Arbuscular mycorrhizal(AM)fungi contribute globally to ecosystem services and play an important role in sustainable crop production.However,it is unclear which factors contribute most to their colonization and communi...Arbuscular mycorrhizal(AM)fungi contribute globally to ecosystem services and play an important role in sustainable crop production.However,it is unclear which factors contribute most to their colonization and community structure at different sites,particularly in understudied ecosystems.This study investigated the AM fungal communities associated with switchgrass(Panicum virgatum L.)in the understudied acidic and oligotrophic pine barrens ecosystem using next-generation sequencing.Switchgrass was also sampled from agroecosystems,as well as,from a native prairie for comparison.The pine barrens switchgrass harbored a distinct AM fungal community−Acaulospora and Ambispora were almost exclusively found in the pine barrens sites,and some of these species may represent undescribed taxa.Glomus was the most ubiquitous AM fungal genus recovered from all sites.This study suggests differences in the AM fungal community structure under different soil properties and land uses.This is the first sequence-based report of the AM fungal communities in the pine barrens ecosystem.展开更多
Aims Serpentine barrens of the Mid-Atlantic United States are globally rare,grass-dominated ecosystems thought to exclude C3 spe-cies and characterized by unique soil composition.However,like many grassland ecosystems...Aims Serpentine barrens of the Mid-Atlantic United States are globally rare,grass-dominated ecosystems thought to exclude C3 spe-cies and characterized by unique soil composition.However,like many grassland ecosystems globally,these sites are presently facing encroachment by surrounding forest.In this ecosystem,the tendril climbing vine,Smilax rotundifolia,forms dense thickets around bar-rens that typically precede forest encroachment.While numerous factors speculatively initiate and promote encroachment in these systems,few studies have examined photosynthetic responses of serpentine grasses to changes in resource availability initiated by encroachers or physiological ability of encroaching S.rotundifolia to colonize high-light barren environments.We sought to under-stand both environmental and physiological dynamics of encroach-ment along an irradiance gradient in these systems.Methods At three serpentine barren sites in southeastern Pennsylvania,physiological responses of the native grasses Sorghastrum nutans and Schizachyrium scoparium to increased shading by S.rotundi-folia were examined.Additionally,the physiological performance of S.rotundifolia in the forest understory was compared to that in sunlit barrens environments.Light-saturated photosynthesis(A_(sat)),stomatal conductance(g_(s)),instantaneous transpiration efficiency(ITE),maximum efficiency of photosystem II(F_(v)/F_(m)),midday leaf water potential(ψ_(leaf))and specific leaf area(SLA)were measured for all species over the course of the 2014 growing season.Two-way analyses of variance were used to assess changes in these param-eters across growing environments,as well as seasonally for each species.Multiple regression analyses were also performed to inves-tigate the influence of vapor pressure deficit(D)and leaf tempera-ture(T_(leaf))on A_(sat) and ITE.Important Findings Light-saturated photosynthesis was significantly greater in S.rotun-difolia growing in sun than in the shade(P<0.001)and early in the season(P=0.012).Sun S.rotundifolia had up to 27%greater A_(sat) than shaded plants.Even with reducedψleaf in the barrens,S.rotundifolia maintained high g_(s) though A_(sat) was limited by high D later in the growing season.These data are in agreement with recent research suggesting that plants are not subject to water limi-tation in Mid-Atlantic barrens.Unexpectedly,shaded grasses at the encroachment interface did not exhibit any significant reduc-tion in A_(sat).Declines in grass photosynthesis do not likely occur until S.rotundifolia rhizomes transition into monotypic thickets,completely excluding grasses.Encroachment by S.rotundifolia appears to be primarily facilitated by its ability to capitalize on light resources early on in the summer growing season,when environ-mental conditions are less stressful.展开更多
A single-qubit quantum classifier(SQC)based on a gradient-free optimization(GFO)algorithm,named the GFO-based SQC,is proposed to overcome the effects of barren plateaus caused by quantum devices.Here,a rotation gate R...A single-qubit quantum classifier(SQC)based on a gradient-free optimization(GFO)algorithm,named the GFO-based SQC,is proposed to overcome the effects of barren plateaus caused by quantum devices.Here,a rotation gate R_(X)(φ)is applied on the single-qubit binary quantum classifier,and the training data and parameters are loaded intoφin the form of vector multiplication.The cost function is decreased by finding the value of each parameter that yields the minimum expectation value of measuring the quantum circuit.The algorithm is performed iteratively for all parameters one by one until the cost function satisfies the stop condition.The proposed GFO-based SQC is demonstrated for classification tasks in Iris and MNIST datasets and compared with the Adam-based SQC and the quantum support vector machine(QSVM).Furthermore,the performance of the GFO-based SQC is discussed when the rotation gate in the quantum device is under different types of noise.The simulation results show that the GFO-based SQC can reach a high accuracy in reduced time.Additionally,the proposed GFO algorithm can quickly complete the training process of the SQC.Importantly,the GFO-based SQC has a good performance in noisy environments.展开更多
Traveling is one major theme of Fitzgerald's novel Tender Is the Night. This fashionable activity for the 1920 s Americans is represented in the novel as ostensibly bearing different meanings to the main character...Traveling is one major theme of Fitzgerald's novel Tender Is the Night. This fashionable activity for the 1920 s Americans is represented in the novel as ostensibly bearing different meanings to the main characters, but a deeper look would reveal that it is unanimously resorted to as a weapon against the spiritual barrenness caused by the cult of business, and more importantly, as a way to the experience of rootedness.展开更多
Compared to other crops,maize production demands relatively high temperatures.However,temperatures exceeding 35℃lead to adverse effects on maize yield.High temperatures(≥35℃)are consistently experienced by summer m...Compared to other crops,maize production demands relatively high temperatures.However,temperatures exceeding 35℃lead to adverse effects on maize yield.High temperatures(≥35℃)are consistently experienced by summer maize during its reproductive growth stage in the North China Plain,which is likely to cause irreversible crop damage.This study investigated the effects of elevating temperature(ET)treatment on the yield component of summer maize,beginning at the 9th unfolding leaf stage and ending at the tasseling stage.Results demonstrated that continuous ET led to a decrease in the elongation rate and activity of silks and an elongated interval between anthesis and silking stages,and eventually decreased grain number at ear tip and reduced yield.Although continuous ET before tasseling damaged the anther structure,reduced pollen activity,delayed the start of the pollen shedding stage,and shortened the pollen shedding time,it was inferred,based on phenotypical and physiological traits,that continuous ET after the 9th unfolding leaf stage influenced ears and therefore may have more significant impacts.Overall,when maize plants were exposed to ET treatment in the ear reproductive development stage,the growth of ears and tassels was blocked,which increased the occurrence of barren ear tips and led to large yield losses.展开更多
A systematic account of micro-textures and a few compositional profiles of plagioclase from high-alumina basaltic aa lava erupted during the year 1994-1995, from Barren Island Volcano, NE India ocean, are presented fo...A systematic account of micro-textures and a few compositional profiles of plagioclase from high-alumina basaltic aa lava erupted during the year 1994-1995, from Barren Island Volcano, NE India ocean, are presented for the first time. The identified micro-textures can be grouped into two categories: (i) Growth related textures in the form of coarse/fine-sieve morphology, fine-scale oscillatory zoning and resorption surfaces resulted when the equilibrium at the crystal-melt interface was fluctuated due to change in temperature or H20 or pressure or composition of the crystallizing melt; and (ii) morphological texture, like glomerocryst, synneusis, swallow-tailed crystal, microlite and broken crystals, formed by the influence of dynamic behavior of the crystallizing magma (convection, turbulence, degassing, etc.). Each micro-texture has developed in a specific magmatic environment, accordingly, a first order magma plumbing model and crystallization dynamics are envisaged for the studied lava unit. Magma generated has undergone extensive fractional crystallization of An-rich plagioclase in stable magmatic environment at a deeper depth. Subsequently they ascend to a shallow chamber where the newly brought crystals and pre-existing crystals have undergone dynamic crystallization via dissolution-regrowth processes in a convective self- mixing environment. Such repeated recharge-recycling processes have produced various populations of plagioclase with different micro-textural stratigraphy in the studied lava unit. Intermittent degassing and eruption related decompression have also played a major role in the final stage of crystallization dynamics.展开更多
High-order finite element method (FEM) formulation also referred to as spectral element method (SEM) formulation is currently implemented in this paper for 3-dimensional (3-D) elasto-plastic problems in stability asse...High-order finite element method (FEM) formulation also referred to as spectral element method (SEM) formulation is currently implemented in this paper for 3-dimensional (3-D) elasto-plastic problems in stability assessment of large- scale slopes (vegetated and barren slopes) in different instability conditions such as seismic and saturation. We have reviewed the SEM formulation, and have sought its applicability for vegetated slopes. Utilizing p (high-order polynomial degree or spectral degrees) and h (mesh operation for quality meshing in required elemental budgets) refining techniques in the existing FEM, the complexity of problem domain can be well addressed in greater numerical stability. Unlike the existing FEM formulation, this high-order FEM employs the same integration and interpolation points to achieve a progressive response of the instability, which drastically reduces the computational costs (formation of diagonalized mass matrix) and offers significant benefits to slope instability computations for serial and parallel implementations. With this formulation, we have achieved the following three qualities in slope instability modeling: 1) geometric flexibility of the finite elements, 2) high computational efficiency, and 3) reliable spectral accuracy. A sample problem has also been presented in this paper, which has accommodated all aforesaid numerical qualities.展开更多
The Pine Barrens in New York State are dominated by pitch pine(Pinus ridgida) and scrub oaks(Quercus ilicifolia and Q. prinoides). With fire suppression over the last 90 years or so, P. rigida regeneration has become ...The Pine Barrens in New York State are dominated by pitch pine(Pinus ridgida) and scrub oaks(Quercus ilicifolia and Q. prinoides). With fire suppression over the last 90 years or so, P. rigida regeneration has become sparse, even in areas set aside to preserve this type of vegetation. We evaluated the effects of fire and an alternative disturbance(mechanical removal of vegetation)for increasing P. rigida regeneration in the Albany Pine Bush Preserve in eastern New York State. By comparing cover, diameter and height of P. rigida, Q. ilicifolia, Q.prinoides, and Vaccinium spp.(blueberry) growing on the sites with a known fire history, we documented structural and compositional changes in the vegetation since its establishment. We also compared sites on which Quercus sprouts were controlled through mechanical removal. In the years following a disturbance, height and cover of Q. ilicifolia increased continuously and the species became increasingly competitive. Both the density of P. rigida seedlings and Vaccinium cover decreased significantly as the diameter and height of Quercus increased. Our results confirmed that the dominance by P. rigida could be attributed to periodic fires at intervals of 20–25 years. We conclude that removing Q. ilicifolia can favor P. rigida dominance on the barren without fire by releasing pine seedlings from competition.展开更多
Gardaneh Salavat porphyry copper system is located in the northwest of Iran. It comprises a quartz diorite to diorite porphyritic intrusion that created extensive alteration haloes in the host rocks. Despite all techn...Gardaneh Salavat porphyry copper system is located in the northwest of Iran. It comprises a quartz diorite to diorite porphyritic intrusion that created extensive alteration haloes in the host rocks. Despite all technical considerations, the exploration activities did not yield to ore discovery. As the matter of fact, all of the geological,geophysical, and geochemical characteristics of a porphyry Cu-Au deposit exist but there is no economic mineralization. Detailed examinations suggest that the only reasonable explanation can be related to the infertility or low metal endowment of the porphyritic intrusion. The reasons include(1) anomalous ranges of Cu, Au, and Mo rather than economic ore grades,(2) weakly development of potassic alteration,(3) probably sulfur saturation of magma that occurred before intrusion emplacement in the host rocks, and(4) probably low metal endowment in the regional scale and the lack of known porphyry copper deposits in close neighborhoods. It is tried to test the proposed hypothesis with the introduced fertility indicators based on major and trace element geochemistry. However,current fertility indicators could not prove or reject the proposed hypothesis for Gardaneh Salavat porphyritic intrusion because of the high-K calc-alkaline to shoshonitic nature of the intrusive rocks together with the unavailability of relatively fresh/unaltered samples. This case study is notable to examine because(1) it shows that characterization of fertile from barren intrusions seems to be as important as vectoring towards concealed porphyry copper deposits, especially while dealing with deep exploration targets that are associated with high financial risks, and(2) it highlights the inefficiencies and uncertainties in introduced magma fertility indicators for porphyry copper intrusions. As a result, it is of high importance to conduct an overarching investigation on other possible fertility indicators as a fundamental need for the future of the exploration industry.展开更多
Increasing the planting density is one way to enhance grain production in maize.However,high planting density brings about growth and developmental defects such as barrenness,which is the major factor limiting grain y...Increasing the planting density is one way to enhance grain production in maize.However,high planting density brings about growth and developmental defects such as barrenness,which is the major factor limiting grain yield.In this study,the barrenness was characterized in an association panel comprising 280 inbred lines under normal(67500 plants ha–1,ND)and high(120000 plants ha–1,HD)planting densities in 2017 and 2018.The population was genotyped using 776254 single nucleotide polymorphism(SNP)markers with criteria of minor allele frequency>5%and<20%missing data.A genome-wide association study(GWAS)was conducted for barrenness under ND and HD,as well as the barrenness ratio(HD/ND),by applying a Mixed Linear Model that controls both population structure and relative kinship(Q+K).In total,20 SNPs located in nine genes were significantly(P<6.44×10–8)associated with barrenness under the different planting densities.Among them,seven SNPs for barrenness at ND and HD were located in two genes,four of which were common under both ND and HD.In addition,13 SNPs for the barrenness ratio were located in seven genes.A complementary pathway analysis indicated that the metabolic pathways of amino acids,such as glutamate and arginine,and the mitogen-activated protein kinase(MAPK)signaling pathway might play important roles in tolerance to high planting density.These results provide insights into the genetic basis of high planting density tolerance and will facilitate high yield maize breeding.展开更多
Quantifying soil conservation service is critical for sustainable land management. However, the traditional algo-rithm includes a gap between barren land and real soil erosion (BSERef), and its paradox is that a mass ...Quantifying soil conservation service is critical for sustainable land management. However, the traditional algo-rithm includes a gap between barren land and real soil erosion (BSERef), and its paradox is that a mass of barrenland rarely exists in ecologically adaptable areas with fertile soils, which might overestimate soil conservationservice. This study suggests a practical algorithm to effectively evaluate soil conservation service of differentecosystems. We propose a new algorithm based on the difference between cropland without control practicesand real soil erosion (CSERef), which is compared with the BSERef algorithm. Our results show that: (1) a nearlyfive times smaller mean soil conservation amount of cropland occurred in the CSERef algorithm (3.76×106 t·yr–1)than in the BSERef algorithm (20.04×106 t·yr–1);(2) land use has higher explanatory power for the spatial dif-ferentiation of soil conservation rate in the CSERef algorithm (15.93% – 46.34%) than in the BSERef algorithm(5.95% – 44.49%). Our results demonstrate that the BSERef algorithm overestimates the soil conservation serviceof cropland in ecologically adaptable areas, whereas the CSERef algorithm can effectively assess the influence ofland use change induced by anthropogenic activities on soil conservation service. Furthermore, we develop anassessment framework in terms of land use classification system following the Chinese Academy of Sciences. Theframework considers that for water bodies, there is no soil conservation service;for non-ecologically adaptable ar-eas (unused land) with vast barren lands and vegetation cover below 5%, the BSERef algorithm is recommended;the CSERef algorithm is suggested to use in ecologically adaptable areas (including woodland, grassland, crop-land and construction land). This assessment framework can provide scientific assistance for decision-makers toformulate strategies for sustainable land management.展开更多
Dongchuan District of Kunming City has undulating terrain with large fluctuations, fragile ecological environment, low rainfall and high evaporation, coupled with frequent debris flow activities, resulting in very low...Dongchuan District of Kunming City has undulating terrain with large fluctuations, fragile ecological environment, low rainfall and high evaporation, coupled with frequent debris flow activities, resulting in very low forest coverage rate in Dongchuan. In this study, a comprehensive and systematic investigation was carried out to the green planting of barren hills in Dongchuan District from January to June, 2016. The results showed that the major planting tree species in the region with an altitude of less than 1 600 m were Leucaena leucocephala, Cupressus torulosa, L. leucocephala, C. torulosa, Celtis yunnanensis, Melia azedarach , among which L. leucocephala had become of pioneer tree species of afforestation in the Dongchuan dry-hot valley. The major planting tree species at the altitude of 1 600-2 500 m were C. torulosa, Sabina chinensis, Alnus nepalensis, C. yunnanensis, and Pinus armandi , and at the altitude of over 2 500 m, the major tree species were Sabina chinensis, Abies georgei var. smithii, P.densata. Based on the investigation, suggestions were proposed for the existing problems in the greening and planting of Dongchuan barren hills, in order to provide certain theoretical basis for the sustainable development of forestry in Dongchuan.展开更多
Barren ground caribou are one of the most important natural resources for northern aboriginal peoples in Canada, and their responsible management has been identified as a top priority by northern communities and gover...Barren ground caribou are one of the most important natural resources for northern aboriginal peoples in Canada, and their responsible management has been identified as a top priority by northern communities and governments. This study is aimed to assess the impacts of summer range forage availability and quality on Bathurst caribou’s productivity and abundance. Despite well documented effects of habitat nutrition on individual animal, few studies have been able to link nutrition and population demographics in a quantitative fashion, probably because caribou productivity and abundance could be potentially affected by many factors (e.g., habitat, harvest, predators, diseases/parasites, extreme weather, climate change, industrial development, and pollution), and yet long-term data for many of these factors are not available. By determining the upper envelope curve between summer range indicators and caribou productivity, this study made such assessment possible. Our results indicate that summer range indicators derived from long-term remote sensing time series and climate records can explain 59% of the variation in late-winter calf:cow ratio during 1985 and 2012. As a measure of caribounet productvitiy, the late-winter calf:cow ratio, together with the mortality rate, in turn determined population dynamics.展开更多
Innovation empowers the battle against desertification and sandification in China,With birds chirping and lushplants swaying in the breeze,the shelterbelts intheoncebarrensand sea inAlxa Left Banner,a county-level adm...Innovation empowers the battle against desertification and sandification in China,With birds chirping and lushplants swaying in the breeze,the shelterbelts intheoncebarrensand sea inAlxa Left Banner,a county-level administrative division,are brimming with vitality.展开更多
Tne copper-nickel factory's emissions in the Murmansk region,Russia,led to the degradanon of plant cover and topsoil with the subsequent formation of industrial barrens.In this study,the industrial barrens were re...Tne copper-nickel factory's emissions in the Murmansk region,Russia,led to the degradanon of plant cover and topsoil with the subsequent formation of industrial barrens.In this study,the industrial barrens were remediated by means of Technosol engineering,when grasses were sown on the two different types of mining wastes (carbonatite and serpentinite-magnesite) covered by hydroponic vermiculite.The serpentinite-magnesite waste was significantly different from the carbonatite waste in the content of silicon (Si) and manganese (Mn),pH,and texture.Both wastes had an alkaline pH level and high content of calcium (Ca) and magnesium (Mg).The vegetation and Technosol properties at the remediated sites were analyzed in 2017 and compared to the initial state (2010 year) to assess the efficiency of the long-term remediation.The quality and sustainability of Technosols based on the serpentinite-magnesite wastes were substantially higher compared to the carbonatite-based Technosol.Biomass and a projective cover of the grass community depended on Si content in the original mining waste and were found to be higher in the serpentinite-magnesite Technosol.The content of organic carbon and its fractions,microbial biomass and basal respiration after seven years of Technosol evolution was comparable to natural values.These parameters were directly related to plant cover state and were inversely proportional to copper (Cu) content in Technosol.The Technosol development led to the reduction of nickel (Ni) and Cu migration in soil-plant ecosystems due to neutralization and adsorption properties of mining wastes and phytostabilization by underground parts of grass communities.The Technosol development in its early stage of pedogenesis indicates the efficiency of applied remediation technology to the degraded acidic soil under the conditions of industrial atmospheric pollution.展开更多
We compared small mammal community composition among undisturbed habitats and habitats disturbed by military operations on Warren Grove Gunnery Range(WGR)in the New Jersey Pinelands.WGR is one of the largest tracts of...We compared small mammal community composition among undisturbed habitats and habitats disturbed by military operations on Warren Grove Gunnery Range(WGR)in the New Jersey Pinelands.WGR is one of the largest tracts of protected land within this globally rare ecosystem.Disturbance in the form of fire,mowing,soil disruption and logging has had a large effect on small mammal occurrence and distribution.Of the 14 small mammal species that occur in the Pinelands,9 live on WGR,including large populations of the southern bog lemming(Synaptomys cooperi Baird,1858)and meadow jumping mouse[Zapus hudsonius(Zimmermann,1780)].Simpson’s Index of Diversity was 0 for most disturbed sites and was generally greater in wetlands than in uplands.White-footed mouse[Peromyscus leucopus(Rafinesque,1818)]was the most common species on WGR and had a dominant effect on species diversity and community similarity indices.It dominated upland habitats and was the only species to occur in several disturbed habitats,whereas all 9 species occurred in wetlands.Principal components analysis indicated that most variation in species diversity was explained by disturbance and differences between upland and wetland habitats,due to presence of white-footed mice in disturbed and upland sites.Meadow jumping mice,southern bog lemmings and red-back voles[Myodes gapperi(Vigors,1830)]were positively correlated with wetland habitats,and pine voles[Microtus pinetorum(Le Conte,1830)],short-tail shrews[Blarina brevicauda(Say,1823)]and eastern chipmunks[Tamias striatus(Linnaeus,1758)]were associated with uplands.Habitat heterogeneity at WGR,including extensive undisturbed wetlands and uplands supported a rich diversity of small mammal species.展开更多
Land is the root of rural revitalization, and its core is to reinvigorate land resources through the building up of land capacity. Since the late 1990s, land consolidation efforts have been widely extended to all part...Land is the root of rural revitalization, and its core is to reinvigorate land resources through the building up of land capacity. Since the late 1990s, land consolidation efforts have been widely extended to all parts of China. Land consolidation has served as an essential instrument for reinvigorating stock land, strengthening intensive land use, timely supplementing cultivated land, and promoting agricultural modernization, as well as urban-rural integration. This study uses a typical poor village(Dadao Village) in a state-designated impoverished county(Fuping County, Hebei Province), to analyze the socioeconomic benefits and eco-environmental impacts of land consolidation. With the aid of first-hand data from questionnaire surveys, face-to-face interviews and the visual interpretation of land use and land cover changes(LUCC), we found that: 1) the barren hilly land consolidation(BHLC)helps to promote the transformation of resource-advantages into asset-advantages in poverty-stricken areas. In 2017, 60.16% households in the study area gained the additional transferred-income with an annual average of 2843 yuan, while 19.11% households received the wage-income with an annual average of 9871 yuan. 2) Land consolidation inspires farmers' enthusiasm to participate in village government and helps alleviate rural poverty. From 2014 to 2017, land consolidation has helped 585 poor in the village out of poverty. Meanwhile,by land consolidation, most farmers' attitudes towards land consolidation have shifted from"not caring" to "have great concern," and their identity cognition has gradually changed from being bystanders to becoming decision makers and supervisors. 3) Further analysis demonstrated that land consolidation could not only increase the quantity and quality of arable land,but also have a certain impact on eco-environment. During 2014–2016, the BHLC in the study area transformed 242.12 ha unused barren hilly land and open forest land into well-facilitated arable land, and increased the average arable land by 0.19 ha per capita. Also, the index of land use intensity increased by 27.01% between 2014 and 2016. Farmers' perceptions of environmental awareness have confirmed that such high-intensity LUCC were significant enough to make two-side impacts on eco-environment. We appeal to establish a combined organization and encouragement mechanism of rural land consolidation, to take the full breadth and depth of farmers' participation into consideration, and to formulate more scientific and sustainable land consolidation planning. Also, we put forward some suggestions and notes for the implementation and promotion of BHLC model. These findings can provide beneficial references for those involved in policymaking and planning in the areas of land consolidation and poverty alleviation in China, as well as other developing countries around the world.展开更多
The P-T conditions of auriferous and barren quartz veins from Kopylovsky,Kavkaz and Krasnoye gold deposits in Proterozoic black shales of Bodaybo ore region are presented the first time in this study.Fluid inclusions ...The P-T conditions of auriferous and barren quartz veins from Kopylovsky,Kavkaz and Krasnoye gold deposits in Proterozoic black shales of Bodaybo ore region are presented the first time in this study.Fluid inclusions trapped in auriferous quartz are aqueous Na±K-Mg chloride with salinity of 6 wt.%-8.8 wt.%NaCleqv.Homogenization temperatures vary from 260 to 350℃,and calculated trapping pressures are 1.2-1.6 kbar.The fluids trapped in barren quartz have more complicated compositions with Na,K,Mg and Fe chlorides,salinity up to 13 wt.%NaCleqv,and homogenization temperatures ranging between 140 and 280℃.The volatiles in fluids are dominated by H2O,followed by CO2 with minor amounts of CH4 and N2.We suppose that auriferous and barren quartz veins have been formed due to the basic metamorphogenic fluid as evidenced by the close slat and gas fluid composition.展开更多
基金supported by the National Science Foundation(grant number DEB 1452971)Rutgers Alberts Research Awards in Biodiversity,Rutgers Center for Turfgrass Science and the New Jersey Agricultural Experiment Station to N.Zhangthe National Military Family Association,and the Garden Club of America。
文摘Arbuscular mycorrhizal(AM)fungi contribute globally to ecosystem services and play an important role in sustainable crop production.However,it is unclear which factors contribute most to their colonization and community structure at different sites,particularly in understudied ecosystems.This study investigated the AM fungal communities associated with switchgrass(Panicum virgatum L.)in the understudied acidic and oligotrophic pine barrens ecosystem using next-generation sequencing.Switchgrass was also sampled from agroecosystems,as well as,from a native prairie for comparison.The pine barrens switchgrass harbored a distinct AM fungal community−Acaulospora and Ambispora were almost exclusively found in the pine barrens sites,and some of these species may represent undescribed taxa.Glomus was the most ubiquitous AM fungal genus recovered from all sites.This study suggests differences in the AM fungal community structure under different soil properties and land uses.This is the first sequence-based report of the AM fungal communities in the pine barrens ecosystem.
文摘Aims Serpentine barrens of the Mid-Atlantic United States are globally rare,grass-dominated ecosystems thought to exclude C3 spe-cies and characterized by unique soil composition.However,like many grassland ecosystems globally,these sites are presently facing encroachment by surrounding forest.In this ecosystem,the tendril climbing vine,Smilax rotundifolia,forms dense thickets around bar-rens that typically precede forest encroachment.While numerous factors speculatively initiate and promote encroachment in these systems,few studies have examined photosynthetic responses of serpentine grasses to changes in resource availability initiated by encroachers or physiological ability of encroaching S.rotundifolia to colonize high-light barren environments.We sought to under-stand both environmental and physiological dynamics of encroach-ment along an irradiance gradient in these systems.Methods At three serpentine barren sites in southeastern Pennsylvania,physiological responses of the native grasses Sorghastrum nutans and Schizachyrium scoparium to increased shading by S.rotundi-folia were examined.Additionally,the physiological performance of S.rotundifolia in the forest understory was compared to that in sunlit barrens environments.Light-saturated photosynthesis(A_(sat)),stomatal conductance(g_(s)),instantaneous transpiration efficiency(ITE),maximum efficiency of photosystem II(F_(v)/F_(m)),midday leaf water potential(ψ_(leaf))and specific leaf area(SLA)were measured for all species over the course of the 2014 growing season.Two-way analyses of variance were used to assess changes in these param-eters across growing environments,as well as seasonally for each species.Multiple regression analyses were also performed to inves-tigate the influence of vapor pressure deficit(D)and leaf tempera-ture(T_(leaf))on A_(sat) and ITE.Important Findings Light-saturated photosynthesis was significantly greater in S.rotun-difolia growing in sun than in the shade(P<0.001)and early in the season(P=0.012).Sun S.rotundifolia had up to 27%greater A_(sat) than shaded plants.Even with reducedψleaf in the barrens,S.rotundifolia maintained high g_(s) though A_(sat) was limited by high D later in the growing season.These data are in agreement with recent research suggesting that plants are not subject to water limi-tation in Mid-Atlantic barrens.Unexpectedly,shaded grasses at the encroachment interface did not exhibit any significant reduc-tion in A_(sat).Declines in grass photosynthesis do not likely occur until S.rotundifolia rhizomes transition into monotypic thickets,completely excluding grasses.Encroachment by S.rotundifolia appears to be primarily facilitated by its ability to capitalize on light resources early on in the summer growing season,when environ-mental conditions are less stressful.
基金Project supported by the National Natural Science Foundation of China(Grant No.62375140)Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX190900)。
文摘A single-qubit quantum classifier(SQC)based on a gradient-free optimization(GFO)algorithm,named the GFO-based SQC,is proposed to overcome the effects of barren plateaus caused by quantum devices.Here,a rotation gate R_(X)(φ)is applied on the single-qubit binary quantum classifier,and the training data and parameters are loaded intoφin the form of vector multiplication.The cost function is decreased by finding the value of each parameter that yields the minimum expectation value of measuring the quantum circuit.The algorithm is performed iteratively for all parameters one by one until the cost function satisfies the stop condition.The proposed GFO-based SQC is demonstrated for classification tasks in Iris and MNIST datasets and compared with the Adam-based SQC and the quantum support vector machine(QSVM).Furthermore,the performance of the GFO-based SQC is discussed when the rotation gate in the quantum device is under different types of noise.The simulation results show that the GFO-based SQC can reach a high accuracy in reduced time.Additionally,the proposed GFO algorithm can quickly complete the training process of the SQC.Importantly,the GFO-based SQC has a good performance in noisy environments.
文摘Traveling is one major theme of Fitzgerald's novel Tender Is the Night. This fashionable activity for the 1920 s Americans is represented in the novel as ostensibly bearing different meanings to the main characters, but a deeper look would reveal that it is unanimously resorted to as a weapon against the spiritual barrenness caused by the cult of business, and more importantly, as a way to the experience of rootedness.
基金fnancially supported by the National Key Research and Development Program of China(2018YFD0300704)the Special Funds for Public Welfare Industry(Agriculture)Research,China(201203029)+1 种基金the Open Foundation of State Key Laboratory of Crop Biology in China(2019KF03)the Open Foundation of Chinese Academy of Agricultural Sciences,China/Key Laboratory of Crop Water Use and Regulation,Ministry of Agriculture and Rural Affairs,China(FIRI2019-02-0103)。
文摘Compared to other crops,maize production demands relatively high temperatures.However,temperatures exceeding 35℃lead to adverse effects on maize yield.High temperatures(≥35℃)are consistently experienced by summer maize during its reproductive growth stage in the North China Plain,which is likely to cause irreversible crop damage.This study investigated the effects of elevating temperature(ET)treatment on the yield component of summer maize,beginning at the 9th unfolding leaf stage and ending at the tasseling stage.Results demonstrated that continuous ET led to a decrease in the elongation rate and activity of silks and an elongated interval between anthesis and silking stages,and eventually decreased grain number at ear tip and reduced yield.Although continuous ET before tasseling damaged the anther structure,reduced pollen activity,delayed the start of the pollen shedding stage,and shortened the pollen shedding time,it was inferred,based on phenotypical and physiological traits,that continuous ET after the 9th unfolding leaf stage influenced ears and therefore may have more significant impacts.Overall,when maize plants were exposed to ET treatment in the ear reproductive development stage,the growth of ears and tassels was blocked,which increased the occurrence of barren ear tips and led to large yield losses.
文摘A systematic account of micro-textures and a few compositional profiles of plagioclase from high-alumina basaltic aa lava erupted during the year 1994-1995, from Barren Island Volcano, NE India ocean, are presented for the first time. The identified micro-textures can be grouped into two categories: (i) Growth related textures in the form of coarse/fine-sieve morphology, fine-scale oscillatory zoning and resorption surfaces resulted when the equilibrium at the crystal-melt interface was fluctuated due to change in temperature or H20 or pressure or composition of the crystallizing melt; and (ii) morphological texture, like glomerocryst, synneusis, swallow-tailed crystal, microlite and broken crystals, formed by the influence of dynamic behavior of the crystallizing magma (convection, turbulence, degassing, etc.). Each micro-texture has developed in a specific magmatic environment, accordingly, a first order magma plumbing model and crystallization dynamics are envisaged for the studied lava unit. Magma generated has undergone extensive fractional crystallization of An-rich plagioclase in stable magmatic environment at a deeper depth. Subsequently they ascend to a shallow chamber where the newly brought crystals and pre-existing crystals have undergone dynamic crystallization via dissolution-regrowth processes in a convective self- mixing environment. Such repeated recharge-recycling processes have produced various populations of plagioclase with different micro-textural stratigraphy in the studied lava unit. Intermittent degassing and eruption related decompression have also played a major role in the final stage of crystallization dynamics.
文摘High-order finite element method (FEM) formulation also referred to as spectral element method (SEM) formulation is currently implemented in this paper for 3-dimensional (3-D) elasto-plastic problems in stability assessment of large- scale slopes (vegetated and barren slopes) in different instability conditions such as seismic and saturation. We have reviewed the SEM formulation, and have sought its applicability for vegetated slopes. Utilizing p (high-order polynomial degree or spectral degrees) and h (mesh operation for quality meshing in required elemental budgets) refining techniques in the existing FEM, the complexity of problem domain can be well addressed in greater numerical stability. Unlike the existing FEM formulation, this high-order FEM employs the same integration and interpolation points to achieve a progressive response of the instability, which drastically reduces the computational costs (formation of diagonalized mass matrix) and offers significant benefits to slope instability computations for serial and parallel implementations. With this formulation, we have achieved the following three qualities in slope instability modeling: 1) geometric flexibility of the finite elements, 2) high computational efficiency, and 3) reliable spectral accuracy. A sample problem has also been presented in this paper, which has accommodated all aforesaid numerical qualities.
文摘The Pine Barrens in New York State are dominated by pitch pine(Pinus ridgida) and scrub oaks(Quercus ilicifolia and Q. prinoides). With fire suppression over the last 90 years or so, P. rigida regeneration has become sparse, even in areas set aside to preserve this type of vegetation. We evaluated the effects of fire and an alternative disturbance(mechanical removal of vegetation)for increasing P. rigida regeneration in the Albany Pine Bush Preserve in eastern New York State. By comparing cover, diameter and height of P. rigida, Q. ilicifolia, Q.prinoides, and Vaccinium spp.(blueberry) growing on the sites with a known fire history, we documented structural and compositional changes in the vegetation since its establishment. We also compared sites on which Quercus sprouts were controlled through mechanical removal. In the years following a disturbance, height and cover of Q. ilicifolia increased continuously and the species became increasingly competitive. Both the density of P. rigida seedlings and Vaccinium cover decreased significantly as the diameter and height of Quercus increased. Our results confirmed that the dominance by P. rigida could be attributed to periodic fires at intervals of 20–25 years. We conclude that removing Q. ilicifolia can favor P. rigida dominance on the barren without fire by releasing pine seedlings from competition.
文摘Gardaneh Salavat porphyry copper system is located in the northwest of Iran. It comprises a quartz diorite to diorite porphyritic intrusion that created extensive alteration haloes in the host rocks. Despite all technical considerations, the exploration activities did not yield to ore discovery. As the matter of fact, all of the geological,geophysical, and geochemical characteristics of a porphyry Cu-Au deposit exist but there is no economic mineralization. Detailed examinations suggest that the only reasonable explanation can be related to the infertility or low metal endowment of the porphyritic intrusion. The reasons include(1) anomalous ranges of Cu, Au, and Mo rather than economic ore grades,(2) weakly development of potassic alteration,(3) probably sulfur saturation of magma that occurred before intrusion emplacement in the host rocks, and(4) probably low metal endowment in the regional scale and the lack of known porphyry copper deposits in close neighborhoods. It is tried to test the proposed hypothesis with the introduced fertility indicators based on major and trace element geochemistry. However,current fertility indicators could not prove or reject the proposed hypothesis for Gardaneh Salavat porphyritic intrusion because of the high-K calc-alkaline to shoshonitic nature of the intrusive rocks together with the unavailability of relatively fresh/unaltered samples. This case study is notable to examine because(1) it shows that characterization of fertile from barren intrusions seems to be as important as vectoring towards concealed porphyry copper deposits, especially while dealing with deep exploration targets that are associated with high financial risks, and(2) it highlights the inefficiencies and uncertainties in introduced magma fertility indicators for porphyry copper intrusions. As a result, it is of high importance to conduct an overarching investigation on other possible fertility indicators as a fundamental need for the future of the exploration industry.
基金the 2020 Research Program of Sanya Yazhou Bay Science and Technology City,China(SKJC-2020-02-005)the Agricultural Science and Technology Innovation Program(ASTIP)of Chinese Academy of Agricultural Sciences(CAAS-ZDRW202004 and CAAS-ZDRW202109).
文摘Increasing the planting density is one way to enhance grain production in maize.However,high planting density brings about growth and developmental defects such as barrenness,which is the major factor limiting grain yield.In this study,the barrenness was characterized in an association panel comprising 280 inbred lines under normal(67500 plants ha–1,ND)and high(120000 plants ha–1,HD)planting densities in 2017 and 2018.The population was genotyped using 776254 single nucleotide polymorphism(SNP)markers with criteria of minor allele frequency>5%and<20%missing data.A genome-wide association study(GWAS)was conducted for barrenness under ND and HD,as well as the barrenness ratio(HD/ND),by applying a Mixed Linear Model that controls both population structure and relative kinship(Q+K).In total,20 SNPs located in nine genes were significantly(P<6.44×10–8)associated with barrenness under the different planting densities.Among them,seven SNPs for barrenness at ND and HD were located in two genes,four of which were common under both ND and HD.In addition,13 SNPs for the barrenness ratio were located in seven genes.A complementary pathway analysis indicated that the metabolic pathways of amino acids,such as glutamate and arginine,and the mitogen-activated protein kinase(MAPK)signaling pathway might play important roles in tolerance to high planting density.These results provide insights into the genetic basis of high planting density tolerance and will facilitate high yield maize breeding.
文摘Quantifying soil conservation service is critical for sustainable land management. However, the traditional algo-rithm includes a gap between barren land and real soil erosion (BSERef), and its paradox is that a mass of barrenland rarely exists in ecologically adaptable areas with fertile soils, which might overestimate soil conservationservice. This study suggests a practical algorithm to effectively evaluate soil conservation service of differentecosystems. We propose a new algorithm based on the difference between cropland without control practicesand real soil erosion (CSERef), which is compared with the BSERef algorithm. Our results show that: (1) a nearlyfive times smaller mean soil conservation amount of cropland occurred in the CSERef algorithm (3.76×106 t·yr–1)than in the BSERef algorithm (20.04×106 t·yr–1);(2) land use has higher explanatory power for the spatial dif-ferentiation of soil conservation rate in the CSERef algorithm (15.93% – 46.34%) than in the BSERef algorithm(5.95% – 44.49%). Our results demonstrate that the BSERef algorithm overestimates the soil conservation serviceof cropland in ecologically adaptable areas, whereas the CSERef algorithm can effectively assess the influence ofland use change induced by anthropogenic activities on soil conservation service. Furthermore, we develop anassessment framework in terms of land use classification system following the Chinese Academy of Sciences. Theframework considers that for water bodies, there is no soil conservation service;for non-ecologically adaptable ar-eas (unused land) with vast barren lands and vegetation cover below 5%, the BSERef algorithm is recommended;the CSERef algorithm is suggested to use in ecologically adaptable areas (including woodland, grassland, crop-land and construction land). This assessment framework can provide scientific assistance for decision-makers toformulate strategies for sustainable land management.
基金Supported by the Forestry Science and Technology Innovation Project of Yunnan([2014]CX05)
文摘Dongchuan District of Kunming City has undulating terrain with large fluctuations, fragile ecological environment, low rainfall and high evaporation, coupled with frequent debris flow activities, resulting in very low forest coverage rate in Dongchuan. In this study, a comprehensive and systematic investigation was carried out to the green planting of barren hills in Dongchuan District from January to June, 2016. The results showed that the major planting tree species in the region with an altitude of less than 1 600 m were Leucaena leucocephala, Cupressus torulosa, L. leucocephala, C. torulosa, Celtis yunnanensis, Melia azedarach , among which L. leucocephala had become of pioneer tree species of afforestation in the Dongchuan dry-hot valley. The major planting tree species at the altitude of 1 600-2 500 m were C. torulosa, Sabina chinensis, Alnus nepalensis, C. yunnanensis, and Pinus armandi , and at the altitude of over 2 500 m, the major tree species were Sabina chinensis, Abies georgei var. smithii, P.densata. Based on the investigation, suggestions were proposed for the existing problems in the greening and planting of Dongchuan barren hills, in order to provide certain theoretical basis for the sustainable development of forestry in Dongchuan.
文摘Barren ground caribou are one of the most important natural resources for northern aboriginal peoples in Canada, and their responsible management has been identified as a top priority by northern communities and governments. This study is aimed to assess the impacts of summer range forage availability and quality on Bathurst caribou’s productivity and abundance. Despite well documented effects of habitat nutrition on individual animal, few studies have been able to link nutrition and population demographics in a quantitative fashion, probably because caribou productivity and abundance could be potentially affected by many factors (e.g., habitat, harvest, predators, diseases/parasites, extreme weather, climate change, industrial development, and pollution), and yet long-term data for many of these factors are not available. By determining the upper envelope curve between summer range indicators and caribou productivity, this study made such assessment possible. Our results indicate that summer range indicators derived from long-term remote sensing time series and climate records can explain 59% of the variation in late-winter calf:cow ratio during 1985 and 2012. As a measure of caribounet productvitiy, the late-winter calf:cow ratio, together with the mortality rate, in turn determined population dynamics.
文摘Innovation empowers the battle against desertification and sandification in China,With birds chirping and lushplants swaying in the breeze,the shelterbelts intheoncebarrensand sea inAlxa Left Banner,a county-level administrative division,are brimming with vitality.
基金the Russian Foundation for Basic Research Project 16-35-60022Analysis of C quantity and quality was supported by the Russian Science Foundation Project 17-77-20046Data analysis and processing were supported by the RUDN University“5-100”Project.
文摘Tne copper-nickel factory's emissions in the Murmansk region,Russia,led to the degradanon of plant cover and topsoil with the subsequent formation of industrial barrens.In this study,the industrial barrens were remediated by means of Technosol engineering,when grasses were sown on the two different types of mining wastes (carbonatite and serpentinite-magnesite) covered by hydroponic vermiculite.The serpentinite-magnesite waste was significantly different from the carbonatite waste in the content of silicon (Si) and manganese (Mn),pH,and texture.Both wastes had an alkaline pH level and high content of calcium (Ca) and magnesium (Mg).The vegetation and Technosol properties at the remediated sites were analyzed in 2017 and compared to the initial state (2010 year) to assess the efficiency of the long-term remediation.The quality and sustainability of Technosols based on the serpentinite-magnesite wastes were substantially higher compared to the carbonatite-based Technosol.Biomass and a projective cover of the grass community depended on Si content in the original mining waste and were found to be higher in the serpentinite-magnesite Technosol.The content of organic carbon and its fractions,microbial biomass and basal respiration after seven years of Technosol evolution was comparable to natural values.These parameters were directly related to plant cover state and were inversely proportional to copper (Cu) content in Technosol.The Technosol development led to the reduction of nickel (Ni) and Cu migration in soil-plant ecosystems due to neutralization and adsorption properties of mining wastes and phytostabilization by underground parts of grass communities.The Technosol development in its early stage of pedogenesis indicates the efficiency of applied remediation technology to the degraded acidic soil under the conditions of industrial atmospheric pollution.
基金funded by the US Air Force National Guard through the US Army Medical Research Acquisition Activity(USAMRAA Award No.DAMD17-02-2-0045)。
文摘We compared small mammal community composition among undisturbed habitats and habitats disturbed by military operations on Warren Grove Gunnery Range(WGR)in the New Jersey Pinelands.WGR is one of the largest tracts of protected land within this globally rare ecosystem.Disturbance in the form of fire,mowing,soil disruption and logging has had a large effect on small mammal occurrence and distribution.Of the 14 small mammal species that occur in the Pinelands,9 live on WGR,including large populations of the southern bog lemming(Synaptomys cooperi Baird,1858)and meadow jumping mouse[Zapus hudsonius(Zimmermann,1780)].Simpson’s Index of Diversity was 0 for most disturbed sites and was generally greater in wetlands than in uplands.White-footed mouse[Peromyscus leucopus(Rafinesque,1818)]was the most common species on WGR and had a dominant effect on species diversity and community similarity indices.It dominated upland habitats and was the only species to occur in several disturbed habitats,whereas all 9 species occurred in wetlands.Principal components analysis indicated that most variation in species diversity was explained by disturbance and differences between upland and wetland habitats,due to presence of white-footed mice in disturbed and upland sites.Meadow jumping mice,southern bog lemmings and red-back voles[Myodes gapperi(Vigors,1830)]were positively correlated with wetland habitats,and pine voles[Microtus pinetorum(Le Conte,1830)],short-tail shrews[Blarina brevicauda(Say,1823)]and eastern chipmunks[Tamias striatus(Linnaeus,1758)]were associated with uplands.Habitat heterogeneity at WGR,including extensive undisturbed wetlands and uplands supported a rich diversity of small mammal species.
基金National Key Research and Development Program of China,No.2017YFC0504701Key Project of National Social Science Foundation of China,No.15ZDA021National Natural Science Foundation of China,No.41871183,No.41601172
文摘Land is the root of rural revitalization, and its core is to reinvigorate land resources through the building up of land capacity. Since the late 1990s, land consolidation efforts have been widely extended to all parts of China. Land consolidation has served as an essential instrument for reinvigorating stock land, strengthening intensive land use, timely supplementing cultivated land, and promoting agricultural modernization, as well as urban-rural integration. This study uses a typical poor village(Dadao Village) in a state-designated impoverished county(Fuping County, Hebei Province), to analyze the socioeconomic benefits and eco-environmental impacts of land consolidation. With the aid of first-hand data from questionnaire surveys, face-to-face interviews and the visual interpretation of land use and land cover changes(LUCC), we found that: 1) the barren hilly land consolidation(BHLC)helps to promote the transformation of resource-advantages into asset-advantages in poverty-stricken areas. In 2017, 60.16% households in the study area gained the additional transferred-income with an annual average of 2843 yuan, while 19.11% households received the wage-income with an annual average of 9871 yuan. 2) Land consolidation inspires farmers' enthusiasm to participate in village government and helps alleviate rural poverty. From 2014 to 2017, land consolidation has helped 585 poor in the village out of poverty. Meanwhile,by land consolidation, most farmers' attitudes towards land consolidation have shifted from"not caring" to "have great concern," and their identity cognition has gradually changed from being bystanders to becoming decision makers and supervisors. 3) Further analysis demonstrated that land consolidation could not only increase the quantity and quality of arable land,but also have a certain impact on eco-environment. During 2014–2016, the BHLC in the study area transformed 242.12 ha unused barren hilly land and open forest land into well-facilitated arable land, and increased the average arable land by 0.19 ha per capita. Also, the index of land use intensity increased by 27.01% between 2014 and 2016. Farmers' perceptions of environmental awareness have confirmed that such high-intensity LUCC were significant enough to make two-side impacts on eco-environment. We appeal to establish a combined organization and encouragement mechanism of rural land consolidation, to take the full breadth and depth of farmers' participation into consideration, and to formulate more scientific and sustainable land consolidation planning. Also, we put forward some suggestions and notes for the implementation and promotion of BHLC model. These findings can provide beneficial references for those involved in policymaking and planning in the areas of land consolidation and poverty alleviation in China, as well as other developing countries around the world.
基金the State Contract of the Institute of Mineralogy,South-Urals Federal Research Center of Mineralogy and Geoecology,Urals Branch,Russian Academy of Sciences(Project for 2019-2021)the Basic Research Foundation of Russia(No.16-05-00580).
文摘The P-T conditions of auriferous and barren quartz veins from Kopylovsky,Kavkaz and Krasnoye gold deposits in Proterozoic black shales of Bodaybo ore region are presented the first time in this study.Fluid inclusions trapped in auriferous quartz are aqueous Na±K-Mg chloride with salinity of 6 wt.%-8.8 wt.%NaCleqv.Homogenization temperatures vary from 260 to 350℃,and calculated trapping pressures are 1.2-1.6 kbar.The fluids trapped in barren quartz have more complicated compositions with Na,K,Mg and Fe chlorides,salinity up to 13 wt.%NaCleqv,and homogenization temperatures ranging between 140 and 280℃.The volatiles in fluids are dominated by H2O,followed by CO2 with minor amounts of CH4 and N2.We suppose that auriferous and barren quartz veins have been formed due to the basic metamorphogenic fluid as evidenced by the close slat and gas fluid composition.