The addition of biochar(BC)or Arbuscular mycorrhizal fungi(AMF)alone has been reported to promote plant growth,while their synergistic effects on Allium schoenoprasum root morphology and rhizosphere fungal community i...The addition of biochar(BC)or Arbuscular mycorrhizal fungi(AMF)alone has been reported to promote plant growth,while their synergistic effects on Allium schoenoprasum root morphology and rhizosphere fungal community in barren soil is still unclear.In this study,we investigated the effects of BC and AMF(Funneliformis mosseae)on plant growth and root morphology in barren soil and revealed the structure of soil fungal communities Therefore,a greenhouse pot trial consisting of five treatments was enforced.The results showed that the combination of biochar and AMF significantly improved plant biomass,nutrient uptake,mycorrhizal colonization rates and soil properties and significantly impacted rhizosphere fungal community composition and structure.Biochar significantly increased the fungal community stability and enhanced their positive correlation with plants.Our findings indicated that the combination of AMF and biochar play synergic role for plant growth and rhizosphere fungal community in barren soil.展开更多
Fire is an important ecological factor and what constitutes appropriate fire management is much debated in the US and elsewhere. The role of fire as a source of greenhouse gases has been intensively investigated, but ...Fire is an important ecological factor and what constitutes appropriate fire management is much debated in the US and elsewhere. The role of fire as a source of greenhouse gases has been intensively investigated, but less is known about the production rate of the solid black carbon residue from fires. Black carbon accumulates in soil as it has longer turnover times than plant residues. To understand the significance of black carbon production during wildfire, we quantified black carbon using hydropyrolysis in O and A horizons before and after a prescribed bum at four sites in the New Jersey Pine Barrens forest in the North-Eastern US. Black carbon was found in both O- and A-horizons at all investigated sites, stocks in the range of 61.31-168.15 g m^-2 in the O-horizon and 169.59-425.25 g m^-2 in the A-horizon. Total black carbon stocks did not increase following the fire suggesting that either black carbon production in fires may be small compared to the variability, or that equivalent amounts of black carbon formed in previous fires may have been consumed in the fire. The study raises questions about how black carbon production and consumption in ftres can be quantified separately.展开更多
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
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
Abstract This study was conducted to clarify the characteristics high-pressure water sprayer in the period from June 2010 to April 2011 of algal succession following rock scraping using hoe or We divided the research ...Abstract This study was conducted to clarify the characteristics high-pressure water sprayer in the period from June 2010 to April 2011 of algal succession following rock scraping using hoe or We divided the research area off the eastern coast of Korean near Imwon into 3 categories depending upon the severity of the barren ground, i.e., the urchin barren-affected, urchin bar- ren-ongoing and urchin barren-free areas. In April 2011, in the urchin barren-affected area with 25 seaweed species, the cover per- centage and importance value （IV） of erustose coralline algae were higher than those of other species. In the urchin barren-ongoing area with 33 seaweed species, crustose coralline algae （mean IV=62%） as well as Sargassum sp. （mean IV=28%）, and Gelidium amansii （mean IV= 19%） were observed following rock scraping. In the urchin barren-free area where seaweed communities were relatively abundant with 42 species, a variety of algal species including G. amansii （mean IV = 32%） underwent algal succession. Overall, it was observed that, as an aspect of algal succession, the weaker the barren ground severity was, the more frequent and di- verse the seaweeds were, and the more complex the succession pattern was in the study. As an aspect of recovering algal community, rock scraping using hoe was shown to be superior to the method using high-pressure water spraying. Therefore, we conclude that rock scraping using hoe is a very effective strategy for recovering the algal community in urchin barren-ongoing area.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
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
The North American design community typically regards green roofs as inhospitable environments for native plants due to the infrastructure’s characteristic thin soils,low organic matter,temperature fluctuations,and w...The North American design community typically regards green roofs as inhospitable environments for native plants due to the infrastructure’s characteristic thin soils,low organic matter,temperature fluctuations,and wind exposure.Consequently,green roofs are often planted with an industry-standard palette of non-native Sedum and Phedimus species that are adept at withstanding stress,but lack biodiversity and visual interest,and offer little food or shelter to native birds and insects.Regionally specific reference plant communities that thrive in similarly harsh growing conditions can positively influence green roof design throughout North America,and consequently provide ecosystem services,contribute to habitat conservation,and increase human exposure to the beauty and benefits of native plants.展开更多
基金the Key Research and Development Program of Anhui Province(Grant No.202204c06020021)Natural Science Foundation of China(Grant Nos.U21A20235 and 32201308).
文摘The addition of biochar(BC)or Arbuscular mycorrhizal fungi(AMF)alone has been reported to promote plant growth,while their synergistic effects on Allium schoenoprasum root morphology and rhizosphere fungal community in barren soil is still unclear.In this study,we investigated the effects of BC and AMF(Funneliformis mosseae)on plant growth and root morphology in barren soil and revealed the structure of soil fungal communities Therefore,a greenhouse pot trial consisting of five treatments was enforced.The results showed that the combination of biochar and AMF significantly improved plant biomass,nutrient uptake,mycorrhizal colonization rates and soil properties and significantly impacted rhizosphere fungal community composition and structure.Biochar significantly increased the fungal community stability and enhanced their positive correlation with plants.Our findings indicated that the combination of AMF and biochar play synergic role for plant growth and rhizosphere fungal community in barren soil.
文摘Fire is an important ecological factor and what constitutes appropriate fire management is much debated in the US and elsewhere. The role of fire as a source of greenhouse gases has been intensively investigated, but less is known about the production rate of the solid black carbon residue from fires. Black carbon accumulates in soil as it has longer turnover times than plant residues. To understand the significance of black carbon production during wildfire, we quantified black carbon using hydropyrolysis in O and A horizons before and after a prescribed bum at four sites in the New Jersey Pine Barrens forest in the North-Eastern US. Black carbon was found in both O- and A-horizons at all investigated sites, stocks in the range of 61.31-168.15 g m^-2 in the O-horizon and 169.59-425.25 g m^-2 in the A-horizon. Total black carbon stocks did not increase following the fire suggesting that either black carbon production in fires may be small compared to the variability, or that equivalent amounts of black carbon formed in previous fires may have been consumed in the fire. The study raises questions about how black carbon production and consumption in ftres can be quantified separately.
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.
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supported by a grant from the NIFS Fisheries Research Project ‘Development for Coast-Specific IMTA Technology (R2016015)’, Republic of Korea
文摘Abstract This study was conducted to clarify the characteristics high-pressure water sprayer in the period from June 2010 to April 2011 of algal succession following rock scraping using hoe or We divided the research area off the eastern coast of Korean near Imwon into 3 categories depending upon the severity of the barren ground, i.e., the urchin barren-affected, urchin bar- ren-ongoing and urchin barren-free areas. In April 2011, in the urchin barren-affected area with 25 seaweed species, the cover per- centage and importance value （IV） of erustose coralline algae were higher than those of other species. In the urchin barren-ongoing area with 33 seaweed species, crustose coralline algae （mean IV=62%） as well as Sargassum sp. （mean IV=28%）, and Gelidium amansii （mean IV= 19%） were observed following rock scraping. In the urchin barren-free area where seaweed communities were relatively abundant with 42 species, a variety of algal species including G. amansii （mean IV = 32%） underwent algal succession. Overall, it was observed that, as an aspect of algal succession, the weaker the barren ground severity was, the more frequent and di- verse the seaweeds were, and the more complex the succession pattern was in the study. As an aspect of recovering algal community, rock scraping using hoe was shown to be superior to the method using high-pressure water spraying. Therefore, we conclude that rock scraping using hoe is a very effective strategy for recovering the algal community in urchin barren-ongoing area.
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.
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.
文摘The North American design community typically regards green roofs as inhospitable environments for native plants due to the infrastructure’s characteristic thin soils,low organic matter,temperature fluctuations,and wind exposure.Consequently,green roofs are often planted with an industry-standard palette of non-native Sedum and Phedimus species that are adept at withstanding stress,but lack biodiversity and visual interest,and offer little food or shelter to native birds and insects.Regionally specific reference plant communities that thrive in similarly harsh growing conditions can positively influence green roof design throughout North America,and consequently provide ecosystem services,contribute to habitat conservation,and increase human exposure to the beauty and benefits of native plants.
