Spatial-temporal variations and driving factors of soil organic carbon in forest ecosystems of Northeast China

Forest soil carbon is a major carbon pool of terrestrial ecosystems,and accurate estimation of soil organic carbon(SOC)stocks in forest ecosystems is rather challenging.This study compared the prediction performance of three empirical model approaches namely,regression kriging(RK),multiple stepwise regression(MSR),random forest(RF),and boosted regression trees(BRT)to predict SOC stocks in Northeast China for 1990 and 2015.Furthermore,the spatial variation of SOC stocks and the main controlling environmental factors during the past 25 years were identified.A total of 82(in 1990)and 157(in 2015)topsoil(0–20 cm)samples with 12 environmental factors(soil property,climate,topography and biology)were selected for model construction.Randomly selected80%of the soil sample data were used to train the models and the other 20%data for model verification using mean absolute error,root mean square error,coefficient of determination and Lin's consistency correlation coefficient indices.We found BRT model as the best prediction model and it could explain 67%and 60%spatial variation of SOC stocks,in 1990,and 2015,respectively.Predicted maps of all models in both periods showed similar spatial distribution characteristics,with the lower SOC in northeast and higher SOC in southwest.Mean annual temperature and elevation were the key environmental factors influencing the spatial variation of SOC stock in both periods.SOC stocks were mainly stored under Cambosols,Gleyosols and Isohumosols,accounting for 95.6%(1990)and 95.9%(2015).Overall,SOC stocks increased by 471 Tg C during the past 25 years.Our study found that the BRT model employing common environmental factors was the most robust method for forest topsoil SOC stocks inventories.The spatial resolution of BRT model enabled us to pinpoint in which areas of Northeast China that new forest tree planting would be most effective for enhancing forest C stocks.Overall,our approach is likely to be useful in forestry management and ecological restoration at and beyond the regional scale.

QTL analysis for ascorbic acid content in strawberry fruit reveals a complex genetic architecture and association with GDP-L-galactose phosphorylase

Strawberry(Fragaria×ananassa)fruits are an excellent source of L-ascorbic acid(AsA),a powerful antioxidant for plants and humans.Identifying the genetic components underlying AsA accumulation is crucial for enhancing strawberry nutritional quality.Here,we unravel the genetic architecture of AsA accumulation using an F1 population derived from parental lines‘Candonga’and‘Senga Sengana’,adapted to distinct Southern and Northern European areas.To account for environmental effects,the F1 and parental lines were grown and phenotyped in five locations across Europe(France,Germany,Italy,Poland and Spain).Fruit AsA content displayed normal distribution typical of quantitative traits and ranged five-fold,with significant differences among genotypes and environments.AsA content in each country and the average in all of them was used in combination with 6,974 markers for quantitative trait locus(QTL)analysis.Environmentally stable QTLs for AsA content were detected in linkage group(LG)3A,LG 5A,LG 5B,LG 6B and LG 7C.Candidate genes were identified within stable QTL intervals and expression analysis in lines with contrasting AsA content suggested that GDP-L-Galactose Phosphorylase FaGGP(3A),and the chloroplast-located AsA transporter gene FaPHT4;4(7C)might be the underlying genetic factors for QTLs on LG 3A and 7C,respectively.We show that recessive alleles of FaGGP(3A)inherited from both parental lines increase fruit AsA content.Furthermore,expression of FaGGP(3A)was two-fold higher in lines with high AsA.Markers here identified represent a useful resource for efficient selection of new strawberry cultivars with increased AsA content.

Growth and Photosynthesis Responses of a Super Dwarf Rice Genotype to Shade and Nitrogen Supply

Specific aspects of plant cultivation require tests under fully controlled environmentalconditions with restricted energy supply, such as orbit-based space laboratories and low-light conditions.For these growing conditions, super dwarf plants have been developed as model crops, and a gibberellindeficientSuper Dwarf Rice genotype was proposed as a model crop for space flight plant experiments.We tested this genotype in a climate chamber experiment under different illumination and nitrogen supplylevels to assess its suitability under scenarios with limited resource availability. A 25% reduction inillumination led to a 75% reduction in yield, mainly due to a 60% reduction in formed tillers and 20%reduction in grain weight, and a 80% reduction in illumination caused total yield loss. Leaf area underreduced illumination was significantly lower, and only marginal changes in the dimensions of leaves wereobserved. Plant photosynthesis was not significantly different between control and 75% illumination. Thiswas explained by a higher photochemical efficiency under lower light conditions and a reduced mesophyllresistance. Therefore, we concluded that this genotype is well-suited for plant experiments under spaceand light-limited conditions since it kept its small stature and showed no shade avoidance mechanisms,such as leaf elongation, which would complicate experiments under low-light conditions. Nitrogenconcentrations of 2.8 and 1.4 mmol/L led to no differences in plant growth. We concluded that a nitrogenconcentration of 1.4 mmol/L is sufficient for this genotype under the light intensities.

Localized bursting of mesocarp cells triggers catastrophic fruit cracking

The so-called rain-cracking of sweet cherry fruit severely threatens commercial production.Simple observation tells us that cuticular microcracking(invisible)always precedes skin macrocracking(visible).The objective here was to investigate how a macrocrack develops.Incubating detached sweet cherry fruit in deionized water induces microcracking.Incubating fruit in D2O and concurrent magnetic resonance imaging demonstrates that water penetration occurs only(principally)through the microcracks,with nondetectable amounts penetrating the intact cuticle.Optical coherence tomography of detached,whole fruit incubated in deionized water,allowed generation of virtual cross-sections through the zone of a developing macrocrack.Outer mesocarp cell volume increased before macrocracks developed but increased at a markedly higher rate thereafter.Little change in mesocarp cell volume occurred in a control zone distant from the crack.As water incubation continued,the cell volume in the crack zone decreased,indicating leaking/bursting of individual mesocarp cells.As incubation continued still longer,the crack propagated between cells both to form a long,deep macrocrack.Outer mesocarp cell turgor did not differ significantly before and after incubation between fruit with or without macrocracks;nor between cells within the crack zone and those in a control zone distant from the macrocrack.The cumulative frequency distribution of the logtransformed turgor pressure of a population of outer mesocarp cells reveals all cell turgor data followed a normal distribution.The results demonstrate that microcracks develop into macrocracks following the volume increase of a few outer mesocarp cells and is soon accompanied by cell bursting.

Nitrogen acquisition,fixation and transfer in maize/alfalfa intercrops are increased through root contact and morphological responses to interspecies competition

Nitrogen(N)fixation by legumes and nitrogen transfer to cereals have been considered as important pathways for overyielding and higher N use efficiency in cereal/legume intercropping systems.However,the extent to which root morphology contributes to N fixation and transfer is unclear.A two-factorial greenhouse experiment was conducted to quantify the N fixation,transfer and root morphology characteristics of the maize/alfalfa intercropping system in two consecutive years using the 15N-urea leaf labeling method,and combining two N levels with three root separation techniques.N application could inhibit N fixation and transfer in a maize/alfalfa intercropping system.Irrespective of the N application level,compared with plastic sheet separation(PSS),no separation(NS)and nylon mesh separation(NNS)significantly increased the total biomass(36%)and total N content(28%),while the N fixation rate also sharply increased by 75 to 134%,and the amount of N transferred with no root barrier was 1.24–1.42 times greater than that with a mesh barrier.Redundancy analysis(RDA)showed that the crown root dry weight(CRDW)of maize and lateral root number(LRN)of alfalfa showed the strongest associations with N fixation and transfer.Our results highlight the importance of root contact for the enhancement of N fixation and transfer via changes in root morphology in maize/alfalfa intercropping systems,and the overyielding system was achieved via increases in maize growth,at the cost of smaller decreases in alfalfa biomass production.

Non-peptide ligands in the characterization of peptide receptors at the interface between neuroendocrine and mental diseases

Hypothalamic receptors for neuropeptide Y, melaninconcentrating hormone, melanocortins and orexins/ hypocretins as well as for the downstream signaling corticotrophic factor have been discussed broadly for their influence on food intake and reward but also on several psychiatric disorders. For the development of non-peptide ligands for the in vivo detection of alterations in density and affinity of such G-protein coupled (GPCRs) peptide receptors the requirements to affinity and pharmacokinetics have been shifted to thresholds markedly distict from classical GPCRs to dissociation constants ported originally as potential therapeutics in the treatment of obesity among which some are suitable candidates for labeling as PET or SPECT-tracers providing receptor affinities even below 0.1 nM. These could be unique tools not only for better understanding of the mechanism of obesity but also for investigations of extrahypothalamic role of “feeding receptors” at the interface between neuroendocrine and mental diseases.

Soil organic matter amendments in date palm groves of the Middle Eastern and North African region:a mini-review

Countries in the Middle Eastern and North African (MENA) region are among the most water-scarce regions in the world, and their dryland soils are usually poor in organic carbon content (<0.5%). In this study, we summarize examples of how people in the few oases of the MENA region overcome environmental challenges by sustainably managing economically important date production. On the basis of the limited studies found in the existing literature, this mini-review focuses on the role of traditional soil organic matter amendments beneath the soil surface as a key tool in land restoration. We conclude that soil organic matter amendments can be very successful in restoring soil water and preventing the soil from salinization.

Immediate and legacy effects of snow exclusion on soil fungal diversity and community composition

Background:Soil fungi play crucial roles in ecosystem functions.However,how snow cover change associated with winter warming affects soil fungal communities remains unclear in the Tibetan forest.Methods:We conducted a snow manipulation experiment to explore immediate and legacy effects of snow exclusion on soil fungal community diversity and composition in a spruce forest on the eastern Tibetan Plateau.Soil fungal communities were performed by the high throughput sequencing of gene-fragments.Results:Ascomycota and Basidiomycota were the two dominant fungal phyla and Archaeorhizomyces,Aspergillus and Amanita were the three most common genera across seasons and snow manipulations.Snow exclusion did not affect the diversity and structure of soil fungal community in both snow-covered and snow-free seasons.However,the relative abundance of some fungal communities was different among seasons.Soil fungal groups were correlated with environmental factors(i.e.,temperature and moisture)and soil biochemical variables(i.e.,ammonium and enzyme).Conclusions:These results suggest that the season-driven variations had stronger impacts on soil fungal community than short-term snow cover change.Such findings may have important implications for soil microbial processes in Tibetan forests experiencing significant decreases in snowfall.

加强区域化建设提升生物经济影响力

不断发布或更新的生物经济战略反映出各国/地区发展生物经济的雄心壮志。生物经济概念的不清晰(模糊性)及方法的多样性常引起争议,公众很难理解生物经济是做什么以及它能为现代社会发展提供什么实质上的解决方案,导致生物经济及其方法难以在实践中得到应用,甚至被简化为生物技术。基于上述分析,提出本文的核心观点——生物经济区域化,并给出了区域化背景下生物经济的定义:在可持续经济的框架内,生产和利用生物资源(包括知识)为所有部门提供产品、工艺和服务。随后,本文分析了欧盟发展可持续生物经济区域的相关举措,并重点阐述了发展生物经济所必需的要素,包括自然资源、人力资本、工业资本和技术等。最后介绍与生物经济相关的区域产业集群,其中重点介绍了德国莱茵生物经济示范区和生物经济科学中心。

Comparison of smoothness-constrained and geostatistically based cross-borehole electrical resistivity tomography for characterization of solute tracer plumes

Experiments using electrical resistivity tomography(ERT) have shown promising results in reducing the uncertainty of solute plume characteristics related to estimates based on the analysis of local point measurements only.To explore the similarities and differences between two cross-borehole ERT inversion approaches for characterizing salt tracer plumes,namely the classical smoothness-constrained inversion and a geostatistically based approach,we performed two-dimensional synthetic experiments.Simplifying assumptions about the solute transport model and the electrical forward and inverse model allowed us to study the sensitivity of the ERT inversion approaches towards a variety of basic conditions,including the number of boreholes,measurement schemes,contrast between the plume and background electrical conductivity,use of a priori knowledge,and point conditioning.The results show that geostatistically based and smoothness-constrained inversions of electrical resistance data yield plume characteristics of similar quality,which can be further improved when point measurements are incorporated and advantageous measurement schemes are chosen.As expected,an increased number of boreholes included in the ERT measurement layout can highly improve the quality of inferred plume characteristics,while in this case the benefits of point conditioning and advantageous measurement schemes diminish.Both ERT inversion approaches are similarly sensitive to the noise level of the data and the contrast between the solute plume and background electrical conductivity,and robust with regard to biased input parameters,such as mean concentration,variance,and correlation length of the plume.Although sophisticated inversion schemes have recently become available,in which flow and transport as well as electrical forward models are coupled,these schemes effectively rely on a relatively simple geometrical parameterization of the hydrogeological model.Therefore,we believe that standard uncoupled ERT inverse approaches,like the ones discussed and assessed in this paper,will continue to be important to the imaging and characterization of solute plumes in many real-world applications.

Groundwater Geochemistry and Saltwater Intrusion in the Dakar Coastal Area, Senegal

Groundwater levels and water samples were collected from 20 drinking water pumping and piezometer wells in the urban area of Dakar coastal region in the year 2019. The pH-value, electrical conductivity, as well as calcium, magnesium, sodium, potassium, chloride, sulfate, bicarbonate, and nitrate concentrations were measured to assess the hydrochemical quality of the infrabasaltic aquifer in the area. The present work carried out a hydrochemical analysis to interpret the groundwater chemistry of the aquifer. The results of this chemical analysis indicate that Na+ > Mg2+ > Ca2+ > K+ was the most dominant cation sequence in the groundwater, while Cl- > HCO3- > SO42- > NO3- was the most dominant one for anions. The chemical analysis of our samples showed, that the Cl-Ca-Mg facies was dominant in the aquifer, while Cl-Na-K and HCO3-Na-K facies represent 20% and 10% of the groundwater sampled, respectively. A comparison of the measured groundwater quality in relation to WHO drinking water quality standards revealed that 80% of the water samples are suitable for drinking purposes. Ca enrichment, Simpson ratio, ratio of sodium chloride, and calculating Base Exchange (BEX) indices for the samples revealed that the groundwater is mainly affected by three factors: seawater intrusion due to aquifer overexploitation on one hand, and freshening processes and nitrate pollution, on the other, mainly caused by the groundwater flow from the unconfined aquifer.

Spatial heterogeneity of flesh-cell osmotic potential in sweet cherry affects partitioning of absorbed water

A fleshy fruit is commonly assumed to resemble a thin-walled pressure vessel containing a homogenous carbohydrate solution.Using sweet cherry(Prunus avium L.)as a model system,we investigate how local differences in cell water potential affect H2O and D2O(heavy water)partitioning.The partitioning of H2O and D2O was mapped nondestructively using magnetic resonance imaging(MRI).The change in size of mesocarp cells due to water movement was monitored by optical coherence tomography(OCT,non-destructive).Osmotic potential was mapped using microosmometry(destructive).Virtual sections through the fruit revealed that the H2O distribution followed a net pattern in the outer mesocarp and a radial pattern in the inner mesocarp.These patterns align with the disposition of the vascular bundles.D2O uptake through the skin paralleled the acropetal gradient in cell osmotic potential gradient(from less negative to more negative).Cells in the vicinity of a vascular bundle were of more negative osmotic potential than cells more distant from a vascular bundle.OCT revealed net H2O uptake was the result of some cells loosing volume and other cells increasing volume.H2O and D2O partitioning following uptake is non-uniform and related to the spatial heterogeneity in the osmotic potential of mesocarp cells.

GeoAmazonas—GIS for Water Resources Management

Geographic Information Systems (GIS) are used essentially for spatial analysis. They can lead to the development of methods for analyzing and planning the use of geographical space and, consequently, are helpful to the decision making process, assisting those responsible for planning the use of a certain territory. This article is a result of the “Project for the Integrated and Sustainable Management of Trans- boundary Hydric Resources of the Amazon Basin considering Variability and Climate Change”, which has the goal of strengthening institutional guidelines in order to plan and execute activities related to the protection of the land, hydric resources and sustainable management of the Amazon Basin, considering the existing impacts of climatic changes. This article aims at analyzing the process of building and implementing the GeoAmazonas GIS as one of the instruments for managing the basin, including its contribution for standardizing different data sources in the entire area of the basin and the identification of conflicts related the use of water resources and vulnerability situations.

The synergies of SMAP enhanced and MODIS products in a random forest regression for estimating 1 km soil moisture over Africa using Google Earth Engine

Due to the coarse scale of soil moisture products retrieved from passive microwave observations(SMPMW),several downscaling methods have been developed to enable regional scale applications.However,it can be challenging for users to access final data products and algorithms,as well as managing different data sources and formats,various data processing methods,and the complexity of the workflows from raw data to information products.Here,the Google Earth Engine(GEE),which as of late offers SMPMW,is used to implement a workflow for retrieving 1 km SM at a depth of 0-5 cm using MODIS optical/thermal measurements,the SM_(PMW)coarse scale product,and a random forest regression.The proposed method was implemented on the African continent to estimate weekly SM maps.The results of this study were evaluated against in-situ measurements of three validation networks.Overall,in comparison to the original SM_(PMW)product,which was limited by a spatial resolution of only 9 km,this method is able to estimate SM at 1 km spatial resolution with acceptable accuracy(an average correlation coefficient of 0.64 and a ubRMSD of 0.069 m^(3)/m^(3)).The results show that the proposed method in GEE provides a precise estimation of SM with a higher spatial resolution across the entire continent.

3D U-Net Segmentation Improves Root System Reconstruction from 3D MRI Images in Automated and Manual Virtual Reality Work Flows

Magnetic resonance imaging(MRI)is used to image root systems grown in opaque soil.However,reconstruction of root system architecture(RSA)from 3-dimensional(3D)MRI images is challenging.Low resolution and poor contrast-to-noise ratios(CNRs)hinder automated reconstruction.Hence,manual reconstruction is still widely used.Here,we evaluate a novel 2-step work flow for automated RSA reconstruction.In the first step,a 3D U-Net segments MRI images into root and soil in super-resolution.In the second step,an automated tracing algorithm reconstructs the root systems from the segmented images.We evaluated the merits of both steps for an MRI dataset of 8 lupine root systems,by comparing the automated reconstructions to manual reconstructions of unaltered and segmented MRI images derived with a novel virtual reality system.We found that the U-Net segmentation offers profound benefits in manual reconstruction:reconstruction speed was doubled(+97%)for images with low CNR and increased by 27%for images with high CNR.Reconstructed root lengths were increased by 20%and 3%,respectively.Therefore,we propose to use U-Net segmentation as a principal image preprocessing step in manual work flows.The root length derived by the tracing algorithm was lower than in both manual reconstruction methods,but segmentation allowed automated processing of otherwise not readily usable MRI images.Nonetheless,model-based functional root traits revealed similar hydraulic behavior of automated and manual reconstructions.Future studies will aim to establish a hybrid work flow that utilizes automated reconstructions as scaffolds that can be manually corrected.

Low soil C:N ratio results in accumulation and leaching of nitrite and nitrate in agricultural soils under heavy rainfall

Nitrate (NO-3) and nitrite (NO2-) leaching threatens groundwater quality.Soil C:N ratio,i.e.,the ratio of soil organic carbon to total nitrogen,affects mineralization,nitrification,and denitrification;however,its mechanism for driving soil NO-3and NO-2accumulation and leaching remains unclear.Here,a field investigation in a fluvo-aquic soil and a soil column experiment were performed to explore the relationships between soil C:N ratio and soil NO-3and NO-2leaching in three soil layers (0–20,20–40,and 40–60 cm) under heavy rainfall (rainfall rate>25 mm d-1).The field investigation results showed that both soil NO-3-N and NO-2-N contents decreased exponentially (P<0.001) with increasing soil C:N ratio in each soil layer.Furthermore,negative exponential relationships (P<0.001) were found between soil C:N ratio and both NO-3-N and NO-2-N concentrations in soil solution in each soil layer under heavy rainfall.The soil column divided into three layers was leached with simulated heavy rainfall;the results confirmed negative exponential relationships (P<0.05) between soil C:N ratio and both NO-3-N and NO-2-N concentrations in the leachate from each soil layer.A total of 18 soil samples obtained from three depths at six field sites during the rainy season were used to elucidate the microbial mechanisms induced by soil C:N ratio using high-throughput sequencing and real-time polymerase chain reaction.High abundances of ammonifying bacteria (Flavobacterium,Bacillu,and Pseudomonas),ammonia-oxidizing bacteria (Nitrosospira),and nirS/K gene were observed when soil C:N was low,concomitant with low abundances of NO-2-oxidizing bacteria (Nitrospira) and narG gene.Partial least squares path modeling showed that the high NO-3and NO-2levels at low soil C:N ratio might be attributed to the inhibition of NO-3reduction (i.e.,low narG gene) and NO-2oxidation (i.e.,low Nitrospira) and thus the accumulation of soil NO-3and NO-2,respectively.Therefore,the leaching of NO-2and NO-3in low C:N soils requires more attention during the rainy season.

Genomic,transcriptomic,and metabolomic analysis of Oldenlandia corymbosa reveals the biosynthesis and mode of action of anti-cancer metabolites

Plants accumulate a vast array of secondary metabolites,which constitute a natural resource for pharmaceuticals.Oldenlandia corymbosa belongs to the Rubiaceae family,and has been used in traditional medicine to treat different diseases,including cancer.However,the active metabolites of the plant,their biosynthetic pathway and mode of action in cancer are unknown.To fill these gaps,we exposed this plant to eight different stress conditions and combined different omics data capturing gene expression,metabolic profiles,and anti-cancer activity.Our results show that O.corymbosa extracts are active against breast cancer cell lines and that ursolic acid is responsible for this activity.Moreover,we assembled a high-quality genome and uncovered two genes involved in the biosynthesis of ursolic acid.Finally,we also revealed that ursolic acid causes mitotic catastrophe in cancer cells and identified three high-confidence protein binding targets by Cellular Thermal Shift Assay(CETSA)and reverse docking.Altogether,these results constitute a valuable resource to further characterize the biosynthesis of active metabolites in the Oldenlandia group,while the mode of action of ursolic acid will allow us to further develop this valuable compound.

Emerging contaminants:A One Health perspective

Environmental pollution is escalating due to rapid global development that often prioritizes human needs over planetary health.Despite global efforts to mitigate legacy pollutants,the continuous introduction of new substances remains a major threat to both people and the planet.In response,global initiatives are focusing on risk assessment and regulation of emerging contaminants,as demonstrated by the ongoing efforts to establish the UN’s Intergovernmental Science-Policy Panel on Chemicals,Waste,and Pollution Prevention.This review identifies the sources and impacts of emerging contaminants on planetary health,emphasizing the importance of adopting a One Health approach.Strategies for monitoring and addressing these pollutants are discussed,underscoring the need for robust and socially equitable environmental policies at both regional and international levels.Urgent actions are needed to transition toward sustainable pollution management practices to safeguard our planet for future generations.

Plant Phenotyping:Past,Present,and Future

A plant develops the dynamic phenotypes from the interaction of the plant with the environment.Understanding these processes that span plant’s lifetime in a permanently changing environment is essential for the advancement of basic plant science and its translation into application including breeding and crop management.The plant research community was thus confronted with the need to accurately measure diverse traits of an increasingly large number of plants to help plants to adapt to resource-limiting environment and low-input agriculture.In this overview,we outline the development of plant phenotyping as a multidisciplinary field.We sketch the technological advancement that laid the foundation for the development of phenotyping centers and evaluate the upcoming challenges for further advancement of plant phenotyping specifically with respect to standardization of data acquisition and reusability.Finally,we describe the development of the plant phenotyping community as an essential step to integrate the community and effectively use the emerging synergies.

A terrestrial observatory approach to the integrated investigation of the effects of deforestation on water,energy,and matter fluxes

Integrated observation platforms have been set up to investigate consequences of global change within a terrestrial network of observatories （TERENO） in Germany. The aim of TERENO is to foster the understanding of water, energy, and matter fluxes in terrestrial systems, as well as their biological and physical drivers. Part of the Lower Rhine Valley-Eifel observatory of TERENO is located within the Eifel National Park. Recently, the National Park forest management started to promote the nat- ural regeneration of near-natural beech forest by removing a significant proportion of the spruce forest that was established for timber production after World War II. Within this context, the effects of such a disturbance on forest ecosystem functioning are currently investigated in a deforestation experiment in the Wtistebach catchment, which is one of the key experimental re- search sites within the Lower Rhine Valley-Eifel observatory. Here, we present the integrated observation system of the Wiistebach test site to exemplarily demonstrate the terrestrial observatory concept of TERENO that allows for a detailed mon- itoring of changes in hydrological and biogeochemical states and fluxes triggered by environmental disturbances. We present the observation platforms and the soil sampling campaign, as well as preliminary results including an analysis of data con- sistency. We specifically highlight the capability of integrated datasets to enable improved process understanding of the post-deforestation changes in ecosystem functioning.