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Microbial communities play a crucial role in ocean ecology and global biogeochemical processes. However, understanding the intricate interactions among diversity, taxonomical composition, functional traits, and how these factors respond to climate change remains a significant challenge. Here, we propose seven distinct ecological statuses by systematically considering the diversity, structure, and biogeochemical potential of the ocean microbiome to delineate their biogeography. Anthropogenic climate change is expected to alter the ecological status of the surface ocean by influencing environmental conditions, particularly nutrient and oxygen contents. Our predictive model, which utilizes machine learning, indicates that the ecological status of approximately 32.44% of the surface ocean may undergo changes from the present to the end of this century, assuming no policy interventions. These changes mainly include poleward shifts in the main taxa, increases in photosynthetic carbon fixation and decreases in nutrient metabolism. However, this proportion can decrease significantly with effective control of greenhouse gas emissions. Our study underscores the urgent necessity for implementing policies to mitigate climate change, particularly from an ecological perspective. Zhang et al. propose the ecological status of the ocean by considering microbial diversity, structure, and biogeochemical potential. Ecological status of 32.44% surface ocean will change due to climate change in 2100, assuming no policy intervention. [ABSTRACT FROM AUTHOR]

Inorganic fertilizers are widely used to provide crops with significant amounts of nitrogen (N) and phosphorus (P), but can exacerbate soil carbon (C) limitation and acidification. Crop residues with distinct ecological stoichiometry from inorganic fertilizers can help balance soil ecological stoichiometry and thus increase soil organic matter accumulation. The combined use of inorganic fertilizers and crop residues is expected to alleviate the metabolic limitations of organisms and enhance soil C, N, and P sequestration, hence increasing grain yields. However, the effects of this practice on soil C, N, and P stocks and grain yield remain unclear. In this study, we conducted a meta-analysis of 806 paired data to investigate the impact of crop residue return combined with inorganic fertilizer on soil and grain yield across different land uses (paddy, upland, paddy-upland rotation) and soil profiles (0–60 cm). Our findings indicate that crop residue return significantly enhances soil C (8–13%) stocks across all soil layers, particularly in the topsoil (0–20 cm). Soil N (9%) and P (5%) stocks also increase significantly in the topsoil. In uplands, crop residue return can mitigate soil acidification and increase grain yield (by 7%). Moreover, the soil C and N stocks increase depending on the initial soil pH, C and N levels, and C:N ratio. In contrast, the soil P stock increase depends on rainfall, while the grain yield increase is closely linked to the soil texture and fertilizer rate. Our study highlights that crop residue return can increase topsoil C, N, and P stocks, which can benefit crop growth and environmental mitigation efforts. Furthermore, this practice can increase C stocks in deeper soil horizons (below 20 cm), providing a long-term solution to mitigate climate change. [ABSTRACT FROM AUTHOR]

Aims: Broad-leaved tree species are important group building tree species of typical zonal vegetation in subtropical China. Yet, the impacts of mixed broad-leaved plantations on microbial community and enzymatic stoichiometry are not well understood. Methods: We evaluated soil microbial community structure and enzymatic stoichiometry using rhizosphere and non-rhizosphere soil samples of Machilus pauhoi from three forest plantation (pure M. pauhoi forest (CK), M. pauhoi with Cerasus campanulata mixed forest (MC), M. pauhoi with Manglietia glauca mixed forest (MM)) in subtropical China. Results: P concentration of rhizosphere soil in MC was higher than that in CK, and soil TC, TN, SOC, DOC of non-rhizosphere soil in MC were higher than those in MM. Different mixed plantations had significant effects on G+/G−, being its value lower in MC than in CK and MM. The microbial P limitation in rhizosphere soil was higher than that in non-rhizosphere soil. The relative microbial C limitation did not change significantly amongst different treatment. Soil TC, TN, SOC and DOC are critical factors affecting the microbial community structure. Conclusion: Mixing with Cerasus campanulata is more beneficial to reducing soil P deficiency and improving soil microbial community structure of young M. pauhoi afforestation in a mid-subtropical region of China. [ABSTRACT FROM AUTHOR]

Accurate and high-resolution crop yield and crop water productivity (CWP) datasets are required to understand and predict spatiotemporal variation in agricultural production capacity; however, datasets for maize and wheat, two key staple dryland crops in China, are currently lacking. In this study, we generated and evaluated a long-term data series, at 1-km resolution of crop yield and CWP for maize and wheat across China, based on the multiple remotely sensed indicators and random forest algorithm. Results showed that MOD16 products are an accurate alternative to eddy covariance flux tower data to describe crop evapotranspiration (maize and wheat RMSE: 4.42 and 3.81 mm/8d, respectively) and the proposed yield estimation model showed accuracy at local (maize and wheat rRMSE: 26.81 and 21.80%, respectively) and regional (maize and wheat rRMSE: 15.36 and 17.17%, respectively) scales. Our analyses, which showed spatiotemporal patterns of maize and wheat yields and CWP across China, can be used to optimize agricultural production strategies in the context of maintaining food security. Measurement(s) crop yield and crop water productivity Technology Type(s) remote sensing and machine learning [ABSTRACT FROM AUTHOR]

Antibiotic resistance genes (ARGs) have accelerated microbial threats to human health in the last decade. Many genes can confer resistance, but evaluating the relative health risks of ARGs is complex. Factors such as the abundance, propensity for lateral transmission and ability of ARGs to be expressed in pathogens are all important. Here, an analysis at the metagenomic level from various habitats (6 types of habitats, 4572 samples) detects 2561 ARGs that collectively conferred resistance to 24 classes of antibiotics. We quantitatively evaluate the health risk to humans, defined as the risk that ARGs will confound the clinical treatment for pathogens, of these 2561 ARGs by integrating human accessibility, mobility, pathogenicity and clinical availability. Our results demonstrate that 23.78% of the ARGs pose a health risk, especially those which confer multidrug resistance. We also calculate the antibiotic resistance risks of all samples in four main habitats, and with machine learning, successfully map the antibiotic resistance threats in global marine habitats with over 75% accuracy. Our novel method for quantitatively surveilling the health risk of ARGs will help to manage one of the most important threats to human and animal health. Antibiotic resistance genes (ARGs) have accelerated microbial threats to human health. Here, Zhang et al. analyze 4572 metagenomic samples to illustrate the global patterns of ARG distribution in diverse habitats. They quantitatively evaluate the health risk to humans of 2561 ARGs by integrating human accessibility, mobility, pathogenicity and clinical availability. With the machine learning, they map the antibiotic resistance threats in global marine habitats. [ABSTRACT FROM AUTHOR]

The emergence and spread of antibiotic resistance in aquatic environment such as rivers, lakes, and sewage have accelerated microbial threats to human health by promoting the growth of specific waterborne pathogens and transferring them from the ecosystems to humans. Identifying the unexpected drivers of and bottlenecks for human risk assessment of waterborne antibiotic resistance are crucial in understanding and managing the global ARGs transfer. We showed our current understanding of the factors, residual pollutants, bacteriophages, bacterial communities, and the unexpected players’ protists in driving emergence and transfer of waterborne antibiotic resistance. Heterotrophic protists mainly induce waterborne antibiotic resistance because they can accelerate the transfer of ARGs between bacteria and provide optimal environments for antibiotic-resistant pathogens. Current research, however, still cannot provide a comprehensive understanding of the molecular mechanisms of the impacts of protists on waterborne antibiotic resistance. We have, therefore, summarized the key information that is currently missing and discussed the assessment of resistance risk on human health and finally provided some management strategies. [ABSTRACT FROM AUTHOR]

Traits are the primary attributes that distinguish a species niche. Species and higher taxa are part of a structured phylogeny, and variation in plant traits depends on lineage as well as on environmental conditions. Therefore, it is crucial to investigate linkages between taxonomic identity, shared ancestry, and environment for understanding the variation in leaf traits. We investigated the evolutionary relationships, based on multiple gene sequences among 26 plant species sampled along an elevational gradient from 650 to 3600 m a.s.l. in the central Himalaya. We tested for the phylogenetic signal based on three different measures in 10 leaf traits having a significant association with the resource acquisition-conservation trade-offs axis and influencing plant growth, development, and ecological performance. We further assessed the role of elevation and growth forms as the potential drivers of leaf traits variation while controlling for phylogeny. 5 out of 10 leaf traits showed significant phylogenetic signal. Plant species clustered more often by growth forms at the tips of the phylogeny indicating multiple instances of independent evolution. Evergreen taxa showed niche separation with deciduous and incorporated larger trait variation. Trait variations were guided by both growth forms and elevation when accounted for phylogeny. Growth form has a higher contribution to trait variation compared to elevation. Trade-offs were detected between resource conservation and resource acquisition machinery traits (that would maximise carbon gain), differing between growth forms and along elevation. [ABSTRACT FROM AUTHOR]

A model that can assess the structure and functionality of the soil/plant/atmosphere (SPA) continuum along spatial and temporal gradients using specific and measurable variables remains a key objective and challenge in ecological research of terrestrial ecosystems. We analyze the model proposed in this issue by Silva and Lambers (2020) that tries to meet this challenge and further propose complementary points of view to base the model on easy straightforward measurable variables incorporating new recent holistic views of terrestrial ecosystems. Silva and Lambers (2020) explain how symbiotic and competitive strategies involving plants and soil microorganisms through the ecological succession influence scale-free patterns of carbon, nutrient, and water use from individual organisms to landscapes. The algorithms in their model use measurable variables such as specific leaf area (SLA), leaf area index (LAI), stomatal conductance (g), photosynthetic rate (A), gross primary production (GPP), or net primary production (NPP). Other variables, such as the rates of resource depletion or uptake and the level of resources needed to ensure survival, however, are very difficult to determine in the field, impeding the use of these algorithms in some cases. SPA models should thus consider being complemented and reinforced by new emerging holistic approaches and avoid the use of variables that are difficult to measure as much as possible. Integrative approaches such as the biogeochemical niche theory and global C balance, including measurable variables such as bio-elemental composition of soils, microbes and plants should thus be considered. [ABSTRACT FROM AUTHOR]

Cyanobacterial blooms are a global ecological problem that directly threatens human health and crop safety. Cyanobacteria have toxic effects on aquatic microorganisms, which could drive the selection for resistance genes. The effect of cyanobacterial blooms on the dispersal and abundance of antibiotic-resistance genes (ARGs) of concern to human health remains poorly known. We herein investigated the effect of cyanobacterial blooms on ARG composition in Lake Taihu, China. The numbers and relative abundances of total ARGs increased obviously during a Planktothrix bloom. More pathogenic microorganisms were present during this bloom than during a Planktothrix bloom or during the non-bloom period. Microcosmic experiments using additional aquatic ecosystems (an urban river and Lake West) found that a coculture of Microcystis aeruginosa and Planktothrix agardhii increased the richness of the bacterial community, because its phycosphere provided a richer microniche for bacterial colonization and growth. Antibiotic-resistance bacteria were naturally in a rich position, successfully increasing the momentum for the emergence and spread of ARGs. These results demonstrate that cyanobacterial blooms are a crucial driver of ARG diffusion and enrichment in freshwater, thus providing a reference for the ecology and evolution of ARGs and ARBs and for better assessing and managing water quality. Qi Zhang, Zhenyan Zhang et al. show that the numbers and relative abundance of antibiotics-resistance genes increase during a cyanobacterial bloom in Lake Taihu of China. This correlation provides insights to the ecologists and the policy makers who manage the quality of fresh water. [ABSTRACT FROM AUTHOR]

The drivers of global change, including increases in atmospheric CO2 concentrations, N and S deposition, and climate change, likely affect the nutritional status of forests. Here we show forest foliar concentrations of N, P, K, S and Mg decreased significantly in Europe by 5%, 11%, 8%, 6% and 7%, respectively during the last three decades. The decrease in nutritional status was especially large in Mediterranean and temperate forests. Increasing atmospheric CO2 concentration was well correlated with the decreases in N, P, K, Mg, S concentrations and the increase of N:P ratio. Regional analyses indicated that increases in some foliar nutrient concentrations such as N, S and Ca in northern Europe occurred associated with increasingly favourable conditions of mean annual precipitation and temperature. Crucial changes in forest health, structure, functioning and services, including negative feedbacks on C capture can be expected if these trends are not reversed. Penuelas et al analyse foliar concentrations of nutrients in the main tree species of European forests using data collected over 30 years, together with changes in atmospheric CO2 levels, N and S deposition and climate. They find that foliar concentrations of N, P, K, S and Mg have decreased in central and southern Europe, with implications for forest ecosystems. [ABSTRACT FROM AUTHOR]

Land use policies have turned southern China into one of the most intensively managed forest regions in the world, with actions maximizing forest cover on soils with marginal agricultural potential while concurrently increasing livelihoods and mitigating climate change. Based on satellite observations, here we show that diverse land use changes in southern China have increased standing aboveground carbon stocks by 0.11 ± 0.05 Pg C y−1 during 2002–2017. Most of this regional carbon sink was contributed by newly established forests (32%), while forests already existing contributed 24%. Forest growth in harvested forest areas contributed 16% and non-forest areas contributed 28% to the carbon sink, while timber harvest was tripled. Soil moisture declined significantly in 8% of the area. We demonstrate that land management in southern China has been removing an amount of carbon equivalent to 33% of regional fossil CO2 emissions during the last 6 years, but forest growth saturation, land competition for food production and soil-water depletion challenge the longevity of this carbon sink service. Forest management may play an important role in climate change mitigation. Here, Tong et al. combine remote sensing and machine learning modelling to map forest cover dynamics in southern China during 2002–2017, showing effects on carbon sequestration that are extensive but of uncertain longevity and possible negative impact on soil water. [ABSTRACT FROM AUTHOR]

Describes possible approaches to modifying gap models to account for climate-change variables. Growth and allocation in models with aggregated growth functions; Incorporation of climatic-change factors into gap models; Application of gap models to climatic-change studies.

In the original publication of the article, under the discussion section, the following sentence "taxa to accumulate a larger fraction of leaf dry mass before the arrival of the rainy season (LmRS)." was separated from the previous sentence and published as two paragraphs. [ABSTRACT FROM AUTHOR]

Tropical savannas comprise mixed woodland grassland ecosystems in which trees and grasses compete for water resources thereby maintaining the spatial structuring of this ecosystem. A global change in rainfall climatology may impact the structure of tropical savanna ecosystems by favouring woody plants, relative to herbaceous vegetation. Here we analysed satellite data and observed a relatively higher increase in woody vegetation (5%) as compared to the increase in annual maximum leaf area index (LAImax, an indicator of the total green vegetation production) (3%) in arid and semi-arid savannas over recent decades. We further observed a declining sensitivity of LAImax to annual rainfall over 56% of the tropical savannas, spatially overlapping with areas of increased woody cover and altered rainfall climatology. This suggests a climate-induced shift in the coexistence of woody and herbaceous vegetation in savanna ecosystems, possibly caused by altered hydrological conditions with significance for land cover and associated biophysical effects such as surface albedo and evapotranspiration. Changing rainfall patterns may drive changes in the structure of tropical savanna. Here Zhang et al. use satellite data from global tropical savannas, and find evidence to suggest that altered rainfall may be favouring woody plants over herbaceous plants in these ecosystems. [ABSTRACT FROM AUTHOR]

Plant functional traits directly affect ecosystem functions. At the species level, trait combinations depend on trade-offs representing different ecological strategies, but at the community level trait combinations are expected to be decoupled from these trade-offs because different strategies can facilitate co-existence within communities. A key question is to what extent community-level trait composition is globally filtered and how well it is related to global versus local environmental drivers. Here, we perform a global, plot-level analysis of trait-environment relationships, using a database with more than 1.1 million vegetation plots and 26,632 plant species with trait information. Although we found a strong filtering of 17 functional traits, similar climate and soil conditions support communities differing greatly in mean trait values. The two main community trait axes that capture half of the global trait variation (plant stature and resource acquisitiveness) reflect the trade-offs at the species level but are weakly associated with climate and soil conditions at the global scale. Similarly, within-plot trait variation does not vary systematically with macro-environment. Our results indicate that, at fine spatial grain, macro-environmental drivers are much less important for functional trait composition than has been assumed from floristic analyses restricted to co-occurrence in large grid cells. Instead, trait combinations seem to be predominantly filtered by local-scale factors such as disturbance, fine-scale soil conditions, niche partitioning and biotic interactions.