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[Objective] By analyzing the effects of different mixed forest patterns on the soil particle characteristics of the Kubuqi Desert, this study provides scientific basis for the efficient and sustainable management of sandy land forests. [Methods] Four representative mixed-forest configuration patterns along the section of the Yellow River in Kubuzi Desert were selected. Soil samples were taken from 0—80 cm soil depth. The laser particle size method was used for the determination of soil particle size and calculation of the mean soil particle size (Mz), sorting coefficient (δ), skewness (SK), kurtosis (KG), and fractal dimensional characteristics. [Results] (1) The dominant grain sizes in the study area were fine sand and medium sand. The four different vegetation configuration patterns had a significant refining effect on soil grain size, and the content of clay, silt, and very fine sand increased by 141.37%～415.38%, 105.75%～724.73%, and 64.93%～1597.36%, respectively, compared with the control group CK. (2) After the camping of the four vegetation configuration modes, the average grain size of the soil layer at different depths increased significantly, ranging from 2.44%～20.33%. (3) After comparing the grain size parameters of the soil under different configuration modes, it was found that the value of fractal dimension was positively correlated with the value of kurtosis and negatively correlated with the average grain size. [Conclusion] The degree of soil particle size refinement is related to the configuration mode. Different plant configuration modes on soil particle size refinement are mainly concentrated in the surface layer, and the effect of refinement gradually reduces with the increase of soil layer depth. The average particle size of soil layer at different depths increases significantly, the sorting grade of soil particles decreases, and the particle distribution becomes more discrete. The distribution of soil particles shows a gradual tendency to be broad and flat. The soil particles develop toward positive bias. The fractal dimension of soil particles at different depths of soil layer increases significantly (p＜0.05). [ABSTRACT FROM AUTHOR]

The management mode of forests has significant impacts on soil nutrients. However, with global changes, there is scant evidence to suggest whether the soil nutrients in planted and natural forests have a consistent response mechanism to environmental changes. Utilizing soil nutrient data from 263 planted forests and 434 natural forests in China, collected through field surveys of 298 forests and literature searches from 2005 to 2020, this study explores the differences in soil nutrients between natural and planted forests and their controlling factors. The results indicate that the soil available phosphorus content in natural forests is significantly higher than in planted forests (p < 0.001), and the soil pH is significantly lower than in planted forests (p < 0.001), while there is no significant difference in soil nitrogen content between the two (p > 0.05). With increases in Mean Annual Temperature (MAT) and Mean Annual Precipitation (MAP), soil available phosphorus content significantly increased, and soil pH significantly decreased (p < 0.001). Stand factors (such as stand age and stand density) have a greater influence on soil nutrients in natural forests than in planted forests. Climate factors contribute the most to the spatial variability of soil nutrients in both planted and natural forests. Compared with climate factors, stand factors and forest key leaf traits (such as leaf area, specific leaf area, leaf nitrogen and phosphorus content) had relatively little effect on soil nutrients in planted and natural forests. Climate factors directly or indirectly affect the soil nutrients of planted and natural forests by influencing stand factors and key leaf functional traits, and their direct effects are greater than their indirect effects. The results of this study demonstrate that forest soil nutrients of different types respond to global change in distinct patterns. In future forest management, special attention should be paid to the differences between artificial forests and natural forests. [ABSTRACT FROM AUTHOR]

The ecological niche separation of microbial interactions in forest ecosystems is critical to maintaining ecological balance and biodiversity and has yet to be comprehensively explored in microbial ecology. This study investigated the impacts of soil properties on microbial interactions and carbon metabolism potential in forest soils across 67 sites in China. Using redundancy analysis and random forest models, we identified soil pH and dissolved organic matter (DOM) aromaticity as the primary drivers of microbial interactions, representing abiotic conditions and resource niches, respectively. Our network comparison results highlighted significant differences in microbial interactions between acidic and non-acidic soils, suggesting the critical influences of abiotic conditions on microbial interactions. Conversely, abiotic resource niches played a more pivotal role in shaping the carbon metabolism of soil microbes, supporting the concept that resource niche-based processes drive microbial carbon cycling. Additionally, we demonstrated that microbial interactions contributed significantly to ecosystem function stability and served as potential ecological indicators of microbial functional resilience under environmental stress. These insights emphasize the critical need to preserve microbial interactions for effective forest ecosystem management and projection of ecological outcomes in response to future environmental changes. [ABSTRACT FROM AUTHOR]

Soil organic carbon (SOC) studies often lack uniform sampling methods, which has resulted in evident discrepancies in the SOC stock estimates. The need to find a way forward to standardize the protocol for sampling methods and accurate assessment of SOC stock has led to carrying out this investigation and comparing the variation in SOC concentration and stock using soil profile (by genetic horizon, SP) and soil column (by layers, SC) based approaches. Soil samples were collected according to the genetic horizons (H1, H2, H3, H4) by following the soil profile (SP) approach and soil data for the soil column approach (at 0–30, 30–60, and 60–90 cm as L1, L2, and L3, respectively) were calculated from the values of the soil profile approach. Across the horizons, the highest SOC concentration was observed in H1 (1.28%) and H1 (34.0 Mg C ha−1) also showed 69% more SOC stock than H2 (20.1 Mg C ha−1). In the layers of soil columns, the maximum SOC stock was observed in L1 (38.5 Mg C ha−1) followed by L2 (27.6 Mg C ha−1) and L3 (17.0 Mg C ha−1). Estimation of SOC stocks in topsoil revealed that sampling by layers (38.5 Mg C ha−1) had 13.2% higher SOC in comparison to pedogenic horizons (34.0 Mg C ha−1), while in the subsoil, SOC stock (49.3 Mg C ha−1) was statistically higher with soil profile method. Furthermore, the study suggests the collection of soil samples following the genetic horizon in sites with well-developed soil profiles. [ABSTRACT FROM AUTHOR]

Simple Summary: Minor and trace elements are found in the environment in extremely small quantities but have powerful bioscience roles, and they may cause hazardous effects when levels exceed certain limits. Consequently, it is essential to ascertain the concentrations of these elements within the soil. This paper addresses the distribution of 12 minor and trace elements in five different forests and soil depths in the Winter Olympic core area and explores the mechanisms driving element distribution. The results of this study indicate that soil minor and trace elements are mainly influenced by climatic factors and soil properties, and no direct effect of vegetation type on soil element distribution was observed in this study. Understanding the distribution of minor and trace elements in forest soils across the core area can provide important information on soil succession patterns in the boreal forest and may help elucidate the response of elemental distributions to climate change. Minor and trace elements in soil play a crucial role in regulating ecological processes that sustain the functionality of forest ecosystems. In this study, we have selected three conifer forests (Pinus sylvestris, Picea asperata, Larix principis-rupprechtii), one broadleaf forest (Betula Platyfilla) and one mixed forest of Betula Platyfilla and Larix principis-rupprechtii in the Winter Olympic core area and determined the pattern of 12 typical elements (B, Fe, V, Cr, Ni, Co, Mn, As, Cu, Zn, Sn and Se) in soils and their main drivers in the three different soil layers (A, B and C horizon) in each soil profile. Our results showed that the concentrations of B, Fe, Cr, Cu, Ni and Sn were mainly enriched in the broadleaf forest and mixed broadleaf–conifer forest zones, and the average concentrations of Co, Mn, V, Zn, As and Se were mainly enriched in coniferous forest zones in contrast. We have observed that the mean concentrations of Fe, Cr, Ni, Zn, As, Sn and Co increase with soil depth in the BP forest. The concentrations of Se and Cu were higher in the A layer than the C layer. The piecewise structural equation modeling (piecewiseSEM) results visualized a direct and negative effect on B, Fe, V, Cr and Ni concentrations due to soil temperature, while the concentrations of Se is mainly influenced by soil temperature and soil properties. [ABSTRACT FROM AUTHOR]

The Amazon ecosystem plays a vital role in global climate regulation and biodiversity conservation but faces escalating threats from deforestation and degradation. The resulting secondary forests (SFs) provide a promising opportunity for Transformative Territorial Management, fostering restoration and enhancing conservation values. This study evaluated aboveground biomass (AGB), species diversity, forest structure, and soil properties in SFs of the Colombian Amazon along a chronosequence, from early to mature successional stages, in landscapes of mountains and of hills to identify key indicators for effective restoration management. The results show a consistent increase in AGB, species diversity, forest structure, and soil quality with forest age, though recovery patterns varied between both landscapes evaluated. Topographic differences influenced successional dynamics, with mountainous landscapes showing faster early recovery compared to the steadier, linear growth observed in hill areas. In hills, AGB at 10 years reached 12.65% of the biomass expected in a mature forest, increasing to nearly 42% by 40 years of abandonment, at a rate of 0.708 Mg C ha−1 year−1. In contrast, in the mountain landscape, AGB at 10 years reached approximately 8.35% of the carbon in a mature forest and increased to nearly 63.55% at 40 years. Forest age and soil properties emerged as primary drivers of AGB recovery, while diversity and forest structure played indirect but significant roles. In hill areas, soil conservation practices are critical for maintaining steady growth, whereas mountain regions benefit from assisted natural regeneration (ANR) to accelerate recovery. These findings highlight the importance of prioritizing the management of SFs as a central strategy for achieving restoration goals. Such practices are essential to enhance the ecological resilience of SFs and ensure their long-term sustainability, fostering their role as key contributors to restoration efforts and the provision of ecosystem services. [ABSTRACT FROM AUTHOR]

Societal Impact Statement: Highland forests of Mozambique have been strongly modified by human activities for millennia. Some highlands have sheer rock cliffs and are highly inaccessible to people and appear relatively undisturbed. Evidence from the forest and soils of inaccessible Mount Lico show that the fire regime has changed over the recent millennia. As climate and fire regimes continue to change, management of highland ecosystems will be crucial to sustain the high biodiversity and mountain‐water resources that provide key ecosystem services to people living close to these forests. Summary: The sheer rock cliffs of the Mount Lico inselberg, northern Mozambique, is relatively inaccessible to people. A 0.57 km2 forest covers the top of the isolated mountain, and the tree demographics and soil offer an opportunity to investigate the long‐term fire ecology of the forests of the western, leeside of the mountain and potential for changing regional hydroclimate of the Late Holocene.On the western side of the mountaintop, a 20 × 20 m plot was surveyed for tree taxa, heights and bole diameters. A 220 cm deep pit was dug into the forest soil and analysed to describe the soil texture and carbon content. Charcoal was quantified on sieved subsamples and classified into charcoal morphologies that were then grouped by how readily entrainable on an index score. Three radiocarbon dates were collected from pieces charcoal.The forest is a combination of montane and woodland tree taxa that differed from the older, more mesic eastern side and reflected differential disturbance patterns. The reddish loam soils dated to the Middle Holocene. Charcoal was present in all soil subsamples and varied little until increasing consistently during the past millennium. The charcoal morphologies suggested a combination of locally derived charcoal and charcoal derived from the surrounding lowlands with the latter increasing in the past centuries.Few Holocene paleoenvironmental records have been developed from tropical soils in Africa and are useful in locations that do not host lakes and wetlands. Both tree demographics and soil charcoal suggest that changing forest disturbance regimes began during the past millennium. An understanding of history informs future conservation and appropriate management of these special places. [ABSTRACT FROM AUTHOR]

Unregulated trampling in natural and urban forests compacts the soil, and the plants suffer. In an urban forest in Moscow, soil bulk density in heavily trampled sites increases significantly: 1.6–1.8 g/cm3 compared with 0.6–0.7 g/cm3 on sites under negligible human pressure. As soil density increases, heavy metals and their mobile fractions accumulate in the soil and roots. Amongst forest species capable of loosening soil and thereby improving its physicochemical properties, larch has the lowest soil density (0.42–0.57 g/cm−3) and appears to reduce the toxicity of heavy metals in forest and forest park landscapes. [ABSTRACT FROM AUTHOR]

Soil microorganisms, especially diazotrophic bacteria, are vital for ecosystem sustainability, significantly contributing to nitrogen cycling and biodiversity conservation. Understanding the impact of different land-use practices on soil microorganisms, especially synthetic fertilizer addition, is essential for sustainable agriculture. This study compares soil properties, bacterial densities, and responses to fertilization in secondary forest soils and adjacent oil palm plantation soils located in PT Kerry Sawit Indonesia, Central Kalimantan. A greenhouse experiment was conducted using both secondary forest and oil palm plantation soils to evaluate the impacts of different synthetic fertilizers on nitrogen-fixing bacteria and soybean agronomic performance. Total soil bacteria and diazotrophic bacteria, essential for nitrogen fixation, were analyzed through microbiological assays and qPCR focusing on the nifH gene. Our findings show that oil palm plantation soils had higher levels of nitrogen, phosphate, and nitrate, while secondary forest soils had a higher abundance of diazotrophic bacteria. Furthermore, excessive nitrogen fertilization was found to reduce microbial density, negatively impacting plant sustainability, highlighting the importance of customized fertilizer management. The study highlights the intricate connections between land-use practices and microbial populations, providing valuable insights for balancing agricultural productivity with ecological sustainability. [ABSTRACT FROM AUTHOR]

The impact of plant litter on soil carbon (C) cycling is influenced by external nitrogen (N) deposition and plant litter chemistry. While previous research has mainly focused on inorganic N deposition and its effect on plant litter decomposition and soil C cycling, the influence of organic N remains poorly understood. In this study, we conducted a 180-day incubation experiment to investigate how different N forms (NH4NO3, Urea 50% + Glycine 50%) and litter chemistry (varying lignin/N ratios) affect CO2 emissions from an acidic Moso bamboo (Phyllostachys edulis) forest soil. Our findings indicate that litter addition increased soil CO2 emissions and the proportion of CO2-C to Total C (considering added litter-C as a part of total C). Specifically, Moso bamboo leaf litter with a lower lignin/N ratio led to higher soil CO2 emissions and CO2-C/Total C ratios. The combined addition of litter and N exhibited an antagonistic effect on soil CO2 emissions, with inorganic N having a more pronounced effect compared to organic N. This antagonistic effect was attributed to the N addition-induced soil acidification, thereby inhibiting microbial activities and reducing soil respiration promoted by litter input. This effect was confirmed by random forest analysis and partial least squares path modeling, which further identified soil dissolved organic C and pH as critical factors positively influencing soil CO2 emissions. Overall, our study suggests that atmospheric N deposition can mitigate litter-induced soil CO2 emissions, particularly under inorganic N forms and when leaf litters with high lignin/N ratios are introduced. [ABSTRACT FROM AUTHOR]

It is widely accepted that old-aged forest can accumulate soil organic carbon (SOC). How microbial physiological traits respond to forest age and whether they drive SOC sequestration in old-aged forest remain elusive. Therefore, we compared the microbial C use efficiency (CUE), biomass turnover rate (rB), microbial biomass C (MBC) and necromass C (MNC) across soil profiles from middle and old-aged forest and evaluated how these microbial traits are related to SOC storage. The results revealed that both forests could accumulate SOC and old-aged forest supported higher SOC storage than middle-aged forest from 2005 to 2020. Moreover, SOC was concentrated on the surface soils of middle-aged forest, whereas it was more distributed across the deeper soil profile in old-aged forest. Compared with middle-aged forest, the O, A and B soil layers of old-aged forest presented increases in microbial CUE (17.8%, 36.9% and 25.0%, respectively), rB (43.7%, 39.7% and 10.8%, respectively), MBC (114.8%, 81.1% and 122.9%, respectively), and MNC content (47.0%, 22.2% and 21.6%, respectively). Random forest analysis suggested that SOC accumulation is controlled mainly by microbial physiological traits rather than other factors including environmental variables. Specifically, microbial CUE and turnover rates increased in old-aged forest, resulting in higher MBC and MNC contents, which in turn led to SOC accumulation. Moreover, the effects of plant and soil properties on SOC storage are regulated mainly by microbial-physiological parameters and the size of microbial C pools. Our findings provide valuable insights into the microbial mechanisms underlying SOC storage in old-aged forest. [ABSTRACT FROM AUTHOR]

Specific interactions between bacteria and ectomycorrhizal fungi (EcMF) can benefit plant health, and saprotrophic soil fungi represent a potentially antagonistic guild to these mutualisms. Yet there is little field‐derived experimental evidence showing how the relationship among these three organismal groups manifests across time. To bridge this knowledge gap, we experimentally reduced EcMF in forest soils and monitored both bacterial and fungal soil communities over the course of a year. Our analyses demonstrate that soil trenching shifts the community composition of fungal communities towards a greater abundance of taxa with saprotrophic traits, and this shift is linked to a decrease in both EcMF and a common ectomycorrhizal helper bacterial genus, Burkholderia, in a time‐dependent manner. These results not only reveal the temporal nature of a widespread tripartite symbiosis between bacteria, EcMF and a shared host tree, but they also refine our understanding of the commonly referenced 'Gadgil effect' by illustrating the cascading effects of EcMF suppression and implicating soil saprotrophic fungi as potential antagonists on bacterial‐EcMF interactions. [ABSTRACT FROM AUTHOR]

There will be a significant increase in anthropogenic load on the soils of the Prinevskaya lowland in the nearest decade due to the fact that a significant territory is occupied by St. Petersburg. The main objective is a study of the sanitary-hygienic state and soil diversity of the Prinevskaya lowland in case of a high degree of agricultural soil development there and the significant role of the lithological factor. Soils were studied at the following land use and land cover: agricultural and fallow soils of agrolandscapes; forest soils; and soils of industrial areas. Studies were carried out using morphological descriptions and analyses of chemical, physical, and biological properties. The most vulnerable land use are forest and agricultural and fallow zones, where active accumulation of priority toxicants of anthropogenic origin can occur. Geochemical peculiarities of studied soils are deficit of Mn, Cu, Mo, and Zn in soil-forming rock materials and accumulation of strontium and lead in arable horizons. The soils examined show minimal contamination with trace elements, as verified by a range of individual and combined ecotoxicological indicators. Urban development planning, particularly in St. Petersburg, should prioritize the preservation of biodiversity and soil resources. [ABSTRACT FROM AUTHOR]

Analyzing the spatial and temporal changes in the carbon budget and its influencing factors is the basis for formulating effective measures to reduce emissions and increase sinks. This study establishes a carbon budget assessment model for forest enterprises, calculating forest carbon stocks and enterprise emissions using volume-derived biomass and emission factor methods. The spatiotemporal evolution characteristics of carbon budgets for forest enterprises in the key state-owned forest area (2017–2021) were analyzed using various methods, including the Mann-Kendall (MK) test and hotspot analysis. Influencing factors are identified through correlation analysis and the optimal parameter geographical detector (OPGD), while their spatial-temporal variations and causal relationships are analyzed using the geographical and temporal weighted regression model (GTWR) and structural equation modeling (SEM). The carbon budget in the Greater Khingan Range state-owned forest area averaged 10.16 × 106 t CO2-eq from 2017 to 2021, showing a gradual upward trend. The average annual carbon budget of forest enterprises was 1.02 × 106 t CO2-eq, which was highest in the central regions and lowest in the periphery. Soil pH, forest area, and elevation are the primary factors. The interaction between paired factors enhances the explanatory power of their impact, and the effects of different influencing factors exhibit both positive and negative variations across forest enterprises. In addition, the middle-aged forest tending area and average annual precipitation positively influenced forest area and soil pH, indirectly enhancing the carbon budget through multifactor interactions. This research can enhance the understanding of the carbon budget in forest enterprises, providing scientific support for the ecological protection of state-owned forests and contributing to the development of sustainable forestry practices that indirectly benefit societal well-being and economic resilience. [ABSTRACT FROM AUTHOR]

Forests have a key role in mitigating both non-biological and biological ecological disturbances. However, major disturbances (soil pollution, shift from native forest species to exoticones, forested watersheds and climate changes) can have different impacts on a forest's soil microbiome. Because the soil microbial community of forests has a key role in a variety of ecosystem services that promote the forest's health, this review tries to answer the following questions: (i) Which are the main ecological disturbances that drive the responses of the forest soil microbiome? (ii) How can we measure these changes? For this aim, the review summarizes details on the tree vegetation type, the microbial communities in forest ecosystems, and the mutual influence between plants, soil, and microbiomes. Microbial communities are shaped by factors such as soil type and composition, plant and vegetation types, nutrient levels and soil fertility, disturbance patterns, symbiotic associations, biotic interactions, and the progression of forest succession. Anthropogenic activities produce a rapid response in the microbial communities, leading to both short- and long-term alterations. Harvesting processes reduce drastically the microbiome diversity, forcing a shift from specialized to more generalist microorganisms. Restoration scenarios indicate a re-establishment of microbial communities to a level similar to the native forest, but with a high percentage of replaced native microorganisms. This review emphasizes that the forest soil microbiome is shaped by a range of environmental, ecological, and biotic factors. The primary drivers of the soil microbiome in forest ecosystems discussed in this review include soil composition and nutrient availability, plant community structure, microbial interactions within the soil, disturbances, succession, and temporal dynamics. When considered together, these factors interact in complex ways, influencing the diversity, function, and resilience of the soil microbiome in forest ecosystems. [ABSTRACT FROM AUTHOR]

Moss–cyanobacteria associations serve as significant nitrogen fixers and represent the primary nitrogen sink in boreal forests. Fungi, which are essential for soil biogeochemical cycling, have community structures intrinsically linked to forest ecosystem health and productivity. Using high-throughput sequencing, we investigated differences between moss-covered and non-moss soils in two alpine forests (both plantation and natural forests) by examining soil nitrogen contents, fungal community structure, composition, and functional guilds. Results demonstrated that moss cover enhanced soil nutrient contents, including total carbon, total nitrogen, and inorganic nitrogen. It also altered fungal community characteristics, resulting in higher Chao1 and Shannon diversity indices, as well as a more complex fungal network. Notable changes in functional guilds included an increase in saprotrophic fungi abundance and a decrease in ectomycorrhizal fungi. Our findings support the concept that moss cover creates distinct soil environments: moss-covered soils attract decomposers and nutrient-mobilizing fungi (particularly saprotrophs and ectomycorrhiza), while non-moss soils favor ectomycorrhizal fungi that relieve nutrient limitation through extensional mycelial networks. These findings highlight the critical role of moss cover in sustaining forest soil health and resilience, positioning it as a cornerstone of carbon and nutrient cycling within forest ecosystems. [ABSTRACT FROM AUTHOR]

Implementing thinning practices can enhance the growth of plantation forests and improve soil health. Nevertheless, the impacts of thinning applications on soil quality, large-diameter timber production of Castanopsis hystrix, and ecosystem multifunctionality are poorly understood. Therefore, we chose two sample plots, unthinned (control) and thinned, to investigate productivity and ecosystem multifunctionality after thinning for six years. Results revealed that thinning significantly reduced the soil's bulk density, enhanced large-diameter timber growth, and undermined ecosystem multifunctionality in the short term compared to control (unthinning) treatment. Compared to the control, the thinning treatment considerably enhanced the soil organic carbon (0–30 cm soil layer) and tree diameter at breast height (20–30 cm), and enhanced shrub leaf nitrogen (N), shrub root N, herb aboveground N, Gram-positive bacteria (0–10 cm soil layer), and Gram-positive bacteria (20–30 cm soil layer) contents by 29.61%, 65.29%, 44.61%, 274.35%, and 323.44%, respectively. Furthermore, the thinning application could improve the N and P resorption efficiency more than control. Furthermore, compared with control, thinning treatment maximized decomposition and nutrient cycling function by 11.81% and 143.40%, respectively. Moreover, total PLFA content significantly impacts carbon stocks, wood production, and water regulation functions. In conclusion, this study underscores the considerable potential of thinning in augmenting large-diameter timber production by stimulating the positive effects of forest stands. These findings provide valuable insights for ecosystem multifunctionality elevation and the judicious application of thinning to improve forestry productivity, facilitating sustainable development in the forestry sector. [ABSTRACT FROM AUTHOR]

Climate warming affects the carbon cycle in terrestrial environments. However, the effects of warming on the change rate of soil organic carbon (SOC) content in forest soils are unclear. Here, we extracted 276 data points from 98 published papers to examine the effects of warming on the change rate of SOC content in the soil mineral profile (0–20 or 0–30 cm), focusing on the regulatory effects of warming magnitude and duration and the humidity index. Warming promoted an increase in SOC content from 67.47 to 69.90 g kg−1 in forest soils, with a change rate of SOC content of 0.85 g kg−1 yr−1 on a global scale. The change rate of SOC content decreased from 1.22 to 0.11 g kg−1 yr−1 at a warming magnitude of 0–2 and >2 °C, respectively, and it changed from 0.96 to −0.81 to −0.51 g kg−1 yr−1 at warming durations of 0–5, 5–10, and >10 years, respectively. The change rate of SOC content was higher at a humidity index value of 30–50 than at 0–30 and >50. Although climate warming increases the SOC content, the change rate of SOC content decreases with increased magnitude and duration of warming but increases with an increased humidity index. These findings help elucidate SOC accumulation in the context of climate change. [ABSTRACT FROM AUTHOR]

In this study, we investigated the changes in the communities of arbuscular mycorrhizal fungi (AMF) and their driving factors across eight vegetation succession stages in the Sanjiang Plain, Northeast China, original natural wetland (NW), wetland edge (EW), shrub-invaded wetland (IW), shrub-dominated wetland (DW), young-Betula forest (YB), mature-Betula forest (MB), Populus and Betula mixed forest (PB), and conifer forest (CF), using Illumina MiSeq sequencing. As this research has revealed, significant differences exist in soil physicochemical indicators, including moisture content (MC), pH, soil organic carbon (SOC), total nitrogen (TN), available nitrogen (AN), total phosphorus (TP), and available phosphorus (AP). As vegetation succession progresses, the diversity and structure of AMF communities also undergo changes, with the Simpson diversity index being highest in coniferous forests (CF) and the Abundance-based Coverage Estimator (ACE) and Chao1 indices being elevated in shrub-dominated wetlands (PB). Non-metric multidimensional scaling (NMDS) analysis reveals distinct differences in AMF communities across various succession stages. Furthermore, stacked bar charts indicate that the genus Glomus dominates in most wetland and forest succession stages but is nearly absent in CF, where it is replaced by the genus Paraglomus. Canonical correspondence analysis (CCA) demonstrates that SOC has a more significant impact on AMF communities during the EW stage of succession, while AP and TP exert greater influence during the CF stage as well as the MB and YB stages. AN, on the other hand, plays a more prominent role in shaping AMF communities during the IW and NW stages. PICRUSt2 predictions reveal that enzymes such as alcohol dehydrogenase and L-aminoadipate-semialdehyde dehydrogenase are most abundant in YB, whereas pathways like 4-amino-2-methyl-5-diphosphomethylpyrimidine biosynthesis are most enriched in IW. These findings uncover the close interplay between soil physicochemical properties and AMF community dynamics, aiming to deepen our understanding of the relationships among soil physicochemical properties, AMF community changes, and succession dynamics in wetland and forest ecosystems. [ABSTRACT FROM AUTHOR]

The agroforestry system provides a new option for P. notoginseng cultivation. However, the effects on soil health and microbial communities are still incomplete when monoculture coniferous forests are converted to P. notoginseng–pine plantations. To assess soil health, samples from five P. notoginseng–pine plantations were collected, including healthy plants and root-diseased plants, as well as plantation control soil. The samples were analyzed for physical, chemical, and biological aspects and soil microbial communities. Our results suggested that P. notoginseng planted under pine forest was more conducive to increased microbial biomass carbon, soil dissolved organic nitrogen, particulate organic nitrogen, and soil enzyme activities compared with uncultivated control soil. A quantitative assessment of soil health demonstrated that the comprehensive soil quality index (SQI) of P. notoginseng-cultivated soil exhibited marked increases of 79.41% and 119.85% in comparison with the control soil. The observed alterations in soil characteristics could be attributed to variations in the soil microbiome. This implies that changes in SQI positively regulate bacterial and fungal abundance in P. notoginseng–pine agroforestry ecosystems mainly through biological properties. This comprehensive SQI assessment helps to guide the cultivation of P. notoginseng under forest and improve soil quality for P. notoginseng–pine agroforestry ecosystems. [ABSTRACT FROM AUTHOR]

Soil biological characteristics are highly sensitive to land use changes, making them valuable indicators of soil quality. This study assesses the effects of three land use types (agriculture, rangeland, and forest) and elevation variations on soil microbial parameters and their spatial distribution in the Khaneghah region. Standard physicochemical and biological properties of the soil were measured on a total of 72 soil samples collected using systematic and random sampling techniques. Spatial distribution maps of the biological indices were generated using geostatistical techniques, specifically the Kriging method, within a geographic information system (GIS). The results revealed significantly higher values for microbial biomass carbon (MBC = 900 mg Cmic-CO2 kg−1), nitrogen (MBN = 8.97 mg Nmic kg−1), basal respiration (BR = 25.1 mg C-CO2 g−1 day−1), and the total microbial population (MPN = 0.63 × 109 cells g−1) in forest soils compared to rangeland and agricultural soils. The alignment between land use maps and biological index maps reinforced these findings. Although the correlations between biological indices and physicochemical properties were generally weak (positive or negative), organic matter content, field capacity moisture, and silt percentage exhibited a slight positive correlation with most of the microbial indices evaluated. The comparison of soil microbial indices with the digital elevation model map indicated higher levels of MBC, MBN, BR, and MPN at elevated regions. However, the microbial quotient and metabolic quotient (qCO₂) did not show significant changes with increasing elevation. The study also confirmed the effectiveness of Kriging interpolation in mapping specific soil microbial indices, as the correlation between Kriging estimates and measured values at sampling points exceeded 0.2, demonstrating statistical significance at a 5% confidence level. [ABSTRACT FROM AUTHOR]

Climate change is associated with an increased risk in the occurrence of wildfires. Forests store large amounts of carbon (C), which are threatened by these wildfires. Pyrogenic material produced after a wildfire constitutes an important part of the soil organic carbon pool in forest soils. Microorganisms play an important role in the cycling of C. This study investigated microbial activity in dissolved char from burned wood from two tree species in different stages of decay. The char from branches of beech and Norway spruce was produced under laboratory fire conditions and extracted in water after which microbial activity was measured for a 4-week period. Further stages of decay resulted in increased flammability with higher peak temperatures and combustion completeness. For the beech samples, further decay also resulted in a decrease of extractable C but a higher proportion of stable C. Further decay resulted in less respiration for beech and more for Norway spruce. With less C being respired, this points towards an increased C sequestration potential in the form of microbial C and microbial derived products for beech compared to Norway spruce. This study provided a workflow to assess the effects of dissolved char on microbial activity by mimicking natural fire conditions. It also indicated the need for future research to further elucidate the underlying mechanisms explaining why fire-originated dissolved char of wood in different decay stages influences microbial respiration with diverging effects per species. [ABSTRACT FROM AUTHOR]

The common pine sawfly, Diprion pini (Linnaeus, 1758) (Hymenoptera: Diprionidae), is a well‐known defoliating pest of various pine forests almost all over the world, including Europe. It can cause damage to many pine species but usually opts for Pinus sylvestris Linnaeus and P. nigra subsp. laricio (Poiret) Maire. The prohibition of the use of chemical insecticides in forests (at least for Türkiye) has led to the fact that other control methods have come to the fore in the control of this pest. In this respect, biological control agents, which are eco‐friendly and can persist in the field over time, providing long‐term control for plant protection, have an important potential in the control of D. pini. Therefore, in this study, entomopathogenic fungi were isolated from pine forest soils and identified by gene sequencing and phylogenetic analysis. Ten isolates (DP‐37, DP‐38, DP‐45, DP‐46, DP‐49, DP‐53, DP‐54, DP‐57, DP‐58 and DP‐63) were identified as Beauveria pseudobassiana, four isolates (DP‐35, DP‐41, DP‐52, and DP‐61) were identified as B. bassiana, and only one isolate was identified as Metarhizium robertsii (DP‐15). All isolates were tested against the larvae of the pest under laboratory conditions, and the highest mortality and mycosis values (96.6% and 63.3%, respectively) were obtained from B. pseudobassiana DP‐57. This isolate was also tested against the pest under outdoor conditions using different conidial concentrations. Based on probit analysis, the LC50 and LC90 values were estimated to be 1.309 × 107 and 1.21 × 1010 conidia/ml, respectively. The results showed that B. pseudobassiana DP‐57 could be a good candidate in the biological control of D. pini. [ABSTRACT FROM AUTHOR]

Urban forest soils are complex environments subjected to various stressors that alter chemical and microbial properties. To understand soil chemistry and bacterial community patterns in urban forest soils with respect to site identity and multiflora rose (Rosa multiflora) invasion, soils were collected from beneath R. multiflora, native spice bush (Lindera benzoin), and uncovered ground in three forests in Newark, Delaware. High-throughput sequencing was used to analyze bacterial communities with corresponding soil chemical properties. Soil chemistry and operational taxonomic unit (OTU) communities were explained by site rather than by shrub cover type. Unlike other invasive plant studies, R. multiflora had minimal effects on either soil chemistry or bacterial communities. Phylum level bacterial communities were more uniform under shrub cover versus no cover, indicative of a generalized plant effect shaping soil microbiomes. Correlations between bacterial phyla and soil chemistry varied, with some phyla positively or negatively correlating with the same property at different sites. Filters for bacterial communities differ across forest scales, where sites and sampling location primarily correlate with OTU communities yet shrub presence mediates phylum level organization. Forest soil studies should consider location-based differences in bacterial communities and their correlations with soil chemistry before generalizing outcomes for whole macrosystems. [ABSTRACT FROM AUTHOR]

Thermal processes are emerging as promising solutions to recovering phosphorus and other nutrient elements from anaerobic digestates. The feasibility of nutrient element recovery depends largely on the fates of nutrient elements and heavy metals during thermal processing. This study assesses the partitioning of macronutrients (N, P, K, Na, Ca and Mg) and heavy metals (Zn, Cu, and Mn) between condensed and gaseous phases during thermal conversion of cattle slurry digestates in gas atmospheres of pyrolysis, combustion, and gasification processes. This study also assesses the chemical forms of macronutrients retained in combustion ashes. The partitioning of elements between condensed and gaseous phases was quantified by mass balances based on elemental analyses of char and ash residues. The char and ash residues were prepared in a fixed-bed, batch reactor at temperatures within the range 800–1000 °C. Powder X-ray diffraction was used to identify the chemical forms of macronutrient elements in combustion ashes. Volatilisation of P was low (< 20%) when the digestates were heated in inert and oxidising atmospheres, whereas a reducing atmosphere volatilized P to a major extent (~ 60% at 1000 °C). Oxidising atmospheres increased volatilisation of N but suppressed volatilisation of K, Na, and Zn. Volatilisation of the following elements was low (< 30%) in all investigated operating conditions: Ca, Mg, Mn, and Cu. The combustion ashes contained both high concentrations of P (around 7 w/w%) and acceptable concentrations of regulated heavy metals (Cu, and Zn) for application on agricultural and forest soils in Finland. Phosphorous was retained in the combustion ashes in the form of whitlockite. This form of P is expected to be available to plants when the ashes are added to soil. [ABSTRACT FROM AUTHOR]

Energy crops make modest but not negligible demands on soil nutrients. In grey forest soils in the Western Forest-Steppe of Ukraine and compared to rotational grain, legumes and oilseeds, 20-years cultivation of miscanthus brought about a decrease of 2.8 times of boron and 3.6 times of magnesium in the top 20 cm soil layer but an increase of 3.4 times in cobalt, 1.9 times in iron and 3 times in exchangeable calcium. Under Virginia mallow (Sida hermaphrodita L.), a reduction of boron by 1.4 times and 1.15 times of iron was found compared to soil under arable crops. The least difference between macro- and microelements was found under cup plant (Silphium perfoliatum L.). [ABSTRACT FROM AUTHOR]

Tree roots and their fungal symbionts mediate the response of rhizosphere soil organic carbon (SOC) decomposition to climate warming, specifically the temperature sensitivity of soil microbial respiration (Q10), which is a critical parameter for projecting the magnitude of terrestrial soil C‐climate feedbacks. However, the intensity of the rhizosphere effects (RE; rhizosphere soils vs. bulk soils) on Q10 in forest soils associated with different mycorrhizal groups and their seasonal dynamics are poorly understood. Here, we selected nine tree species associated with either arbuscular mycorrhizal (AM) or ectomycorrhizal (EM) fungi in subtropical forests of China and collected bulk soil and rhizosphere soil in both the warm and cold seasons to explore the RE on Q10, respectively. Our results showed a positive RE on Q10 (ranging from 20.1% to 87.5%) for all tree species, independent of the season. For EM tree species, the RE on Q10 was 64.5% higher in the warm season and 44.4% higher in the cold season, compared with AM tree species. The RE on Q10 of AM and EM tree species was 44.8% and 65.0% larger in the warm season than that in the cold season, respectively. Fine root traits (including biomass, the carbon‐to‐nitrogen ratio, and soluble sugar content) predominantly controlled the RE on Q10 in AM‐dominated forests, whereas the RE on soil properties (such as NH4+$$ {\mathrm{NH}}_{4^{+}} $$ and C availability) dominantly governed the RE on Q10 in EM‐dominated forests. Furthermore, the RE on Q10 was also positively correlated with the RE on soil microbial phospholipid fatty acids in both AM‐ and EM‐dominated forests. These findings suggest that rhizosphere soils in EM‐dominated forests are more susceptible to C losses under climate warming than those in AM‐dominated forests, compared with their respective bulk soils, potentially limiting rhizosphere SOC sequestration. The greater vulnerability of EM‐dominated forests underscores the importance of accounting for root–soil interactions, mycorrhizal associations, and seasonal dynamics in C‐climate models to improve predictions of SOC cycling and its feedback to global warming. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

The productivity of economically valuable focal trees in mixtures is often improved by inclusion of lower‐value nursing species, but the mechanisms underpinning such effects are poorly resolved. This gap in understanding limits the capacity to develop efficient planting strategies for forests and woodlands to contribute to net‐zero and other critical ecosystem functions. Here, we undertook a plant–soil feedback experiment to test the hypothesis that feedback effects improve the biomass of Sitka spruce [Picea sitchensis (Bong.) Carr] in soil conditioned by monocultures of heterospecific nurse species, and a mixture comprising Sitka spruce and heterospecifics, compared to soil conditioned by only Sitka spruce. Sitka spruce saplings had greater biomass in soil conditioned by Scots pine monocultures (Pinus sylvestris L.) and the mixture compared to their own soil or soil conditioned by silver birch (Betula pendula Roth). Statistical models showed that colonization of ectomycorrhizal fungi on tree roots in the feedback phase was positively related to seedling biomass, and significantly influenced plant growth strategy. Soil inorganic nitrogen concentrations were strongly affected by monocultures and mixtures in the conditioning phase, but these effects were not related to biomass of seedlings in the feedback phase. However, the positive associations among microbial biomass nitrogen, extractable ammonium in soil, and the activity of the nitrogen‐degrading enzyme N‐acetylglucosaminidase may influence seedling biomass in the longer‐term by stimulating nitrogen cycling. Synthesis and applications. Our findings show that in the crucial early phases of tree growth, plant–soil feedback plays an important role in shaping productivity of Sitka spruce and the nitrogen cycle in forest soils, the latter which may have important consequences for tree biomass in the longer‐term. Our findings demonstrate the importance of the nursing effect in the early stages of plant growth and provide a mechanistic explanation both for long‐held observations of nursing effects in forestry systems and for biodiversity effects in natural woodlands. The nursing effect was largely driven by the activity of symbiotic ectomycorrhizal fungi, and therefore it is important for practitioners to ensure nursing species monocultures or mixtures support ectomycorrhizal fungi that are compatible with high‐value target species. [ABSTRACT FROM AUTHOR]

Soil health receives the increased attention of researchers worldwide to evaluate the sustainability of agricultural land management. Chemical, physical and biological indicators are essential to reflect the soil functioning capacity and its quality. Thus, the aim of this study was to determine the soil health and quality of banana crops compared with natural forests. The experimental area included three counties: Eldorado, Registro and Sete Barras, located in Baixo Vale do Ribeira, in the state of São Paulo, Brazil. In each county, soil from banana orchards was compared with soil collected from the natural Atlantic Forest in the transitional regeneration phase, in split-plot design, considering each county as a block. Soil health was evaluated through six soil quality indexes developed using different strategies to define the minimum dataset, data interpretation (linear or non-linear scoring curves) and integration (additive or weighted). Compared with natural forests, in general, banana crop soil showed elevated values of the chemical indicators, mainly due to the frequent fertiliser applications. A slight decrease, but still adequate, of physical indicators, primarily related to soil aeration and similar results in biological indicators. All soil quality indexes tested here can be used to verify soil health; however, soil quality index-2 was the best for a total dataset, and soil management assessment framework was the best for a minimum dataset, demonstrating no statistical difference in soil health between banana and forest soil systems. [ABSTRACT FROM AUTHOR]

Summary: Forest soils play a pivotal role as global carbon (C) sinks, where the dynamics of soil organic matter (SOM) are significantly influenced by ectomycorrhizal (ECM) fungi. While correlations between ECM fungal community composition and soil C storage have been documented, the underlying mechanisms behind this remain unclear.Here, we conducted controlled experiments using pure cultures growing on naturally complex SOM extracts to test how ECM fungi regulate soil C and nitrogen (N) dynamics in response to varying inorganic N availability, in both monoculture and mixed culture conditions.ECM species dominant in N‐poor soils exhibited superior SOM decay capabilities compared with those prevalent in N‐rich soils. Inorganic N addition alleviated N limitation for ECM species but exacerbated their C limitation, reflected by reduced N compound decomposition and increased C compound decomposition. In mixed cultures without inorganic N supplementation, ECM species with greater SOM decomposition potential facilitated the persistence of less proficient SOM decomposers. Regardless of inorganic N availability, ECM species in mixed cultures demonstrated a preference for C over N, intensifying relatively labile C compound decomposition.This study highlights the complex interactions between ECM species, their nutritional requirements, the nutritional environment of their habitat, and their role in modifying SOM. [ABSTRACT FROM AUTHOR]

Pinus radiata D. Don is the most widely planted forest species in Chile, making it crucial to understand carbon pools in adult plantations. This study aimed to evaluate the effect of soil type and site productivity on the total carbon stock in adult radiata pine plantations, considering sites with contrasting water and nutrient availability. We selected 10 sites with sandy and recent volcanic ash soils, representing a productivity gradient. At each site, three 1000 m2 plots were established to quantify the carbon stock of total biomass using allometric equations and in situ carbon assessments of the forest floor and mineral soil (up to 1 m deep). The results indicated significantly higher carbon stocks in the mineral soil of recent ash sites (281.4 Mg ha⁻1) compared to sandy soils (139.9 Mg ha⁻1). The total site carbon was also higher in recent ash (473.2 Mg ha⁻1) than in sandy sites (330.9 Mg ha⁻1). A significant relationship was found between stand productivity and soil organic carbon (r2 = 0.88), as well as total carbon stock (r2 = 0.91) when considering soil type. These findings highlight the importance of including assessments up to 1 m depth and developing soil type and productivity models to improve site carbon stock estimates. [ABSTRACT FROM AUTHOR]

The contribution of biotic factors to the variation of soil carbon stock in forests of the Republic of Karelia, Leningrad oblast (Karelian Peninsula), and Bryansk oblast (Bryansk Forest Nature Reserve), formed on soil-forming rocks of light granulometric composition, is assessed. Groups of biotic predictors characterizing the vegetation and macrofauna are analyzed, and their contribution to the variation of the soil carbon stock in soil layers and horizons is estimated using the hierarchical decomposition method. It is shown that in coniferous-broad-leaved forests the relative contribution of biotic predictors to the variation of litter carbon stocks is higher, while in boreal forests, it is in the mineral layers of 0–50 cm. The most informative predictor for the OFH subhorizon of the litter and mineral horizons was the indicator of litter quality of the C : N ratio. [ABSTRACT FROM AUTHOR]

The recovery of large soil invertebrates (macrofauna) associated with changes in the properties of the litter during natural spruce reforestation on post-agrogenic weakly acid sandy/silty loam soils in the Smolensk Lakeland National Park (western part of Russia) is studied. This work is based on the data of the study of the chronosequence including the following stages: E0, young fallows and agrocenosis; E1, perennial meadows; E2, young birch forests of 10–30 years of age; E3, middle-aged birch forests (36–64 years old) with spruce dominance in the lower woody layer; E4, forests with birch dominance (70–80 years old) and spruce emergence in the upper woody layer; E5, spruce–birch forests (80–100 years old) with the formation of window mosaics due to birch loss; E6, conditionally indigenous spruce forests 90–100 years old with pronounced window mosaics and windfall–soil complexes. It is shown that the litter stocks and the thickness, the carbon content in it increase during reforestation. In agrocenoses and young fallows, the organogenic horizon is fragmentary and is represented by the fall of current years. Litter consisting of material in an intermediate state of decomposition (Oe horizon) appears in young birch forests. Organic material in an advanced state of decomposition (Oa horizon) is characteristic of the middle and late stages of spruce reforestation. The diversity of invertebrates inhabiting the litter also increases naturally. The diversity of the epigeic macrofauna increases: earthworms appear and the number and biomass of other saprophages (bipedal millipedes, molluscs) and predators (spiders, beetles, labiopods) increase. A positive correlation between the thickness of the Oa horizon and the biomass of epi-endogeic earthworms was found. [ABSTRACT FROM AUTHOR]

Objective］ To study the characteristics of changes in chemical properties and diversity and structural composition of soil microbial com munities in Pinus yun-nanensis soils on the Central Y unnan Plateau under nitrogen deposition, and to analyze the correlation between soil microorganisms and soil chemical properties, in order to provide a scientific basis for understanding the trend of changes in nutrient cycling in forest soil ecosystems under nitrogen deposition and observing soil microbiological changes. Method] The soil of jP. yunnanensis forests on the Central Yunnan Plateau was selected as the research object, CO (NH)2 was used as the N source, and four different gradients were set up for simulated N deposition experiments, including control CK _ N 0 g/(• a)], low nitrogen LN _ N 10 g/(• a)]: medium nitrogen MN _N 20 g/(• a)], and high nitrogen HN _N 25 g/(m2 • a)], the structure and diversity of soil bacterial and fungal community were analyzed, and the characteristics of the changes of soil pH, T()C, TN, TI\NH--N and NO;, - N were determined.: Results] (1) Tn both the dry and rainy seasons, soil pH and TOC content were reduced, and TN was increased under each N treatment when compared with CK, and both NH才 一 N and NO:, -- N were increased at MN and HN compared to CK; (2) Both bacterial and fungal a-diversity were higher in the rainy season than in the dry season; bacterial a-diversity increased at LN under both seasons compared to CK, whereas fungi a-diversity increased at LN in the dry season; (3) Tn both the dry and rainy seasons, the dominant bacterial phyla were Proteobacteria, A ci do bacteria and Actinobacteria, and the dominant fungal phyla were Basidiomycota, A scorn y cot a and Mortierellomycota; (4) The dominant bacterial and fungal genera were significantly correlated with pH, TOC, TN and N()f--N during the dry and wet seasons. Conclusion] Nitrogen deposition can provide soil microorganisms with effective nutrients such as NH才 一 N and NO, --N, but soil acidification due to nitrogen deposition can reduce soil TOC content and affect the structure of soil microbial communities. [ABSTRACT FROM AUTHOR]

Objective］ Soil microbial metabolic efficiency profoundly affects soil nutrient cycling and soil carbon sequestration in the recovery process of eroded and degraded areas. However, it is unclear how tree species mixture affects soil extracellular enzyme stoichiometry and microbial carbon-utilization efficiency in single Pinus massoniana plantation in the eroded red soil area. Methods］ Tn this study, we used single F. massoniana plantation, and F. massoniana and Schima sup er ba mixed plantation with different restoration years, determined the soil physicochemical properties, extracellular enzyme activity and phospholipid fatty acid markers of different forests, and calculated the soil enzyme stoichiometric ratio and microbial carbon-utilization efficiency (CUE). Results］ (1) With the increase of restoration years, soil acid phosphatase (AP) and 0-glucosidase (|3G) activities were significantly reduced, while C: NEea(pG: NAG), vector length (VL) and vector angle (VA) of the mixed forest were lower than that of pure forest, while C: eea(pG: AP) and N: Peea(NAG: AP) showed the opposite trend, indicating that long-term mixing is beneficial to alleviate the carbon limitation and phosphorus limitation of microorganisms. (2) Mixing was beneficial to improve CUE and significantly increased with the increase of forest age. Specifically, compared with that of Y39-CF and Y19-MF, CUE of Y39-MF significantly increased by 200. 00% and 136. 84%, respectively.(3) By analyzing the characteristics of soil enzyme activity and the relationship between CUE and environmental factors, it was found that soil carbon, nitrogen and phosphorus availability was an important influencing factor, mainly affecting AP activity, C: PEEA, N :, VL, VA and CUE: while the stoichiometric ratio of soil nutrients mainly affected pG activity and C5 Neea-(4) The results of redundancy analysis (RDA) showed that the ratio of fungi and bacteria mainly affected the characteristics of soil enzyme activity and ClJE in the mixed forest, while the main influencing factors in pure forest were actinomyces and Gram-negative bacteria. Conclusion] Mixing tree species significantly improves forest soil nutrients, affects the release of soil extracellular enzymes, and improves CUE, and it is conducive to soil carbon sequestration. Therefore, the differences between pure forest and secondary forest should be considered in future management and research of P. massoniana forest. [ABSTRACT FROM AUTHOR]

Objective］ The forest coverage rate in the Yangtze River Delta region reaches 33.4%, and the underlying surface soil may have an important impact on the regional greenhouse gas budget. To explore the characteristics of changes in CHi and N, () fluxes in the forest ecosystem soil in this region, as well as the effects of soil physicochemical properties and litter on these two greenhouse gas fluxes. Methods］ Taking the typical broad-leaved forest soil in Hangzhou, Zhejiang Province as the research object, soil-air interface CHi and N2O fluxes were continuously measured from November 2022 to November 2023 by the static chambergas chromatography method._Results］ The average annual absorption fluxes of CHi in the soil without litter (S) and soil with litter (SL) treatments were(47.82± 18.54), (36.80+ 13.55)/ig/Cm2 • h), as well as the average emission fluxes of NA) were (8(). 74 土 45. 24), (52. 7() ± 25. 98)/ig/(m2 • h), respectively. The seasonal variations of CH- absorption fluxes were similar under the two treatments of S and SL, with the absorption flux in spring and summer being higher than that in autumn and winter. The N, () emission fluxes of the two treatments also showed similar seasonal variations, with the highest in summer, followed by spring, and lower in autumn and winter. Litter had a significant impact on CH- absorption and N2O emissions, with litter remove leading to a 29.9% increase in CHi influx and a 53.2% increase in N, () efflux. Correlation analysis revealed that the CHi absorption flux and N, O emission flux under the two treatments were significantly positively correlated with soil organic carbon content and soil temperature, respectively (p 〈().()5). The CHi absorption flux had a significant negative correlation with soil bulk density under SL treatment (p〈().()5). Conclusion] The research results indicate that broad-leaved forests have an important role in forest carbon sinks, and the management of soil litter in broad-leaved forest is crucial for balancing CHi absorption and N, () emissions, as well as mitigating climate warming. [ABSTRACT FROM AUTHOR]

The primary objective of this research study is to assess the water quality of La Compañía and Nexapa rivers in Los Volcanes Biosphere Reserve (Mexico) through the analysis of physical and chemical parameters during wet and dry periods. Twelve locations with different land uses are examined from September 2018 until June 2019. Twenty environmental variables are assessed in situ and in the laboratory in accordance with Mexican environmental regulations. Gathered data are compared with the standards established in the regulations for water for human consumption and aquatic life. The results show that BOD, COD, N-NH4+, TSS, SS, and heavy metals (Cd, Cr, Pb and Fe) exceed permissible limits. The soils with the greatest impact on water quality are seasonal agricultural soils and forest disturbed. It is concluded that human activities and volcanic emissions affect river water quality--an improvement alternative is phytoremediation with native species. [ABSTRACT FROM AUTHOR]

Forests are the reservoir for a vast amount of terrestrial soil organic carbon (SOC) globally. With increasing soil depth, the age of SOC reportedly increases, implying resistance to change. However, we know little about the processes that underpin deep SOC persistence and what deep SOC is vulnerable to climate change. This review summarizes the current knowledge of deep forest SOC, the processes regulating its cycling, and the impacts of climate change on the fate of deep forest SOC. Our understanding of the processes that influence deep SOC cycling and the extent of SOC stores is limited by available data. Accordingly, there is a large degree of uncertainty surrounding how much deep SOC there is, our understanding of the influencing factors of deep SOC cycling, and how these may be distinct from upper soil layers. To improve our ability to predict deep SOC change, we need to more accurately quantify the deep SOC pool and deepen our knowledge of how factors related to the tree root–soil–microbiome control deep SOC storage and cycling. Thereby, addressing the uncertainty of deep SOC contribution in the global C exchange with climate change and concomitant impacts on forest ecosystem function and resilience. [ABSTRACT FROM AUTHOR]

Microbial carbon (C) use efficiency (CUE) describes the proportion of organic C used by microorganisms for anabolic processes, which increases with soil organic C (SOC) content on a global scale. However, it is unclear whether a similar relationship exists during natural vegetation restoration in terrestrial ecosystems. Here, we investigated the patterns of CUE along a 160‐year vegetation restoration chronosequence (from farmland to climax forest) estimated by stoichiometric modeling; additionally, we examined the relationship between CUE and SOC content and combined these results with a meta‐analysis. The combination indicated that vegetation restoration decreased CUE from 0.35 to 0.28. Surprisingly, SOC content increased with decreasing CUE during vegetation restoration because forest soils have low pH values and high microbial phosphorus limitations compared to early ecosystems, implying that climax forests may not sequester as much soil C as expected. The shift in soil pH was the most important predictor of CUE compared to climate, plant, and microbial factors. CUE changes were directly induced by soil pH and not by the pH‐induced microbial community. Alkaline soil acidification tended to decrease CUE. This first large‐scale estimate of the relationship between CUE and SOC during natural restoration highlights the need to strengthen C sink management in mature forests to sustain their C sequestration potential. [ABSTRACT FROM AUTHOR]

Deadwood, a vital component of forest ecosystems, constitutes a quintessential carbon reservoir that must be disclosed under the United Nations Framework Convention on Climate Change. This reservoir, comprising fallen logs, snags, and stumps, markedly affects carbon dynamics over decades. In this study, deadwood carbon stocks were quantified using data from 2674 sites in Japan surveyed between 2011 and 2015 via the National Forest Soil Carbon Inventory, and the deadwood carbon attributes in the country were explored. Deadwood were surveyed using the line intersect method for fallen logs and the belt transect method for stumps and snags. In Japan, the deadwood carbon stock (measured in t-C/ha) was quantified at 7.5 ± 9.74 (mean ± SD), with fallen logs at 3.26 ± 4.43, stumps at 2.45 ± 5.69, and snags at 1.80 ± 5.27, with significant differences detected among these stocks (p <.001). Considering deadwood carbon accumulation in Japan, planted forests exhibited a significantly larger (p <.001) deadwood carbon stock than natural forests. Moreover, planted forests exhibited a higher proportion of fallen logs than snags and stumps, indicating the effects associated with logs left on forest floors after thinning. Based on these findings, deadwood carbon stocks have the potential to bolster the validation and refinement of computational models used in carbon accounting. [ABSTRACT FROM AUTHOR]

Objective The aim is to explore the feasibility and environmental risks of water-based drilling cuttings desert soilization. Methods The basic properties, soil fertility, and heavy metal and organic pollutant characteristics of water-based drilling cuttings were systematically analyzed. Further, planting experiments were carried out after mixing water-based drilling cuttings with desert soil and carbon sink forest soil. Results The contents of available potassium, available zinc and available magnesium in the water-based drilling cuttings are high, while pH, contents of salt cation exchange capacity and soluble chlorine are the main restriction factors of soilization, and the contents of heavy metals and organic pollutants are lower than the standard values. After planting, pH, the contents of salt, soluble chlorine, and quick-acting potassium have decreased by 6.95%, 60.67%, 62.42%, and 11.00% on average, respectively. Conversely, cation exchange capacity and organic matter contents have increased by 557.98% and 41.95% on average, respectively. The results showed that the physical and chemical properties of soil have been significantly improved, and the growth of plants in mixed soil is better than that in water-based drilling cuttings and desert soil. The mixing mass ratio of water-based drilling cuttings to desert soil was recommended to be 8∶2 or 7∶3. Conclusions Soilization utilization of water-based drilling cuttings is feasible and environmentally safe is high. Further research is needed on soil amendments that break through the restrictive factors, improve fertility, monitor the risk of biological enrichment, and realize more efficient and safe utilization of water-based drilling cuttings soilization. [ABSTRACT FROM AUTHOR]

Land planarians (Geoplanidae) are predatory platyhelminths that inhabit mainly forest soils. The subfamily Geoplaninae is exclusive to the Neotropics. Although some phylogenetic studies have included a range of Geoplaninae genera, some, such as Amaga and Bogga, have not yet been considered in detail. This work aims to improve the understanding of the systematics of these two genera, focusing on the morphological and molecular (28S rDNA and COX1 genes) aspects of three species. We examined 13 geoplanin specimens recently collected in Colombia. Two of the described species are new to science (Amaga vesiculosa sp. nov. and Amaga aglandulosa sp. nov.), and Bogga bogotensis is redescribed from newly collected material. Complementary description of Amaga becki is also given from photomicrographs of the type material. The molecular phylogenetic relationships showed that the two new species are monophyletic, while the genus Amaga is merophyletic because it includes Bogga. The morphological reinterpretation of Bogga bogotensis and molecular phylogenies support the view that this species is a member of Amaga. Accordingly, Amaga is rediagnosed and Bogga is considered its junior synonym. [ABSTRACT FROM AUTHOR]

Soil carbon dioxide (CO2) fluxes are a critical component in understanding carbon sequestration. In sub-Saharan Africa, empirically measured CO2 emissions data from diverse land-use systems is limited. Soil CO2 emission rates were measured in the Limpopo Province, South Africa for 12 months at two-week intervals in natural systems (forest and shrubland) and commercially managed orchards (avocado and citrus) to establish seasonal dynamics of soil CO2 emissions across these land-use systems. The results showed a variation in emission rates with the variation depending on the season. In the spring and winter, soil CO2 emission rates in citrus were four times higher than in the shrubland due to higher moisture levels. However, in the summer season, the forest emission rates were 40% higher than in citrus due to higher soil organic carbon content. Organic carbon stocks were higher in the forest (1.19 kg/m2) compared to the other land uses. This study revealed differences in soil CO2 emission rates among land-use systems, with the cumulative amount of CO2 emitted over a 12-month period following the order: forest (39.3 tons/ha) > citrus (36.1 tons/ha) > shrubland (28.1 tons/ha) > avocado (26.9 tons/ha). Thus, understanding the emission patterns from various ecosystems can inform strategies for mitigating greenhouse gas emissions. [ABSTRACT FROM AUTHOR]

Soil microbial biomass carbon (MBC) plays an essential role in driving and regulating global cycling of carbon (C) which is critically important to climate system. However, the pivotal transect-scale determinant factor for the content of soil MBC, along with the variation pattern in different natural forests and soils has not been sufficiently investigated. In this study, 252 soils samples (6 replicates and 3 depths for each site) were sampled from 14 forests which lie in 7 soil types along the 4000 km North-South transect of Eastern China. We found that the highest content of soil MBC in the whole soil profile with 556.69 ± 14.59 mg C kg− 1 occurred in the subalpine coniferous forest, and the lowest content was observed with 53.11 ± 10.22 mg C kg− 1 in warm coniferous forest. From the angle of soil type, in the whole soil profile Haplic Andosol had the highest content of soil MBC with 480 mg C kg− 1, while Haplic ferralsol possessed the lowest content of MBC with 102 mg C kg− 1. In addition, over the North-South transect of Eastern China the strongest correlation was observed in between the content of soil MBC and altitude (ALT) (R2 = 0.64), followed by soil type (R2 = -0.61), mean annual temperature (MAT) (R2 = -0.56). We concluded that the content of soil MBC in natural forests is mainly controlled by ALT on a transect scale. We believed that the soil C in Yue spruce-fir forest was relatively stable, which can be an option to be a specific forest to optimize forest management and to contribute to mitigating climate change. [ABSTRACT FROM AUTHOR]

Communication is fundamental in the animal kingdom, essential to interactions such as mating, defense, and parental care. Vibrational communication has often been overlooked in the past, but in recent decades, it has become clear that insects use substrate vibrations as a communication signal. In burying beetles of the genus Nicrophorus, which are known for their biparental brood care, both parents stridulate. Spending a considerable period of their lives underground, it is very likely the beetles utilize vibrations as part of their communication system. As playback experiments are challenging with this species, this study looked at the physical propagation of the signal of Nicrophorus vespilloides Herbst (Coleoptera: Siliphidae) through three soil types, as well as behavior, to see whether vibrational communication is possible. The aims were to determine: (1) whether the soils used in the laboratory compare to soil from the field, (2) whether the distance of propagation is enough for the range the beetles cover during brood care, (3) whether the two sexes show a difference in stridulation likelihood, (4) whether propagation of defensive signals differs from brood care signals, and (5) whether we can determine a behavior during stridulations that shows a clear and useable reaction to the signal. We manipulated beetles to induce stridulation and then used laser Doppler vibrometers to record the signals using three substrates and various distances, alongside behavioral observations. We showed that the three substrates tested, peat, coconut coir, and forest soil, displayed differences in terms of vibrational propagation, and that burying beetle stridulation signals can be transmitted up to about 25 cm in the soil. We also showed that the location where the animals stridulate exerts a significant influence on the total duration and number of stridulations. Overall, vibrational communication is in principle conceivable in this species, as the signals are transmitted far enough in the natural substrate to allow complex communication, opening possibilities for vibrational communication during this biparental brood care. [ABSTRACT FROM AUTHOR]

A century of beech bark disease (BBD) in North America has transformed hardwood forests by reducing the canopy biomass of American beech (Fagus grandifolia), even as beech has come to dominate the sapling layer of many forests. We do not understand the extent to which environmental change drivers such as climate, acidic atmospheric deposition (and its legacy of acidified soils), and invasive disease (BBD) may have contributed to this transformation. We investigated how BBD effects and tree community composition varied along a well-documented soil acidity gradient in the northeastern United States. We surveyed overstory and sapling layer tree species composition, BBD effects, and soil chemistry on 30 watersheds in forests co-dominated by beech and sugar maple (Acer saccharum). We analyzed potential drivers of community composition, BBD, and beech sapling density using linear models and non-metric multidimensional scaling. Predictors accounted for soil chemistry, climate, overstory beech (importance value, IV), mortality, and BBD defect. Overall overstory species composition varied most along the acidity gradient, while beech and BBD severity varied along their own distinct environmental gradient. Species composition of the overstory and sapling layers diverged significantly, with the latter dominated by beech. Beech sapling density was positively related to the proportion of standing dead overstory beech and soil exchangeable aluminum, but was unrelated to the overall proportion of overstory beech or their BBD severity. The dominance of sapling layers by beech may have resulted from a gradual accumulation of canopy-opening events precipitated by BBD and sugar maple decline, the latter driven by stressors such as acidification and climate change. [ABSTRACT FROM AUTHOR]