Curtis dissimilarity, non-metric multidimensional scaling). Overall plant α-diversity was highest in natural regeneration and lowest in active restoration, whereas tree-layer diversity was highest in active restoration and shrub and herb layers were richer under natural regeneration. Preliminary data from our camera traps suggested that animal species richness ranked late-successional forest > natural regeneration > active restoration, but evenness peaked in active restoration, suggesting early-stage homogenization. Plant β-diversity indicated stronger compositional divergence among active restoration sites and greater similarity between natural regeneration and the reference forest; both modes converged toward the reference forest over time but followed distinct patterns. These findings suggest that active restoration accelerates structural development yet increases between-site heterogeneity, whereas natural regeneration maintains higher overall diversity and compositional similarity to reference communities. Our results provide preliminary empirical guidance for selecting restoration strategies in similar karst coal-mine landscapes. Full article

As carbon cycling and global environmental protection gain increasing attention, forest disturbance research has intensified worldwide. Constrained by limited data availability, existing frameworks often rely on extracting individual spectral bands for simple binary disturbance detection, lacking systematic approaches to visualize and classify causes of disturbance over large areas. Accurately identifying disturbance types is critical because different disturbances (e.g., fires, logging, pests) exhibit vastly different impacts on forest structure, successional pathways and, consequently, forest carbon sequestration and storage capacities. This study proposes an integrated remote sensing and deep learning (DL) method for forest disturbance type identification, enabling high-precision monitoring in Northeast China from 1992 to 2023. Leveraging the Google Earth Engine platform, we integrated Landsat time-series data (30 m resolution), Global Forest Change data, and other multi-source datasets. We extracted four key vegetation indices (NDVI, EVI, NBR, NDMI) to construct long-term forest disturbance feature series. A comparative analysis showed that the proposed convolutional neural network (CNN) model with six feature bands achieved 5.16% higher overall accuracy and a 6.92% higher Kappa coefficient than a random forest (RF) algorithm. Remarkably, even with only six features, the CNN model outperformed the RF model trained on fifteen features, achieving a 0.4% higher overall accuracy and a 0.58% higher Kappa coefficient, while utilizing 60% fewer parameters. The CNN model accurately classified forest disturbances—including fires, pests, logging, and geological disasters—achieving a 92.26% overall accuracy and an 89.04% Kappa coefficient. This surpasses the 81.4% accuracy of the Global Forest Change product. The method significantly improves the spatiotemporal accuracy of regional-scale forest monitoring, offering a robust framework for tracking ecosystem dynamics. Full article

Norway spruce (Picea abies (L.) H. Karst.) is a primary forest-forming species in the European part of Russia, both in terms of its distribution and economic importance. A number of studies indicate that one of the reasons for the disturbance of spruce forests is linked to rising temperatures, particularly the detrimental effects of extreme droughts. The aim of our research is to identify changes in the structural and functional organization of mature spruce forests at the center of the East European Plain. The study was conducted in intact spruce forests using resurveyed vegetation relevés within the Smolensk–Moscow Upland, with relevés repeated after 40 years (in 1985 and 2025). Changes in structural and functional parameters of spruce communities were analyzed. The results showed that significant disturbances of the tree layer led to changes in the vegetation of subordinate layers, as well as the successional dynamics of spruce forests. It was found that following the collapse of old-growth spruce stands, two types of secondary succession developed: (1) with the renewal of spruce and (2) with active development of shrubs (hazel and rowan) and undergrowth of broadleaved species. It was also demonstrated that the typological diversity of the studied communities changed over 40 years not only due to the loss of the tree layer and the formation of new “non-forest” types but also because several mixed spruce-broadleaved communities transitioned into broadleaved ones, and pine–spruce communities of boreal origin shifted to nemoral types. An analysis of the complete species composition of spruce forests based on Ellenberg’s scales scoring revealed changes in habitat conditions over the 40-year period. A noticeable trend was an increase in the proportion of thermophilic and alkaliphilic species, indicating a shift toward a nemoral vegetation spectrum. It is expected that under the current forest management regime, the next 40 to 60 years will see a decline in the proportion of spruce within mixed stands, potentially culminating in the complete collapse of monospecific spruce forests in the center of the East European Plain. Full article

Old-growth forests are crucial for biodiversity conservation and climate change mitigation due to their high carbon storage, structural complexity, and resilience to environmental stressors. Yet, such ecosystems are rare in Europe, and their ecological functioning remains poorly understood. This study assesses the capacity of Quercus pyrenaica forests in the Montesinho-Nogueira Natura 2000 site (Bragança, Portugal) to develop maturity attributes under different forest management histories. We compare an area with low human intervention for over 80 years (10.2 ha) to two areas harvested for traditional small-scale firewood and timber extraction around 30 years ago (11.4 ha and 2.73 ha). Dendrometric measurements, carbon storage, floristic inventories of understory vegetation, and regeneration surveys were conducted across 42 sub-plots during June–July 2024. Results show that older forests store significantly more carbon and support greater biodiversity, evenness and regeneration, while younger forests present higher values of species richness, including several rare taxa. Our findings suggest that under favorable conditions, secondary forests can recover substantial biomass and carbon stocks within a few decades, while mature stands continue to accumulate carbon and maintain complex structures. Differences in floristic composition between sites may also reflect distinct silvopastoral practices between patches, such as itinerant grazing through forest patches, which historically characterized the Montesinho landscape. These results highlight the value of preserving a mosaic of successional stages, as both mature and intermediate-phase forests, together with compatible human activities, provide complementary biodiversity benefits and contribute to the multifunctionality of Mediterranean agroforestry systems. Full article

Impatiens parviflora DC. occurs in various plant communities. Its occurrence has been confirmed in Poland across 13 natural habitats protected under the Habitats Directive. The aim of our work is to determine the differences between the plots with and without I. parviflora in terms of the species richness and ecological conditions of the 9180* habitat-type forest. Using data from 315 plots on which a phytosociological relevés was carried out, we analyzed the geographical variability, the Shannon-Winner index and the indicator species for old forests. Flora diversity was represented using the DCA, and the IndVal index was calculated to determine the species that best characterize the differentiated groups. The highest percentage of monitoring plots with I. parviflora is located in the Sudetes Mountains (67.7%) and the lowest in the Bieszczady Mountains (7.5%). Plots with I. parviflora were characterized by significantly lower tree cover, a higher number of tree species in the stand, a lower height of both the understory and herb layer and a lower number of old forest species. Impatiens parviflora does not affect the total number of species in the understorey but is associated with a lower proportion of species typical of old forests. The presence of I. parviflora also correlates with a higher proportion of young trees in the understorey, suggesting a link with successional processes and habitat disturbance. The spread of I. parviflora is limited by shade-loving trees such as Abies alba Mill. and Fagus sylvatica L. The diversity of the distribution of I. parviflora depends on local conditions, so conservation efforts should take into account the local ecological context. Full article

Climate change has a profound impact on the spatio-temporal patterns and successional dynamics of forest ecosystems, particularly at forest edges. The Altay Mountains are located at the junction of China, Russia, Kazakhstan and Mongolia, and the southern edge of the boreal forest in interior Eurasia. It is highly necessary to compare the differences in the responses of forest ecosystems in large transnational mountain ranges to climate change under the background of climate change. This study analyzed 558 tree cores collected from 20 sample sites dominated by Siberian larch (Larix sibirica Ledeb.) in the high-elevation of Altay Mountains. Using tree-ring width data and meteorological observations from Altay Mountains both in China and Russia, we investigated how climate influences the radial growth of L. sibirica across these regions. The results indicate that temperature is the primary factor driving radial growth, with early summer temperatures acting as the main growth-limiting factor on both China and Russia. Notably, the radial growth-climate response is stronger in Russia than China. Despite ongoing climate change, the dominant climatic drivers of radial growth in the Altay Mountains have remained stable, with temperature continuing to exert a significant and consistent influence on L. sibirica growth in the high-elevation of Altay Mountains. This study enhances our understanding of the climate change impacts on boreal forest ecosystems and highlights potential risks to forest health in the Altay Mountains. Full article