Search Results (7,110)

Invasive Phytophthora species are increasingly impacting UK landscapes. Most recently, cryptic outbreaks of P. pluvialis Reeser, Sutton & E. Hansen have occurred on western hemlock and Douglas fir at several forest sites across Britain. To better understand the ubiquity and life cycle of this pathogen in British forests and the assemblages of co-inhabiting Phytophthora species, metabarcoding and baiting methodologies were applied to soil, stream water, and rainwater samples collected over a full calendar year from seventeen sites across Britain. Thirty-five Phytophthora species were detected across all sites, substrates, and detection methods, with most detections occurring in stream water by metabarcoding. The three most frequently detected species were (1) P. pluvialis, (2) P. gonapodyides H.E. Petersen & Buisman and (3) P. ramorum Werres, De Cock & Man in ‘t’ veld. Other species detected included the regulated pathogens P. austrocedri Greslen & Hansen, P. kernoviae Brasier, Beales & S.A. Kirk and P. lateralis Tucker & Milbraith, as well as P. ornamentata Scanu, Linald & T. Jung, a new species record for the UK. Phytophthora pluvialis was most frequently detected in March, with rainfall trap metabarcoding data suggesting that aerial dissemination occurs predominantly in late winter/early spring. Consistent detections of P. pluvialis in soil by metabarcoding indicate the potential for soilborne transfer of this pathogen by animal or human vectors, including equipment or machinery in forest operations. The study’s findings are discussed in relation to understanding how P. pluvialis spreads and the approaches needed to address key knowledge gaps in relation to inoculum sources. The results provide a baseline for Phytophthora diversity in British commercial forests, facilitating a greater understanding of typical and unusual trends in species assemblages. This study also consolidates the value of metabarcoding as an effective surveillance tool for Phytophthora in commercial forests. Full article

Climate change and injudicious nitrogen addition alter the soil physico-chemical properties and microbial activity in oligotrophic forest soil, which disrupts the nitrogen cycle balance. Nevertheless, recommended fertilizer forms and levels are considered to be crucial for stable nitrogen application. We established a short-term field trial for the first time using a randomized complete block design under the yellow larch forest, with six treatments applied, including urea CO(NH₂)₂, ammonium chloride NH₄Cl, and sodium nitrate NaNO₃ at concentrations of 10 and 20 kg N hm⁻² yr⁻¹, each extended by three replicates. The gene abundances were measured using quantitative PCR (qPCR), in which the abundance levels of AOA (amoA) and nirS were higher under high CO(NH₂)₂ 2.87 × 10¹⁰ copies g⁻¹ dry soil and low NO₃⁻ 8.82 × 10⁹ copies g⁻¹ dry soil, compared to CK, representing 2.8-fold and 1.5-fold increases, respectively. We found niche partitioning as revealed despite AOA (amoA) increasing in number, AOB (amoA) contributing more to ammonia oxidation while nirS proved opportunistic under stress conditions. This was supported by distinct significant correlations among factors, in which soil urease enzymatic activity (S-UE) was associated with AOA (amoA) and nirK, while AOB (amoA) and nirS positively correlated with NH₄⁺ content and soil potential of hydrogen (pH), respectively. Among the applied treatments, high-level NO₃⁻ increased total nitrogen content and had a significant effect on soil N-acetyl-β-d-glucosaminidase (S-NAG) and soil acid protease (S-ACPT) activity. In summary, we observed an increase in Larix olgensis growth with high nitrogen retention. Full article

Agricultural productivity is closely linked to the spatial variability of soil physical properties. However, high variability makes it difficult to implement effective management strategies, and the constant expansion of eucalyptus plantations in certain areas alters the soil’s physical properties. This study conducted a geostatistical analysis of the physical properties of a soil in Sogamoso, Boyacá (Colombia), which contains areas with different management practices and vegetation cover, among which the presence of Eucalyptus globulus stands out. Ninety-seven points were sampled in an area of 29.1 ha, with multiple land uses. The data were analyzed using descriptive statistics and geostatistical analysis, which determined the semivariogram parameters, the degree of spatial dependence, and the best-fitting interpolation model for mapping. A correlation analysis between variables was also performed. Analysis of variance showed no significant differences among vegetation covers (dense forest, grass-crop mosaic, weedy grassland, and crop mosaic), indicating structural homogeneity. The hydraulic conductivity (K_sat) had the highest coefficient of variation (CV), at 141.9%, while particle density had the lowest CV, at 9.25%. K_sat (exponential model, range = 207 m) and porosity (spherical model, range = 98 m) showed a strong spatial dependence. K_sat was lower in areas with eucalyptus (0.01 to 0.2 m day⁻¹), attributed to hydrophobicity induced by organic compounds emitted by these plantations. Soil moisture contents showed lower values in areas with eucalyptus, corroborating their high water consumption. Soil aggregates were lower when eucalyptus plantations were on slopes greater than 15%. Porosity showed an inverse correlation with apparent density (r² = −0.86). Full article

Tropical and subtropical forests account for approximately one-third of global terrestrial gross primary productivity (GPP), and the diurnal patterns of GPP strongly regulate the land–atmosphere CO₂ interactions and feedback to the climate. Combined with ground eddy-covariance (EC) flux towers, geostationary satellites offer significant advantages for continuously monitoring these diurnal variations in the “breathing of biosphere”. Here we utilized half-hourly optical signals from the Himawari-8 Advanced Himawari Imager (H8/AHI) geostationary satellite and tower-based EC flux data to investigate the diurnal variations in subtropical forest GPP and its drivers. Results showed that three machine learning models well estimated the diurnal patterns of subtropical forest GPP, with the determination coefficient (R²) ranging from 0.71 to 0.76. Photosynthetically active radiation (PAR) is the primary driver of the diurnal cycle of GPP, modulated by temperature, soil water content, and vapor pressure deficit. Moreover, the effect magnitude of PAR on GPP varies across three timescales. This study provides robust technical support for diurnal forest GPP estimations and the possibility for large-scale estimations of diurnal GPP over tropics in the future. Full article

In the context of global climate change and efforts toward “carbon peak and carbon neutrality,” forest resource protection and restoration have become fundamental to ecological civilization. The genetic improvement of trees, as the primary component of forest ecosystems, holds strategic importance for ecological security, resource supply, and carbon neutrality. Traditional tree breeding techniques, including selective and hybrid breeding, have established robust technical systems through extensive practice. However, these methods face limitations such as extended cycles, reduced efficiency, and constrained genetic gains in meeting contemporary requirements. Modern biotechnologies, including genomic selection (GS), gene editing (CRISPR/Cas9), and marker-assisted selection (MAS), substantially enhance the precision and efficiency of genetic improvement. Nevertheless, exclusive reliance on either traditional or modern methods proves insufficient for addressing complex environmental adaptation and rapid breeding requirements. Consequently, the integration of traditional breeding with modern biotechnology to develop intelligent, sustainable, and efficient breeding strategies has emerged as a central focus in tree genetics and breeding. An integrated “step-by-step” approach warrants promotion, supported by a multi-source data sharing platform, an optimized core germplasm repository, and a “climate-soil-genotype” matching model to facilitate the region-specific deployment of improved varieties. Full article

In the face of mounting challenges related to limited availability of urban land and ecological degradation, emerging novel ecosystems offer unique opportunities for ecological regeneration, social redefinition of space, and alternative urban visions. This study presents the multi-layer analysis of the Goccia Forest in Milan (Italy), a wild urban woodland that has developed over sealed and polluted post-industrial land, aiming to investigate the potential of this novel ecosystem to sustain Nature-based Solutions (NbSs). Using an integrated approach (surveys on fauna, vascular flora, lichens, analysis of forest evolution, mapping of sealed surfaces, and soil characterization) the research looks at the novel ecosystem as a whole, highlighting its ecological dynamics and Ecosystem Services (ES). La Goccia Forest serves as a prime example of how the implementation of NbSs is intricately intertwined with the spontaneous regeneration of urban brownfields. The present study offers the opportunity to rethink urban policies, ensuring their alignment with the demands of the population and the latest scientific knowledge. Full article

Aerobic soils serve as significant sinks for atmospheric methane, with their effectiveness influenced by the diversity and activity of soil methanotrophs. Land-use changes, particularly the conversion of natural ecosystems to agriculture, can substantially alter these microbial communities. A promising strategy to restore methane oxidation capacity is the introduction of active, ambient methane-oxidizing bacteria. The stable methane-oxidizing microbial consortium T1, dominated by Methylocystis (74%), was isolated from the soil of the unique Chernevaya Taiga forest ecosystem. The effects of inoculating this consortium were evaluated in a four week laboratory incubation experiment, using microcosms of soddy-podzolic agro-soil. Methane oxidation potential was assessed to measure methanotroph activity; methanotrophs were quantified using qPCR targeting pmoA genes; and the diversity of soil microbial communities was examined through 16S rRNA gene profiling. Inoculated soils exhibited significantly higher methane oxidation potentials compared to non-inoculated soils. Furthermore, pmoA gene copy numbers in the inoculated soils were significantly elevated (10⁶ copies pmoA g⁻¹), indicating stable persisted methanotrophic populations throughout the incubation period. These findings suggest that enriched methanotrophic consortium inoculation into agro-soils may be a promising strategy for restoring methane-oxidizing activity. 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

Bamboo forest density is a factor that critically impacts the growth of moso bamboo, soil quality, and productivity. In this study, four bamboo forest density treatment groups were established under a long-term bamboo-stocking retention model, namely 1200 ± 100, 1800 ± 100, 2400 ± 100, and 3000 ± 100 plants·hm⁻², while a traditional management model focused on selective logging, with a bamboo forest density of 2100 ± 100 plants·hm⁻² (CK), serving as the control group. The study aimed to investigate the impact of bamboo forest density on bamboo shoots, roots, and soil, identify key influencing factors, and determine the optimal management density for this management model. Under the novel management model, bamboo shoot yield and number exhibited a unimodal response to stand density. At a density of 2400 plants·hm⁻², the bamboo shoot yield reached its highest value of 18,822 kg·hm⁻², with 7080 shoots·hm⁻². Under the density of 2400 plants·hm⁻², the specific root length, specific root surface area and total nitrogen, phosphorus and potassium contents of 0–1 mm fine roots were higher, and the contents of soil organic matter, total nitrogen, available phosphorus and available potassium were also better. Correlation analysis showed that the bamboo shoot yield and the number of shoots were closely related to soil quality (water content, organic matter, total nitrogen, available phosphorus and available potassium), and the effect of root total nitrogen content on shoot yield was particularly significant (the explanation rate was 75.7%). The comprehensive growth status assessment (D3 > D4 > D2 > CK > D1) showed that there were differences in the performance of different density treatment groups. This information could help bamboo farmers improve yield while protecting soil quality. Full article

Direct seeding is considered a versatile and cost-effective approach to forest regeneration; however, its broader application is limited by low seedling survival rates and species-specific regeneration requirements, which often necessitate site preparation. We investigated the emergence, survival, and growth of Korean ash (Fraxinus chinensis subsp. rhynchophylla (Hance) A.E.Murray) seedlings regenerated by direct seeding over six years following two site preparation treatments—scarification and mixing—to determine appropriate site preparation methods for direct seeding and to assess the effects of site preparation treatments on soil, understory vegetation, and seedling growth. Additionally, the seed germination, shoot and root lengths, and biomass of the seedlings were investigated over 50 days in a growth chamber using soils from each site preparation treatment to examine early-stage growth responses. Both scarification and mixing treatments enhanced seed germination and seedling establishment. Seedling emergence rates were similar between the treatments; however, the seedling mortality and the height and coverage of competing understory vegetation were significantly greater at the scarification treatment than at the mixing treatment during the first year (p < 0.05). Both treatments reduced minimum winter soil temperatures during the first two years, with frost heaving identified as a primary cause of early seedling mortality. From the second year onward, seedling growth was significantly greater in the mixing treatment (p < 0.05), which also more effectively suppressed competing vegetation. A shallow depth mixing treatment (<5 cm) is recommended for direct seeding of Korean ash, as it reduces frost heaving damage and facilitates seedling survival and growth by minimizing understory competition. Full article

Acrobeloides nanus is a cosmopolitan, parthenogenetic soil nematode that is widely distributed across various terrestrial environments, including forests, sand dunes, and agricultural lands. In Korea, this nematode was first isolated from soil collected from a potato farm. It has been used as a biological indicator for monitoring contamination caused by divalent metals such as copper and zinc. In this study, A. nanus was isolated from the soil collected from a cucumber farm, and its identity was confirmed using both morphological and molecular markers. Spray-induced gene silencing using double-stranded RNA (dsRNA) represents a promising new strategy for pest control. Here, we tested a spraying dsRNA that would specifically suppress the target genes in A. nanus. Three genes (Pat-10, Unc-87, and vATPase-B) were targeted, and their expression levels were assessed following treatment with their corresponding dsRNAs. The dsRNAs were sprayed onto the nematode diet. As the concentration of dsRNA increased, the expression levels of the target genes were significantly reduced, leading to notable nematode mortality. However, nematicidal activity varied among the three different dsRNAs. To practically assess these dsRNAs under field conditions, the dsRNAs were applied to the soil containing the nematodes by a drenching application. Significant mortality was observed in treatments with dsRNAs targeting vATPase-B or Pat-10, but not with dsRNA targeting Unc-87. To enhance nematicidal activity in soil, the dsRNAs were formulated with chitosan. This formulation significantly improved the stability of dsRNAs under soil conditions and increased their control efficacy against A. nanus. This study suggests that the drenching technique offers an effective strategy to the control of soil-dwelling nematode pests affecting agricultural crops. Full article

Chinese forest ecosystems are key carbon sinks that significantly contribute to lowering carbon emissions. Accurate Net Ecosystem Productivity (NEP) estimations are essential for evaluating their carbon sequestration capabilities and overall health. This study employed the Physiological Principles Predicting Growth-Satellites (3-PGS) and soil heterotrophic respiration models to simulate China’s forest carbon sinks and sources distribution from 2013 to 2023. Then, climatic factors influencing NEP changes were examined through the application of a geographical detector model. The net carbon sequestered was 1.71 ± 0.09 PgC with an annual average of 0.156 ± 0.0071 PgC, signifying a substantial carbon sink in China’s forest. The annual NEP was highest in evergreen broadleaf forests (352.12 gC m⁻²) and lowest in deciduous needleleaf forests (148.31 gC m⁻²). NEP in China’s forests increased by a rate of 1.67 gC m⁻² annually, with most regions exhibiting a 275.32 gC m⁻² annual carbon sink. The geographical detector model analysis showed that solar radiation, precipitation, and vapor pressure deficit were the main drivers of NEP change, while temperature and frost days had a secondary influence. Furthermore, the interaction between solar radiation and temperature variables showed the greatest impact. This study can enhance the understanding of carbon sink and source distribution in China, serve as a reference for regional carbon cycle research, and provide key insights for policymakers in developing effective climate strategies. 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

In recent years, China has invested substantial funds in ecological restoration, achieving significant accomplishments. The forest coverage rate in the Chengde Bashang area, located in the transitional zone between the monsoon and non-monsoon regions, has now reached 82%. However, the area has also encountered a series of environmental issues, including lake shrinkage, soil salinization, and large-scale die-offs of planted forests. Whether the forests in this region can achieve sustainable development in the future, and whether ecological restoration should prioritize tree planting or grass cultivation, are critical questions that require attention. By studying the historical vegetation dynamics in afforested areas, we can better understand the relationship between climatic environmental changes and vegetation, providing baseline data for future ecological restoration. This study utilized AMS ¹⁴C dates to establish a chronological framework for the core and employed pollen to investigate vegetation dynamics over the past 5000 years in the artificial Larix Mill. forest area. The vegetation and environmental history of this core can be divided into three zones: Zone 1 (5100–4100 a B.P.): vegetation was dominated by pine and spores, with low herbaceous pollen content. Zone 2 (4100–1400 a B.P.): vegetation was primarily herbaceous. Zone 3 (1400 a B.P.–present): arboreal pollen content increased slightly, but herbaceous plants remained dominant. This period included the warm–dry Medieval Warm Period (1400–900 a B.P.), the cold–humid Little Ice Age (900–300 a B.P.), and the recent 300 years of anthropogenic disturbance. Notably, the large-scale afforestation efforts in recent decades are clearly reflected in the profile. A comparative analysis of records from the monsoon–non-monsoon transition zone reveals that, except for Angulinao Lake, other records were dominated by herbaceous vegetation over the past 2000 years. Additionally, the Mu Us Sandy Land, Hunshandake Sandy Land, Hulunbuir Sandy Land, and Horqin Sandy Land in China have experienced aeolian sand accumulation over the same period. Given the anticipated warming–desiccation trend, phytoremediation strategies should favor xerophytic shrubs and herbaceous over monospecific forest plantations. Full article

The assessment of microplastics (MPs) in terrestrial ecosystems has garnered increasing global attention due to their accumulation and migration in soils, which may have potential impacts on soil health, biodiversity, and agricultural productivity. However, research on their distribution and interactions in soil remains limited, especially in tropical regions. This study aimed to characterize MPs extracted from tropical soil samples and relate their abundance to soil and terrain attributes under different land uses (forest, grassland, and agriculture). Soil samples were collected from an experimental farm in Lavras, Minas Gerais, Southeastern Brazil, to determine soil physical and chemical attributes and MP abundance in a micro-watershed. These locations were also used to obtain terrain attributes from a digital elevation model and the normalized difference vegetation index (NDVI). The majority of microplastics found in all samples were identified as polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), and vinyl polychloride (PVC). The spatial distribution of MP was rather heterogeneous, with average abundances of 3826, 2553, and 3406 pieces kg⁻¹ under forest, grassland, and agriculture, respectively. MP abundance was positively related to macroporosity and sand content and negatively related to clay content and most chemical attributes. Regarding terrain attributes, MP abundance was negatively correlated with plan curvature, convergence index, and vertical distance to channel network, and positively related to topographic wetness index. These findings indicate that continuous water fluxes at both the landscape and soil surface scales play a key role, suggesting a tendency for higher MP accumulation in lower-lying areas and soils with greater porosity. These conditions promote MP transport and accumulation through surface runoff and facilitate their entry into the soil. Full article