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Spatial distribution of vegetation carbon stock among different organs over the Tibetan Plateau:on an intensive field survey
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作者 Weixiang Cai Nianpeng He Li Xu 《Journal of Forestry Research》 2025年第1期311-320,共10页
Tibetan Plateau,as one of the most carbon intensive regions in China,is crucial in the carbon cycle,and accurately estimating its vegetation carbon density(C_(VEG))is essential for assessing regional and national carb... Tibetan Plateau,as one of the most carbon intensive regions in China,is crucial in the carbon cycle,and accurately estimating its vegetation carbon density(C_(VEG))is essential for assessing regional and national carbon balance.However,the spatial distribution of regional C_(VEG) is not available remains highly uncertain due to lack of systematic research,especially for different organs.Here,we investigated the spatial distribution patterns and driving factors of C_(VEG) among different plant organs(leaf,branch,trunk and root)by systematically field grid-sampling 2040 field-plots of plant communities over the Tibetan Plateau from 2019 to 2020.The results showed that the carbon content of plant organs ranged from 255.53 to 515.58 g kg^(-1),with the highest in branches and the lowest in roots.Among the different plant functional groups,the highest C_(VEG) was found in evergreen coniferous forests,and the lowest in desert grasslands,with an average C_(VEG) of 1603.98 g m^(-2).C_(VEG) increased spatially from northwest to southeast over the Tibetan Plateau,with MAP being the dominant factor.Furthermore,the total vegetation carbon stock on the Tibetan Plateau was estimated to be 1965.62 Tg for all vegetation types.Based on the comprehensive field survey dataset,the Random Forest model effectively predicted and mapped the spatial distribution of C_(VEG)(including aboveground,belowground,and the total biomass carbon density)over the Tibetan Plateau with notable accuracy(validation R2 values were 71%,56%,and 64%for C_(AGB),C_(BGB),and C_(VEG),respectively)at a spatial resolution of 1 km×1 km.Our findings can help improve the accuracy of regional carbon stock estimations and provide parameters for carbon cycle model optimization and remote sensing calibration in the future. 展开更多
关键词 Tibetan Plateau vegetATION Carbon density Carbon stock Machine learning
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Impact of vegetation coverage and configuration on urban temperatures:a comparative study of 31 provincial capital cities in China
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作者 Chengcong Wang Zhibin Ren +6 位作者 Peng Zhang Yujie Guo Shengyang Hong Wenhai Hong Xinyu Wang Ruoxuan Geng Fanyue Meng 《Journal of Forestry Research》 2025年第1期163-177,共15页
Urban vegetation plays a crucial role in regulating temperatures and heat waves in urban areas.However,the influence of vegetation coverage and its configuration on surface temperatures in different climate zones at a... Urban vegetation plays a crucial role in regulating temperatures and heat waves in urban areas.However,the influence of vegetation coverage and its configuration on surface temperatures in different climate zones at a national scale is unclear.To address this,we utilized high-resolution data to detect spatial patterns for 31 provincial capital cities in China.We integrated day and night surface temperatures to determine the influence of vegetative coverage and configuration on urban temperatures across different climate zones and city sizes.Our study revealed that a subtropical monsoon climate and medium-sized cities had the highest vegetative coverage and shape complexity.The best connectivity and agglomeration of vegetation were found in a temperate monsoon climate and large cities.In contrast,small cities,especially those under a temperate continental climate,had low vegetation coverage,high fragmentation,and weak agglomeration and connectivity.In addition,vegetative coverage had a negative impact on daytime surface temperatures,especially in large cities in a subtropical monsoon climate.However,an increase in vegetation coverage could result in warming at night in small cities in temperate continental climates.Although urban vegetation configuration also contributed to moderating surface temperatures,especially at night,they did not surpass the influence of vegetation coverage.The effect on nighttime temperatures of the configuration of vegetation increased by 3–6%relative to that of daytime temperatures,especially in large cities in a temperate monsoon climate.The contribution vegetation coverage and configuration interaction to cooling efficiency decreased at night,especially in medium-sized cities in a temperate continental climate by 3–5%.In addition,this study identified several moderating effects of natural and social factors on the relationship between urban vegetation coverage and surface temperatures.High duration of sunshine,low humidity and high wind speed significantly enhanced the negative impact of vegetation coverage on surface temperatures.In addition,the moderating effect of vegetation coverage was more pronounced in low population density cities and high gross domestic product.This study enhances understanding of the ecological functions of urban vegetation and provides a valuable scientific basis and strategic recommendations for optimizing urban vegetation and improving urban environmental quality. 展开更多
关键词 Daytime and nighttime urban temperatures Landscape patterns Moderating effect Urban vegetation coverage
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Rapid screening of 420 pesticide residues in fruits and vegetables using ultra high performance liquid chromatography combined with quadrupole-time of flight mass spectrometry 被引量:7
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作者 Junmei Ma Sufang Fan +5 位作者 Liqiong Yang Liangna He Hongwen Zhai Xiaowei Ren Qiang Li Yan Zhang 《Food Science and Human Wellness》 SCIE CSCD 2023年第4期1064-1070,共7页
A new method for screening and identification 420 pesticide residues in fruits and vegetables by ultra-performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry(UPLC-Q-TOF/MS)were deve... A new method for screening and identification 420 pesticide residues in fruits and vegetables by ultra-performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry(UPLC-Q-TOF/MS)were developed.The samples were extracted with acetonitrile/acetic acid(99:1,V/V),and clean-up by SinChERS-Nano(single-step,cheap,effective,rugged,safe,nano)column,determined by UPLC-Q-TOF/MS.The accurate mass database and MS/MS database which contains 420 pesticides were established,the automatic retrieval of detection results was carried on according to the accurate mass,retention time,isotope ratio,ion fragment information,and so on.Method verification was performed on leeks samples.The results showed that 420 pesticides had good linearity in the range of 0.1-100μg/L,and the correlation coeffificients(R2)was greater than 0.990.The limits of detections(LODs)and limits of quantifications(LOQs)of 420 pesticides were in range of 0.05-2.0 and 0.1-5.0μg/L,respectively.The average spike recoveries at 3 levels were 70.1%to 119.7%,and the relative standard deviations(RSD)were lower than 20%(n=6).With this method,a survey of pesticide residues was conducted for 110 samples of 10 different fruits and vegetables,which provided scientific data for ensuring pesticide residue safety of the fruits and vegetables consumed daily by the public.This method was simple,sensitive and accurate,and could be used for rapid screening of 420 pesticide residues in fruits and vegetables. 展开更多
关键词 UPLC-Q-TOF/MS SinChERS-Nano column Pesticide residues Fruits and vegetables
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Selected fermented indigenous vegetables and fruits from Malaysia as potential sources of natural probiotics for improving gut health 被引量:2
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作者 Olaide Olawunmi Ajibola Raymond Thomas Babatunde Femi Bakare 《Food Science and Human Wellness》 SCIE CSCD 2023年第5期1493-1509,共17页
In the Peninsular Malaysia and Northern Borneo island of Malaysia, various rich indigenous leafy vegetables and fruits grow and contribute to the nutritional and dietary values of the population. They have high water ... In the Peninsular Malaysia and Northern Borneo island of Malaysia, various rich indigenous leafy vegetables and fruits grow and contribute to the nutritional and dietary values of the population. They have high water contents, thus, naturally vulnerable to rapid food spoilage. Food preservation and processing play a vital role in the inhibition of food pathogens in fruits and vegetables that are prevalent in Malaysia. Lactic acid fermentation is generally a local-based bioprocess, among the oldest form and well-known for food-processing techniques among indigenous people there. The long shelf life of fermented vegetables and fruits improves their nutritional values and antioxidant potentials. Fermented leaves and vegetables can be utilized as a potential source of probiotics as they are host for several lactic acid bacteria such as Lactobacillus confusus, Weissella paramesenteroides, Enterococcus faecalis, Lactobacillus plantarum, Lactobacillus buchneri, Lactobacillus paracasei, Lactobacillus pentosus, Pediococcus acidilactici, Pediococcus pentosaceus and Leuconostoc mesenteroides. These strains may be more viable in metabolic systems whereby they can contribute to a substantial increase in essential biologically active element than industrial starter cultures. This review is aimed to address some essential fermented fruits and vegetables in Malaysia and their remarkable reputations as a potential sources of natural probiotics. 展开更多
关键词 ETHNIC Leafy vegetables FRUIT FERMENTATION Lactic acid bacteria MALAYSIA
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Twelve family members with tetramine poisoning after consumption of vegetables grown in polluted soils
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作者 Yan-qing Liu Xiao-xia Lu +7 位作者 Chun-yan Wang Ming-fei Peng Xiao-bo Peng Yun Jiang Le-xin Zheng Dan-dan Yuan Xi-gang Zhang Ze-wu Qiu 《World Journal of Emergency Medicine》 SCIE CAS CSCD 2023年第3期250-252,共3页
The main toxic component of tetramine is tetramethylenedisulfotetramine(TETS).It is a sulfonamide derivative without special antidote,tasteless and tasteless,with high toxicity and high mortality.[1]It was first disco... The main toxic component of tetramine is tetramethylenedisulfotetramine(TETS).It is a sulfonamide derivative without special antidote,tasteless and tasteless,with high toxicity and high mortality.[1]It was first discovered by a German scientist Hagen in 1949.Although its use has been banned worldwide due to its high toxicity and mortality rate,it is still available in certain countries and has led to cases of intentional and unintentional poisoning.Tetramine blocksγ-neurons,leading to dizziness,fatigue,nausea,vomiting,convulsions,and other symptoms.[2-4]Due to the lack of recognized effective antidotes,many poisoned people suff ocate and die as a result of continuous spasms of the respiratory muscles.[5-7]Tetramine poisoning sometimes occurs,but it is rare for vegetables grown in tetraminecontaminated soil to cause group poisoning after being eaten. 展开更多
关键词 MORTALITY POISONING vegetables
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Multi-Task Timing Assignment Algorithm for Intelligent Production of Vegetables in Open Field
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作者 Huarui Wu Huaji Zhu +3 位作者 Jingqiu Gu Wei Guo Ning Zhang Xiao Han 《Journal of Beijing Institute of Technology》 EI CAS 2023年第3期352-362,共11页
Vegetable production in the open field involves many tasks,such as soil preparation,ridging,and transplanting/sowing.Different tasks require agricultural machinery equipped with different agricultural tools to meet th... Vegetable production in the open field involves many tasks,such as soil preparation,ridging,and transplanting/sowing.Different tasks require agricultural machinery equipped with different agricultural tools to meet the needs of the operation.Aiming at the coupling multi-task in the intelligent production of vegetables in the open field,the task assignment method for multiple unmanned tractors based on consistency alliance is studied.Firstly,unmanned vegetable production in the open field is abstracted as a multi-task assignment model with constraints of task demand,task sequence,and the distance traveled by an unmanned tractor.The tight time constraints between associated tasks are transformed into time windows.Based on the driving distance of the unmanned tractor and the replacement cost of the tools,an expanded task cost function is innovatively established.The task assignment model of multiple unmanned tractors is optimized by the consensus based bundle algorithm(CBBA)with time windows.Experiments show that the method can effectively solve task conflict in unmanned production and optimize task allocation.A basic model is provided for the cooperative task of multiple unmanned tractors for vegetable production in the open field. 展开更多
关键词 vegetABLE unmanned tractor multi-task allocation task collaboration
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Filtration assisted pretreatment for rapid enrichment and accurate detection of Salmonella in vegetables
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作者 Bin Li Hanling Wang +5 位作者 Jianguo Xu Wei Qu Li Yao Bangben Yao Chao Yan Wei Chen 《Food Science and Human Wellness》 SCIE CSCD 2023年第4期1167-1173,共7页
Rapid detection of target foodborne pathogens plays more and more significant roles in food safety,which requires the efficiency,sensitivity,and accuracy.In this research,we proposed a new st rategy of isothermal-mole... Rapid detection of target foodborne pathogens plays more and more significant roles in food safety,which requires the efficiency,sensitivity,and accuracy.In this research,we proposed a new st rategy of isothermal-molecular-amplification integrated with lateral-flow-strip for rapid detection of Salmonella without traditional enrichment-culture.Th e designed syringe-assisted-filtration can contribute to simultaneous collection and concentration of target bacterium from vegetable samples in just 3 min,resolving the drawbacks of traditional random sampling protocols.After simple and convenient ultrasonication,samples can be directly amplified at 39℃ in 25 min and the amplicons are qualitatively and quantitatively analyzed with the designed lateral-flow-strip in 5 min.Finally,satisfied results have been achieved within 40 min,which greatly improve the efficiency while the accuracy is also guaranteed.Furthermore,all detection steps can be completed under instrument-free conditions.This method will hold great promise for target pathogen detection in the resource-limited district,or for emergency on-site identification. 展开更多
关键词 vegetables SALMONELLA Filtration enrichment Culture-free detection Enzymatic recombinase amplification(ERA) Lateral flow strip(LFS) Rapid detection Food safety
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Modelling analysis embodies drastic transition among global potential natural vegetations in face of changing climate
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作者 Zhengchao Ren Lei Liu +1 位作者 Fang Yin Xiaoni Liu 《Forest Ecosystems》 SCIE CSCD 2024年第2期184-192,共9页
Potential natural vegetation(PNV)is a valuable reference for ecosystem renovation and has garnered increasing attention worldwide.However,there is limited knowledge on the spatio-temporal distributions,transitional pr... Potential natural vegetation(PNV)is a valuable reference for ecosystem renovation and has garnered increasing attention worldwide.However,there is limited knowledge on the spatio-temporal distributions,transitional processes,and underlying mechanisms of global natural vegetation,particularly in the case of ongoing climate warming.In this study,we visualize the spatio-temporal pattern and inter-transition procedure of global PNV,analyse the shifting distances and directions of global PNV under the influence of climatic disturbance,and explore the mechanisms of global PNV in response to temperature and precipitation fluctuations.To achieve this,we utilize meteorological data,mainly temperature and precipitation,from six phases:the Last Inter-Glacial(LIG),the Last Glacial Maximum(LGM),the Mid Holocene(MH),the Present Day(PD),2030(20212040)and 2090(2081–2100),and employ a widely-accepted comprehensive and sequential classification sy–stem(CSCS)for global PNV classification.We find that the spatial patterns of five PNV groups(forest,shrubland,savanna,grassland and tundra)generally align with their respective ecotopes,although their distributions have shifted due to fluctuating temperature and precipitation.Notably,we observe an unexpected transition between tundra and savanna despite their geographical distance.The shifts in distance and direction of five PNV groups are mainly driven by temperature and precipitation,although there is heterogeneity among these shifts for each group.Indeed,the heterogeneity observed among different global PNV groups suggests that they may possess varying capacities to adjust to and withstand the impacts of changing climate.The spatio-temporal distributions,mutual transitions and shift tendencies of global PNV and its underlying mechanism in face of changing climate,as revealed in this study,can significantly contribute to the development of strategies for mitigating warming and promoting re-vegetation in degraded regions worldwide. 展开更多
关键词 Potential natural vegetation Global warming vegetation classification Predicted model CSCS
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Can urban forests provide acoustic refuges for birds?Investigating the influence of vegetation structure and anthropogenic noise on bird sound diversity
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作者 Zezhou Hao Chengyun Zhang +8 位作者 Le Li Bing Sun Shuixing Luo Juyang Liao Qingfei Wang Ruichen Wu Xinhui Xu Christopher A.Lepczyk Nancai Pei 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第2期163-175,共13页
As a crucial component of terrestrial ecosystems,urban forests play a pivotal role in protecting urban biodiversity by providing suitable habitats for acoustic spaces.Previous studies note that vegetation structure is... As a crucial component of terrestrial ecosystems,urban forests play a pivotal role in protecting urban biodiversity by providing suitable habitats for acoustic spaces.Previous studies note that vegetation structure is a key factor influencing bird sounds in urban forests;hence,adjusting the frequency composition may be a strategy for birds to avoid anthropogenic noise to mask their songs.However,it is unknown whether the response mechanisms of bird vocalizations to vegetation structure remain consistent despite being impacted by anthropogenic noise.It was hypothesized that anthropogenic noise in urban forests occupies the low-frequency space of bird songs,leading to a possible reshaping of the acoustic niches of forests,and the vegetation structure of urban forests is the critical factor that shapes the acoustic space for bird vocalization.Passive acoustic monitoring in various urban forests was used to monitor natural and anthropogenic noises,and sounds were classified into three acoustic scenes(bird sounds,human sounds,and bird-human sounds)to determine interconnections between bird sounds,anthropogenic noise,and vegetation structure.Anthropogenic noise altered the acoustic niche of urban forests by intruding into the low-frequency space used by birds,and vegetation structures related to volume(trunk volume and branch volume)and density(number of branches and leaf area index)significantly impact the diversity of bird sounds.Our findings indicate that the response to low and high frequency signals to vegetation structure is distinct.By clarifying this relationship,our results contribute to understanding of how vegetation structure influences bird sounds in urban forests impacted by anthropogenic noise. 展开更多
关键词 Anthropogenic noise Bird sounds Urban forests vegetation structure
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Terrain or climate factor dominates vegetation resilience?Evidence from three national parks across different climatic zones in China
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作者 Shuang Liu Lingxin Wu +3 位作者 Shiyong Zhen Qinxian Lin Xisheng Hu Jian Li 《Forest Ecosystems》 SCIE CSCD 2024年第4期526-542,共17页
Vegetation resilience(VR),providing an objective measure of ecosystem health,has received considerable attention,however,there is still limited understanding of whether the dominant factors differ across different cli... Vegetation resilience(VR),providing an objective measure of ecosystem health,has received considerable attention,however,there is still limited understanding of whether the dominant factors differ across different climate zones.We took the three national parks(Hainan Tropical Rainforest National Park,HTR;Wuyishan National Park,WYS;and Northeast Tiger and Leopard National Park,NTL)of China with less human interference as cases,which are distributed in different climatic zones,including tropical,subtropical and temperate monsoon climates,respectively.Then,we employed the probabilistic decay method to explore the spatio-temporal changes in the VR and their natural driving patterns using Geographically Weighted Regression(GWR)model as well.The results revealed that:(1)from 2000 to 2020,the Normalized Difference Vegetation Index(NDVI)of the three national parks fluctuated between 0.800 and 0.960,exhibiting an overall upward trend,with the mean NDVI of NTL(0.923)>HTR(0.899)>WYS(0.823);(2)the positive trend decay time of vegetation exceeded that of negative trend,indicating vegetation gradual recovery of the three national parks since 2012;(3)the VR of HTR was primarily influenced by elevation,aspect,average annual temperature change(AATC),and average annual precipitation change(AAPC);the WYS'VR was mainly affected by elevation,average annual precipitation(AAP),and AAPC;while the terrain factors(elevation and slope)were the main driving factors of VR in NTL;(4)among the main factors influencing the VR changes,the AAPC had the highest proportion in HTR(66.7%),and the AAP occupied the largest area proportion in WYS(80.4%).While in NTL,elevation served as the main driving factor for the VR,encompassing 64.2%of its area.Consequently,our findings indicated that precipitation factors were the main driving force for the VR changes in HTR and WYS national parks,while elevation was the main factors that drove the VR in NTL.Our research has promoted a deeper understanding of the driving mechanism behind the VR. 展开更多
关键词 National parks vegetation resilience NDVI Probabilistic decay model Driving factors
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A review:Health benefits and physicochemical characteristics of blended vegetable oils
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作者 Hina Daud Memon Sarfaraz Ahmed Mahesar +3 位作者 Sirajuddin Huseyin Kara Syed Tufail Hussain Sherazi Mohammad Younis Talpur 《Grain & Oil Science and Technology》 CAS 2024年第2期113-123,共11页
Oil blending is the method of choice used worldwide to improve oxidative stability and nutritional value.There is no such edible oil/fat that meets all the recommendations from the health point of view.The fatty acid ... Oil blending is the method of choice used worldwide to improve oxidative stability and nutritional value.There is no such edible oil/fat that meets all the recommendations from the health point of view.The fatty acid composition of vegetable oils decides the fate of the oil.Pure single oil is unable to provide a balanced amount of fatty acids(FAs)required/recommended on a daily intake basis.Blending oils/fats is an appropriate procedure of physically mixing multiple oils in suitable proportions which may provide functional lipids with improved antioxidant potential and desirable physical and chemical properties.This review piled up the accessible data on the blending of diverse oils/fats in the combination of binary,ternary,quaternary,or other types of oils into a single blended oil.Blending can be found very convincing towards appropriate FA profile,enhancement in physicochemical characteristics,and augmented stability for the period of storage or when used as cooking/frying processes which could ultimately serve as an effectual dietary intervention towards the health protectiveness. 展开更多
关键词 vegetable oil Oil blending Physicochemical properties Nutritional benefits
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Early response of understory vegetation to the mass dieback of Norway spruce in the European lowland temperate forest
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作者 Jan Marek Matuszkiewicz Andrzej N.Affek +1 位作者 Piotr Zaniewski Ewa Kołaczkowska 《Forest Ecosystems》 SCIE CSCD 2024年第2期214-225,共12页
Spruce-dominated forests are commonly exposed to disturbances associated with mass occurrences of bark beetles.The dieback of trees triggers many physical and chemical processes in the ecosystem resulting in rapid cha... Spruce-dominated forests are commonly exposed to disturbances associated with mass occurrences of bark beetles.The dieback of trees triggers many physical and chemical processes in the ecosystem resulting in rapid changes in the vegetation of the lower forest layers.We aimed to determine the response of non-tree understory vegetation to the mass dieback of Norway spruce(Picea abies)in the first years after the disturbance caused by the European spruce bark beetle(Ips typographus)outbreak.Our study area was the Białowieża Biosphere Reserve covering the Polish part of the emblematic Białowieża Forest,in total 597km^(2).The main data source comprised 3,900 phytosociological relevés(combined spring and summer campaigns)collected from 1,300 systematically distributed forest sites in 2016–2018–the peak years of the bark beetle outbreak.We found that the understory responded immediately to mass spruce dieback,with the most pronounced changes observed in the year of the disturbance and the subsequent year.Shade-tolerant forest species declined in the initial years following the mass spruce dieback,while hemicryptophytes,therophytes,light-demanding species associated with non-forest seminatural communities,as well as water-demanding forest species,expanded.Oxalis acetosella,the most common understory species in the Białowieża Forest,showed a distinct fluctuation pattern,with strong short-term expansion right after spruce dieback,followed by a gradual decline over the next 3–4 years to a cover level 5 percentage points lower than before the disturbance.Thus,our study revealed that mass spruce dieback selectively affects individual herb species,and their responses can be directional and non-directional(fluctuation).Furthermore,we demonstrated that the mass dieback of spruce temporarily increases plant species diversity(α-diversity). 展开更多
关键词 Forest disturbance Bark beetle outbreak Picea abies Ips typographus Response of understory vegetation Herbaceous species Biaowieza Forest
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2024年蔬菜市场形势分析和2025年展望
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作者 张晶 周向阳 +2 位作者 迟亮 吴建寨 刘继芳 《中国蔬菜》 北大核心 2025年第1期1-6,共6页
2024年,我国蔬菜市场价格总体基本符合常年季节性波动规律,但夏秋季节偏高位运行。受不利天气及其延续性影响,预计2024年冬季、2025年春季菜价上行较往年偏缓,上涨区间可能相对较长。考虑到2024年菜价整体偏高,在田面积同比增加,预计202... 2024年,我国蔬菜市场价格总体基本符合常年季节性波动规律,但夏秋季节偏高位运行。受不利天气及其延续性影响,预计2024年冬季、2025年春季菜价上行较往年偏缓,上涨区间可能相对较长。考虑到2024年菜价整体偏高,在田面积同比增加,预计2025年春季蔬菜供应总体有保障。 展开更多
关键词 蔬菜 市场形势 展望
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电动叶菜收获机速度协同控制系统设计与试验
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作者 左志宇 李东旭 +5 位作者 毛罕平 韩绿化 胡建平 张晓东 牟晋东 顾灵杰 《农机化研究》 北大核心 2025年第1期33-38,共6页
针对电动叶菜收获机切割、输送和行走三者速度不协调导致的叶菜损伤率高、功耗大和收获效率低等问题,开发了一种电动叶菜收获机速度协同控制系统。系统以可编程逻辑控制器为核心,利用信息传感模块对割刀电机的电流、电压和转速进行数据... 针对电动叶菜收获机切割、输送和行走三者速度不协调导致的叶菜损伤率高、功耗大和收获效率低等问题,开发了一种电动叶菜收获机速度协同控制系统。系统以可编程逻辑控制器为核心,利用信息传感模块对割刀电机的电流、电压和转速进行数据采集;主控模块根据速度协同控制算法对采集信号进行处理,得到负载信息并协同切割、输送和行走三者速度。田间试验结果表明:系统稳定可靠,能够根据收获情况动态协同各部件速度参数,叶菜损伤率为8.88%;与传统定速控制方法相比,收获机功耗降低了13.1%,收获效率提升了33.4%。 展开更多
关键词 叶菜收获机 速度协同 损伤率 田间试验
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宁南黄土区中庄小流域土壤密度坡面变化及尺度效应
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作者 韩新生 许浩 +5 位作者 刘广全 安钰 董立国 王月玲 万海霞 郭永忠 《水土保持研究》 北大核心 2025年第2期72-82,共11页
[目的]分析土壤密度在坡面上的变化特征及尺度效应,探讨土壤密度坡面尺度转换路径,为精准监测土壤密度、科学评价土壤功能、指导土壤资源管理提供理论依据。[方法]在宁夏南部半干旱黄土丘陵区中庄小流域,选择3个退耕还林还草后的典型坡... [目的]分析土壤密度在坡面上的变化特征及尺度效应,探讨土壤密度坡面尺度转换路径,为精准监测土壤密度、科学评价土壤功能、指导土壤资源管理提供理论依据。[方法]在宁夏南部半干旱黄土丘陵区中庄小流域,选择3个退耕还林还草后的典型坡面,按坡位从上至下设置了5个样地,调查各样地的植被类型、土地利用、立地条件等,采用环刀法分层测定了200 cm深度的土壤密度。[结果]在东坡、西坡、南坡,土壤密度随土层加深基本表现为线性增加,土层每加深10 cm土壤密度平均增加0.0062,0.0036,0.0075 g/cm^(3),其原因为植被根系、土壤有机质、压实作用的土层差异。在0—200 cm土层,东坡和南坡土壤密度坡面均值均为1.22 g/cm^(3),低于西坡(1.26 g/cm^(3))。3个坡面土壤密度的坡面变化存在差异,东坡、西坡、南坡沿坡变化表现为逐渐增加或先增后减、先升后降、先降后升,整体上为坡面下部大于上部,主要原因包括植被类型、土地利用、人类活动、恢复年限等坡面差异。以离坡顶水平距离增加100 m土壤密度坡面滑动平均值的变化量评价坡面尺度效应,0—200 cm土层的平均土壤密度坡面尺度效应在东坡为0.032(g/cm^(3))/100 m,在西坡为0.024(g/cm^(3))/100 m(离坡顶0—250 m)和-0.007(g/cm^(3))/100 m(离坡顶250—329 m),在南部为-0.011(g/cm^(3))/100 m(离坡顶0—140 m)和0.018(g/cm^(3))/100 m(离坡顶140—368 m)。构建3个坡面不同坡位样地各土层的土壤密度与坡面均值的比值随离坡顶水平距离增加而变化的关系式(R2>0.80,p<0.0001),且基于拟合关系式预测的土壤密度坡面均值的相对误差均小于2.5%,藉此可由任一坡位样地土壤密度测定值准确便捷地估算坡面均值。[结论]半干旱黄土区土壤密度坡面变化和坡位差异明显,且植被类型、人为干扰、土地利用等对土壤密度坡面分布格局影响较大,未来应加强主要作用因子对土壤密度坡面变化及尺度效应的贡献研究。 展开更多
关键词 土壤密度 坡面变化 尺度效应 植被类型 半干旱黄土区
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黔桂地区20年间植被时空变化及其对地理环境的响应
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作者 冯达 段亚锋 李婷婷 《水土保持研究》 北大核心 2025年第2期255-262,共8页
[目的]研究黔桂地区植被时空变化及其对地理环境的响应,为区域生态恢复工程效益评估和进一步恢复提供科学参考。[方法]基于NDVI数据,结合植被本底值和变化趋势,将区域植被分为9种状态类型;利用均一化面积指数分析不同状态类型植被对岩... [目的]研究黔桂地区植被时空变化及其对地理环境的响应,为区域生态恢复工程效益评估和进一步恢复提供科学参考。[方法]基于NDVI数据,结合植被本底值和变化趋势,将区域植被分为9种状态类型;利用均一化面积指数分析不同状态类型植被对岩性、地貌、土壤和地形位指数等地理特征的响应。[结果](1) 2001—2020年NDVI年均值波动增加,平均趋势率为1.8×10^(-3)/a,恢复趋势、退化趋势和稳定状态的植被面积分别占30.8%,9.1%和60.1%;(2)稳定型植被在低、中、高覆盖植被中面积占比逐渐降低,而退化型和恢复型的面积占比均依次增加;(3)纯碳酸盐岩上高覆盖植被均一化面积指数低于均值、低覆盖植被高于均值,而碎屑岩正好相反;(4)植被对红壤和水稻土的响应与本底覆盖度相关;(5)低覆盖稳定型植被在岩溶峡谷区集中分布,峰丛洼地的高覆盖植被优势明显;(6)低覆盖植被与地形位的响应关系明显,中覆盖植被受地形位影响较小。[结论]黔桂地区植被总体呈改善趋势,不同植被状态类型空间分布不均,赤红壤和岩溶峡谷上的植被相对稳定,黄壤区和峰林平原的高覆盖植被单向退化较为明显,高覆盖和低覆盖植被分别集中分布于地形位中值和低值区。 展开更多
关键词 黔桂地区 喀斯特 植被状态类型 地理环境 响应
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基于随机位移方法的河道植被区悬沙沉积分布计算模型
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作者 李川 孙思晨 +2 位作者 单钰淇 刘永浩 刘超 《工程科学与技术》 北大核心 2025年第1期48-56,共9页
天然河道中,水生植被影响水流特性与悬沙输移规律,使得河道植被区的悬沙沉积分布相比于无植被区更加复杂,模拟难度更高。为探究河道植被区悬沙沉积分布,本文将改进边界条件后的随机位移模型引入植被作用下的水沙输移研究,融合真实形态... 天然河道中,水生植被影响水流特性与悬沙输移规律,使得河道植被区的悬沙沉积分布相比于无植被区更加复杂,模拟难度更高。为探究河道植被区悬沙沉积分布,本文将改进边界条件后的随机位移模型引入植被作用下的水沙输移研究,融合真实形态植被对水流特性的影响,提出了适用于真实形态植被(以芦苇为例)下的悬沙沉积分布计算模型。为验证计算模型的准确性,本文选用具有真实外形的仿真芦苇开展水槽试验,详细测量了不同泥沙粒径、水流条件和植被密度下的芦苇区悬沙沉积沿程分布。试验结果发现:泥沙粒径、上游平均流速和植被密度均影响河道芦苇区的悬沙沉积分布,其中,对植被区前端的悬沙沉积量影响尤为显著。植被区泥沙补给是否受限会导致悬沙沉积呈现两种截然不同的分布。本文提出的数值计算模型可较好地模拟泥沙补给不受限条件下河道植被区的悬沙沉积分布,模拟结果与试验结果的量级和变化趋势均吻合较好;但该模型不能捕捉泥沙补给受限条件下植被区的悬沙沉积分布。综上,本文提出的基于随机位移方法的计算模型可较准确地预测河道植被区的悬沙沉积沿程分布,但仅适用于植被区泥沙补给不受限的情况。 展开更多
关键词 河道植被区 随机位移模型 仿真芦苇 悬沙沉积分布
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利用核心SNP标记构建豆类蔬菜品种指纹图谱
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作者 吴新义 刘娜 +2 位作者 汪宝根 龚亚明 李国景 《浙江农业科学》 2025年第2期363-369,共7页
豆类蔬菜是我国重要的蔬菜作物。为促进豆类蔬菜品种权保护,以豇豆和菜用豌豆为研究对象,分别利用物种特异的核心单核苷酸多态性(SNP)标记构建了52份豇豆品种(系)和48份豌豆种质的DNA指纹图谱,并对14份豇豆品种(系)的种子纯度进行了检... 豆类蔬菜是我国重要的蔬菜作物。为促进豆类蔬菜品种权保护,以豇豆和菜用豌豆为研究对象,分别利用物种特异的核心单核苷酸多态性(SNP)标记构建了52份豇豆品种(系)和48份豌豆种质的DNA指纹图谱,并对14份豇豆品种(系)的种子纯度进行了检测。该研究结果表明,基于竞争性等位基因特异性PCR(KASP)技术的SNP标记可以用于豆类蔬菜品种的品种权保护、种子真伪区分以及种子纯度鉴定,建议尽快制订并发布基于SNP标记的豆类蔬菜品种鉴定技术标准,为种业和产业健康发展提供技术支撑。 展开更多
关键词 豆类蔬菜 SNP标记 KASP 品种保护 种子纯度
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不同类型外掺料对植被混凝土抗冻性能的影响
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作者 郑蔚 刘大翔 +5 位作者 张琳瑶 杨悦舒 丁瑜 夏栋 肖海 许文年 《金属矿山》 北大核心 2025年第1期300-308,共9页
植被混凝土生态修复技术在非冻土区、短时冻土区向季节性冻土区推广过程中发现,土体的物理、力学性能在冻融作用下均有所劣化。在冻融条件下,比较了不同类型外掺料(玄武岩纤维和棕纤维、硅粉和粉煤灰、木质活性炭和矿质活性炭)对植被混... 植被混凝土生态修复技术在非冻土区、短时冻土区向季节性冻土区推广过程中发现,土体的物理、力学性能在冻融作用下均有所劣化。在冻融条件下,比较了不同类型外掺料(玄武岩纤维和棕纤维、硅粉和粉煤灰、木质活性炭和矿质活性炭)对植被混凝土的物理、力学性能的影响,综合选择了提升抗冻性能效果最佳的外掺料类型。研究结果表明:30次冻融循环后,添加纤维的植被混凝土试件表面完整性最好,仅在棱角区域出现轻微剥落;添加矿物外掺料的植被混凝土试件随着矿物外掺料含量的增加,表面完整性变差;添加活性炭的植被混凝土试件在冻融循环后虽未出现较大程度的质量损失,但表面均有白色物质析出和局部沙化现象,且随着掺量增加,表面微裂纹增多。纤维类对植被混凝土试件在冻融条件下的改良作用最佳,有效提升了植被混凝土试件的无侧限抗压能力和致密程度,增强了其塑性特征;添加硅粉与粉煤灰等矿物外掺料不利于植被混凝土试件无侧限抗压强度的提升,矿物外掺料的添加使得植被混凝土试件的内部结构更加疏松,矿物外掺料掺量的增加对植被混凝土试件的影响更大,在冻融作用下更易受到破坏;活性炭的添加不利于植被混凝土试件的密实度以及强度的提升,且木质活性炭比矿质活性炭对植被混凝土试件的影响更加明显。 展开更多
关键词 植被混凝土 冻融作用 外掺料 抗冻性能 超声波速 无侧限抗压强度
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浅谈一种矿山复绿配套养护设备的设计思路
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作者 杨浩 颜文琴 +1 位作者 杨晓 吴毅 《西部探矿工程》 2025年第2期57-60,64,共5页
植被养护一直以来都是矿山复绿工程中的难点和痛点,企业虽投入了大量精力财力,但植被复绿效果依旧差强人意。植被长势与植被养护之间矛盾日益突出,尤其是在大型露天矿山生态修复工程中更为明显。露天矿山开采面积大、采区不连续、养护... 植被养护一直以来都是矿山复绿工程中的难点和痛点,企业虽投入了大量精力财力,但植被复绿效果依旧差强人意。植被长势与植被养护之间矛盾日益突出,尤其是在大型露天矿山生态修复工程中更为明显。露天矿山开采面积大、采区不连续、养护设备首期投入成本高(养护管网管距长、扬程高)等多重因素制约,导致复绿植被长期得不到合理的养护而长势颓废。为解决上述问题,提出一种多料仓可装载不同养料的、养护管网可伸缩的、机动的矿山复绿配套养护设备,丰富矿山植被养护的方法,供同行参考。 展开更多
关键词 矿山复绿 植被长势 养护 设计
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