The pollution of metal ions triggers great risks of damaging biodiversity and biodiversity-driven ecosystem multifunctioning, whether microbial functional gene can mirror ecosystem multifunctionality in nonferrous metal mining areas remains largely unknown. Macrogenome sequencing and statistical tools are used to decipher linkage between functional genes and ecosystem multifunctioning. Soil samples were collected from subdams in a copper tailings area at various stages of restoration. The results indicated that the diversity and composition of soil bacterial communities were more sensitive than those of the fungal and archaeal communities during the restoration process. The mean method revealed that nutrient, heavy metal, and soil carbon, nitrogen, and phosphorus multifunctionality decreased with increasing bacterial community richness, whereas highly significant positive correlations were detected between the species richness of the bacterial, fungal, and archaeal communities and the multifunctionality of the carbon, nitrogen, and phosphorus functional genes and of functional genes for metal resistance in the microbial communities. SEM revealed that soil SWC and pH were ecological factors that directly influenced abiotic factor-related EMF; microbial diversity was a major biotic factor influencing the functional gene multifunctionality of the microbiota; and different abiotic and biotic factors associated with EMF had differential effects on whole ecosystem multifunctionality. These findings will

Climate change has exposed desert ecosystems to frequent extreme disturbances, including wet-dry cycles and freeze-thaw events, which accelerate desertification on a global scale. The limited nutrient availability characteristic of these ecosystems may constrain microbial survival and growth, making them more vulnerable to environmental perturbations and stressors. However, how nutrient availability modulates the stability of soil ecological communities and functions in desert ecosystems remains poorly understood. In this study, we examined how nutrient addition, applied either before or after disturbances, affects the resistance of bacterial communities and multifunctionality to drought and freeze events in desert ecosystems. Our findings revealed that freeze-thaw events, rather than drought, significantly reduced bacterial diversity, with all disturbances altering the community structure. Pre-disturbance nutrient addition notably improved the resistance of soil bacterial diversity and community composition to disturbances, which played a critical role in maintaining multifunctionality in desert ecosystems. This enhanced bacterial resistance was strongly associated with increased bacterial network complexity and the enrichment of disturbance-tolerant taxa. Our results highlight the pivotal role of nutrient availability in stabilising soil bacterial communities and multifunctionality under extreme climatic conditions in desert ecosystems. These findings offer valuable insights and practical strategies for the ecological protection and management of desertification.

Overgrazing is the primary human-induced cause of soil degradation in the Caatinga biome, intensely threatening lands vulnerable to desertification. Grazing exclusion, a simple and cost-effective practice, could restore soils' ecological functions. However, comprehensive insights into the effects of overgrazing and grazing exclusion on Caatinga soils' multifunctionality are lacking. This study examines (i) how overgrazing impacts multiple soil indicators, functions, and overall soil health (SH) and (ii) whether natural early forest growth post-grazing exclusion enhances critical soil functions for ecosystem restoration. We compared preserved dense forests, longterm overgrazed pastures (over 30 years), and young fenced-off open forests (three years old) along a longitudinal transect in the Caatinga biome: 36 degrees W (Sao Bento do Una), 37 degrees W (Sertania), and 40 degrees W (Araripina). Soil samples from the 0-20 cm layer were analyzed for thirteen physical, chemical, and biological indicators for a structured SH assessment, calculating index scores based on soil functions. Forest-to-pasture transition and subsequent overgrazing consistently compacted the soils and decreased nitrogen, carbon (C), microbial biomass C, and glomalin protein, thus degrading the soil's physical, chemical, and biological functions. Regionally, this conversion depleted 14.7 Mg C ha(-1) and reduced overall SH scores by 18%, severely impacting biological functions ( e.g.,-43% for sustaining biological activity). No significant differences in functions or SH were found between grazed pastures and open forests. SH scores and C stocks were highly interrelated (r > 0.5; p < 0.001), suggesting that C losses and SH deterioration were closely aligned. We conclude that overgrazing degrades soil multifunctionality and health across the Caatinga biome, with biological functions most severely damaged and legacies obstructing soil recovery for up to three years of grazing exclusion. Future SH studies should include open forest chronosequences with older ages and active restoration practices ( e.g., planting trees or green manure) to enhance Caatinga's ecological restoration knowledge and efforts.

Ecosystem multifunctionality means that the ecosystem has the ability to provide multiple functions simultaneously. The study of the ecosystem multifunctionality provides an important basis for the understanding of the ecosystem function and management. Despite the plant community restoration is an important driver of changes in biodiversity and ecosystem multifunctionality, we still little know about the scaling effects the relationship between different dimensions of biodiversity and ecosystem multifunctionality. In this study, we investigated the relative contributions of different dimensions of plant diversity (e.g., species diversity, functional diversity and phylogenetic diversity) changes in ecosystem multifunctionality under different restoration stages (10, 30 and 40 years) in a human-damaged Liaodong oak (Quercus wutaishanica) plant communities in northern China. The results found that (1) ecosystem multifunctionality index was significantly higher in the middle (30 years) and late (40 years) stages of restoration than the early stage (10 years) of restoration. (2) Species richness and phylogenetic diversity were significantly higher in the early stage (10 years) of restoration than in the middle (30 years) and late (40 years) stages of restoration, however, functional dispersion was significantly higher in the later stages (40 years) of restoration than in the early (10 years) and middle stages (30 years) of restoration. (3) Ecosystem multifunctionality is primarily driven by photosynthetic traits of dominant species. The results of this study deepen the under-standing of the relationship between plant diversity and ecosystem multifunctionality in the forests of northern

Introduction: Fusarium-induced root rot of Carya cathayensis (C. cathayensis) is a typical soil-borne disease that has severely damaged the Carya cathayensis industry in China. Understanding the interaction among soil microbial communities, soil characteristics, and pathogenic bacteria is very important for the ecological prevention and control of Carya cathayensis root rot. Methods: We used Miseq Illumina high-throughput sequencing technology to study the microbial community in the rhizosphere soil of healthy and diseased C. cathayensis, quantified the abundance of bacteria, fungi, and pathogenic fungi, and combined these with soil chemistry and enzyme activity indicators to analyze the characteristics of healthy and diseased rhizosphere soils. Results: We found that the pH, soil organic carbon(SOC), available nitrogen (AN), available phosphorus (AP), available potassium (AK),N-acetyl-beta-D-glucosaminidase (NAG) beta-glucosidase (BG), fungal gene copy number, bacterial community diversity and network complexity of the diseased soil were significantly lower (p < 0.05), while Fusarium graminearum copies number levels increased (p < 0.05). Additionally, the study found that healthy soils were enriched with beneficial bacteria such as Subgroup_7 (0.08%), MND1 (0.29%), SWB02 (0.08%), and Bradyrhizobium (0.09%), as well as potential pathogen-suppressing fungi such as Mortierella (0.13%), Preussia (0.03%), and Humicol (0.37%), were found to be associated with the growth and development of C. cathayensis. Discussion: In summary, this research comprehensively reveals the differences in environmental and biological factors between healthy and diseased soils, as well as their correlations. It provides a theoretical basis for optimal soil environmental regulation and the construction of healthy microbial communities. This foundation facilitates the development of multifaceted strategies for the prevention and control of C. cathayensis root rot.

Semi-natural grasslands and their diverse biota are threatened by changes in land-use like afforestation, abandonment of traditional practices, urban development or conversion into intensive agricultural land. Extensive loss and fragmentation of semi-natural grasslands consequently affects ecosystem functioning inherit to open landscapes and the sustainable provision of ecosystem services. Ecological restoration of grasslands has potential to halt further decline and hopefully reverse some of the damage done to the grasslands and vital ecosystem services they provide. By assessing grasslands before and after the restoration, we evaluated how restoring overgrown and forested semi-natural grasslands to open grasslands impacts nine ecosystem services: habitat maintenance, soil condition maintenance, soil carbon storage, pollination, pest regulation, provision of wild food and medicinal herbs, forage production, wood production and recreation. We also analyzed the relationship between ecosystem multifunctionality and species richness of multiple organism groups. We found that already few years after restoration, restored grasslands exhibited rapidly increasing biodiversity and ecosystem service provision. Similarly, the overall ecosystem multifunctionality increased significantly after restoration in previously overgrown and afforested grasslands. However, while a robust and strong positive relationship between multitrophic diversity and ecosystem multifunctionality existed before restoration, this relationship was somewhat weakened after restoration. We propose two potential explanations: first, the previously distinct condition classes became more similar, starting to resemble open grassland habitats in their species richness and composition. Second, the relationship may have been weakened by the temporarily disrupted and transitional nature of the ecosystem post-restoration, due to varying recovery rates among different species groups and ecosystem services. Notably, soil-related services (carbon storage and soil maintenance) take longer to respond to restoration, compared to other services. In addition, we detected significant negative impact of prolonged drought on pest regulation and forage production service in both restored and unrestored areas. Semi-natural grasslands are both biodiversity and ecosystem service hotspots in European landscapes and restoring these habitats significantly increases the provision potential of important ecosystem services. However, restoration planning must consider landscape history, regional characteristics and the importance of long-term monitoring for getting the most accurate results.

We explored the activation of defense genes and the changes in volatile profiles in olive (Olea europaea var. Picual) plants subjected to mechanical wounding and prior soil inoculation with the fungus Trichoderma afroharzianum T22. Our findings indicate a sustained effect of the inoculant in olive plants, which shifted the constitutive volatile emission more significantly towards an aldehyde-dominated blend than the mechanical damage alone. Furthermore, we found that wounding alone did not alter the expression of hydroperoxide lyase genes associated with aldehyde biosynthesis. However, this expression was significantly enhanced when combined with prior T22 inoculation. Mechanical wounding amplified the plant's immediate defensive response by enhancing the upregulation of the direct defense enzyme acetone cyanohydrin lyase. Trichoderma afroharzianum T22 also modulated direct defense, although to a lesser extent, and its effect persisted 9 months after inoculation. Metagenomic analyses revealed that aerial mechanical damage did influence specific root bacterial functions. Specifically, an upregulation of predicted bacterial functions related to various metabolic processes, including responses to biotic and abiotic stresses, was observed. On the contrary, T22's impact on bacterial functional traits was minor and/or transient.

BackgroundGlobal warming is affecting all cold environments, including the European Alps and Arctic regions. Here, permafrost may be considered a unique ecosystem harboring a distinct microbiome. The frequent freeze-thaw cycles occurring in permafrost-affected soils, and mainly in the seasonally active top layers, modify microbial communities and consequently ecosystem processes. Although taxonomic responses of the microbiomes in permafrost-affected soils have been widely documented, studies about how the microbial genetic potential, especially pathways involved in C and N cycling, changes between active-layer soils and permafrost soils are rare. Here, we used shotgun metagenomics to analyze the microbial and functional diversity and the metabolic potential of permafrost-affected soil collected from an alpine site (Val Lavirun, Engadin area, Switzerland) and a High Arctic site (Station Nord, Villum Research Station, Greenland). The main goal was to discover the key genes abundant in the active-layer and permafrost soils, with the purpose to highlight the potential role of the functional genes found.ResultsWe observed differences between the alpine and High Arctic sites in alpha- and beta-diversity, and in EggNOG, CAZy, and NCyc datasets. In the High Arctic site, the metagenome in permafrost soil had an overrepresentation (relative to that in active-layer soil) of genes involved in lipid transport by fatty acid desaturate and ABC transporters, i.e. genes that are useful in preventing microorganisms from freezing by increasing membrane fluidity, and genes involved in cell defense mechanisms. The majority of CAZy and NCyc genes were overrepresented in permafrost soils relative to active-layer soils in both localities, with genes involved in the degradation of carbon substrates and in the degradation of N compounds indicating high microbial activity in permafrost in response to climate warming.ConclusionsOur study on the functional characteristics of permafrost microbiomes underlines the remarkably high functional gene diversity of the High Arctic and temperate mountain permafrost, including a broad range of C- and N-cycling genes, and multiple survival and energetic metabolisms. Their metabolic versatility in using organic materials from ancient soils undergoing microbial degradation determine organic matter decomposition and greenhouse gas emissions upon permafrost thawing. Attention to their functional genes is therefore essential to predict potential soil-climate feedbacks to the future warmer climate.

Global climate change has altered soil freeze-thaw (FT) patterns but less is known about the responses of soil microbial diversity, soil multifunctionality, and their relationship to FT events. Daxing'an Mountains in China, located in high-latitude permafrost ecosystems, are one of the most sensitive areas to climate change and FT patterns. Here, simulated FT conditions were used to determine the impact of FT events on soil microbial diversity and multifunctionality as well as to elucidate the relationships between bacterial and fungal diversity and multifunctionality. Community composition, alpha-diversity index, and co-occurrence network complexity of fungi significantly changed during FT events, whereas the same parameters did not exhibit significant alterations for bacteria. Soil fungal communities were more sensitive to FT events than soil bacterial communities. FT events significantly affected soil multifunctionality. A random forest analysis showed that the fungal diversity index was the main predictor of soil multifunctionality. Moreover, changes in soil abiotic factors also affected the relationship between soil microbial diversity and multifunctionality. Soil multifunctionality was also constrained by fungal community network complexity. Structural equation model showed that the FT amplitude and FT cycles exerted different impact paths on soil multifunctionality. The effect of FT cycles on soil multifunctionality (0.289) was greater than that of FT amplitude (0.080). As global climate change is expected to accelerate in the future, extension of the FT period in high-altitude and high-latitude regions may have a severe impact on soil function compared to extreme low temperatures caused by the presence of thin snow cover.