Search Results (1,663)

This study investigates the spatial distribution characteristics and influencing factors of soil organic carbon (SOC) in the Tamarix chinensis forest ecosystem in Changyi National Marine Ecological Special Reserve, China. Five sampling routes and 32 sampling points were established; 293 soil samples were collected every 10 cm from the surface downwards. GIS spatial analysis techniques were employed to analyze the overall, horizontal, and vertical distribution characteristics of SOC within the 0–100 cm depth range. The results show that SOC content in the reserve ranges from 1.0 to 10.0 gC/kg, with an average of 2.5–8.2 gC/kg. High-SOC zones are in the southwest, where human disturbance is minimal and vegetation is dense, whereas low-SOC areas are in the west, and the north suffers from frequent tides and salinization. Horizontally, the surface SOC (0–10 cm) increased from 2.30 gC/kg in the east to 9.15 gC/kg in the western tidal flat. Vertically, six profile types were identified; the fluctuating type dominated (74.07%). Eight ecological zones were delineated based on land cover and function: the Tamarix core area exhibited surface aggregation with a depth-wise decline; the ecological restoration zone showed a mid-depth peak; and the moisture-proof dam zone displayed a “shallow-rise–deep-drop” pattern. Storm surges, moisture-proof dams, ecological zoning, and restoration projects were key drivers of SOC distribution. Full article

Soil microbial communities are pivotal in maintaining ecosystem functions, particularly in alpine regions with highly heterogeneous environmental conditions. However, the influence of vegetation type on soil microbial communities in high-elevation areas remains insufficiently understood. This study investigates the dynamics of soil microbial communities across grassland, shrubland, and forest ecosystems on the southern slope of the Qilian Mountains. Soil bacterial and fungal communities were examined using high-throughput 16S rRNA and ITS gene sequencing, and their potential ecological functions were inferred using the FAPROTAX and FUNGuild databases. Analysis of similarity (ANOSIM) based on Bray–Curtis distances revealed significant differences in bacterial and fungal community structures among vegetation types, with forest soils showing greater intra-group variability and more distinct microbial assemblages. Acidobacteriota and Proteobacteria were the dominant bacterial phyla, while Basidiomycota and Ascomycota predominated among fungi. Fungal communities in forest soils were dominated by ectomycorrhizal taxa, closely linked to coniferous forests dominated by Picea crassifolia. Overall, the structure and functional diversity of soil microbial communities were governed by soil physicochemical properties, particularly soil pH, which emerged as a key influencing factor. These findings deepen our understanding of microbial ecological processes in alpine environments and offer valuable insights for effective vegetation management and ecosystem conservation in mountainous regions. Full article

Prescribed burning significantly influences the microbial communities and physicochemical characteristics of forest soils. However, studies on the impacts of prescribed burning on the stability of soil microbial co-occurrence networks, as well as on the combined effects of post-fire soil depth gradients and their interactions on soil physicochemical properties and microbial communities, remain poorly understood. This study was conducted in a subtropical Pinus yunnanensis plantation that has undergone annual prescribed burns since 2007. Using 16S and ITS rRNA gene sequencing techniques alongside analyses of soil physicochemical properties, we collected and examined soil samples from different depths (0–5 cm, 5–10 cm, and 10–20 cm) in June 2024. The study found that prescribed burning enhanced the complexity and stability of bacterial co-occurrence networks, boosting both the diversity (prescribed burning/unburned control: 3/1) and the abundance (prescribed burning/unburned control: 8/2) of key taxa, which were essential for maintaining bacterial community network stability. However, it also intensified competitive interactions (prescribed burning/unburned control: 0.3162/0.0262) within the community. Moreover, prescribed burning had a significant effect on the diversity, structure, and composition of microbial communities and the physicochemical properties in the 0–5 cm soil layer, while also showing notable effects in the 5–20 cm layer. Prescribed burning also enhanced the coupling between the soil environment and bacterial community composition. The bacterial community showed negative correlations with most physicochemical properties. Soil organic matter (SOM) (p = 0.002) and available potassium (AK) (p = 0.042) were identified as key determinants shaping the post-fire bacterial community structure. The relationship between physicochemical parameters and fungal community composition was weaker. Urease (UE) (p = 0.036) and total potassium (TK) (p = 0.001) emerged as two key factors influencing the composition of post-fire fungal communities. These results elucidate the distinct functional roles of bacteria and fungi in post-fire ecosystem recovery, emphasizing their contributions to maintaining the stability and functionality of microbial communities. The study provides valuable insights for refining prescribed burning management strategies to promote sustainable forest ecosystem recovery. Full article

As a perceptual representation of ecosystem structure and function, the soundscape has become an important indicator for evaluating ecological health and assessing the impacts of human disturbances. Understanding the spatiotemporal heterogeneity of soundscapes is essential for revealing ecological processes and human impacts in protected areas. This study investigates such heterogeneity in Zhangjiajie National Forest Park using deep learning approaches. To this end, we constructed a dataset comprising eight representative sound source categories by integrating field recordings with online audio (BBC Sound Effects Archive and Freesound), and trained a classification model to accurately identify biophony, geophony, and anthrophony, which enabled the subsequent analysis of spatiotemporal distribution patterns. Our results indicate that temporal variations in the soundscape are closely associated with circadian rhythms and tourist activities, while spatial patterns are strongly shaped by topography, vegetation, and human interference. Biophony is primarily concentrated in areas with minimal ecological disturbance, geophony is regulated by landforms and microclimatic conditions, and anthrophony tends to mask natural sound sources. Overall, the study highlights how deep learning-based soundscape classification can reveal the mechanisms by which natural and anthropogenic factors structure acoustic environments, offering methodological references and practical insights for ecological management and soundscape conservation. Full article

Urbanization is a driving force of landscape transformation. One of the ecosystems most vulnerable to urban expansion processes is montane forests located in high altitude mountainous regions. Despite their significance for biodiversity, regulation of the hydrological cycle, stability, prevention of soil erosion, and potential for organic carbon storage, these forest ecosystems show high vulnerability and risk due to the global urbanization process. We analyzed the potential variations produced by land cover change in some attributes related to soil organic matter in transitional forest fragments due to the expansion of a predominantly urban matrix landscape. We identified and characterized a fragment of a high montane evergreen forest in the Western Cordillera of the Northern Andes located in the urban limits of Quito. Then, we comparatively analyzed the variations in the attributes associated with soil organic carbon: soil organic matter, density, texture, nitrogen, phosphorus, and pH. We also considered the following soil coverages: forest, eucalyptus plantations, and grassland. We viewed the latter two as hinge coverages between forests and urban expansion. Finally, we estimated variations in soil organic carbon stock in the three analyzed coverages. For the montane forest fragment, we identified 253 individuals distributed among 18 species, corresponding to 10 families and 14 genera. We found significant variations in soil attributes associated with organic matter and an estimated 66% reduction in the carbon storage capacity of montane soils when they lose their natural cover and are replaced by Eucalyptus globulus plantations. Urban planning strategies should consider the conservation and restoration of natural and degraded peri-urban areas, ensuring sustainability and utilizing nature-based solutions for global climate change adaptation and mitigation. Peri-urban agroforestry systems represent an opportunity to replace and restore conventional forestry or crop plantation systems in peri-urban areas that affect the structure and function of ecosystems and, therefore, the goods and services derived from them. Full article

Marine shelled organisms exhibit diverse growth strategies shaped by species-specific traits and environmental conditions that critically influence their ecological roles, particularly within Marine Animal Forests (MAF), which are structurally complex habitats and biodiversity-rich habitats. This review compiles and compares empirical growth data for 16 bivalve and gastropod species across seven families, classified as full MAF contributors (Pinna nobilis, Flexopecten glaber, Pecten maximus, and Placopecten magellanicus), partial MAF contributors (Cerastoderma edule, C. glaucum, Chamelea gallina, Ruditapes philippinarum, Mercenaria mercenaria, Panopea generosa, Anadara kagoshimensis, A. inaequivalvis, and Tegillarca granosa), and ecologically relevant non-MAF species (Buccinum undatum, Hexaplex trunculus, and Rapana venosa). Age estimation methods included direct techniques, such as shell growth ring and opercular annulus analysis, alongside indirect approaches, such as length-frequency analysis, stable isotope profiling, and mark–recapture studies. Growth trajectories were modelled using von Bertalanffy growth function (VBGF) parameters to estimate the shell size from ages 1 to 4. Based on these estimates, species were categorised into slow, moderate, fast, and exceptional growth groups. These classifications were further explored through hierarchical clustering that grouped species according to their VBGF-derived growth values, revealing consistent and contrasting life history strategies. This comparative analysis should enhance the understanding of molluscan growth dynamics and support the conservation and management of MAF-associated ecosystems by informing restoration planning, guiding species selection, and contributing to evidence-based policy development. Full article

Silvicultural practices significantly influence the diversity and composition of soil fungal communities, which play crucial roles in maintaining forest ecosystem functionality. This study evaluated the impact of three silvicultural treatments, consisting of liberation cutting, first thinning, and second thinning, on rhizospheric fungal and ectomycorrhizal (ECM) fungi communities in Pinus forests located in Puebla, Mexico. Using high-throughput metabarcoding of the internal transcribed spacer (ITS2) region, we identified 346 fungal genera across all treatments, with Ascomycota and Basidiomycota being the dominant phyla. Alpha diversity indices revealed a trend toward higher fungal richness for first thinning, followed by liberation cutting and lower values for second thinning. A beta diversity analysis demonstrated significant shifts in the fungal community composition across treatments, highlighting the influence of the thinning intensity. The proportions of different functional guilds were consistent across the treatments. However, compositional differences were observed, mainly in soil and wood saprotrophs and in pathogenic taxa. Liberation cutting showed enrichment in ECM taxa such as Russula and Cenococcum, whereas Tuber, Humaria, and Tricholoma were decreased for first thinning and Russula was decreased for second thinning. These findings underscore the need for sustainable forest management practices that balance productivity with the conservation of fungal biodiversity to ensure ecosystem stability and functionality. Full article

Landscape patterns serve as important drivers of macroinvertebrate biodiversity. However, the mechanisms through which landscape dynamics influence biodiversity across different elevation gradients in undammed rivers remain poorly understood. Here, this study investigated macroinvertebrate communities in the Chishui River, which represents the only undammed tributary maintaining a natural flow regime in the upper Yangtze River. We documented 97 macroinvertebrate taxa (3 phyla, 16 orders, and 57 families) with a mean density of 314.93 ind./m². NMDS and PERMANOVA analyses revealed significant spatial heterogeneity in macroinvertebrate community composition, but no overall seasonal variation. However, functional diversity indices (e.g., FRic) exhibited seasonal fluctuations across the river system. Furthermore, we assessed nine landscape metrics to capture heterogeneity, complexity, and fragmentation effects. Random forest modeling with nine predictors revealed that landscape heterogeneity primarily drove functional diversity in the upstream areas, whereas landscape fragmentation was the dominant factor in the downstream areas. Functional diversity, which reflects trait-based ecological roles, provides more direct insights into ecosystem processes than taxonomic diversity alone. Notably, the taxonomic diversity indices (Margalef richness, Shannon–Wiener diversity, Simpson diversity, and Pielou evenness index) showed no significant correlations with landscape metrics. These findings highlight the critical role of functional diversity in evaluating landscape-mediated ecological effects. For effective conservation, management strategies should prioritize reducing anthropogenic disturbances in downstream areas while preserving natural landscape heterogeneity. Full article

Intra-specific variation in functional traits and their inter-relationships reflect how plants allocate resources, adapt, and evolve in response to environmental changes. This study investigated eight functional traits—leaf area (LA), specific leaf area (SLA), leaf dry matter content (LDMC), chlorophyll content (CHL), leaf nitrogen content (LNC), leaf phosphorus content (LPC), twig tissue density (TTD), and wood density (WD)—in Cunninghamia lanceolata plantations of three stand ages (15, 30, and 50 years), using a space-for-time substitution approach. We examined differences in trait values, intra-specific variation, and trait correlations across forest ages and diameter classes. The results showed that (1) Functional traits exhibited varying degrees of intra-specific variation, with LA having the highest coefficient of variation (21.66%) and LPC is lowest (9.31%). (2) Forest age had a stronger influence on trait variation than diameter class, with all traits differing significantly across ages, while only WD varied significantly among diameter classes. (3) PC1 (25.5%) and PC2 (19.4%) together explained approximately 44.9% of the total variation, with PC1 primarily reflecting functional trait changes driven by forest age. PCA results showed that LA and CHL tended to exhibit higher values in young forests, whereas SLA, LDMC, LPC, and LNC had relatively higher values in mature forests. This pattern suggests a shift in functional trait expression from resource acquisition to resource conservation strategies with increasing forest age. (4) Significant positive correlations between LNC and LPC, and negative correlations between SLA and LDMC, were observed in most groups, except in large-diameter trees at the over-mature stage. C. lanceolata adjusts trait combinations to enhance fitness across developmental stages. Juvenile trees adopt traits favoring efficient light and nutrient use to support rapid growth and competition. Middle-aged trees prioritize balanced water and nutrient use to maintain productivity and resist disturbances. Mature trees focus on sustained resource use and offspring protection to support ecosystem stability and regeneration. These findings reveal age-specific adaptive strategies and provide insights into the coordination and trade-offs among traits in response to environmental conditions. Full article

The degradation of Mediterranean forest ecosystems, such as holm oak forests, has intensified in recent decades due to climate change, forest fires, and deforestation, compromising the natural regeneration of the soil. In this context, it is essential to apply sustainable strategies to restore soil and promote plant growth, thus helping the regeneration of the ecosystem. One of these strategies is the use of plant growth-promoting bacteria (PGPB) in combination with recovered organic waste, such as that from wastewater treatment plants (WWTPs). In this paper, the effects of a biofertilizer formulated from WWTP residue (with and without sterilization), supplemented with two PGPB strains (Bacillus pretiosus and Pseudomonas agronomica), on the growth of holm oak seedlings (Quercus ilex) were evaluated under field conditions. A study was carried out on its nutritional composition, the rhizospheric cenoantibiogram, and its functional and taxonomic microbial diversity. Nine combinations of chemical and biological treatments using irrigation with water as a control were compared. The results showed that treatments with WWTP, especially combined with PGPB strains, promoted greater plant development and a lower seedling mortality rate. The cenoantibiogram exhibited a reduction in the resistance profile in soils treated with biofertilizer, without affecting soil microbial diversity, which remained unaltered across treatments, as confirmed by metagenomic and functional diversity analyses. Overall, this research reinforces the viability of the use of biofertilizers recovered from WWTP as an ecological and effective strategy for the recovery of degraded holm oak forests. Full article

Forest soil greenhouse gas emissions play a critical role in global climate change. This review synthesizes the mechanisms of temperature change impacts on forest soil greenhouse gas (CO₂, CH₄, N₂O) emissions, the complex response patterns of ecosystems, and existing knowledge gaps in current research. We highlight several critical mechanisms, such as the high temperature sensitivity (Q₁₀) of methane (CH₄) and CO₂ emissions from high-latitude peatlands, and the dual effect of chronic nitrogen deposition, which can cause short-term stimulation but long-term suppression of soil CO₂ emissions. It emphasizes how climatic factors, soil characteristics, vegetation types, and anthropogenic disturbances (such as forest management and fire) regulate emission processes through multi-scale interactions. This review further summarizes the advancements and limitations of current research methodologies and points out future research directions. These include strengthening long-term multi-factor experiments, developing high-precision models that integrate microbial functional genomics and isotope tracing techniques, and exploring innovative emission reduction strategies. Ultimately, this synthesis aims to provide a scientific basis and key ecological threshold references for developing climate-resilient sustainable forest management practices and effective climate change mitigation policies. Full article

Aboveground biomass (AGB) in grasslands is a vital metric for assessing ecosystem functioning and health. Accurate and efficient AGB estimation is essential for the scientific management and sustainable use of grassland resources. However, achieving low-cost, high-efficiency AGB estimation via remote sensing remains a key challenge. This study integrates Sentinel-1 and Sentinel-2 imagery to derive 38 multi-source feature variables, including backscatter coefficients, texture, spectral reflectance, vegetation indices, and topographic factors. These features are combined with AGB data from 112 field plots in the Three Parallel Rivers area. Feature selection was performed using Pearson correlation, Random Forest (RF), and SHAP values to identify optimal variable sets. Genetic Programming (GP) was then applied for nonlinear optimization of the selected features. Three machine learning models—RF, GBRT, and KNN—were used to estimate AGB and generate spatial distribution maps. The results revealed notable differences in model accuracy, with RF performing best overall, outperforming GBRT and KNN. After GP optimization, all models showed improved performance, with the RF model based on RF-selected features achieving the highest accuracy (R² = 0.90, RMSE = 0.31 t/ha, MAE = 0.23 t/ha), improving R² by 0.03 and reducing RMSE and MAE by 0.05 and 0.03 t/ha, respectively. Spatial mapping showed the AGB ranged from 0.41 to 3.59 t/ha, with a mean of 1.39 t/ha, closely aligned with the actual distribution characteristics. This study demonstrates that the RF model, combined with multi-source features and GP optimization, provides an effective approach to grassland AGB estimation and supports ecological monitoring in complex areas. Full article

Forest disturbance is a major driver shaping the structure and function of plantation ecosystems. Current research predominantly focuses on single forest types or landscape scales. However, species-level fine-scale assessments of disturbance dynamics are still scarce. In this study, we investigated Chinese fir (Cunninghamia lanceolata), Armand pine (Pinus armandii), and Yunnan pine (Pinus yunnanensis) plantations in the mountainous eastern Yunnan Plateau. We developed a Spatial Coupling Framework of Disturbance Legacy (SC-DL) to systematically elucidate the spatial associations between contemporary species distribution patterns and historical disturbance regimes. Using the Google Earth Engine (GEE) platform, we reconstructed pixel-level disturbance trajectories by integrating long-term Landsat time series (1993–2024) and applying the LandTrendr algorithm. By fusing multi-source remote sensing features (Sentinel-1/2) with terrain factors, employing RFE, and performing a multi-model comparison, we generated 10 m-resolution species distribution maps for 2024. Spatial overlay analysis quantified the cumulative proportion of the historically disturbed area and the spatial aggregation patterns of historical disturbances within current species ranges. Key results include the following: (1) The model predicting disturbance year achieved high accuracy (R² = 0.95, RMSE = 2.02 years, MAE = 1.15 years). The total disturbed area from 1993 to 2024 was 872.7 km², exhibiting three distinct phases. (2) The random forest (RF) model outperformed other classifiers, achieving an overall accuracy (OA) of 95.17% and a Kappa coefficient (K) of 0.93. Elevation was identified as the most discriminative feature. (3) Significant spatial differentiation in disturbance types emerged: anthropogenic disturbances (e.g., logging and reforestation/afforestation) dominated (63.1% of total disturbed area), primarily concentrated within Chinese fir zones (constituting 70.2% of disturbances within this species’ range). Natural disturbances accounted for 36.9% of the total, with fire dominating within the Yunnan pine range (79.3% of natural disturbances in this zone) and drought prevailing in the Armand pine range (71.3% of natural disturbances in this zone). (4) Cumulative disturbance characteristics differed markedly among species zones: Chinese fir zones exhibited the highest cumulative proportion of disturbed area (42.6%), with strong spatial aggregation. Yunnan pine zones followed (36.5%), exhibiting disturbances linearly distributed along dry–hot valleys. Armand pine zones showed the lowest proportion (20.9%), characterized by sparse disturbances within fragmented, high-altitude habitats. These spatial patterns reflect the combined controls of topographic adaptation, management intensity, and environmental stress. Our findings establish a scientific basis for identifying disturbance-prone areas and inform the development of differentiated precision management strategies for plantations. Full article

Lichens, complex symbiotic associations between fungi and photosynthetic partners, are widespread in terrestrial ecosystems but remain poorly studied in tropical dry forests (TDFs). This review synthesizes current knowledge on the diversity, ecological roles, adaptive traits, and ethnobotanical uses of lichens in TDFs, with a focus on the Neotropics. As most lichens discussed here are crustose species that inhabit tree bark, this paper also provides a thoughtful review of the origin, distribution, and highly heterogeneous floristic composition of TDFs, which directly shape lichen habitats. It discusses how lichens have evolved to cope with seasonal water stress, emphasizing desiccation tolerance as a key feature of the symbiosis. This review also explores lichen community composition, interactions with host trees, microclimatic conditions, herbivory, and soil crust formation. Despite evidence of high species richness, functional diversity, and ecological importance, lichens in TDFs are largely overlooked in conservation strategies. Moreover, several regions remain vastly understudied, and many species likely remain undescribed. Ethnolichenological practices, though scarce, underscore the cultural and medicinal value of these organisms. Given the high rates of habitat loss and endemism in TDFs, there is a pressing need to expand research on lichen diversity and to investigate the evolutionary origins of their survival strategies. The conservation of these lichens is inseparable from the conservation of TDFs themselves. Understanding how lichens adapt to the harsh and variable conditions of TDFs is essential for integrating them into biodiversity conservation and ecosystem restoration frameworks. Full article

This study systematically documented macrofungal diversity in Beijing, China (field surveys conducted from 2020 to 2024) using line-transect and random sampling. A total of 1056 species were identified, spanning 2 phyla, 7 classes, 25 orders, 109 families, and 286 genera. The inventory includes 12 new species, 456 new records for Beijing, 79 new records for China, and comprises 116 edible, 56 edible–medicinal, 123 medicinal, and 58 poisonous species. Among these, 542 species were assessed against China’s Macrofungi Redlist, revealing eight species needing conservation attention (seven Near Threatened, one Vulnerable). Analysis revealed stark differences in dominant taxa between natural ecosystems (protected areas) and urban green spaces/parks. In natural areas, macrofungi are dominated by 31 families (e.g., Russulaceae, Cortinariaceae) and 47 genera (e.g., Russula, Cortinarius). Ectomycorrhizal lineages prevailed, highlighting their critical role in forest nutrient cycling, plant symbiosis, and ecosystem integrity. In urban areas, 10 families (e.g., Agaricaceae, Psathyrellaceae) and 17 genera (e.g., Leucocoprinus, Coprinellus) were dominant. Saprotrophic genera dominated, indicating their adaptation to decomposing organic matter in human-modified habitats and the provision of ecosystem services. The study demonstrates relatively high macrofungal diversity in Beijing. The distinct functional guild composition—ectomycorrhizal dominance in natural areas versus saprotrophic prevalence in urban zones—reveals complementary ecosystem functions and underscores the conservation value of protected habitats for maintaining vital mycorrhizal networks. These findings provide fundamental data and scientific support for regional biodiversity conservation and sustainable macrofungal resource development. Full article