In this study,the influence of soil properties on the failure behavior and mechanism of slope under earthquake after rainfall was studied with shaking table test in the laboratory,in which the failure process of slope...In this study,the influence of soil properties on the failure behavior and mechanism of slope under earthquake after rainfall was studied with shaking table test in the laboratory,in which the failure process of slope and instant responses of water content and pore water pressure were tested.Based on the principle of similarity,a model test was designed.The experimental results showed that soil properties exhibit significant influence on failure mode and failure mechanism of slope.Local flowslide,local failure,and creep flowslide failure modes appear in the slope exposed to only rainfall.However,under earthquake after rainfall,the other three failure modes occur,i.e.,local slip failure,overall slip failure,and shallow scouring and creep flowslide failure.The spatial distribution of water content and pore water pressure are the two key factors leading to slope failure.Furthermore,due to the difference of permeability,the soil properties not only affect the spatial distribution of water content of the slope after rainfall,resulting in the peak pore water pressure which occurs mainly near the foot of the slope and near the bedrock interface in the middle and lower parts of the slope,but also affect the dissipation of excess pore water pressure in the process of earthquake.Finally,it is discovered that different types of soil lead to significant differences in the peak acceleration of slope failure.The critical acceleration of slope with coarse-grained soil is greater than that of slope with fine-grained soil.The critical acceleration of slope failure shows a close relationship with soil properties.展开更多
This article presents a 2017 LiDAR-DEM guided 1-m resolution examination of field-surveyed elevation and soil property variations (5 × 5 m spacings) conducted in 1977 across a hummocky New Brunswick field used fo...This article presents a 2017 LiDAR-DEM guided 1-m resolution examination of field-surveyed elevation and soil property variations (5 × 5 m spacings) conducted in 1977 across a hummocky New Brunswick field used for potato production. This examination revealed that the field incurred minor elevation differences likely due to upslope erosion as revealed through increasing Sand % and CF % with increasing elevation, and increasing Silt % along low-lying areas. Soil moisture, field capacity, permanent wilting and nitrate nitrogen (NO<sub>3</sub>-N) also increased at downslope locations. Directly as well as indirectly, soil pH, ammonium nitrogen (NH<sub>4</sub>-N), Caesium<sup>137</sup> (Cs<sup>137</sup>) and Mehlich-3 extracted Ca, Mg, K, Fe, Mn, Cu, and Zn were likewise affected by topographic location. Factor analyzing these variables led to: 1) a Soil Loss Factor that captured 24% of the textural variations;2) a Soil-Cropping Factor accounting for 16% of the N, P, K, Ca, Mg, Mn variations;3) a Soil Organic Matter (SOM) Factor relating 9% of the in-field variations for SOM, Fe, Zn, Cu to via organo-metal complexation and low NO<sub>3</sub>-N retention. Many of the topographic variations increased or decreased with the metric DEM-projected depth-to-water index (DTW) index. This index was set to 0 along DEM-derived flow channels with minimum upslope flow-accumulation areas of 0.1, 0.25, 0.5, 1 or 4 ha. Among these, the DTW > 4 ha threshold was useful for reproducing the textural variations, while the DTW > 0.25 ha threshold assisted in capturing trends pertaining to moisture retention and elemental concentrations.展开更多
The montane forests of Garhwal Himalaya were investigated for tree species composition and diversity in relation to environmental and edaphic variables.A stratified random sampling approach was adopted to collect the ...The montane forests of Garhwal Himalaya were investigated for tree species composition and diversity in relation to environmental and edaphic variables.A stratified random sampling approach was adopted to collect the field data from each forest.A total of 39 tree species belonging to 31 genera and 23 families were recorded from the sampling area(6 forest stands ×10 plots in each).Lauraceae with 5 species was the largest family while Quercus(4 species) emerged as the largest genus.Species-area curve(asymptote) predicted more species than the observed number of species.Cluster analysis has shown that the two Abies pindrow dominant forest stands had the highest similarity in tree species composition.The tree stem density ranged from 540-1170 ha-1,basal area 23.01-55.94 m^2 ha-1,ShannonWiener diversity index 1.69-2.49,evenness index0.42-0.74,beta diversity 0.40-0.82 and similarity index 0.17-0.54 in the six studied forests.Two-way indicator species analysis(TWINSPAN) identified four distinct tree communities in the study area with Daphniphyllum himalayense,Abies pindrow,Quercus oblongata,and Pinus roxburghii as indicator species of corresponding communities.Canonical correspondence analysis(CCA) ascertained the TWINSPAN results and revealed the relation of tree species with environmental and edaphic variables.The phytosociological attributes of tree species varied from one forest stand to another;however,the tree species richness,density,and diversity peaked at intermediate elevation on the north aspect.Findings reveal that tree composition and diversity in the montane forests of Garhwal Himalaya are influenced by both environmental(elevation and slope aspect)and soil variables(texture,water holding capacity,moisture content,available N,exchangeable P,and pH).This study will help in understanding the forest distribution across the western Himalaya,guiding the conservationists and policymakers in carrying out conservation-related management activities,designing the long-term monitoring studies and assessing the effects of ongoing and future climate change and disturbances.展开更多
Alpine grassland of the Tibetan Plateau has undergone severe degradation, even desertification. However, several questions remain to be answered, especially the response mechanisms of vegetation biomass to soil proper...Alpine grassland of the Tibetan Plateau has undergone severe degradation, even desertification. However, several questions remain to be answered, especially the response mechanisms of vegetation biomass to soil properties. In this study, an experiment on degradation gradients was conducted in an alpine meadow at the Zoige Plateau in 2017. Both vegetation characteristics and soil properties were observed during the peak season of plant growth. The classification and regression tree model(CART) and structural equation modelling(SEM) were applied to screen the main factors that govern the vegetation dynamics and explore the interaction of these screened factors. Both aboveground biomass(AGB) and belowground biomass(BGB) experienced a remarkable decrease along the degradation gradients. All soil properties experienced significant variations along the degradation gradients at the 0.05 significance level. Soil physical and chemical properties explained 54.78% of the variation in vegetation biomass along the degradation gradients. AGB was mainly influenced by soil water content(SWC), soil bulk density(SBD), soil organic carbon(SOC), soil total nitrogen(STN), and pH. Soil available nitrogen(SAN), SOC and p H, had significant influence on BGB. Most soil properties had positive effects on AGB and BGB, while SBD and p H had a slightly negative effect on AGB and BGB. The correlations of SWC with AGB and BGB were relatively less significant than those of other soil properties. Our results highlighted that the soil properties played important roles in regulating vegetation dynamics along the degradation gradients and that SWC is not the main factor limiting plant growth in the humid Zoige region. Our results can provide guidance for the restoration and improvement of degraded alpine grasslands on the Tibetan Plateau.展开更多
Terracing greatly affects soil properties,ecosystem services,human welfare and geographical sustainability.The purpose of this article is to determine the influence of terracing on soil properties across diverse regio...Terracing greatly affects soil properties,ecosystem services,human welfare and geographical sustainability.The purpose of this article is to determine the influence of terracing on soil properties across diverse regions in China.Three representative terrace types,including dryland loess terraces,dry-stone terraces,and paddy terraces,were selected as case study areas.Soil sampling was stratified according to thickness of soil layers in each terraced area.Based on field investigations and soil sampling,combined with the means of variance,correlation,redundancy and regression analysis,we analyzed the characteristics of soil properties in the terraces across three areas.Results showed that:(1)alterations of soil physicochemical properties mainly depend on differences between soil parent materials in such regions;(2)Due to the existence of“four-element isomorphism”in the ecosystem and reasonable human activities,paddy terraces had the greatest impact on soil properties which is mainly reflected in decreasing soil pH and increasing SOC,TN,and TK;(3)The content of SOC and TN in different areas was higher in terraced fields than in the sloped lands and decreased with soil deepening;(4)To maintain sufficient supply of soil nutrients and support the sustainability of agricultural terraces,it is necessary to apply manure to improve soil fertility and accelerate its aggregation in the terraces.For example,an increase in the application of nitrogen fertilizer in terraced fields in Hebei and Gansu provinces,which have a serious deficiency in soil available phosphorus(AP),is necessary to get greater amounts of P fertilization.The present study offers a theoretical foundation for the sustainability of terraced ecosystems through efficient crop production,which is the basis for strengthening the ecological security of terraced areas and promoting regional sustainability in those fragile mountains.展开更多
In the permafrost regions of the Qinghai-Tibet Plateau(QTP),the permafrost table has a significant effect on the stability of geotechnical engineering.The thermal boundaries and soil properties are the key factors aff...In the permafrost regions of the Qinghai-Tibet Plateau(QTP),the permafrost table has a significant effect on the stability of geotechnical engineering.The thermal boundaries and soil properties are the key factors affecting the permafrost table.Complex geological environments and human activities can lead to the uncertainties of thermal boundaries and soil properties.In this paper,an array of field experiments and Monte Carlo(MC)simulations of thermal boundaries and soil properties are carried out.The coefficient of variation(COV),scale of fluctuation(SOF),and autocorrelation distance(ACD)of uncertainties of thermal boundaries and soil properties are investigated.A stochastic analysis method of the probabilistic permafrost table is then proposed,and the statistical properties of permafrost table on the QTP are computed by self-compiled program.The proposed stochastic analysis method is verified with the calculated and measured temperature observations.According to the relationship between ACD and SOF for the five theoretical autocorrelation functions(ACFs),the effects of ACF,COV,and ACD of soil properties and the COV of thermal boundaries on the permafrost tables are analyzed.The results show that the effects of different ACFs of soil properties on the standard deviation(SD)of permafrost table depth are not obvious.The SD of permafrost table depth increases with time,and the larger the COVs of thermal boundaries and soil properties,the deeper the SD of permafrost table;the longer the ACD of soil properties,the shallower the SD of permafrost table.This study can provide a reference for the stability analysis of geotechnical engineering on the QTP considering the uncertainties of thermal boundaries and soil properties.展开更多
Patterns of woody regeneration in terms of species composition and diversity were studied in mixed deciduous forest (MDF) and deciduous dipterocarp forest (DDF) in Minbyin reserved forest of Lewe Township. A total of ...Patterns of woody regeneration in terms of species composition and diversity were studied in mixed deciduous forest (MDF) and deciduous dipterocarp forest (DDF) in Minbyin reserved forest of Lewe Township. A total of 57 plant species of MDF belonging to 28 families and 342 individuals and 25 plant species of DDF consist of 15 families and 285 individuals were identified. Plant species diversity was quantitatively higher in the MDF (H' = 3.68) compared to the DDF (H' = 2.39). Tectona grandis showed the highest density (30), dominance (4.40 m<sup>2</sup>) and IVI (27.01) of MDF and Dipterocarpus tuberculatus also composed the highest density (109), dominance (9.02 m<sup>2</sup>) and IVI (81.87) in DDF. The smallest diameter class (10 - 20 cm) comprised with 29 species, 103 individuals in MDF and 18 species, 85 individuals in DDF. The size class distribution displayed a reverse J-shaped pattern. The largest numbers of species were concentrated in the smallest height class in both investigated forests because of height and diameter distribution is closely related. The total densities of seedlings and saplings were 1219 and 531 ha<sup>-1</sup> in MDF and 988 and 444 ha<sup>-1</sup> in DDF respectively. Although soil texture of (40 - 50 cm) and (90 - 100 cm) were sandy clay loam in mixed deciduous forest, the other layers of both investigated forests were sandy loam.展开更多
The potential ability of the Vis-NIR (350 - 2500 nm) laboratory spectroscopy for prediction of soil properties has been demonstrated in the literature. The aim of this work was to predict different soil properties of ...The potential ability of the Vis-NIR (350 - 2500 nm) laboratory spectroscopy for prediction of soil properties has been demonstrated in the literature. The aim of this work was to predict different soil properties of soils collected in Mugan plain (Azerbaijan) using PLSR models and cross-validation. Carbonatation and salinisation are the main pedogenetic processes in Muganplain, therefore there is a need to monitor total carbonates and soil electrical conductivity (EC). The result of work was positive and both total carbonates and EC showed the best result (SE = 2.90, R<sup>2</sup>-0.90 and SE-0.09, R<sup>2</sup>-0.82, respectively). This parameter using PLSR, SOM (SE-0.54, R<sup>2</sup>-0.83), CEC (SE-0.43, R<sup>2</sup>-0.62), and Total P (SE-0.50, R<sup>2</sup>-0.73) is predicted and result is over optimist. Total N (SE-0.04, R<sup>2</sup>-0.44), and pH (SE-0.02, R<sup>2-</sup>0.51) demonstrated low prediction quality.展开更多
In an era of climate change, understanding the factors that impact root systems can improve our understanding of carbon cycling in forest ecosystems. The study objective was to determine the impact of climatic conditi...In an era of climate change, understanding the factors that impact root systems can improve our understanding of carbon cycling in forest ecosystems. The study objective was to determine the impact of climatic conditions on the biomass and morphology of roots of different tree species along an elevation gradient, and consequently on properties of montane forest soils. The study plots were established at three different elevations(600, 800 and1000 m a.s.l.) along a slope with an inclination of 15°. The research plots were located in a beech stand(Fagus sylvatica L.) and fir stand(Abies alba Mill.). Soil samples were collected from each study plot, for which basic physical and chemical properties were determined. Additionally, we determined the morphology, production and decomposition rate of fine roots. Our analyses confirmed the significance of climatic conditions in the formation of soil properties, in particular the amount of accumulated carbon and nitrogen content. A decrease of root biomass and reduced root growth were recorded with increasing elevation. The characteristics of roots were linked with the properties of the studied mountain soils, in particular p H, alkaline cation content and content of selected micronutrients. Limitation of root growth in higher elevations affected both study species. Additional research into the formation of tree root morphology is needed, especially in mountainous regions where changes may occur more dynamically. This will provide a better understanding of how stands can cope with different types of environmental stress.展开更多
Understanding the characteristics and influences of various factors on phosphorus(P)fractions is of significance for promoting the efficiency of soil P.Based on long-term experiments on black soil,fluvo-aquic soil,and...Understanding the characteristics and influences of various factors on phosphorus(P)fractions is of significance for promoting the efficiency of soil P.Based on long-term experiments on black soil,fluvo-aquic soil,and loess soil,which belong to Phaeozems,Cambisols,and Anthrosols in the World Reference Base for Soil Resources(WRB),respectively,five fertilization practices were selected and divided into three groups:no P fertilizer(CK/NK),balanced fertilizer(NPK/NPKS),and manure plus mineral fertilizer(NPKM).Soil inorganic P(Pi)fractions and soil properties were analyzed to investigate the characteristics of the Pi fractions and the relationships between Pi fractions and various soil properties.The results showed that the proportion of Ca_(10)-P in the sum of total Pi fractions was the highest in the three soils,accounting for 33.5%in black soil,48.8%in fluvo-aquic soil,and 44.8%in loess soil.Long-term fertilization practices resulted in periodic changes in soil Pi accumulation or depletion.For black soil and fluvo-aquic soil,the Pi accumulation was higher in the late period(10–20 years)of fertilization than in the early period(0–10 years)under NPK/NPKS and NPKM,whereas the opposite result was found in loess soil.The Pi accumulation occurred in all Pi fractions in black soil;mainly in Ca_(8)-P,Fe-P,and Ca_(10)-P in fluvo-aquic soil;and in Ca_(2)-P,Ca_(8)-P,and O-P in loess soil.Under CK/NK,the soil Pi was depleted mainly in the early period in each of the three soils.In addition to the labile Pi(Ca_(2)-P)and moderately labile Pi(Ca_(8)-P,Fe-P,Al-P),the Ca_(10)-P in black soil and fluvo-aquic soil and O-P in loess soil could also be used by crops.Redundancy analysis showed that soil properties explained more than 90%of the variation in the Pi fractions in each soil,and the explanatory percentages of soil organic matter(SOM)were 43.6%in black soil,74.6%in fluvo-aquic,and 38.2%in loess soil.Consequently,decisions regarding the application of P fertilizer should consider the accumulation rate and the variations in Pi fractions driven by soil properties in non-acidic soils.展开更多
:Earth is the most common and important building material used in the construction industry,since it is found in almost every country in the world.Modern earthen construction is alive and well,and is spread over an en...:Earth is the most common and important building material used in the construction industry,since it is found in almost every country in the world.Modern earthen construction is alive and well,and is spread over an enormous geographical area.This technique utilizes various earthen materials and numerous methods,and features many benefits for both construction in general and buildings in particular.Najran,a city located in the south of Saudi Arabia,is distinguished by its heritage of earthen architecture,which displays many advantages and a marvelous variety of types and exterior designs.Many weaknesses of the material,however,along with a lack of knowledge and rapid development have caused the uplifting and destruction of many of Najran’s mud and heritage buildings during the last few generations.Not all soil types are suitable for every building need.Soil specification is thus very important in order to ensure that the materials used in construction meet all requirements.The main goal of this study was to invistegate the suitability of local soils for the earthen building construction.Thus,available local materials of common quality were taken from local sites in Najran.Laboratory experimentation and testing was then performed to determine the properties of those materials.The results showed that local soil properties are suitable for using in the earthen block construction since they satisified the specifications.The results were then recorded for use in further studies,as well as to explore heritage building and rehabilitation,and to improve modern earthen building materials and techniques.展开更多
[Objectives]This study was conducted to investigate the vegetation community characteristics and soil properties of secondary grassland in abandoned farmland areas of different years in Minqin Oasis. [Methods] By the ...[Objectives]This study was conducted to investigate the vegetation community characteristics and soil properties of secondary grassland in abandoned farmland areas of different years in Minqin Oasis. [Methods] By the method of space-for-time substitution, the changes of vegetation community characteristics(species composition, structural characteristics and important values) and soil microbial and enzyme activity were determined, and the correlation between various soil factors was analyzed. [Results](1) There were 39 species belonging to 32 genera of 15 families in the research area, including 8 shrub plants, 15 perennial herbs and 16 annual herbs.(2) Soil microbial biomass carbon, nitrogen and phosphorus contents were higher in the upper layer than in the lower layer, and the phenomenon of “surface aggregation” was obvious. The differences were different with the change of abandoned years.(3) Soil catalase content was the highest among different plots, and soil phosphatase, sucrase and urease all showed a trend of fluctuating decline with the increase in abandoned years. Soil enzyme changes were different in different soil layers. [Conclusions] This study can provide a theoretical basis for the restoration, reconstruction and rational protection and utilization of secondary grassland in abandoned farmland.展开更多
[Objective]The research was designed to explore the effect of long-term stacking of solid waste produced in the coal-burning process of central heating enterprises on physical and chemical properties of soil.[Method]T...[Objective]The research was designed to explore the effect of long-term stacking of solid waste produced in the coal-burning process of central heating enterprises on physical and chemical properties of soil.[Method]This study took the heating enterprises in Shenyang City as the research object.The morphological structure and element composition of coal cinder were determined by continuously collecting coal and cinder samples in different periods.At the same time,the original soil and cinder soil of the stacking site were collected to determine the changes of soil morphological structure,element composition and physical and chemical properties,so as to provide reference for the resource utilization of local cinder waste and the potential pollution risk of the stacking site.[Result]The contents of C,H,O,N,and S non-metallic elements in coal cinder decreased by 69.5%,71.2%,76.0%,74.5%,and 34.6%,respectively when compared with raw coal;while the content of Si increased significantly by 95.7%.The contents of Al,K,and Fe in cinder decreased by 4.3%,60.2%,and 33.3%,respectively,while the contents of Mg and Na increased by 36.1%and 130.9%,respectively.Compared with the original soil,the contents of C,H,and O in shallow cinder soil and deep cinder soil increased by 126.5%,67.9%,80.93%,and 21.3%,25.0%and 42.3%,respectively.The residual carbon existed in the form of activated carbon.The contents of Mg,Al,K,Na,Ca,and Fe in shallow cinder soil and deep cinder soil increased by 61.6%,5.4%,46.1%,35.8%,32.5%,6.3%and 22.3%,12.3%,12.2%,15.6%,5.8%and 2.8%,respectively compared with the original soil.The content of heavy metal elements in coal cinder did not reach the detection limit.Under the scanning electron microscope,the raw coal is mainly block structure,while the cinder is honeycombed and porous and dust.[Conclusion]Cinder stacking can significantly improve the content of organic matter and available K in shallow cinder soil,and improve the porosity and permeability of soil.In addition,cinder waste has high pH and pore structure,which can be used as acid soil conditioner,seedling flower matrix and compound fertilizer filler to take full advantage of cinder waste,improve soil structure and supply nutrients.展开更多
Abandoned land and mansions are always a matter of curiosity to the human beings. They are treated as haunted places in many societies. In the present research, three decrepit abandoned mansions from the southern Bang...Abandoned land and mansions are always a matter of curiosity to the human beings. They are treated as haunted places in many societies. In the present research, three decrepit abandoned mansions from the southern Bangladesh were investigated to measure their floral diversity, physico-chemical properties of soil and the soil-plant interrelationship which is responsible for the diversification of wild flora within the regions. From Shannon and Simpson diversity indexes, it can be deducted that the floral diversity within the abandoned mansions ha</span><span style="font-family:"">s</span><span style="font-family:""> a<span style="color:red;"> </span>positive relationship with their territory size. The high values of Marg<span>alef’s and Menhinick’s species richness indexes confirmed that these areas are a rich source of a large number of plant species. A great variation in soil physico-chemical properties has been observed during the analysis. Soil organic matter, nitrogen, phosphorus, potassium & moisture contents were varied significantly from one quadrat to another in every site. Biplot analysis showed that the distribution of plant species in abandoned mansions </span></span><span style="font-family:"">is</span><span style="font-family:""> primarily determined by the organic matter, pH, moisture and potassium contents of soil. As t</span><span style="font-family:"">hese factors were present in versatile distribution within the studied regions, a great number of plants can grow in the same area simultaneously. So these areas should be protected from human intervention to proce</span><span style="font-family:"">ss</span><span style="font-family:""> natural selection and in situ conservation of plant species.展开更多
The influence of fly ash(FA)applied alone and/or with sewage sludge(SS)on wheat(Triticum vulgare)grain yield,biomass production and soil properties was studied in a field experiment.The results showed that both FA and...The influence of fly ash(FA)applied alone and/or with sewage sludge(SS)on wheat(Triticum vulgare)grain yield,biomass production and soil properties was studied in a field experiment.The results showed that both FA and SS significantly increased grain yield and plant biomass.FA applied alone increased significantly soil pH and EC while FA applied together with SS did not significantly affect them compared to mono FA treatment.Soil pH and EC values increased with time in FA and FA-SS treatments.SS increased soil organic matter and total N content and SS applied together with FA increased also available soil B.From the plant nutrients tested only tissue N concentration was increased significantly in all treatments compared to control.Copper,Zn,Mn,Ni,and Pb at both available and total concentrations are significantly affected.展开更多
Considering that diverse fire severities can affect soil properties differently,the aim of this study was to examine to what extent changes in soil properties caused by fire could condition seedling establishment.This...Considering that diverse fire severities can affect soil properties differently,the aim of this study was to examine to what extent changes in soil properties caused by fire could condition seedling establishment.This new approach is for identifying a new fire cause-effect chain to qualify the impacts of fire on soils with the purpose of using fire as a tool in forest management to favour Pinus halepensis Mill.regeneration.The study area was a reforested P.halepensis area which had been crossed by fire for78.8 ha,causing various degrees of damage.The forest was subdivided into three large areas according to the gravity of crown scorch,[low(LS),medium(MS)and high(HS)severity],on the basis of needle yellowing which usually occurs after exposure to direct flames.Results showed significant differences in soil properties with respect to fire severity.In the HS area,total nitrogen and carbon were considerably reduced while ash and phosphorus contents significantly increased.The changes in soil properties,in particular to nutrient levels,affected P.halepensis regeneration,mainly the first year after the fire.Greater regeneration occurred in areas affected by moderate fire severity in which the temperatures reached increased the mineralization of soil organic matter with the consequent release of nutrients available for seedling growth.Additionally,moderate fire severity suppressed the regeneration of grasses,reducing the interspecific competition.Heights of seedlings were inversely proportional to the density of grasses.Where the number was abundant(LS),the height was modest;conversely,where the number was low(HS),the greater hypsometric differentiation of pine seedlings was observed.These results suggest that moderate fire severity represents an environmental stress(hormesis)altering microscale conditions to increase pine germination and establishment.The exposure of P.halpensis to a moderate environmental factor that is damaging at higher intensities,induces an adaptive beneficial effect on seedling regeneration.This data can re-evaluate the assertion that coniferous burned areas,if left unmanaged,would remain unproductive for an indefinite period.展开更多
The decay rate of standing Korean pine(Pinus koraiensis)in natural forests can be as high as 50%and is likely infl uenced by the soil properties and nutrient and water status of the site.To clarify the relationship be...The decay rate of standing Korean pine(Pinus koraiensis)in natural forests can be as high as 50%and is likely infl uenced by the soil properties and nutrient and water status of the site.To clarify the relationship between the severity of tree decay and soil properties in order to prevent decay in a natural mixed forest in the Xiaoxing'an Mountains,wood strength of standing trees was nondestructively assessed,and the severity of decay of extracted wood cores was quantified based on differences in mass between two decayed increment cores extracted at breast height and an intact increment core near the decayed ones.Soil samples from the critical root zone(non-rhizosphere)of each tree were analyzed for chemical properties and microbial composition.The abundance of chemical elements(especially total N and K)and the species richness of soil microbes increased as decay severity increased.Fungal number(FN)and actinomycetes number(AN)were related to decay severity(R^(2)=0.504).Bacterial number(BN)was higher than FN or AN,but had a minor effect on tree decay.Path analysis showed BN might indirectly inhibit decay by affecting FN.Decay severity was not significantly correlated with either soil fungal or bacterial diversity.These results suggest that forest managers need to monitor levels of fungi and total N and total K levels to reduce the decay of Korean pine.展开更多
This study was conducted in Juniperus excels a stands on the southern slopes of Iran’s Alborz Mountains,to determine the effects of fire and seasonal variations on soil physicochemical properties and enzyme activitie...This study was conducted in Juniperus excels a stands on the southern slopes of Iran’s Alborz Mountains,to determine the effects of fire and seasonal variations on soil physicochemical properties and enzyme activities.A total of 64 composite soil s amples were randomly collected in the spring and fall from two burned and unburned sites at depths of 0-10 and 10-20 cm.The results of a two-way ANOVA analysis indicate that fire increased the organic carbon(OC),total nitrogen(TN),and available phosphorus(P_(ava)) contents of the soil by 16%,59%,and 53%,respectively.Similarly,when burned sites were compared to unburned sites,the activities of acid phosphatase(ACP) and urease enzymes increased by 73% and 12%,respectively.Nevertheless,fire did not affect soil texture,bulk density(BD),pH,electric conductivity(EC),exchangeable potassium(Kexc),or the activities of alkaline phosphatase(ALP) and dehydrogenase.According to two-way ANOVA results,OC,TN,P_(ava),K_(exc),and EC values were significantly higher in the fall,whereas pH and ALP values were significantly higher in the spring.Additionally,phosphorous and dehydrogenase activity were significantly different in selected soil factors at 0-10 and10-20 cm depths.The interaction of fire,season,and soil depth were significant for phosphorous and urease.Moreover,the activity of ALP correlated well with pH(r=0.68),P(r=-0.74),OC(r=-0.53),and TN(r=-0.37),whereas the activity of ACP correlated significantly with OC(r=0.64) and TN(r=0.71).Two years after the fire,soil properties in J.excels a stands had either improved or remained unaffected,returning to pre-fire levels.Additionally,soil chemical properties varied significantly across sampling seasons,which should be considered when comparing and interpreting soil data in future research.展开更多
This study assessed the effect of patch scarification and mounding on the physical properties of the root layer and the success of tree planting in various types of forests.This study was conducted on 12 forest sites ...This study assessed the effect of patch scarification and mounding on the physical properties of the root layer and the success of tree planting in various types of forests.This study was conducted on 12 forest sites in taiga forests of the European part of Russia.A total of 54 plots were set up to assess seedling survival;root collar diameter,height,and heigh increment were measured for 240 seedlings to assess growth.In the rooting layer,240 soil samples were taken to determine physical properties.The study showed that soil treatment methods had no effect on bulk density and total porosity in Cladina sites.However,reduced soil moisture was noted,particularly in mounds,resulting in increased aeration.In Myrtillus sites,there were increased bulk density,reduced soil moisture,and total porosity in the mounds.Mounding treatment in Polytrichum sites resulted in reduced soil moisture and increased aeration porosity.In the Myrtillus and Polytrichum sites,patch scarification had no effects on physical properties.In Polytrichum sites,survival rates,heights,and heigh increments of bareroot Norway spruce seedlings in mounds were higher than in patches;however,the same did not apply to diameter.In Cladina and Myrtillus sites,there was no difference in growth for bareroot and containerised seedlings with different soil treatments.Growing conditions and soil types should be considered when applying different soil treatment methods to ensure high survival rates and successful seedling growth.展开更多
This study aims to investigate the abundance of AMF according to soil properties and altitudes in different cacao plantations of Cameroon. Physico-chemical analyses were made on soil samples collected from three agro-...This study aims to investigate the abundance of AMF according to soil properties and altitudes in different cacao plantations of Cameroon. Physico-chemical analyses were made on soil samples collected from three agro-ecological zones. Soil samples were also used to evaluate directly the AMF abundance following the various altitudes and after trapping by sorghum plant. The results showed that soil properties, AMF spore abundances and colonization fluctuated significantly at different altitudes. The most represented texture was sandy loam. The bimodal zone presented a homogeneous texture (sandy loam) in all its localities. Cacao soil chemical characteristics showed that, the highest nitrogen rate (0.47%;p 0.05, Scott-Knott test) was recorded at Melong in a monomodal zone while Tonga in the Western highlands displayed the lowest rate (0.13%). Soil P concentration was significantly high in monomodal zones (Mbanga and Melong). Soil pH level indicated that the soil from Tonga in the Western highlands was neutral (pH = 6.67), and soils of other localities under study were acidic with the lowest (4.75) pH level recorded at Melong in a monomodal zone. In soil samples, the highest spore density (1.03 spores/g soil) was observed at Ntui in Bimodal zone, while the lowest spore density (0.26 spores/g soil) was observed at Bafang in the Western highlands. Root colonization showed that the sample from Bokito in a bimodal zone displayed the best frequency of mycorrhization (86.11%) while the sample from Bafang in the Western highlands recorded the lowest (27.11%). The PCA analysis highlighted that available phosphorus, pH and altitude all strongly correlated with AMF root colonization ability and can be used as a predictor of AMF colonization ability in cacao rhizosphere.展开更多
基金Sichuan Provincial Science and Technology Plan Project(2021YFS0323,)National Key Research and Development Program(2021YFB2301203)。
文摘In this study,the influence of soil properties on the failure behavior and mechanism of slope under earthquake after rainfall was studied with shaking table test in the laboratory,in which the failure process of slope and instant responses of water content and pore water pressure were tested.Based on the principle of similarity,a model test was designed.The experimental results showed that soil properties exhibit significant influence on failure mode and failure mechanism of slope.Local flowslide,local failure,and creep flowslide failure modes appear in the slope exposed to only rainfall.However,under earthquake after rainfall,the other three failure modes occur,i.e.,local slip failure,overall slip failure,and shallow scouring and creep flowslide failure.The spatial distribution of water content and pore water pressure are the two key factors leading to slope failure.Furthermore,due to the difference of permeability,the soil properties not only affect the spatial distribution of water content of the slope after rainfall,resulting in the peak pore water pressure which occurs mainly near the foot of the slope and near the bedrock interface in the middle and lower parts of the slope,but also affect the dissipation of excess pore water pressure in the process of earthquake.Finally,it is discovered that different types of soil lead to significant differences in the peak acceleration of slope failure.The critical acceleration of slope with coarse-grained soil is greater than that of slope with fine-grained soil.The critical acceleration of slope failure shows a close relationship with soil properties.
文摘This article presents a 2017 LiDAR-DEM guided 1-m resolution examination of field-surveyed elevation and soil property variations (5 × 5 m spacings) conducted in 1977 across a hummocky New Brunswick field used for potato production. This examination revealed that the field incurred minor elevation differences likely due to upslope erosion as revealed through increasing Sand % and CF % with increasing elevation, and increasing Silt % along low-lying areas. Soil moisture, field capacity, permanent wilting and nitrate nitrogen (NO<sub>3</sub>-N) also increased at downslope locations. Directly as well as indirectly, soil pH, ammonium nitrogen (NH<sub>4</sub>-N), Caesium<sup>137</sup> (Cs<sup>137</sup>) and Mehlich-3 extracted Ca, Mg, K, Fe, Mn, Cu, and Zn were likewise affected by topographic location. Factor analyzing these variables led to: 1) a Soil Loss Factor that captured 24% of the textural variations;2) a Soil-Cropping Factor accounting for 16% of the N, P, K, Ca, Mg, Mn variations;3) a Soil Organic Matter (SOM) Factor relating 9% of the in-field variations for SOM, Fe, Zn, Cu to via organo-metal complexation and low NO<sub>3</sub>-N retention. Many of the topographic variations increased or decreased with the metric DEM-projected depth-to-water index (DTW) index. This index was set to 0 along DEM-derived flow channels with minimum upslope flow-accumulation areas of 0.1, 0.25, 0.5, 1 or 4 ha. Among these, the DTW > 4 ha threshold was useful for reproducing the textural variations, while the DTW > 0.25 ha threshold assisted in capturing trends pertaining to moisture retention and elemental concentrations.
文摘The montane forests of Garhwal Himalaya were investigated for tree species composition and diversity in relation to environmental and edaphic variables.A stratified random sampling approach was adopted to collect the field data from each forest.A total of 39 tree species belonging to 31 genera and 23 families were recorded from the sampling area(6 forest stands ×10 plots in each).Lauraceae with 5 species was the largest family while Quercus(4 species) emerged as the largest genus.Species-area curve(asymptote) predicted more species than the observed number of species.Cluster analysis has shown that the two Abies pindrow dominant forest stands had the highest similarity in tree species composition.The tree stem density ranged from 540-1170 ha-1,basal area 23.01-55.94 m^2 ha-1,ShannonWiener diversity index 1.69-2.49,evenness index0.42-0.74,beta diversity 0.40-0.82 and similarity index 0.17-0.54 in the six studied forests.Two-way indicator species analysis(TWINSPAN) identified four distinct tree communities in the study area with Daphniphyllum himalayense,Abies pindrow,Quercus oblongata,and Pinus roxburghii as indicator species of corresponding communities.Canonical correspondence analysis(CCA) ascertained the TWINSPAN results and revealed the relation of tree species with environmental and edaphic variables.The phytosociological attributes of tree species varied from one forest stand to another;however,the tree species richness,density,and diversity peaked at intermediate elevation on the north aspect.Findings reveal that tree composition and diversity in the montane forests of Garhwal Himalaya are influenced by both environmental(elevation and slope aspect)and soil variables(texture,water holding capacity,moisture content,available N,exchangeable P,and pH).This study will help in understanding the forest distribution across the western Himalaya,guiding the conservationists and policymakers in carrying out conservation-related management activities,designing the long-term monitoring studies and assessing the effects of ongoing and future climate change and disturbances.
基金Under the auspices of the China Postdoctoral Science Foundation(No.2017M620889)the Second Tibetan Plateau Scientific Expedition and Research Program(No.2019QZKK0405-05)the State Key Research Development Program of China(No.2016YFC0501803,2016YFC0501802)。
文摘Alpine grassland of the Tibetan Plateau has undergone severe degradation, even desertification. However, several questions remain to be answered, especially the response mechanisms of vegetation biomass to soil properties. In this study, an experiment on degradation gradients was conducted in an alpine meadow at the Zoige Plateau in 2017. Both vegetation characteristics and soil properties were observed during the peak season of plant growth. The classification and regression tree model(CART) and structural equation modelling(SEM) were applied to screen the main factors that govern the vegetation dynamics and explore the interaction of these screened factors. Both aboveground biomass(AGB) and belowground biomass(BGB) experienced a remarkable decrease along the degradation gradients. All soil properties experienced significant variations along the degradation gradients at the 0.05 significance level. Soil physical and chemical properties explained 54.78% of the variation in vegetation biomass along the degradation gradients. AGB was mainly influenced by soil water content(SWC), soil bulk density(SBD), soil organic carbon(SOC), soil total nitrogen(STN), and pH. Soil available nitrogen(SAN), SOC and p H, had significant influence on BGB. Most soil properties had positive effects on AGB and BGB, while SBD and p H had a slightly negative effect on AGB and BGB. The correlations of SWC with AGB and BGB were relatively less significant than those of other soil properties. Our results highlighted that the soil properties played important roles in regulating vegetation dynamics along the degradation gradients and that SWC is not the main factor limiting plant growth in the humid Zoige region. Our results can provide guidance for the restoration and improvement of degraded alpine grasslands on the Tibetan Plateau.
基金This research was funded by the National Natural Science Foun-dation of China(Grant No.41971129,42991233)the National Key Research and Development Program of China(Grant No.2016YFC0501701)the fellowship of China Postdoctoral Science Foun-dation(Grant No.2020M680699)and the Distinguished Membership Project of the Youth Innovation Promotion Association of Chinese Academy of Sciences.
文摘Terracing greatly affects soil properties,ecosystem services,human welfare and geographical sustainability.The purpose of this article is to determine the influence of terracing on soil properties across diverse regions in China.Three representative terrace types,including dryland loess terraces,dry-stone terraces,and paddy terraces,were selected as case study areas.Soil sampling was stratified according to thickness of soil layers in each terraced area.Based on field investigations and soil sampling,combined with the means of variance,correlation,redundancy and regression analysis,we analyzed the characteristics of soil properties in the terraces across three areas.Results showed that:(1)alterations of soil physicochemical properties mainly depend on differences between soil parent materials in such regions;(2)Due to the existence of“four-element isomorphism”in the ecosystem and reasonable human activities,paddy terraces had the greatest impact on soil properties which is mainly reflected in decreasing soil pH and increasing SOC,TN,and TK;(3)The content of SOC and TN in different areas was higher in terraced fields than in the sloped lands and decreased with soil deepening;(4)To maintain sufficient supply of soil nutrients and support the sustainability of agricultural terraces,it is necessary to apply manure to improve soil fertility and accelerate its aggregation in the terraces.For example,an increase in the application of nitrogen fertilizer in terraced fields in Hebei and Gansu provinces,which have a serious deficiency in soil available phosphorus(AP),is necessary to get greater amounts of P fertilization.The present study offers a theoretical foundation for the sustainability of terraced ecosystems through efficient crop production,which is the basis for strengthening the ecological security of terraced areas and promoting regional sustainability in those fragile mountains.
基金This research was supported by Open Fund of State Key Laboratory of Frozen Soil Engineering(Grant No.SKLFSE202017)Key Research and Development Program of Xuzhou(Grant No.KC20179)Major State Basic Research Development Program(Grant No.2012CB026103).
文摘In the permafrost regions of the Qinghai-Tibet Plateau(QTP),the permafrost table has a significant effect on the stability of geotechnical engineering.The thermal boundaries and soil properties are the key factors affecting the permafrost table.Complex geological environments and human activities can lead to the uncertainties of thermal boundaries and soil properties.In this paper,an array of field experiments and Monte Carlo(MC)simulations of thermal boundaries and soil properties are carried out.The coefficient of variation(COV),scale of fluctuation(SOF),and autocorrelation distance(ACD)of uncertainties of thermal boundaries and soil properties are investigated.A stochastic analysis method of the probabilistic permafrost table is then proposed,and the statistical properties of permafrost table on the QTP are computed by self-compiled program.The proposed stochastic analysis method is verified with the calculated and measured temperature observations.According to the relationship between ACD and SOF for the five theoretical autocorrelation functions(ACFs),the effects of ACF,COV,and ACD of soil properties and the COV of thermal boundaries on the permafrost tables are analyzed.The results show that the effects of different ACFs of soil properties on the standard deviation(SD)of permafrost table depth are not obvious.The SD of permafrost table depth increases with time,and the larger the COVs of thermal boundaries and soil properties,the deeper the SD of permafrost table;the longer the ACD of soil properties,the shallower the SD of permafrost table.This study can provide a reference for the stability analysis of geotechnical engineering on the QTP considering the uncertainties of thermal boundaries and soil properties.
文摘Patterns of woody regeneration in terms of species composition and diversity were studied in mixed deciduous forest (MDF) and deciduous dipterocarp forest (DDF) in Minbyin reserved forest of Lewe Township. A total of 57 plant species of MDF belonging to 28 families and 342 individuals and 25 plant species of DDF consist of 15 families and 285 individuals were identified. Plant species diversity was quantitatively higher in the MDF (H' = 3.68) compared to the DDF (H' = 2.39). Tectona grandis showed the highest density (30), dominance (4.40 m<sup>2</sup>) and IVI (27.01) of MDF and Dipterocarpus tuberculatus also composed the highest density (109), dominance (9.02 m<sup>2</sup>) and IVI (81.87) in DDF. The smallest diameter class (10 - 20 cm) comprised with 29 species, 103 individuals in MDF and 18 species, 85 individuals in DDF. The size class distribution displayed a reverse J-shaped pattern. The largest numbers of species were concentrated in the smallest height class in both investigated forests because of height and diameter distribution is closely related. The total densities of seedlings and saplings were 1219 and 531 ha<sup>-1</sup> in MDF and 988 and 444 ha<sup>-1</sup> in DDF respectively. Although soil texture of (40 - 50 cm) and (90 - 100 cm) were sandy clay loam in mixed deciduous forest, the other layers of both investigated forests were sandy loam.
文摘The potential ability of the Vis-NIR (350 - 2500 nm) laboratory spectroscopy for prediction of soil properties has been demonstrated in the literature. The aim of this work was to predict different soil properties of soils collected in Mugan plain (Azerbaijan) using PLSR models and cross-validation. Carbonatation and salinisation are the main pedogenetic processes in Muganplain, therefore there is a need to monitor total carbonates and soil electrical conductivity (EC). The result of work was positive and both total carbonates and EC showed the best result (SE = 2.90, R<sup>2</sup>-0.90 and SE-0.09, R<sup>2</sup>-0.82, respectively). This parameter using PLSR, SOM (SE-0.54, R<sup>2</sup>-0.83), CEC (SE-0.43, R<sup>2</sup>-0.62), and Total P (SE-0.50, R<sup>2</sup>-0.73) is predicted and result is over optimist. Total N (SE-0.04, R<sup>2</sup>-0.44), and pH (SE-0.02, R<sup>2-</sup>0.51) demonstrated low prediction quality.
基金supported by the Ministry of Science and Higher Education of the Republic of Poland(AD11)supported by project No.2021/41/N/NZ9/00264,PRELUDIUM-20,National Science Centre,Poland.
文摘In an era of climate change, understanding the factors that impact root systems can improve our understanding of carbon cycling in forest ecosystems. The study objective was to determine the impact of climatic conditions on the biomass and morphology of roots of different tree species along an elevation gradient, and consequently on properties of montane forest soils. The study plots were established at three different elevations(600, 800 and1000 m a.s.l.) along a slope with an inclination of 15°. The research plots were located in a beech stand(Fagus sylvatica L.) and fir stand(Abies alba Mill.). Soil samples were collected from each study plot, for which basic physical and chemical properties were determined. Additionally, we determined the morphology, production and decomposition rate of fine roots. Our analyses confirmed the significance of climatic conditions in the formation of soil properties, in particular the amount of accumulated carbon and nitrogen content. A decrease of root biomass and reduced root growth were recorded with increasing elevation. The characteristics of roots were linked with the properties of the studied mountain soils, in particular p H, alkaline cation content and content of selected micronutrients. Limitation of root growth in higher elevations affected both study species. Additional research into the formation of tree root morphology is needed, especially in mountainous regions where changes may occur more dynamically. This will provide a better understanding of how stands can cope with different types of environmental stress.
基金the National Key Research and Development Program of China(2021YFD1500205)the National Natural Science Foundation of China(41977103).
文摘Understanding the characteristics and influences of various factors on phosphorus(P)fractions is of significance for promoting the efficiency of soil P.Based on long-term experiments on black soil,fluvo-aquic soil,and loess soil,which belong to Phaeozems,Cambisols,and Anthrosols in the World Reference Base for Soil Resources(WRB),respectively,five fertilization practices were selected and divided into three groups:no P fertilizer(CK/NK),balanced fertilizer(NPK/NPKS),and manure plus mineral fertilizer(NPKM).Soil inorganic P(Pi)fractions and soil properties were analyzed to investigate the characteristics of the Pi fractions and the relationships between Pi fractions and various soil properties.The results showed that the proportion of Ca_(10)-P in the sum of total Pi fractions was the highest in the three soils,accounting for 33.5%in black soil,48.8%in fluvo-aquic soil,and 44.8%in loess soil.Long-term fertilization practices resulted in periodic changes in soil Pi accumulation or depletion.For black soil and fluvo-aquic soil,the Pi accumulation was higher in the late period(10–20 years)of fertilization than in the early period(0–10 years)under NPK/NPKS and NPKM,whereas the opposite result was found in loess soil.The Pi accumulation occurred in all Pi fractions in black soil;mainly in Ca_(8)-P,Fe-P,and Ca_(10)-P in fluvo-aquic soil;and in Ca_(2)-P,Ca_(8)-P,and O-P in loess soil.Under CK/NK,the soil Pi was depleted mainly in the early period in each of the three soils.In addition to the labile Pi(Ca_(2)-P)and moderately labile Pi(Ca_(8)-P,Fe-P,Al-P),the Ca_(10)-P in black soil and fluvo-aquic soil and O-P in loess soil could also be used by crops.Redundancy analysis showed that soil properties explained more than 90%of the variation in the Pi fractions in each soil,and the explanatory percentages of soil organic matter(SOM)were 43.6%in black soil,74.6%in fluvo-aquic,and 38.2%in loess soil.Consequently,decisions regarding the application of P fertilizer should consider the accumulation rate and the variations in Pi fractions driven by soil properties in non-acidic soils.
基金The funding was received by Yaser Khaled Al-Sakkaf.
文摘:Earth is the most common and important building material used in the construction industry,since it is found in almost every country in the world.Modern earthen construction is alive and well,and is spread over an enormous geographical area.This technique utilizes various earthen materials and numerous methods,and features many benefits for both construction in general and buildings in particular.Najran,a city located in the south of Saudi Arabia,is distinguished by its heritage of earthen architecture,which displays many advantages and a marvelous variety of types and exterior designs.Many weaknesses of the material,however,along with a lack of knowledge and rapid development have caused the uplifting and destruction of many of Najran’s mud and heritage buildings during the last few generations.Not all soil types are suitable for every building need.Soil specification is thus very important in order to ensure that the materials used in construction meet all requirements.The main goal of this study was to invistegate the suitability of local soils for the earthen building construction.Thus,available local materials of common quality were taken from local sites in Najran.Laboratory experimentation and testing was then performed to determine the properties of those materials.The results showed that local soil properties are suitable for using in the earthen block construction since they satisified the specifications.The results were then recorded for use in further studies,as well as to explore heritage building and rehabilitation,and to improve modern earthen building materials and techniques.
基金Supported by National and Regional Fund Project (31760709, 31860175)Key R&D Program of Gansu Province (21YF5FA038, 20YF8FA105)。
文摘[Objectives]This study was conducted to investigate the vegetation community characteristics and soil properties of secondary grassland in abandoned farmland areas of different years in Minqin Oasis. [Methods] By the method of space-for-time substitution, the changes of vegetation community characteristics(species composition, structural characteristics and important values) and soil microbial and enzyme activity were determined, and the correlation between various soil factors was analyzed. [Results](1) There were 39 species belonging to 32 genera of 15 families in the research area, including 8 shrub plants, 15 perennial herbs and 16 annual herbs.(2) Soil microbial biomass carbon, nitrogen and phosphorus contents were higher in the upper layer than in the lower layer, and the phenomenon of “surface aggregation” was obvious. The differences were different with the change of abandoned years.(3) Soil catalase content was the highest among different plots, and soil phosphatase, sucrase and urease all showed a trend of fluctuating decline with the increase in abandoned years. Soil enzyme changes were different in different soil layers. [Conclusions] This study can provide a theoretical basis for the restoration, reconstruction and rational protection and utilization of secondary grassland in abandoned farmland.
基金Supported by Open Fund Project of the Key Laboratory of Waste Fertilizer Utilization of the Ministry of Agriculture and Rural Areas (KLFAW201901)
文摘[Objective]The research was designed to explore the effect of long-term stacking of solid waste produced in the coal-burning process of central heating enterprises on physical and chemical properties of soil.[Method]This study took the heating enterprises in Shenyang City as the research object.The morphological structure and element composition of coal cinder were determined by continuously collecting coal and cinder samples in different periods.At the same time,the original soil and cinder soil of the stacking site were collected to determine the changes of soil morphological structure,element composition and physical and chemical properties,so as to provide reference for the resource utilization of local cinder waste and the potential pollution risk of the stacking site.[Result]The contents of C,H,O,N,and S non-metallic elements in coal cinder decreased by 69.5%,71.2%,76.0%,74.5%,and 34.6%,respectively when compared with raw coal;while the content of Si increased significantly by 95.7%.The contents of Al,K,and Fe in cinder decreased by 4.3%,60.2%,and 33.3%,respectively,while the contents of Mg and Na increased by 36.1%and 130.9%,respectively.Compared with the original soil,the contents of C,H,and O in shallow cinder soil and deep cinder soil increased by 126.5%,67.9%,80.93%,and 21.3%,25.0%and 42.3%,respectively.The residual carbon existed in the form of activated carbon.The contents of Mg,Al,K,Na,Ca,and Fe in shallow cinder soil and deep cinder soil increased by 61.6%,5.4%,46.1%,35.8%,32.5%,6.3%and 22.3%,12.3%,12.2%,15.6%,5.8%and 2.8%,respectively compared with the original soil.The content of heavy metal elements in coal cinder did not reach the detection limit.Under the scanning electron microscope,the raw coal is mainly block structure,while the cinder is honeycombed and porous and dust.[Conclusion]Cinder stacking can significantly improve the content of organic matter and available K in shallow cinder soil,and improve the porosity and permeability of soil.In addition,cinder waste has high pH and pore structure,which can be used as acid soil conditioner,seedling flower matrix and compound fertilizer filler to take full advantage of cinder waste,improve soil structure and supply nutrients.
文摘Abandoned land and mansions are always a matter of curiosity to the human beings. They are treated as haunted places in many societies. In the present research, three decrepit abandoned mansions from the southern Bangladesh were investigated to measure their floral diversity, physico-chemical properties of soil and the soil-plant interrelationship which is responsible for the diversification of wild flora within the regions. From Shannon and Simpson diversity indexes, it can be deducted that the floral diversity within the abandoned mansions ha</span><span style="font-family:"">s</span><span style="font-family:""> a<span style="color:red;"> </span>positive relationship with their territory size. The high values of Marg<span>alef’s and Menhinick’s species richness indexes confirmed that these areas are a rich source of a large number of plant species. A great variation in soil physico-chemical properties has been observed during the analysis. Soil organic matter, nitrogen, phosphorus, potassium & moisture contents were varied significantly from one quadrat to another in every site. Biplot analysis showed that the distribution of plant species in abandoned mansions </span></span><span style="font-family:"">is</span><span style="font-family:""> primarily determined by the organic matter, pH, moisture and potassium contents of soil. As t</span><span style="font-family:"">hese factors were present in versatile distribution within the studied regions, a great number of plants can grow in the same area simultaneously. So these areas should be protected from human intervention to proce</span><span style="font-family:"">ss</span><span style="font-family:""> natural selection and in situ conservation of plant species.
文摘The influence of fly ash(FA)applied alone and/or with sewage sludge(SS)on wheat(Triticum vulgare)grain yield,biomass production and soil properties was studied in a field experiment.The results showed that both FA and SS significantly increased grain yield and plant biomass.FA applied alone increased significantly soil pH and EC while FA applied together with SS did not significantly affect them compared to mono FA treatment.Soil pH and EC values increased with time in FA and FA-SS treatments.SS increased soil organic matter and total N content and SS applied together with FA increased also available soil B.From the plant nutrients tested only tissue N concentration was increased significantly in all treatments compared to control.Copper,Zn,Mn,Ni,and Pb at both available and total concentrations are significantly affected.
基金This work was supported by Mediterranea University of Reggio Calabria Italy as part of the Lifelong Learning Program ERASMUS Placement 2013-2014.
文摘Considering that diverse fire severities can affect soil properties differently,the aim of this study was to examine to what extent changes in soil properties caused by fire could condition seedling establishment.This new approach is for identifying a new fire cause-effect chain to qualify the impacts of fire on soils with the purpose of using fire as a tool in forest management to favour Pinus halepensis Mill.regeneration.The study area was a reforested P.halepensis area which had been crossed by fire for78.8 ha,causing various degrees of damage.The forest was subdivided into three large areas according to the gravity of crown scorch,[low(LS),medium(MS)and high(HS)severity],on the basis of needle yellowing which usually occurs after exposure to direct flames.Results showed significant differences in soil properties with respect to fire severity.In the HS area,total nitrogen and carbon were considerably reduced while ash and phosphorus contents significantly increased.The changes in soil properties,in particular to nutrient levels,affected P.halepensis regeneration,mainly the first year after the fire.Greater regeneration occurred in areas affected by moderate fire severity in which the temperatures reached increased the mineralization of soil organic matter with the consequent release of nutrients available for seedling growth.Additionally,moderate fire severity suppressed the regeneration of grasses,reducing the interspecific competition.Heights of seedlings were inversely proportional to the density of grasses.Where the number was abundant(LS),the height was modest;conversely,where the number was low(HS),the greater hypsometric differentiation of pine seedlings was observed.These results suggest that moderate fire severity represents an environmental stress(hormesis)altering microscale conditions to increase pine germination and establishment.The exposure of P.halpensis to a moderate environmental factor that is damaging at higher intensities,induces an adaptive beneficial effect on seedling regeneration.This data can re-evaluate the assertion that coniferous burned areas,if left unmanaged,would remain unproductive for an indefinite period.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.31870537 and 31570547)the Fundamental Research Funds for the Central Universities of China(Grant No.2572018BL08)the Research and Development Project of Application Technology in Harbin(Grant No.2017RAQXJ078)。
文摘The decay rate of standing Korean pine(Pinus koraiensis)in natural forests can be as high as 50%and is likely infl uenced by the soil properties and nutrient and water status of the site.To clarify the relationship between the severity of tree decay and soil properties in order to prevent decay in a natural mixed forest in the Xiaoxing'an Mountains,wood strength of standing trees was nondestructively assessed,and the severity of decay of extracted wood cores was quantified based on differences in mass between two decayed increment cores extracted at breast height and an intact increment core near the decayed ones.Soil samples from the critical root zone(non-rhizosphere)of each tree were analyzed for chemical properties and microbial composition.The abundance of chemical elements(especially total N and K)and the species richness of soil microbes increased as decay severity increased.Fungal number(FN)and actinomycetes number(AN)were related to decay severity(R^(2)=0.504).Bacterial number(BN)was higher than FN or AN,but had a minor effect on tree decay.Path analysis showed BN might indirectly inhibit decay by affecting FN.Decay severity was not significantly correlated with either soil fungal or bacterial diversity.These results suggest that forest managers need to monitor levels of fungi and total N and total K levels to reduce the decay of Korean pine.
文摘This study was conducted in Juniperus excels a stands on the southern slopes of Iran’s Alborz Mountains,to determine the effects of fire and seasonal variations on soil physicochemical properties and enzyme activities.A total of 64 composite soil s amples were randomly collected in the spring and fall from two burned and unburned sites at depths of 0-10 and 10-20 cm.The results of a two-way ANOVA analysis indicate that fire increased the organic carbon(OC),total nitrogen(TN),and available phosphorus(P_(ava)) contents of the soil by 16%,59%,and 53%,respectively.Similarly,when burned sites were compared to unburned sites,the activities of acid phosphatase(ACP) and urease enzymes increased by 73% and 12%,respectively.Nevertheless,fire did not affect soil texture,bulk density(BD),pH,electric conductivity(EC),exchangeable potassium(Kexc),or the activities of alkaline phosphatase(ALP) and dehydrogenase.According to two-way ANOVA results,OC,TN,P_(ava),K_(exc),and EC values were significantly higher in the fall,whereas pH and ALP values were significantly higher in the spring.Additionally,phosphorous and dehydrogenase activity were significantly different in selected soil factors at 0-10 and10-20 cm depths.The interaction of fire,season,and soil depth were significant for phosphorous and urease.Moreover,the activity of ALP correlated well with pH(r=0.68),P(r=-0.74),OC(r=-0.53),and TN(r=-0.37),whereas the activity of ACP correlated significantly with OC(r=0.64) and TN(r=0.71).Two years after the fire,soil properties in J.excels a stands had either improved or remained unaffected,returning to pre-fire levels.Additionally,soil chemical properties varied significantly across sampling seasons,which should be considered when comparing and interpreting soil data in future research.
基金based on studies conducted under a governmental request to“Northern Research Institute of Forestry”for performance of applied research within the remit of the Federal Forestry Agency.Project registration No.122020100319-9。
文摘This study assessed the effect of patch scarification and mounding on the physical properties of the root layer and the success of tree planting in various types of forests.This study was conducted on 12 forest sites in taiga forests of the European part of Russia.A total of 54 plots were set up to assess seedling survival;root collar diameter,height,and heigh increment were measured for 240 seedlings to assess growth.In the rooting layer,240 soil samples were taken to determine physical properties.The study showed that soil treatment methods had no effect on bulk density and total porosity in Cladina sites.However,reduced soil moisture was noted,particularly in mounds,resulting in increased aeration.In Myrtillus sites,there were increased bulk density,reduced soil moisture,and total porosity in the mounds.Mounding treatment in Polytrichum sites resulted in reduced soil moisture and increased aeration porosity.In the Myrtillus and Polytrichum sites,patch scarification had no effects on physical properties.In Polytrichum sites,survival rates,heights,and heigh increments of bareroot Norway spruce seedlings in mounds were higher than in patches;however,the same did not apply to diameter.In Cladina and Myrtillus sites,there was no difference in growth for bareroot and containerised seedlings with different soil treatments.Growing conditions and soil types should be considered when applying different soil treatment methods to ensure high survival rates and successful seedling growth.
文摘This study aims to investigate the abundance of AMF according to soil properties and altitudes in different cacao plantations of Cameroon. Physico-chemical analyses were made on soil samples collected from three agro-ecological zones. Soil samples were also used to evaluate directly the AMF abundance following the various altitudes and after trapping by sorghum plant. The results showed that soil properties, AMF spore abundances and colonization fluctuated significantly at different altitudes. The most represented texture was sandy loam. The bimodal zone presented a homogeneous texture (sandy loam) in all its localities. Cacao soil chemical characteristics showed that, the highest nitrogen rate (0.47%;p 0.05, Scott-Knott test) was recorded at Melong in a monomodal zone while Tonga in the Western highlands displayed the lowest rate (0.13%). Soil P concentration was significantly high in monomodal zones (Mbanga and Melong). Soil pH level indicated that the soil from Tonga in the Western highlands was neutral (pH = 6.67), and soils of other localities under study were acidic with the lowest (4.75) pH level recorded at Melong in a monomodal zone. In soil samples, the highest spore density (1.03 spores/g soil) was observed at Ntui in Bimodal zone, while the lowest spore density (0.26 spores/g soil) was observed at Bafang in the Western highlands. Root colonization showed that the sample from Bokito in a bimodal zone displayed the best frequency of mycorrhization (86.11%) while the sample from Bafang in the Western highlands recorded the lowest (27.11%). The PCA analysis highlighted that available phosphorus, pH and altitude all strongly correlated with AMF root colonization ability and can be used as a predictor of AMF colonization ability in cacao rhizosphere.
