Trees provide multiple ecosystem services such as carbon sequestration,hydrological regulation and habitat for arboreal animals.However,they are often removed to support agricultural enterprises.Despite the importance...Trees provide multiple ecosystem services such as carbon sequestration,hydrological regulation and habitat for arboreal animals.However,they are often removed to support agricultural enterprises.Despite the importance of tree remnants,we know relatively little about how soils differ across sites of varying condition.Here,we describe a study where we examined the relative effects of trees,compared with unvegetated interspaces,on soil functions in remnant patches at sites in good and poor condition in two eucalypt communities in an irrigation area in eastern Australia.We found that,in general,carbon and nutrient cycling were relatively greater beneath trees,and in surface soils,but there were no clear trends in relation to site condition.The values of most soil attributes(e.g.,soluble and exchangeable cations,nitrogen,phosphorus)were greater beneath trees,indicating strong fertile island effects in both communities.Overall,our study confirms the importance of trees in remnant patches in agricultural landscapes,particularly those in sites of poor condition.It also suggests that soil processes may still be relatively intact,even in sites in poor condition.Our study reinforces the need to protect trees in remnant woodland reserves to maintain critical ecosystem functions related to nutrient retention.These remnants are important for achieving sustainable management of agricultural systems.展开更多
Changes in soil biological and biochemical properties under different land uses in the subtropical region of China were investigated in order to develop rational cultivation and fertilization management. A small water...Changes in soil biological and biochemical properties under different land uses in the subtropical region of China were investigated in order to develop rational cultivation and fertilization management. A small watershed of subtropical region of China was selected for this study. Land uses covered paddy fields, vegetable farming, fruit trees, upland crops, bamboo stands, and forestry. Soil biological and biochemical properties included soil organic C and nutrient contents, mineralization of soil organic C, and soil microbial biomass and community functional diversity. Soil organic C and total N contents, microbial biomass C and N, and respiration intensity under different land uses were changed in the following order： paddy fields （and vegetable farming） 〉 bamboo stands 〉 fruit trccs （and upland）. The top surface （0-15 cm） paddy fields （and vegetable farming） were 76.4 and 80.8% higher in soil organic C and total N contents than fruit trees （and upland） soils, respectively. Subsurface paddy soils （15-30 cm） were 59.8 and 67.3% higher in organic C and total N than upland soils, respectively. Soil microbial C, N and respiration intensity in paddy soils （0-15 cm） were 6.36, 3.63 and 3.20 times those in fruit tree （and upland） soils respectively. Soil microbial metabolic quotient was in the order： fruit trees （and upland） 〉 forestry 〉 paddy fields. Metabolic quotient in paddy soils was only 47.7% of that in fruit tree （and upland） soils. Rates of soil organic C mineralization during incubation changed in the order： paddy fields 〉 bamboo stands 〉 fruit trees （and upland） and soil bacteria population： paddy fields 〉 fruit trees （and upland） 〉 forestry. No significant difference was found for fungi and actinomycetes populations. BIOLOG analysis indicated a changing order of paddy fields 〉 fruit trees （and upland） 〉 forestry in values of the average well cell development （AWCD） and functional diversity indexes of microbial community. Results also showed that the conversion from paddy fields to vegetable farming for 5 years resulted in a dramatic increase in soil available phosphorus content while insignificant changes in soil organic C and total N content due to a large inputs of phosphate fertilizers. This conversion caused 53, 41.5, and 41.3% decreases in soil microbial biomass C, N, and respiration intensity, respectively, while 23.6% increase in metabolic quotient and a decrease in soil organic C mineralization rate. Moreover, soil bacteria and actinomycetes populations were increased slightly, while fungi population increased dramatically. Functional diversity indexes of soil microbial community decreased significantly. It was concluded that land uses in the subtropical region of China strongly affected soil biological and biochemical properties. Soil organic C and nutrient contents, mineralization of organic C and functional diversity of microbial community in paddy fields were higher than those in upland and forestry. Overuse of chemical fertilizers in paddy fields with high fertility might degrade soil biological properties and biochemical function, resulting in deterioration of soil biological quality.展开更多
Partial substitution of synthetic nitrogen(N)with organic fertilizers(PSOF)is of great significance in improving soil ecosystem functions in systems that have deteriorated due to the excessive application of chemical ...Partial substitution of synthetic nitrogen(N)with organic fertilizers(PSOF)is of great significance in improving soil ecosystem functions in systems that have deteriorated due to the excessive application of chemical N fertilizer.However,existing studies typically focus on individual soil functions,neglecting the fact that multiple functions occur simultaneously.It remains unclear how PSOF influences multiple soil functions and whether these impacts are related to soil microbial communities.Here,we examined the impacts of partial substitutions(25%–50%)of chemical N fertilizer with organic form(pig manure or municipal sludge)in a vegetable field on soil multifunctionality,by measuring a range of soil functions involving primary production(vegetable yield and quality),nutrient cycling(soil enzyme activities,ammonia volatilization,N leaching,and N runoff),and climate regulation(soil organic carbon sequestration and nitrous oxide emission).We observed that PSOF improved soil multifunctionality,with a 50%substitution of chemical N fertilizer with pig manure being the best management practice;the result was strongly related to the diversities and network complexities of bacteria and fungi.Random forest analysis further revealed that soil multifunctionality was best explained by the bacterial-fungal network complexity,followed by available phosphorus level and bacterial diversity.The PSOF also shifted the composition of bacterial and fungal communities,with increased relative abundances of dominant bacteria phyla,such as Bacteroidetes,Gemmatimonadetes,and Myxococcota,and fungal phyla,such as Basidiomycota and Olpidiomycota.The observed increases in soil multifunctionality were consistent with significant increases in the relative abundances of keystone taxa such as Blastocladiomycota,Chaetomiaceae,and Nocardiopsaceae.Together,these findings indicate that PSOF can enhance interactions within and among microbial communities and that such practices have the potential to improve soil ecosystem multifunctionality and contribute to the development of sustainable agriculture.展开更多
Exploration of soil environmental characteristics governing soil microbial community structure and activity may improve our understanding of biogeochemical processes and soil quality. The impact of soil environmental ...Exploration of soil environmental characteristics governing soil microbial community structure and activity may improve our understanding of biogeochemical processes and soil quality. The impact of soil environmental characteristics especially organic carbon availability after 15-yr different organic and inorganic fertilizer inputs on soil bacterial community structure and functional metabolic diversity of soil microbial communities were evaluated in a 15-yr fertilizer experiment in Changping County, Beijing, China. The experiment was a wheat-maize rotation system which was established in 1991 including four different fertilizer treatments. These treatments included： a non-amended control（CK）, a commonly used application rate of inorganic fertilizer treatment（NPK）; a commonly used application rate of inorganic fertilizer with swine manure incorporated treatment（NPKM）, and a commonly used application rate of inorganic fertilizer with maize straw incorporated treatment（NPKS）. Denaturing gradient gel electrophoresis（DGGE） of the 16 S r RNA gene was used to determine the bacterial community structure and single carbon source utilization profiles were determined to characterize the microbial community functional metabolic diversity of different fertilizer treatments using Biolog Eco plates. The results indicated that long-term fertilized treatments significantly increased soil bacterial community structure compared to CK. The use of inorganic fertilizer with organic amendments incorporated for long term（NPKM, NPKS） significantly promoted soil bacterial structure than the application of inorganic fertilizer only（NPK）, and NPKM treatment was the most important driver for increases in the soil microbial community richness（S） and structural diversity（H）. Overall utilization of carbon sources by soil microbial communities（average well color development, AWCD） and microbial substrate utilization diversity and evenness indices（H＇ and E） indicated that long-term inorganic fertilizer with organic amendments incorporated（NPKM, NPKS） could significantly stimulate soil microbial metabolic activity and functional diversity relative to CK, while no differences of them were found between NPKS and NPK treatments. Principal component analysis（PCA） based on carbon source utilization profiles also showed significant separation of soil microbial community under long-term fertilization regimes and NPKM treatment was significantly separated from the other three treatments primarily according to the higher microbial utilization of carbohydrates, carboxylic acids, polymers, phenolic compounds, and amino acid, while higher utilization of amines/amides differed soil microbial community in NPKS treatment from those in the other three treatments. Redundancy analysis（RDA） indicated that soil organic carbon（SOC） availability, especially soil microbial biomass carbon（Cmic） and Cmic/SOC ratio are the key factors of soil environmental characteristics contributing to the increase of both soil microbial community structure and functional metabolic diversity in the long-term fertilization trial. Our results showed that long-term inorganic fertilizer and swine manure application could significantly improve soil bacterial community structure and soil microbial metabolic activity through the increases in SOC availability, which could provide insights into the sustainable management of China＇s soil resource.展开更多
Soil multifunctionality represents a range of soil processes driven by the interactions between soil abiotic and biotic components.As a group of ubiquitous fungi that form mutualistic symbiotic associations with a vas...Soil multifunctionality represents a range of soil processes driven by the interactions between soil abiotic and biotic components.As a group of ubiquitous fungi that form mutualistic symbiotic associations with a vast array of terrestrial plants,arbuscular mycorrhizal(AM)fungi may play a critical role in maintaining soil multifunctionality,but the characteristics of their contributions remain to be unraveled.This mini review aims to disentangle the contributions of AM fungi to soil multifunctionality.We provide a framework of concepts about AM fungi making crucial contributions to maintaining multiple soil functions,including primary productivity,nutrient cycling,water regulation and purification,carbon and climate regulation,habitat for biodiversity,disease and pest control,and pollutant degradation and detoxification,via a variety of pathways,particularly contributing to soil and plant health.This review contends that AM fungi,as a keystone component of soil microbiome,can govern soil multifunctionality,ultimately promoting ecosystem services.展开更多
Managing fertilization in integrated crop-livestock systems(ICLS)during periods of low nutrient export,known as system fertilization,can optimize nutrient use by enhancing the soil's biochemical and physical-hydri...Managing fertilization in integrated crop-livestock systems(ICLS)during periods of low nutrient export,known as system fertilization,can optimize nutrient use by enhancing the soil's biochemical and physical-hydric properties.However,interdisciplinary studies on processes that improve input utilization in ICLS remain scarce.This study aimed to assess the relationships between the effciencies of different nutrient management strategies in ICLS and pure crop systems(PCS)and the biochemical and physical-hydric quality of soil.Two fertilization strategies(system fertilization and crop fertilization)and two cropping systems(ICLS and PCS)were evaluated in a randomized block design with three replicates.In the PCS,soybean was grown followed by ryegrass as a cover crop.In the ICLS,sheep grazed on the ryegrass.In the crop fertilization,phosphorus and potassium were applied to the soybean planting,and nitrogen was applied in the ryegrass establishment.Nitrogen,phosphorus,and potassium were applied during ryegrass establishment in the system fertilization.Soil quality indexes were calculated using fourteen physical-hydric and biochemical soil indicators,and primary production and nutrient utilization effciency were evaluated.System fertilization in ICLS enhanced the soil functions of water storage and availability for plants,structural stability,and resistance to degradation.System fertilization in ICLS improved the soil quality by 14%over PCS and 13%over crop fertilization in ICLS.Notably,this optimized system yielded the highest primary production.These findings underscore the pivotal role of system fertilization in ICLS to boost food production and enhance soil ecosystem services without increasing the consumption of external fertilizers.They advocate for a strategic shift towards system-level fertilization in integrated systems,and demonstrate for the frst time in ICLS,the delicate balance between nutrient management,soil health,and sustainable productivity.展开更多
To deal with the global and regional issues including food security, climate change, land degradation, biodiversity loss, water resource management, and ecosystem health, detailed accurate spatial soil information is ...To deal with the global and regional issues including food security, climate change, land degradation, biodiversity loss, water resource management, and ecosystem health, detailed accurate spatial soil information is urgently needed. This drives the worldwide development of digital soil mapping. In recent years, significant progresses have been made in different aspects of digital soil mapping. The main purpose of this paper is to provide a review for the major progresses of digital soil mapping in the last decade. First, we briefly described the rise of digital soil mapping and outlined important milestones and their influence, and main paradigms in digital soil mapping. Then, we reviewed the progresses in legacy soil data, environmental covariates, soil sampling, predictive models and the applications of digital soil mapping products. Finally, we summarized the main trends and future prospect as revealed by studies up to now. We concluded that although the digital soil mapping is now moving towards mature to meet various demands of soil information, challenges including new theories, methodologies and applications of digital soil mapping, especially for highly heterogeneous and human-affected environments, still exist and need to be addressed in the future.展开更多
The objective of this study is to analyze soil physical and chemical properties,soil comprehensive functions and impact factors after different years of reclamation.Based on the survey data taken from 216 soil samplin...The objective of this study is to analyze soil physical and chemical properties,soil comprehensive functions and impact factors after different years of reclamation.Based on the survey data taken from 216 soil sampling points in the Fengxian Reclamation Area of the Changjiang (Yangtze) River Estuary,China in April 2009 and remotely sensed TM data in 2006,while by virtue of multivariate analysis of variance (MANOVA),geo-statistical analysis (GA),prin-cipal component analysis (PCA) and canonical correspondence analysis (CCA),it was concluded that:1) With the in-crease in reclamation time,soil moisture,soil salinity,soil electric conductivity and soil particle size tended to decline,yet soil organic matter tended to increase.Soil available phosphorous tended to increase in the early reclamation period,yet it tended to decline after about 49 years of reclamation.Soil nitrate nitrogen,soil ammonia nitrogen and pH changed slightly in different reclamation years.Soil physical and chemical properties reached a steady state after about 30 years of reclamation.2) According to the results of PCA analysis,the weighted value (0.97 in total) that represents soil nutrient factors (soil nitrate nitrogen,soil organic matter,soil available phosphorous,soil ammonia nitrogen,pH and soil particle size) were higher than the weighted value (0.48 in total) of soil limiting factors (soil salinity,soil elec-tric conductivity and soil moisture).The higher the F value is,the better the soil quality is.3) Different land use types play different roles in the soil function maturity process,with farmlands providing the best contribution.4) Soil physi-cal and chemical properties in the reclamation area were mainly influenced by reclamation time,and then by land use types.The correlation (0.1905) of the composite index of soil function (F) with reclamation time was greater than that with land use types (-0.1161).展开更多
A vegetation evolution model influenced by a degeneration of soil ecological functions was set up. Three ideal communities of a) trees, b) shrubs, and c) herbage populations were first simulated. Then numerical simula...A vegetation evolution model influenced by a degeneration of soil ecological functions was set up. Three ideal communities of a) trees, b) shrubs, and c) herbage populations were first simulated. Then numerical simulations of the evolutionary and developmental processes of a natural forest community, which is composed of over 100 species,were conducted. Results of the study showed that a) in all communities, soil degeneration not only drove some weaker species to extinction, but also a few dominant ones; b) there were different response scales with species in an ideal tree metapopulation that could persist as long as a thousand years, with shrubs in an ideal shrub metapopulation that could persevere for several hundred years, and with species in an ideal herbage metapopulation that could become extinct within 10 years; and c) each metapopulation experienced three evolutionary stages during adaptation to the environment: a) the stage of compelled adaptation or resistance, b) the adjusted stage, and c) the stabilized stage.展开更多
Monitoring soil microbial communities can lead to better understanding of the transformation processes of organic carbon in soil. The present study investigated the changes of soil microbial communities during straw d...Monitoring soil microbial communities can lead to better understanding of the transformation processes of organic carbon in soil. The present study investigated the changes of soil microbial communities during straw decomposition in three fields, i.e., cropland, peach orchard and vineyard. Straw decomposition was monitored for 360 d using a mesh-bag method. Soil microbial metabolic activity and functional diversity were measured using the Biolog-Eco system. In all three fields, dried straws with a smaller size decomposed faster than their fresh counterparts that had a larger size. Dried corn straw decomposed slower than dried soybean straw in the early and middle stages, while the reverse trend was found in the late stage. The cropland showed the highest increase in microbial metabolic activity during the straw decomposition, whereas the peach orchard showed the lowest. There was no significant change in the species dominance or evenness of soil microbial communities during the straw decomposition. However, the species richness fluctuated significantly, with the peach orchard showing the highest richness and the cropland the lowest. With different carbon sources, the peach orchard utilised carbon the most, followed by the cropland and the vineyard. In all three fields, carbon was utilized in following decreasing order： saccharides〉amino acids〉polymers〉polyamines〉carboxylic acids〉aromatic compounds. In terms of carbon-source utilization, soil microbial communities in the peach orchard were less stable than those in the cropland. The metabolic activity and species dominance of soil microbial communities were negatively correlated with the straw residual percentage. Refractory components were primarily accumulated in the late stages, thus slowing down the straw decomposition. The results showed that dried and crushed corn straw was better for application in long-term fields. The diversity of soil microbial communities was more stable in cropland than in orchards during the straw decomposition.展开更多
Ammonia（NH3） volatilization is one of the primary pathways of nitrogen（N） loss from soils after chemical fertilizer is applied, especially from the alkaline soils in Northern China, which results in lower efficien...Ammonia（NH3） volatilization is one of the primary pathways of nitrogen（N） loss from soils after chemical fertilizer is applied, especially from the alkaline soils in Northern China, which results in lower efficiency for chemical fertilizers. Therefore, we conducted an incubation experiment using an alkaline soil from Tianjin（p H 8.37–8.43） to evaluate the suppression effect of Trichoderma viride（T. viride） biofertilizer on NH3 volatilization, and compared the differences in microbial community structure among all samples. The results showed that viable T. viride biofertilizer（T） decreased NH3 volatilization by 42.21% compared with conventional fertilizer（（CK）, urea）, while nonviable T. viride biofertilizer（TS） decreased NH3 volatilization by 32.42%. NH3 volatilization was significantly higher in CK and sweet potato starch wastewater（SPSW） treatments during the peak period. T. viride biofertilizer also improved the transfer of ammonium from soil to sweet sorghum. Plant dry weights increased 91.23% and 61.08% for T and TS, respectively, compared to CK. Moreover, T. viride biofertilizer enhanced nitrification by increasing the abundance of ammonium-oxidizing archaea（AOA） and ammonium-oxidizing bacteria（AOB）. The results of high-throughput sequencing indicated that the microbial community structure and composition were significantly changed by the application of T. viride biofertilizer. This study demonstrated the immense potential of T. viride biofertilizer in reducing NH3 volatilization from alkaline soil and simultaneously improving the utilization of fertilizer N by sweet sorghum.展开更多
The soil environmental index(SEI),which is a four digit code system,represents relatively homogenous spatial unit with specific soil capacity to provide ecological or non-production functions.This work aimed to presen...The soil environmental index(SEI),which is a four digit code system,represents relatively homogenous spatial unit with specific soil capacity to provide ecological or non-production functions.This work aimed to present information on rating and economic evaluation of SEI,which is a spatial identifier used for expressing heterogeneity of Slovak agricultural soil to support analysis of soil ecological functions.In this study,SEI index expressed the capacity of soil to accumulate water,immobilise the risk elements and substances and transform risk substances(organic pollutants).Partial evaluations of soil capacity to provide above mentioned functions were used to derive final SEI values.Within the agricultural soils of Slovakia there were 493 combinations of soil environmental index.Each index was expressed through rating(point)value and economic value.Average value of Slovak agricultural land to provide selected ecological soil functions was 55.3 points,which corresponded to 35.946 billionper agricultural land or approximately 1.42per square meter.Spatial identification of SEI codes and relevant database were developed in vector form via geographical information systems of Soil Science and Conservation Research Institute,Bratislava.In addition to using the national soil database system,a strategy was presented for evaluating and pricing of soil ecological function,and the development of an soil environmental index.Assessment and evaluation of vitally important soil functions expressed by SEI can significantly contribute to planning and protection of the soil,and can regulate indiscriminate anthropic interventions in land use decisions.展开更多
At the end of October 2018,a storm of unprecedented strength severely damaged the forests of the eastern sector of the Italian Alps.The affected forest area covers 42,500 ha.The president of one of the damaged regions...At the end of October 2018,a storm of unprecedented strength severely damaged the forests of the eastern sector of the Italian Alps.The affected forest area covers 42,500 ha.The president of one of the damaged regions asked for help from the University of Padua.After eight months of discussion,the authors of this article wrote a consensus text.The sometimes asper debate brought to light some crucial aspects:1)even experienced specialists may have various opinions based on scientific knowledge that lead to conflicting proposals for action.For some of them there is evidence that to restore a destroyed natural environment it is more judicious to do nothing;2)the soil corresponds to a living structure and every ecosystem’s management should be based on it;3)faced with a catastrophe,people and politicians find themselves unarmed,also because they rarely have the scientific background to understand natural processes.Yet politicians are the only persons who make the key decisions that drive the economy in play and therefore determine the near future of our planet.This article is an attempt to respond directly to the governor of a region who formally and prudently asked a university department called"Land,Environment,Agriculture and Forestry"for help before taking decisions;4)the authors also propose an artistic interpretation of facts(uncontrolled storm)and conclusions(listen to the soil).Briefly,the authors identify the soil as an indispensable source for the renewal of the destroyed forest,give indications on how to prepare a map of the soils of the damaged region,and suggest to anchor on this soil map a series of silvicultural and soil management actions that will promote the soil conservation and the faster recovery of the natural dynamic stability and resilience.展开更多
Vegetation types alter soil ecosystems by changing soil fauna community activities and soil physi-cal-chemical properties.However,it is unclear how tree species(natural forest,native and exotic tree plantations)promot...Vegetation types alter soil ecosystems by changing soil fauna community activities and soil physi-cal-chemical properties.However,it is unclear how tree species(natural forest,native and exotic tree plantations)promote changes in the soil ecosystem,and if these changes alter functional groups of soil fauna and ecosystem services.To determine the effects of five decades of old-field veg-etation on soil ecosystems in the Brazilian Atlantic Forest,field sampling of three ecosystems(exotic tree species Pinus elliottii Engelm.plantation,endangered tree species Arau-caria angustifolia(Bertol.)Kuntze plantation,and a natural ecosystem)were carried out,as well using bait-lamina tests and bioassays with collembolans,earthworms and seeds of Lactuca sativa L.Field sampling evaluated the soil fauna community and soil physical-chemical properties.The bait-lamina test in situ was carried out for 14-days to deter-mine fauna feeding activity,and the bioassays evaluated the reproduction of Folsomia candida,the avoidance of Eisenia andrei,and germination of L.sativa in the soil from each ecosystem.The results are:(1)vegetation type altered the soil fauna community composition;(2)soil fauna feeding was reduced in the plantations compared to the natural eco-system;(3)a physical barrier was created by recalcitrant litter that compromised fauna community structure and seed bank germination in situ;and,(4)changes in soil physical-chemical properties promoted decomposers.展开更多
Ten runoff plots with different planting patterns were established for experimental observation in Yangjichong small watershed of Longli County in Karst region of Guizhou Province. Results show that under the same rai...Ten runoff plots with different planting patterns were established for experimental observation in Yangjichong small watershed of Longli County in Karst region of Guizhou Province. Results show that under the same rainfall condition, shrub land, natural grassland and abandoned land presented the best function of soil and water conservation. The function of soil and water conservation was poor for arbor planting pattern, because the shrub layer, herb layer and forest floor were not formed. Because of no-tillage, surface crust and other effects, the function of soil and water conservation in slope farmland was better than that in runoffplots with arbor planting pattern.展开更多
Electromagnetic scattering from a rough surface of layered medium is investigated, and the formulae of the scattering coefficients for different polarizations are derived using the small perturbation method. A rough s...Electromagnetic scattering from a rough surface of layered medium is investigated, and the formulae of the scattering coefficients for different polarizations are derived using the small perturbation method. A rough surface with exponential correlation function is presented for describing a rough soil surface of layered medium, the formula of its scattering coefficient is derived by considering the spectrum of the rough surface with exponential correlation function; the curves of the bistatic scattering coefficient of HH polarization with variation of the scattering angle are obtained by numerical calculation. The influence of the permittivity of layered medium, the mean layer thickness of intermediate medium, the roughness surface parameters and the frequency of the incident wave on the blstatic scattering coefficient is discussed. Numerical results show that the influence of the permittivity of layered medium, the mean layer thickness of intermediate medium, the rms and the correlation length of the rough surface, and the frequency of the incident wave on the bistatic scattering coefficient is very complex.展开更多
Actual evapotranspiration is a key process of hydrological cycle and a sole term that links land surface water balance and land surface energy balance.Evapotranspiration plays a key role in simulating hydrological eff...Actual evapotranspiration is a key process of hydrological cycle and a sole term that links land surface water balance and land surface energy balance.Evapotranspiration plays a key role in simulating hydrological effect of climate change,and a review of evapotranspiration estimation methods in hydrological models is of vital importance.This paper firstly summarizes the evapotranspiration estimation methods applied in hydrological models and then classifies them into the integrated converting methods and the classification gathering methods by their mechanism.Integrated converting methods are usually used in hydrological models and two differences exist among them:one is in the potential evaporation estimation methods,while the other in the function for defining relationship between potential evapora tion and actual evapotranspiration.Due to the higher information requirements of the Pen-man-Monteith method and the existing data uncertainty,simplified empirical methods for calculating potential and actual evapotranspiration are widely used in hydrological models.Different evapotranspiration calculation methods are used depending on the complexity of the hydrological model,and importance and difficulty in the selection of the most suitable evapotranspiration methods is discussed.Finally,this paper points out the prospective de velopment trends of the evapotranspiration estimating methods in hydrological modeling.展开更多
Soil macroinvertebrates play an important role in sustaining production and biodiversity in Australia＇ s tropical savannas. For example, termites, through their foraging and nesting activities, recycle nutrients and ...Soil macroinvertebrates play an important role in sustaining production and biodiversity in Australia＇ s tropical savannas. For example, termites, through their foraging and nesting activities, recycle nutrients and carbon and produce soil pores that facilitate water infiltration. The challenge ahead is to quantitatively understand the relationships and processes that drive this. What roles do different species and functional groups of macroinvertebrates play in various landscape processes？ What are the effects of different land management practices （e.g., domestic cattle grazing, fire） on these relationships, and the consequences for landscape health？ This paper presents preliminary results from studies in northern Australia, that examine the effects of land condition and domestic cattle grazing on soil macroinvertebrates, and the potential for termites to be used as a tool to restore soil function in degraded areas. In northern Australia, increased degradation seems to be associated with declines in the diversity and activity of macroinvertebrates. Termites appear to be one of the most resilient groups, with some species capable of maintaining activity in degraded landscapes.展开更多
Soil microbial alpha diversity is essential for driving ecosystem functions and processes.However,little is known about the beta-diversity affect community functions.Here,we combine distinct community inocula using th...Soil microbial alpha diversity is essential for driving ecosystem functions and processes.However,little is known about the beta-diversity affect community functions.Here,we combine distinct community inocula using the dilution-to-extinction approach with two wheat genotypes to study the effect of microbial diversity loss on rhizosphere community assembly processes,which are related to beta-diversity(between-habitat diversity),and the consequences for ecosystem functions within greenhouse experiment.Compared with alpha-diversity,the bacterial and fungal community beta-diversity are stronger predictors of ecosystem functions(organic matter degradation,phosphorus supply capacity and nitrogen supply capacity),plant genotypes regulated the relationship between microbial diversity and ecosystem functions,with ecosystem functions being significant link to microbial diversity under different wheat genotypes.Loss of microbial diversity decreased the abundance of Bacterial_ASV6(Burkholderia)and increased Fungal_11(Altemaria)within the restored rhizosphere soil.Null modeling analysis showed that the deterministic assembly processes are dominant in bacterial community and fungal high-diversity(alpha-diversity)community,associating with the change of specialized functions(organic matter degradation,phosphorus supply capacity and nitrogen supply capacity)that are correlated with microbial diversity and specific microbial taxa.In addition,these two species were key role for regulating to the network cohesion.Overall,our study pointed out that the regulation of community assembly by microbial diversity loss limits the development of soil ecological functions and weakens the stability of rhizosphere microbial network,highlighting the potential regulatory effect of microbial taxa distribution on microbial community stability and changes of specific ecological functions.展开更多
A range of land management practices are available to achieve better soil quality,but their combined effects remain understudied.We hypothesize that more diverse management practices,meaning higher dissimilarity,lead ...A range of land management practices are available to achieve better soil quality,but their combined effects remain understudied.We hypothesize that more diverse management practices,meaning higher dissimilarity,lead to stronger effects on soil functions and properties.Eight practices(biochar,compost,clay,amorphous silica,basalt,microbial inoculum,reduced physical disturbance and organic matter diversity)were selected with 20 replicates for treatments involving 2,4,or 6 factors and 10 replicates for 8 factor treatments.We investigated the impact of individual factors,factor number,factor dissimilarity and factor composition on soil respiration,soil enzymatic activities(β-glucosidase,β-Dcellobiosidase,β-N-acetylglucosaminidase and phosphatase),soil pH,water stable aggregates and permanganate oxidizable carbon fraction.By including dissimilarity in addition to factor number,variance explained for soil respiration and enzymatic activities increased up to 54.21%.For soil pH and water-stable aggregates,explained variability increased to 65.57%and 57.38%,respectively.More diverse management practices boosted soil microbial activities,enhanced soil aggregate stability,improved soil pH while reducing labile carbon,whereas factor number only influenced water stable aggregates and soil pH.Our study highlights the importance of management practices diversity in soil functions and properties and calls for further research on synergistic combinations of diverse interventions.展开更多
基金supported by the Fundamental Research Funds for the Central Universities of China and David Eldridge by the Hermon Slade Foundation.
文摘Trees provide multiple ecosystem services such as carbon sequestration,hydrological regulation and habitat for arboreal animals.However,they are often removed to support agricultural enterprises.Despite the importance of tree remnants,we know relatively little about how soils differ across sites of varying condition.Here,we describe a study where we examined the relative effects of trees,compared with unvegetated interspaces,on soil functions in remnant patches at sites in good and poor condition in two eucalypt communities in an irrigation area in eastern Australia.We found that,in general,carbon and nutrient cycling were relatively greater beneath trees,and in surface soils,but there were no clear trends in relation to site condition.The values of most soil attributes(e.g.,soluble and exchangeable cations,nitrogen,phosphorus)were greater beneath trees,indicating strong fertile island effects in both communities.Overall,our study confirms the importance of trees in remnant patches in agricultural landscapes,particularly those in sites of poor condition.It also suggests that soil processes may still be relatively intact,even in sites in poor condition.Our study reinforces the need to protect trees in remnant woodland reserves to maintain critical ecosystem functions related to nutrient retention.These remnants are important for achieving sustainable management of agricultural systems.
基金the National Natural Science Foundation of China （40471066） the Knowledge Innovation Program of the Chinese Academy of Sciences （KZCX3-SW-417）.
文摘Changes in soil biological and biochemical properties under different land uses in the subtropical region of China were investigated in order to develop rational cultivation and fertilization management. A small watershed of subtropical region of China was selected for this study. Land uses covered paddy fields, vegetable farming, fruit trees, upland crops, bamboo stands, and forestry. Soil biological and biochemical properties included soil organic C and nutrient contents, mineralization of soil organic C, and soil microbial biomass and community functional diversity. Soil organic C and total N contents, microbial biomass C and N, and respiration intensity under different land uses were changed in the following order： paddy fields （and vegetable farming） 〉 bamboo stands 〉 fruit trccs （and upland）. The top surface （0-15 cm） paddy fields （and vegetable farming） were 76.4 and 80.8% higher in soil organic C and total N contents than fruit trees （and upland） soils, respectively. Subsurface paddy soils （15-30 cm） were 59.8 and 67.3% higher in organic C and total N than upland soils, respectively. Soil microbial C, N and respiration intensity in paddy soils （0-15 cm） were 6.36, 3.63 and 3.20 times those in fruit tree （and upland） soils respectively. Soil microbial metabolic quotient was in the order： fruit trees （and upland） 〉 forestry 〉 paddy fields. Metabolic quotient in paddy soils was only 47.7% of that in fruit tree （and upland） soils. Rates of soil organic C mineralization during incubation changed in the order： paddy fields 〉 bamboo stands 〉 fruit trees （and upland） and soil bacteria population： paddy fields 〉 fruit trees （and upland） 〉 forestry. No significant difference was found for fungi and actinomycetes populations. BIOLOG analysis indicated a changing order of paddy fields 〉 fruit trees （and upland） 〉 forestry in values of the average well cell development （AWCD） and functional diversity indexes of microbial community. Results also showed that the conversion from paddy fields to vegetable farming for 5 years resulted in a dramatic increase in soil available phosphorus content while insignificant changes in soil organic C and total N content due to a large inputs of phosphate fertilizers. This conversion caused 53, 41.5, and 41.3% decreases in soil microbial biomass C, N, and respiration intensity, respectively, while 23.6% increase in metabolic quotient and a decrease in soil organic C mineralization rate. Moreover, soil bacteria and actinomycetes populations were increased slightly, while fungi population increased dramatically. Functional diversity indexes of soil microbial community decreased significantly. It was concluded that land uses in the subtropical region of China strongly affected soil biological and biochemical properties. Soil organic C and nutrient contents, mineralization of organic C and functional diversity of microbial community in paddy fields were higher than those in upland and forestry. Overuse of chemical fertilizers in paddy fields with high fertility might degrade soil biological properties and biochemical function, resulting in deterioration of soil biological quality.
基金supported by the National Natural Science Foundation of China(Nos.41961124004,42207361,and42061124001)。
文摘Partial substitution of synthetic nitrogen(N)with organic fertilizers(PSOF)is of great significance in improving soil ecosystem functions in systems that have deteriorated due to the excessive application of chemical N fertilizer.However,existing studies typically focus on individual soil functions,neglecting the fact that multiple functions occur simultaneously.It remains unclear how PSOF influences multiple soil functions and whether these impacts are related to soil microbial communities.Here,we examined the impacts of partial substitutions(25%–50%)of chemical N fertilizer with organic form(pig manure or municipal sludge)in a vegetable field on soil multifunctionality,by measuring a range of soil functions involving primary production(vegetable yield and quality),nutrient cycling(soil enzyme activities,ammonia volatilization,N leaching,and N runoff),and climate regulation(soil organic carbon sequestration and nitrous oxide emission).We observed that PSOF improved soil multifunctionality,with a 50%substitution of chemical N fertilizer with pig manure being the best management practice;the result was strongly related to the diversities and network complexities of bacteria and fungi.Random forest analysis further revealed that soil multifunctionality was best explained by the bacterial-fungal network complexity,followed by available phosphorus level and bacterial diversity.The PSOF also shifted the composition of bacterial and fungal communities,with increased relative abundances of dominant bacteria phyla,such as Bacteroidetes,Gemmatimonadetes,and Myxococcota,and fungal phyla,such as Basidiomycota and Olpidiomycota.The observed increases in soil multifunctionality were consistent with significant increases in the relative abundances of keystone taxa such as Blastocladiomycota,Chaetomiaceae,and Nocardiopsaceae.Together,these findings indicate that PSOF can enhance interactions within and among microbial communities and that such practices have the potential to improve soil ecosystem multifunctionality and contribute to the development of sustainable agriculture.
基金funded by the National Natural Science Foundation of China(NSFC31301843)the National Nonprofit Institute Research Grant of Chinese Academy of Agricultural Sciences(IARRP-202-5)
文摘Exploration of soil environmental characteristics governing soil microbial community structure and activity may improve our understanding of biogeochemical processes and soil quality. The impact of soil environmental characteristics especially organic carbon availability after 15-yr different organic and inorganic fertilizer inputs on soil bacterial community structure and functional metabolic diversity of soil microbial communities were evaluated in a 15-yr fertilizer experiment in Changping County, Beijing, China. The experiment was a wheat-maize rotation system which was established in 1991 including four different fertilizer treatments. These treatments included： a non-amended control（CK）, a commonly used application rate of inorganic fertilizer treatment（NPK）; a commonly used application rate of inorganic fertilizer with swine manure incorporated treatment（NPKM）, and a commonly used application rate of inorganic fertilizer with maize straw incorporated treatment（NPKS）. Denaturing gradient gel electrophoresis（DGGE） of the 16 S r RNA gene was used to determine the bacterial community structure and single carbon source utilization profiles were determined to characterize the microbial community functional metabolic diversity of different fertilizer treatments using Biolog Eco plates. The results indicated that long-term fertilized treatments significantly increased soil bacterial community structure compared to CK. The use of inorganic fertilizer with organic amendments incorporated for long term（NPKM, NPKS） significantly promoted soil bacterial structure than the application of inorganic fertilizer only（NPK）, and NPKM treatment was the most important driver for increases in the soil microbial community richness（S） and structural diversity（H）. Overall utilization of carbon sources by soil microbial communities（average well color development, AWCD） and microbial substrate utilization diversity and evenness indices（H＇ and E） indicated that long-term inorganic fertilizer with organic amendments incorporated（NPKM, NPKS） could significantly stimulate soil microbial metabolic activity and functional diversity relative to CK, while no differences of them were found between NPKS and NPK treatments. Principal component analysis（PCA） based on carbon source utilization profiles also showed significant separation of soil microbial community under long-term fertilization regimes and NPKM treatment was significantly separated from the other three treatments primarily according to the higher microbial utilization of carbohydrates, carboxylic acids, polymers, phenolic compounds, and amino acid, while higher utilization of amines/amides differed soil microbial community in NPKS treatment from those in the other three treatments. Redundancy analysis（RDA） indicated that soil organic carbon（SOC） availability, especially soil microbial biomass carbon（Cmic） and Cmic/SOC ratio are the key factors of soil environmental characteristics contributing to the increase of both soil microbial community structure and functional metabolic diversity in the long-term fertilization trial. Our results showed that long-term inorganic fertilizer and swine manure application could significantly improve soil bacterial community structure and soil microbial metabolic activity through the increases in SOC availability, which could provide insights into the sustainable management of China＇s soil resource.
基金supported by the National Natural Science Foundation of China(No.41471395)Shandong Provincial Key Research and Development Program of China(No.2019GSF109008)。
文摘Soil multifunctionality represents a range of soil processes driven by the interactions between soil abiotic and biotic components.As a group of ubiquitous fungi that form mutualistic symbiotic associations with a vast array of terrestrial plants,arbuscular mycorrhizal(AM)fungi may play a critical role in maintaining soil multifunctionality,but the characteristics of their contributions remain to be unraveled.This mini review aims to disentangle the contributions of AM fungi to soil multifunctionality.We provide a framework of concepts about AM fungi making crucial contributions to maintaining multiple soil functions,including primary productivity,nutrient cycling,water regulation and purification,carbon and climate regulation,habitat for biodiversity,disease and pest control,and pollutant degradation and detoxification,via a variety of pathways,particularly contributing to soil and plant health.This review contends that AM fungi,as a keystone component of soil microbiome,can govern soil multifunctionality,ultimately promoting ecosystem services.
基金funded by the Funda??o Agrisus through project code‘PA3010/20’the Coordination for the Improvement of Higher Education Personnel,Brasil,under Finance Code 001。
文摘Managing fertilization in integrated crop-livestock systems(ICLS)during periods of low nutrient export,known as system fertilization,can optimize nutrient use by enhancing the soil's biochemical and physical-hydric properties.However,interdisciplinary studies on processes that improve input utilization in ICLS remain scarce.This study aimed to assess the relationships between the effciencies of different nutrient management strategies in ICLS and pure crop systems(PCS)and the biochemical and physical-hydric quality of soil.Two fertilization strategies(system fertilization and crop fertilization)and two cropping systems(ICLS and PCS)were evaluated in a randomized block design with three replicates.In the PCS,soybean was grown followed by ryegrass as a cover crop.In the ICLS,sheep grazed on the ryegrass.In the crop fertilization,phosphorus and potassium were applied to the soybean planting,and nitrogen was applied in the ryegrass establishment.Nitrogen,phosphorus,and potassium were applied during ryegrass establishment in the system fertilization.Soil quality indexes were calculated using fourteen physical-hydric and biochemical soil indicators,and primary production and nutrient utilization effciency were evaluated.System fertilization in ICLS enhanced the soil functions of water storage and availability for plants,structural stability,and resistance to degradation.System fertilization in ICLS improved the soil quality by 14%over PCS and 13%over crop fertilization in ICLS.Notably,this optimized system yielded the highest primary production.These findings underscore the pivotal role of system fertilization in ICLS to boost food production and enhance soil ecosystem services without increasing the consumption of external fertilizers.They advocate for a strategic shift towards system-level fertilization in integrated systems,and demonstrate for the frst time in ICLS,the delicate balance between nutrient management,soil health,and sustainable productivity.
基金supported by the National Natural Science Foundation of China (91325301, 41571130051)
文摘To deal with the global and regional issues including food security, climate change, land degradation, biodiversity loss, water resource management, and ecosystem health, detailed accurate spatial soil information is urgently needed. This drives the worldwide development of digital soil mapping. In recent years, significant progresses have been made in different aspects of digital soil mapping. The main purpose of this paper is to provide a review for the major progresses of digital soil mapping in the last decade. First, we briefly described the rise of digital soil mapping and outlined important milestones and their influence, and main paradigms in digital soil mapping. Then, we reviewed the progresses in legacy soil data, environmental covariates, soil sampling, predictive models and the applications of digital soil mapping products. Finally, we summarized the main trends and future prospect as revealed by studies up to now. We concluded that although the digital soil mapping is now moving towards mature to meet various demands of soil information, challenges including new theories, methodologies and applications of digital soil mapping, especially for highly heterogeneous and human-affected environments, still exist and need to be addressed in the future.
基金Under the auspices of Ministry of Education,China (No.108148)State Key Laboratory of Urban and Regional Ecology (No.SKLURE2010-2-2)+2 种基金National Basic Research Program of China (No.2010CB951203)Key Research Program of Shanghai Science & Technology (No.08231200700,08231200702)111 Project,Ministry of Education,China (No.B08022)
文摘The objective of this study is to analyze soil physical and chemical properties,soil comprehensive functions and impact factors after different years of reclamation.Based on the survey data taken from 216 soil sampling points in the Fengxian Reclamation Area of the Changjiang (Yangtze) River Estuary,China in April 2009 and remotely sensed TM data in 2006,while by virtue of multivariate analysis of variance (MANOVA),geo-statistical analysis (GA),prin-cipal component analysis (PCA) and canonical correspondence analysis (CCA),it was concluded that:1) With the in-crease in reclamation time,soil moisture,soil salinity,soil electric conductivity and soil particle size tended to decline,yet soil organic matter tended to increase.Soil available phosphorous tended to increase in the early reclamation period,yet it tended to decline after about 49 years of reclamation.Soil nitrate nitrogen,soil ammonia nitrogen and pH changed slightly in different reclamation years.Soil physical and chemical properties reached a steady state after about 30 years of reclamation.2) According to the results of PCA analysis,the weighted value (0.97 in total) that represents soil nutrient factors (soil nitrate nitrogen,soil organic matter,soil available phosphorous,soil ammonia nitrogen,pH and soil particle size) were higher than the weighted value (0.48 in total) of soil limiting factors (soil salinity,soil elec-tric conductivity and soil moisture).The higher the F value is,the better the soil quality is.3) Different land use types play different roles in the soil function maturity process,with farmlands providing the best contribution.4) Soil physi-cal and chemical properties in the reclamation area were mainly influenced by reclamation time,and then by land use types.The correlation (0.1905) of the composite index of soil function (F) with reclamation time was greater than that with land use types (-0.1161).
基金Project supported by the National Natural Science Foundation of China (No. 40371108) the National "211" Key Project of China: The environmental evolution and ecological construction on multi-spatio-temporal scales.
文摘A vegetation evolution model influenced by a degeneration of soil ecological functions was set up. Three ideal communities of a) trees, b) shrubs, and c) herbage populations were first simulated. Then numerical simulations of the evolutionary and developmental processes of a natural forest community, which is composed of over 100 species,were conducted. Results of the study showed that a) in all communities, soil degeneration not only drove some weaker species to extinction, but also a few dominant ones; b) there were different response scales with species in an ideal tree metapopulation that could persist as long as a thousand years, with shrubs in an ideal shrub metapopulation that could persevere for several hundred years, and with species in an ideal herbage metapopulation that could become extinct within 10 years; and c) each metapopulation experienced three evolutionary stages during adaptation to the environment: a) the stage of compelled adaptation or resistance, b) the adjusted stage, and c) the stabilized stage.
基金supported by the Soil Erosion and Dryland Farming on Loess Plateau of the State Key Laboratory of Chinese Academy of Sciences (K318009902-1310) the Shaanxi Province Innovative Engineering Project Coordinator (2011K01-48)
文摘Monitoring soil microbial communities can lead to better understanding of the transformation processes of organic carbon in soil. The present study investigated the changes of soil microbial communities during straw decomposition in three fields, i.e., cropland, peach orchard and vineyard. Straw decomposition was monitored for 360 d using a mesh-bag method. Soil microbial metabolic activity and functional diversity were measured using the Biolog-Eco system. In all three fields, dried straws with a smaller size decomposed faster than their fresh counterparts that had a larger size. Dried corn straw decomposed slower than dried soybean straw in the early and middle stages, while the reverse trend was found in the late stage. The cropland showed the highest increase in microbial metabolic activity during the straw decomposition, whereas the peach orchard showed the lowest. There was no significant change in the species dominance or evenness of soil microbial communities during the straw decomposition. However, the species richness fluctuated significantly, with the peach orchard showing the highest richness and the cropland the lowest. With different carbon sources, the peach orchard utilised carbon the most, followed by the cropland and the vineyard. In all three fields, carbon was utilized in following decreasing order： saccharides〉amino acids〉polymers〉polyamines〉carboxylic acids〉aromatic compounds. In terms of carbon-source utilization, soil microbial communities in the peach orchard were less stable than those in the cropland. The metabolic activity and species dominance of soil microbial communities were negatively correlated with the straw residual percentage. Refractory components were primarily accumulated in the late stages, thus slowing down the straw decomposition. The results showed that dried and crushed corn straw was better for application in long-term fields. The diversity of soil microbial communities was more stable in cropland than in orchards during the straw decomposition.
基金supported by the National Science Fund Projects (Nos. 41371266 and 31670507)Innovation in Cross-functional Team Program of the Chinese Academy of Sciences (No. 2015)+1 种基金the Key Research Program of Chinese Academy of Sciences (No. ZDRW-ZS-2016-5)the Key State Science and Technology Program of China (No. 2015ZX07206-006)
文摘Ammonia（NH3） volatilization is one of the primary pathways of nitrogen（N） loss from soils after chemical fertilizer is applied, especially from the alkaline soils in Northern China, which results in lower efficiency for chemical fertilizers. Therefore, we conducted an incubation experiment using an alkaline soil from Tianjin（p H 8.37–8.43） to evaluate the suppression effect of Trichoderma viride（T. viride） biofertilizer on NH3 volatilization, and compared the differences in microbial community structure among all samples. The results showed that viable T. viride biofertilizer（T） decreased NH3 volatilization by 42.21% compared with conventional fertilizer（（CK）, urea）, while nonviable T. viride biofertilizer（TS） decreased NH3 volatilization by 32.42%. NH3 volatilization was significantly higher in CK and sweet potato starch wastewater（SPSW） treatments during the peak period. T. viride biofertilizer also improved the transfer of ammonium from soil to sweet sorghum. Plant dry weights increased 91.23% and 61.08% for T and TS, respectively, compared to CK. Moreover, T. viride biofertilizer enhanced nitrification by increasing the abundance of ammonium-oxidizing archaea（AOA） and ammonium-oxidizing bacteria（AOB）. The results of high-throughput sequencing indicated that the microbial community structure and composition were significantly changed by the application of T. viride biofertilizer. This study demonstrated the immense potential of T. viride biofertilizer in reducing NH3 volatilization from alkaline soil and simultaneously improving the utilization of fertilizer N by sweet sorghum.
基金Supported by the Slovak Research and Development Agency(No.APVV 0131-11)the Scientific Grant Agency of the Ministry of Education of Slovak Republic(Nos.1/0008/13 and VEGA 1/0070/12)
文摘The soil environmental index(SEI),which is a four digit code system,represents relatively homogenous spatial unit with specific soil capacity to provide ecological or non-production functions.This work aimed to present information on rating and economic evaluation of SEI,which is a spatial identifier used for expressing heterogeneity of Slovak agricultural soil to support analysis of soil ecological functions.In this study,SEI index expressed the capacity of soil to accumulate water,immobilise the risk elements and substances and transform risk substances(organic pollutants).Partial evaluations of soil capacity to provide above mentioned functions were used to derive final SEI values.Within the agricultural soils of Slovakia there were 493 combinations of soil environmental index.Each index was expressed through rating(point)value and economic value.Average value of Slovak agricultural land to provide selected ecological soil functions was 55.3 points,which corresponded to 35.946 billionper agricultural land or approximately 1.42per square meter.Spatial identification of SEI codes and relevant database were developed in vector form via geographical information systems of Soil Science and Conservation Research Institute,Bratislava.In addition to using the national soil database system,a strategy was presented for evaluating and pricing of soil ecological function,and the development of an soil environmental index.Assessment and evaluation of vitally important soil functions expressed by SEI can significantly contribute to planning and protection of the soil,and can regulate indiscriminate anthropic interventions in land use decisions.
文摘At the end of October 2018,a storm of unprecedented strength severely damaged the forests of the eastern sector of the Italian Alps.The affected forest area covers 42,500 ha.The president of one of the damaged regions asked for help from the University of Padua.After eight months of discussion,the authors of this article wrote a consensus text.The sometimes asper debate brought to light some crucial aspects:1)even experienced specialists may have various opinions based on scientific knowledge that lead to conflicting proposals for action.For some of them there is evidence that to restore a destroyed natural environment it is more judicious to do nothing;2)the soil corresponds to a living structure and every ecosystem’s management should be based on it;3)faced with a catastrophe,people and politicians find themselves unarmed,also because they rarely have the scientific background to understand natural processes.Yet politicians are the only persons who make the key decisions that drive the economy in play and therefore determine the near future of our planet.This article is an attempt to respond directly to the governor of a region who formally and prudently asked a university department called"Land,Environment,Agriculture and Forestry"for help before taking decisions;4)the authors also propose an artistic interpretation of facts(uncontrolled storm)and conclusions(listen to the soil).Briefly,the authors identify the soil as an indispensable source for the renewal of the destroyed forest,give indications on how to prepare a map of the soils of the damaged region,and suggest to anchor on this soil map a series of silvicultural and soil management actions that will promote the soil conservation and the faster recovery of the natural dynamic stability and resilience.
文摘Vegetation types alter soil ecosystems by changing soil fauna community activities and soil physi-cal-chemical properties.However,it is unclear how tree species(natural forest,native and exotic tree plantations)promote changes in the soil ecosystem,and if these changes alter functional groups of soil fauna and ecosystem services.To determine the effects of five decades of old-field veg-etation on soil ecosystems in the Brazilian Atlantic Forest,field sampling of three ecosystems(exotic tree species Pinus elliottii Engelm.plantation,endangered tree species Arau-caria angustifolia(Bertol.)Kuntze plantation,and a natural ecosystem)were carried out,as well using bait-lamina tests and bioassays with collembolans,earthworms and seeds of Lactuca sativa L.Field sampling evaluated the soil fauna community and soil physical-chemical properties.The bait-lamina test in situ was carried out for 14-days to deter-mine fauna feeding activity,and the bioassays evaluated the reproduction of Folsomia candida,the avoidance of Eisenia andrei,and germination of L.sativa in the soil from each ecosystem.The results are:(1)vegetation type altered the soil fauna community composition;(2)soil fauna feeding was reduced in the plantations compared to the natural eco-system;(3)a physical barrier was created by recalcitrant litter that compromised fauna community structure and seed bank germination in situ;and,(4)changes in soil physical-chemical properties promoted decomposers.
文摘Ten runoff plots with different planting patterns were established for experimental observation in Yangjichong small watershed of Longli County in Karst region of Guizhou Province. Results show that under the same rainfall condition, shrub land, natural grassland and abandoned land presented the best function of soil and water conservation. The function of soil and water conservation was poor for arbor planting pattern, because the shrub layer, herb layer and forest floor were not formed. Because of no-tillage, surface crust and other effects, the function of soil and water conservation in slope farmland was better than that in runoffplots with arbor planting pattern.
基金supported by the National Natural Science Foundation of China (Grant No 60571058)the Specialized Research Fund for the Doctoral Program of Higher Education Institutions of China (Grant No 20070701010)
文摘Electromagnetic scattering from a rough surface of layered medium is investigated, and the formulae of the scattering coefficients for different polarizations are derived using the small perturbation method. A rough surface with exponential correlation function is presented for describing a rough soil surface of layered medium, the formula of its scattering coefficient is derived by considering the spectrum of the rough surface with exponential correlation function; the curves of the bistatic scattering coefficient of HH polarization with variation of the scattering angle are obtained by numerical calculation. The influence of the permittivity of layered medium, the mean layer thickness of intermediate medium, the roughness surface parameters and the frequency of the incident wave on the blstatic scattering coefficient is discussed. Numerical results show that the influence of the permittivity of layered medium, the mean layer thickness of intermediate medium, the rms and the correlation length of the rough surface, and the frequency of the incident wave on the bistatic scattering coefficient is very complex.
基金CAS-CSIRO Cooperative Research Program,No.CJHZ1223National Basic Research Program of China,No.2010CB428406
文摘Actual evapotranspiration is a key process of hydrological cycle and a sole term that links land surface water balance and land surface energy balance.Evapotranspiration plays a key role in simulating hydrological effect of climate change,and a review of evapotranspiration estimation methods in hydrological models is of vital importance.This paper firstly summarizes the evapotranspiration estimation methods applied in hydrological models and then classifies them into the integrated converting methods and the classification gathering methods by their mechanism.Integrated converting methods are usually used in hydrological models and two differences exist among them:one is in the potential evaporation estimation methods,while the other in the function for defining relationship between potential evapora tion and actual evapotranspiration.Due to the higher information requirements of the Pen-man-Monteith method and the existing data uncertainty,simplified empirical methods for calculating potential and actual evapotranspiration are widely used in hydrological models.Different evapotranspiration calculation methods are used depending on the complexity of the hydrological model,and importance and difficulty in the selection of the most suitable evapotranspiration methods is discussed.Finally,this paper points out the prospective de velopment trends of the evapotranspiration estimating methods in hydrological modeling.
文摘Soil macroinvertebrates play an important role in sustaining production and biodiversity in Australia＇ s tropical savannas. For example, termites, through their foraging and nesting activities, recycle nutrients and carbon and produce soil pores that facilitate water infiltration. The challenge ahead is to quantitatively understand the relationships and processes that drive this. What roles do different species and functional groups of macroinvertebrates play in various landscape processes？ What are the effects of different land management practices （e.g., domestic cattle grazing, fire） on these relationships, and the consequences for landscape health？ This paper presents preliminary results from studies in northern Australia, that examine the effects of land condition and domestic cattle grazing on soil macroinvertebrates, and the potential for termites to be used as a tool to restore soil function in degraded areas. In northern Australia, increased degradation seems to be associated with declines in the diversity and activity of macroinvertebrates. Termites appear to be one of the most resilient groups, with some species capable of maintaining activity in degraded landscapes.
文摘Soil microbial alpha diversity is essential for driving ecosystem functions and processes.However,little is known about the beta-diversity affect community functions.Here,we combine distinct community inocula using the dilution-to-extinction approach with two wheat genotypes to study the effect of microbial diversity loss on rhizosphere community assembly processes,which are related to beta-diversity(between-habitat diversity),and the consequences for ecosystem functions within greenhouse experiment.Compared with alpha-diversity,the bacterial and fungal community beta-diversity are stronger predictors of ecosystem functions(organic matter degradation,phosphorus supply capacity and nitrogen supply capacity),plant genotypes regulated the relationship between microbial diversity and ecosystem functions,with ecosystem functions being significant link to microbial diversity under different wheat genotypes.Loss of microbial diversity decreased the abundance of Bacterial_ASV6(Burkholderia)and increased Fungal_11(Altemaria)within the restored rhizosphere soil.Null modeling analysis showed that the deterministic assembly processes are dominant in bacterial community and fungal high-diversity(alpha-diversity)community,associating with the change of specialized functions(organic matter degradation,phosphorus supply capacity and nitrogen supply capacity)that are correlated with microbial diversity and specific microbial taxa.In addition,these two species were key role for regulating to the network cohesion.Overall,our study pointed out that the regulation of community assembly by microbial diversity loss limits the development of soil ecological functions and weakens the stability of rhizosphere microbial network,highlighting the potential regulatory effect of microbial taxa distribution on microbial community stability and changes of specific ecological functions.
基金the China Scholarship Council for a scholarship(CSC number 202108080156 and 202106320023)Open Access funding enabled and organized by Projekt DEAL.
文摘A range of land management practices are available to achieve better soil quality,but their combined effects remain understudied.We hypothesize that more diverse management practices,meaning higher dissimilarity,lead to stronger effects on soil functions and properties.Eight practices(biochar,compost,clay,amorphous silica,basalt,microbial inoculum,reduced physical disturbance and organic matter diversity)were selected with 20 replicates for treatments involving 2,4,or 6 factors and 10 replicates for 8 factor treatments.We investigated the impact of individual factors,factor number,factor dissimilarity and factor composition on soil respiration,soil enzymatic activities(β-glucosidase,β-Dcellobiosidase,β-N-acetylglucosaminidase and phosphatase),soil pH,water stable aggregates and permanganate oxidizable carbon fraction.By including dissimilarity in addition to factor number,variance explained for soil respiration and enzymatic activities increased up to 54.21%.For soil pH and water-stable aggregates,explained variability increased to 65.57%and 57.38%,respectively.More diverse management practices boosted soil microbial activities,enhanced soil aggregate stability,improved soil pH while reducing labile carbon,whereas factor number only influenced water stable aggregates and soil pH.Our study highlights the importance of management practices diversity in soil functions and properties and calls for further research on synergistic combinations of diverse interventions.
