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Environmental Efficiency Analysis of China’s Vegetable Production 被引量:15
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作者 TAOZHANG BAO-DIXUE 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2005年第1期21-30,共10页
To analyze and estimate the environmental efficiency of China’s vegetable production. Methods The stochastic translog frontier model was used to estimate the technical efficiency of vegetable production. Based on... To analyze and estimate the environmental efficiency of China’s vegetable production. Methods The stochastic translog frontier model was used to estimate the technical efficiency of vegetable production. Based on the estimated frontier and technical inefficiency levels, we used the method developed by Reinhard, et al.[1] to estimate the environmental efficiency. Pesticide and chemical fertilizer inputs were treated as environmentally detrimental inputs. Results From estimated results, the mean environmental efficiency for pesticide input was 69.7%, indicating a great potential for reducing pesticide use in China’s vegetable production. In addition, substitution and output elasticities for vegetable farms were estimated to provide farmers with helpful information on how to reallocate input resources and improve efficiency. Conclusion There exists a great potential for reducing pesticide use in China’s vegetable production. 展开更多
关键词 vegetable production Stochastic translog frontier Environmental efficiency ELASTICITIES
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Vegetable Production in Lhasa
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《China's Tibet》 1997年第2期22-22,共1页
关键词 vegetable production in Lhasa
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Effects of long-term partial substitution of inorganic fertilizer with pig manure and/or straw on nitrogen fractions and microbiological properties in greenhouse vegetable soils
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作者 Shuo Yuan Ruonan Li +5 位作者 Yinjie Zhang Hao'an Luan Jiwei Tang Liying Wang Hongjie Ji Shaowen Huang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第6期2083-2098,共16页
Partial substitution of inorganic fertilizers with organic amendments is an important agricultural management practice.An 11-year field experiment(22 cropping periods)was carried out to analyze the impacts of differen... Partial substitution of inorganic fertilizers with organic amendments is an important agricultural management practice.An 11-year field experiment(22 cropping periods)was carried out to analyze the impacts of different partial substitution treatments on crop yields and the transformation of nitrogen fractions in greenhouse vegetable soil.Four treatments with equal N,P_(2)O_(5),and K_(2)O inputs were selected,including complete inorganic fertilizer N(CN),50%inorganic fertilizer N plus 50%pig manure N(CPN),50%inorganic fertilizer N plus 25%pig manure N and 25%corn straw N(CPSN),and 50%inorganic fertilizer N plus 50%corn straw N(CSN).Organic substitution treatments tended to increase crop yields since the 6th cropping period compared to the CN treatment.From the 8th to the 22nd cropping periods,the highest yields were observed in the CPSN treatment where yields were 7.5-11.1%greater than in CN treatment.After 11-year fertilization,compared to CN,organic substitution treatments significantly increased the concentrations of NO_(3)^(-)-N,NH_(4)^(+)-N,acid hydrolysis ammonium-N(AHAN),amino acid-N(AAN),amino sugar-N(ASN),and acid hydrolysis unknown-N(AHUN)in soil by 45.0-69.4,32.8-58.1,49.3-66.6,62.0-69.5,34.5-100.3,and 109.2-172.9%,respectively.Redundancy analysis indicated that soil C/N and OC concentration significantly affected the distribution of N fractions.The highest concentrations of NO_(3)^(-)-N,AHAN,AAN,AHUN were found in the CPSN treatment.Organic substitution treatments increased the activities ofβ-glucosidase,β-cellobiosidase,N-acetyl-glucosamidase,L-aminopeptidase,and phosphatase in the soil.Organic substitution treatments reduced vector length and increased vector angle,indicating alleviation of constraints of C and N on soil microorganisms.Organic substitution treatments increased the total concentrations of phospholipid fatty acids(PLFAs)in the soil by 109.9-205.3%,and increased the relative abundance of G^(+)bacteria and fungi taxa,but decreased the relative abundance of G-bacteria,total bacteria,and actinomycetes.Overall,long-term organic substitution management increased soil OC concentration,C/N,and the microbial population,the latter in turn positively influenced soil enzyme activity.Enhanced microorganism numbers and enzyme activity enhanced soil N sequestration by transforming inorganic N to acid hydrolysis-N(AHN),and enhanced soil N supply capacity by activating non-acid hydrolysis-N(NAHN)to AHN,thus improving vegetable yield.Application of inorganic fertilizer,manure,and straw was a more effective fertilization model for achieving sustainable greenhouse vegetable production than application of inorganic fertilizer alone. 展开更多
关键词 organic substitution management greenhouse vegetable production N fractions microbial community composition extracellular enzyme activity enzyme stoichiometry coefficients
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Phosphorus supply and management in vegetable production systems in China 被引量:2
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作者 Rui WANG Weiming SHI Yilin LI 《Frontiers of Agricultural Science and Engineering》 2019年第4期348-356,共9页
Vegetable production systems involve high rates of chemical and organic fertilizer applications,leading to significant P accumulation in vegetable soils,as well as a decrease in P use efficiency(PUE),which is one of t... Vegetable production systems involve high rates of chemical and organic fertilizer applications,leading to significant P accumulation in vegetable soils,as well as a decrease in P use efficiency(PUE),which is one of the key limiting factors in vegetable production.This review introduces the vegetable production systems in China and their fertilization status,and analyzes probable causes of overfertilization of vegetable fields.Poorly developed root systems and high P demand have led to the need to maintain much higher available P concentrations in the root zone for regular growth of vegetables,which might necessitate higher phosphate fertilizer input than the plants require.Research on strategies to improve vegetable PUE and the mechanisms of these strategies are summarized in this review.Increasing the P uptake by vegetables by supplying P during the critical growth stage and effectively utilizing the accumulated P by optimizing the C:P ratio in soils can substantially increase PUE.These advances will provide a basis for improving PUE and optimizing phosphate fertilizer applications in vegetable production through regulatory measures.In addition,some policies are recommended that could ensure the safety of vegetables and improve product quality.This review also aims to improve understanding of P cycling in vegetable fields and assist in the development of best practices to manage P reserves globally. 展开更多
关键词 phosphate fertilizer phosphorus use efficiency vegetable production systems phosphorus management policy recommendation
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Decomposition of influencing factors and its spatial-temporal characteristics of vegetable production:A case study of China 被引量:1
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作者 Jieqiong Wang Zetian Fu +3 位作者 Biao Zhang Fei Yang Lingxian Zhang Bo Shi 《Information Processing in Agriculture》 EI 2018年第4期477-489,共13页
China is the largest producer and consumer of vegetables,its vegetable industry is playing an important role in the domestic agricultural sector and global vegetable export market.It is important to promote the long-t... China is the largest producer and consumer of vegetables,its vegetable industry is playing an important role in the domestic agricultural sector and global vegetable export market.It is important to promote the long-term sustainable development of Chinese vegetable industry for food security and quality of people’s lives.To find out the intrinsic way to promote the development of Chinese vegetable industry,this paper analyzed the influencing factors of Chinese vegetable production by utilizing the LMDI method and demonstrated the spatial-temporal characteristics of vegetable production through application of the Arc-GIS spatial autocorrelation analysis method.The results showed that the influencing factors of vegetable production were the cultivated land area,multiple cropping index,vegetable planting proportion and vegetable yield per hectare in China.The major driving factor had changed from vegetable planting proportion to vegetable yield per hectare.The influencing degrees of factors on vegetable production are different in different regions,regionalization is therefore a major feature of Chinese vegetable production.The government should take production technology,regionalization-driven effect,and marketing integration into consideration to promote the development of Chinese vegetable industry. 展开更多
关键词 vegetable production Influencing factors Contribution ratio Logarithmic mean Divisia index(LMDI)
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Heavy metal contamination in soils of greenhouse vegetable production systems in a cold region of China
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作者 Pin Lv Zimin Wei +2 位作者 Zhimin Yu Jizhou Zhang Limin Wang 《International Journal of Agricultural and Biological Engineering》 SCIE EI CAS 2019年第2期98-102,共5页
Heavy metal(HM)contamination in soils of greenhouse vegetable production(GVP)systems has drawn increasing attention in terms of food safety.In the present study,64 surface soils were sampled,and the concentrations of ... Heavy metal(HM)contamination in soils of greenhouse vegetable production(GVP)systems has drawn increasing attention in terms of food safety.In the present study,64 surface soils were sampled,and the concentrations of select HMs were determined using atomic absorption spectroscopy.The results showed that the concentrations of cadmium(Cd),lead(Pb),zinc(Zn),copper(Cu),nickel(Ni)and chromium(Cr)in the soils were(0.2±0.2)mg/kg,(26.5±8.4)mg/kg,(101.4±43.2)mg/kg,(29.1±8.6)mg/kg,(24.5±3.3)mg/kg,and(56.5±6.3)mg/kg,and the corresponding accumulation index(AI)values were 2.30,1.10,1.43,1.45,1.07,and 0.97,respectively.The spatial distribution of the HMs suggested that Cd pollution displays a fractionation effect,which may be related to the source of Cd and its mobility.The concentration of Zn was significantly correlated with that of other HMs,implying that a comprehensive interactive effect might occur between Zn and other HMs.Furthermore,the values of the potential ecological risk index(RI)ranged from 41.23 to 185.91,meaning that attention should be paid to HM contamination of GVP soils to ensure food quality and safety. 展开更多
关键词 heavy metal contamination cold region greenhouse vegetable production(GVP) DISTRIBUTION ecological risk food quality food safety
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Long-term straw addition promotes moderately labile phosphorus formation, decreasing phosphorus downward migration and loss in greenhouse vegetable soil 被引量:1
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作者 ZHANG Yin-jie GAO Wei +5 位作者 LUAN Hao-an TANG Ji-wei LI Ruo-nan LI Ming-yue ZHANG Huai-zhi HUANG Shao-wen 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2022年第9期2734-2749,共16页
Phosphorus(P) leaching is a major problem in greenhouse vegetable production with excessive P fertilizer application. Substitution of inorganic P fertilizer with organic fertilizer is considered a potential strategy t... Phosphorus(P) leaching is a major problem in greenhouse vegetable production with excessive P fertilizer application. Substitution of inorganic P fertilizer with organic fertilizer is considered a potential strategy to reduce leaching, but the effect of organic material addition on soil P transformation and leaching loss remains unclear. The X-ray absorption nearedge structure(XANES) spectroscopy technique can determine P speciation at the molecular level. Here, we integrated XANES and chemical methods to explore P speciation and transformation in a 10-year field experiment with four treatments: 100% chemical fertilizer(4 CN), 50% chemical N and 50% manure N(2CN+2MN), 50% chemical N and 50% straw N(2CN+2SN), and 50% chemical N and 25% manure N plus 25% straw N(2CN+2 MSN). Compared with the 4 CN treatment, the organic substitution treatments increased the content of labile P by 13.7–54.2% in the 0–40 cm soil layers, with newberyite and brushite being the main constituents of the labile P. Organic substitution treatments decreased the stable P content;hydroxyapatite was the main species and showed an increasing trend with increasing soil depth. Straw addition(2CN+2SN and 2CN+2 MSN) resulted in a higher moderately labile P content and a lower labile P content in the subsoil(60–100 cm). Moreover, straw addition significantly reduced the concentrations and amounts of total P, dissolved inorganic P(DIP), and particulate P in leachate. DIP was the main form transferred by leaching and co-migrated with dissolved organic carbon. Partial least squares path modeling revealed that straw addition decreased P leaching by decreasing labile P and increasing moderately labile P in the subsoil. Overall, straw addition is beneficial for developing sustainable P management strategies due to increasing labile P in the upper soil layer for the utilization of plants, and decreasing P migration and leaching. 展开更多
关键词 K-edge XANES phosphorus speciation leaching losses sustainable phosphorus management greenhouse vegetable production
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黄河流域生态保护迈向高质量发展的特征——植被绿度、生产力和降水利用效率的差异性变化
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作者 Yang Yu Ting Hua +2 位作者 Liding Chen Zhiqiang Zhang Paulo Pereira 《Engineering》 SCIE EI CAS CSCD 2024年第3期109-119,共11页
Globally,vegetation has been changing dramatically.The vegetation-water dynamic is key to understanding ecosystem structure and functioning in water-limited ecosystems.Continual satellite monitoring has detected globa... Globally,vegetation has been changing dramatically.The vegetation-water dynamic is key to understanding ecosystem structure and functioning in water-limited ecosystems.Continual satellite monitoring has detected global vegetation greening.However,a vegetation greenness increase does not mean that ecosystem functions increase.The intricate interplays resulting from the relationships between vegetation and precipitation must be more adequately comprehended.In this study,satellite data,for example,leaf area index(LAI),net primary production(NPP),and rainfall use efficiency(RUE),were used to quantify vegetation dynamics and their relationship with rainfall in different reaches of the Yellow River Basin(YRB).A sequential regression method was used to detect trends of NPP sensitivity to rainfall.The results showed that 34.53%of the YRB exhibited a significant greening trend since 2000.Among them,20.54%,53.37%,and 16.73%of upper,middle,and lower reach areas showed a significant positive trend,respectively.NPP showed a similar trend to LAI in the YRB upper,middle,and lower reaches.A notable difference was noted in the distributions and trends of RUE across the upper,middle,and lower reaches.Moreover,there were significant trends in vegetation-rainfall sensitivity in 16.86%of the YRB’s middle reaches—14.08%showed negative trends and 2.78%positive trends.A total of 8.41%of the YRB exhibited a marked increase in LAI,NPP,and RUE.Subsequently,strategic locations reliant on the correlation between vegetation and rainfall were identified and designated for restoration planning purposes to propose future ecological restoration efforts.Our analysis indicates that the middle reach of the YRB exhibited the most significant variation in vegetation greenness and productivity.The present study underscores the significance of examining the correlation between vegetation and rainfall within the context of the high-quality development strategy of the YRB.The outcomes of our analysis and the proposed ecological restoration framework can provide decision-makers with valuable insights for executing rational basin pattern optimization and sustainable management. 展开更多
关键词 Vegetation greenness Vegetation productivity Rainfall use efficiency Sensitivity Yellow River Basin
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Efficiency and productivity analysis of vegetable farming within root and tuber-based systems in the humid tropics of Cameroon 被引量:1
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作者 Ajapnwa Akamin Jean-Claude Bidogeza +1 位作者 Jules Rene Minkoua N Victor Afari-Sefa 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2017年第8期1865-1873,共9页
The study analyzes the technical efficiency of vegetable farmers in root and tuber-based farming systems within selected sites of the humid tropics of Cameroon. Multistage sampling was used to collect primary data fro... The study analyzes the technical efficiency of vegetable farmers in root and tuber-based farming systems within selected sites of the humid tropics of Cameroon. Multistage sampling was used to collect primary data from a cross-section of vegetable farmers drawn from eight selected sites in Santa sub division, Northwest region of Cameroon. Stochastic frontier analysis was used to estimate the technical efficiency of vegetable farmer and to examine its determinants. The results showed that farmyard manure was the most productive factor input, followed by farm equipment and labor. The mean technical efficiency level was 67%, revealing production shortfalls and indicating possibilities of significantly increasing production with the current input Jevels. Female, as well as more educated farmers were found to be significantly more efficient than their counterparts. The results also showed that farmers become less technical efficient as farm sizes become larger. Our study findings suggest that smallholder farmers' access to manure, farm implements, and increased women participation in vegetable farming, will produce huge payoffs in vegetable production efficiency in Cameroon. 展开更多
关键词 technical efficiency vegetable productivity farming systems intensification crop diversification stochasticfrontier analysis
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Study on the Potential of China’s Fruit and Vegetable Products Export to the RCEP Partners
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作者 XIE Guo-e WU Jia-meng 《Chinese Business Review》 2022年第3期77-90,共14页
China is one of the world’s major exporters of fruit and vegetable products,and the expansion of fruit and vegetable exports is important for increasing agricultural income.Based on time-varying stochastic frontier g... China is one of the world’s major exporters of fruit and vegetable products,and the expansion of fruit and vegetable exports is important for increasing agricultural income.Based on time-varying stochastic frontier gravity model and trade inefficiency model,this paper empirically analyzes the influencing factors and trade efficiency of China’s fruit and vegetable products export to RCEP partners from 2001 to 2019.The results show that China’s GDP per capita,the population of importing countries,and common language conditions have positive effects on China’s fruit and vegetable products export to RCEP partners.GDP per capita of importing countries,the population of China,and geographical distance between trading parties hinder trade in fruit and vegetable products.The presence of trade inefficiencies constrains China’s fruit and vegetable products export to RCEP partners,with liner shipping connectivity and trade freedom having a positive relationship with export efficiency of fruit and vegetable products.Variable trade costs and fixed trade costs have a negative relationship with export efficiency of fruit and vegetable products,which hinder trade in fruit and vegetable products,while financial freedom and free trade agreements have no significant impact on export efficiency of fruit and vegetable products. 展开更多
关键词 RCEP China’s fruit and vegetable products export trade potential stochastic frontier gravity model
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Analysis of Raw Materials Components of Dry Composite Mixes for Production Food Concentrates
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作者 Tatyana Samuylenko 《Journal of Food Science and Engineering》 2019年第9期355-361,共7页
Background:The simplest and most convenient food technology is the using of dry composite mixtures.They have a lot of advantages.Dry composite mixtures,which would completely be the basis for the production of persona... Background:The simplest and most convenient food technology is the using of dry composite mixtures.They have a lot of advantages.Dry composite mixtures,which would completely be the basis for the production of personalized food concentrates,are not represented.The development of such dry composite mixtures is actual and of scientific and practical interest.The purpose of this research is the selection and justification of local import-substituting raw materials components for dry composite mixtures used as the basis for the production of food concentrates.As the objects of research,the raw materials components of the starch,fruit and vegetable,industry were selected.The work uses currently accepted standard research methods for organoleptic and physic-chemical parameters of raw materials components.The research was carried out within of the project“Theoretical Substantiation of Production Technology and the Development of Import-Substituting Food Products of Functional Purpose Based on Dry Composite Mixtures”,funded by the Belarusian Republican Foundation for Basic Research.Based on the researches,it was found out that in the composition of dry composite mixtures for the production of food concentrates it is expedient to use the following raw materials:potato starch,extruded corn starch,dried carrots,dried beets,dried topinambur and dried apples in chopped form. 展开更多
关键词 Dry composite mixtures food concentrates raw materials components starches processed products of the fruit and vegetable industry
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On-Farm Effects of Drainage System on the Productivity of Chinese Cabbage(Brassica pekinensis L.Rupr.)of Farmers in Svay Rieng Province,Cambodia
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作者 Hong Chhun Chun Nimul +1 位作者 Kang Tithya Inn Sochea 《Journal of Agricultural Science and Technology(B)》 2021年第3期121-125,共5页
The vegetable production in Cambodia has been plagued with poor productivity and broken chain,leaving the comparative advantage to the neighboring countries,namely Vietnam and Thailand.Poor soil condition during wet s... The vegetable production in Cambodia has been plagued with poor productivity and broken chain,leaving the comparative advantage to the neighboring countries,namely Vietnam and Thailand.Poor soil condition during wet season has been significantly impacting the productivity of vegetable production in Cambodia which leads to an introduction of sub-surface drainage system at the root zone of Chinese cabbage under this paper.The aim of the experiment is to determine the possibility in increasing the effectiveness and productivity during wet season of Cambodian vegetable producers.The results of the experiment indicate positive improvement in terms of yield and growth of the Chinese cabbage at a rate of 24%and 34%for T2 and T3,respectively.There are,however,limited practicality and generalization for the research due to the controlling factors during the experiment and the detailed experimental setting which need further analysis,especially economic analysis and following up research work. 展开更多
关键词 Chinese cabbage sub-surface drainage system vegetable production
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Assessing the vulnerability of ecosystems to climate change based on climate exposure, vegetation stability and productivity 被引量:3
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作者 Kai Xu Xiangping Wang +1 位作者 Chao Jiang Osbert Jianxin Sun 《Forest Ecosystems》 SCIE CSCD 2020年第3期315-326,共12页
Background: Global warming has brought many negative impacts on terrestrial ecosystems, which makes the vulnerability of ecosystems one of the hot issues in current ecological research. Here, we proposed an assessment... Background: Global warming has brought many negative impacts on terrestrial ecosystems, which makes the vulnerability of ecosystems one of the hot issues in current ecological research. Here, we proposed an assessment method based on the IPCC definition of vulnerability. The exposure to future climate was characterized using a moisture index(MI) that integrates the effects of temperature and precipitation. Vegetation stability, defined as the proportion of intact natural vegetation that remains unchanged under changing climate, was used together with vegetation productivity trend to represent the sensitivity and adaptability of ecosystems. Using this method, we evaluated the vulnerability of ecosystems in Southwestern China under two future representative concentration pathways(RCP 4.5 and RCP 8.5) with MC2 dynamic global vegetation model.Results:(1) Future(2017–2100) climate change will leave 7.4%(under RCP 4.5) and 57.4% of(under RCP 8.5) of areas under high or very high vulnerable climate exposure;(2) in terms of vegetation stability, nearly 45% of the study area will show high or very high vulnerability under both RCPs. Beside the impacts of human disturbance on natural vegetation coverage(vegetation intactness), climate change will cause obvious latitudinal movements in vegetation distribution, but the direction of movements under two RCPs were opposite due to the difference in water availability;(3) vegetation productivity in most areas will generally increase and remain a low vulnerability in the future;(4) an assessment based on the above three aspects together indicated that future climate change will generally have an adverse impact on all ecosystems in Southwestern China, with non-vulnerable areas account for only about 3% of the study area under both RCPs. However, compared with RCP 4.5, the areas with mid-and highvulnerability under RCP 8.5 scenario increased by 13% and 16%, respectively.Conclusion: Analyses of future climate exposure and projected vegetation distribution indicate widespread vulnerability of ecosystems in Southwestern China, while vegetation productivity in most areas will show an increasing trend to the end of twenty-first century. Based on new climate indicators and improved vulnerability assessment rules, our method provides an extra option for a more comprehensive evaluation of ecosystem vulnerability, and should be further tested at larger spatial scales in order to provide references for regional, or even global, ecosystem conservation works. 展开更多
关键词 Climate change Ecosystem vulnerability Dynamic global vegetation model Vegetation stability Vegetation productivity Southwestern China
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Impacts of climate change on the potential forest productivity based on a climate-driven biophysical model in northeastern China 被引量:1
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作者 Wen-Qiang Gao Xiang-Dong Lei Li-Yong Fu 《Journal of Forestry Research》 SCIE CAS CSCD 2020年第6期2273-2286,共14页
Climate warming is expected to influence forest growth,composition and distribution.However,accurately estimating and predicting forest biomass,potential productivity or forest growth is still a challenge for forest m... Climate warming is expected to influence forest growth,composition and distribution.However,accurately estimating and predicting forest biomass,potential productivity or forest growth is still a challenge for forest managers dealing with land-use at the stand to regional levels.In the present study,we predicted the potential productivity(PP)of forest under current and future climate scenarios(RCP2.6,RCP4.5,RCP6.0 and RCP8.5)in Jilin province,northeastern China by using Paterson’s Climate Vegetation and Productivity(CVP)index model.The PP was validated by comparing it with the mean and maximum net primary production calculated from light energy utilization(GLM_PEM).Our results indicated that using the CVP index model is partially valid for predicting the potential forest productivity in northeastern China.PP exhibited obvious spatial heterogeneity varying from 4.6 to 8.9 m3 ha-1 year-1 with an increasing tendency from northwest to southeast driven by the precipitation across the region.The number of vegetation-active months,precipitation and insolation coefficient were identified as the primary factors affecting PP,but no significant relationship was found for warmest temperature or temperature fluctuation.Under future climate scenarios,PP across the Jilin Province is expected to increase from 1.38%(RCP2.6 in 2050)to 15.30%(RCP8.5 in 2070),especially in the eastern Songnen Plain(SE)for the RCP8.5 scenarios. 展开更多
关键词 Climate vegetation and productivity index Potential productivity Climate change
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Spatiotemporal variation in vegetation net primary productivity and its relationship with meteorological factors in the Tarim River Basin of China from 2001 to 2020 based on the Google Earth Engine 被引量:1
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作者 CHEN Limei Abudureheman HALIKE +1 位作者 YAO Kaixuan WEI Qianqian 《Journal of Arid Land》 SCIE CSCD 2022年第12期1377-1394,共18页
Vegetation growth status is an important indicator of ecological security.The Tarim River Basin is located in the inland arid region of Northwest China and has a highly fragile ecological environment.Assessing the veg... Vegetation growth status is an important indicator of ecological security.The Tarim River Basin is located in the inland arid region of Northwest China and has a highly fragile ecological environment.Assessing the vegetation net primary productivity(NPP)of the Tarim River Basin can provide insights into the vegetation growth variations in the region.Therefore,based on the Google Earth Engine(GEE)cloud platform,we studied the spatiotemporal variation of vegetation NPP in the Tarim River Basin(except for the eastern Gobi and Kumutag deserts)from 2001 to 2020 and analyzed the correlations between vegetation NPP and meteorological factors(air temperature and precipitation)using the Sen slope estimation method,coefficient of variation,and rescaled range analysis method.In terms of temporal characteristics,vegetation NPP in the Tarim River Basin showed an overall fluctuating upward trend from 2001 to 2020,with the smallest value of 118.99 g C/(m2•a)in 2001 and the largest value of 155.07 g C/(m2•a)in 2017.Regarding the spatial characteristics,vegetation NPP in the Tarim River Basin showed a downward trend from northwest to southeast along the outer edge of the study area.The annual average value of vegetation NPP was 133.35 g C/(m2•a),and the area with annual average vegetation NPP values greater than 100.00 g C/(m2•a)was 82,638.75 km2,accounting for 57.76%of the basin.The future trend of vegetation NPP was dominated by anti-continuity characteristic;the percentage of the area with anti-continuity characteristic was 63.57%.The area with a significant positive correlation between vegetation NPP and air temperature accounted for 53.74%of the regions that passed the significance test,while the area with a significant positive correlation between vegetation NPP and precipitation occupied 98.68%of the regions that passed the significance test.Hence,the effect of precipitation on vegetation NPP was greater than that of air temperature.The results of this study improve the understanding on the spatiotemporal variation of vegetation NPP in the Tarim River Basin and the impact of meteorological factors on vegetation NPP. 展开更多
关键词 vegetation net primary productivity(NPP) air temperature precipitation Hurst index Google Earth Engine Tarim River Basin
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Phosphorus accumulation and leaching risk of greenhouse vegetable soils in Southeast China 被引量:6
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作者 Yusef KIANPOOR KALKHAJEH Biao HUANG +2 位作者 Helle SORENSEN Peter EHOLM Hans Christian BHANSEN 《Pedosphere》 SCIE CAS CSCD 2021年第5期683-693,共11页
Over-fertilization has caused significant phosphorus(P)accumulation in Chinese greenhouse vegetable production(GVP)soils.This study,for the first time,quantified profile P accumulation directly from soil P measurement... Over-fertilization has caused significant phosphorus(P)accumulation in Chinese greenhouse vegetable production(GVP)soils.This study,for the first time,quantified profile P accumulation directly from soil P measurements,as well as subsoil P immobilization,in three alkaline coarse-textured GVP soil profiles with 5(S5),15(S15),and 30(S30)years of cultivation in Tongshan,Southeast China.For each profile,soil samples were collected at depths of 0-10(topsoil),10-20,20-40,40-60,60-80,and 80-100 cm.Phosphorus accumulation was estimated from the difference in P contents between topsoil and parent material(60-100 cm subsoil).Phosphorus mobility was assessed from measurements of water-soluble P concentration(P_(Sol)).Finally,P sorption isotherms were produced using a batch sorption experiment and fitted using a modified Langmuir model.High total P contents of 1980(S5),3190(S15),and 2330(S30)mg kg^(-1) were measured in the topsoils versus lower total P content of approximately 600 mg kg^(-1) in the 80-100 cm subsoils.Likewise,topsoil PSol values were very high,varying from 6.4 to 17.0 mg L^(-1).The estimated annual P accumulations in the topsoils were 397(S5),212(S15),and 78(S30)kg ha^(-1) year^(-1).Sorption isotherms demonstrated the dominance of P desorption in highly P-saturated topsoils,whereas the amount of adsorbed P increased in the 80-100 cm subsoils with slightly larger P adsorption capacity.The total P adsorption capacity of the 80-100 cm subsoils at a solution P concentration of0.5 mg L^(-1) was 15.7(S5),8.7(S15),and 6.5(S30)kg ha^(-1),demonstrating that subsoils were unable to secure P concentrations in leaching water below 0.5 mg L^(-1) because of their insufficient P-binding capacity. 展开更多
关键词 greenhouse vegetable production Langmuir model P adsorption capacity P desorption P immobilization P mobility SUBSOIL TOPSOIL
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Threshold of climate extremes that impact vegetation productivity over the Tibetan Plateau
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作者 Zhenggang PIAO Xiangyi LI +4 位作者 Hao XU Kai WANG Shuchang TANG Fei KAN Songbai HONG 《Science China Earth Sciences》 SCIE EI CAS CSCD 2024年第6期1967-1977,共11页
Vegetation growth is adversely impacted by multiple climate extremes related to the water and thermal stress over the Tibetan Plateau(TP).However,it remains unknown at which stress level these climate extremes can tri... Vegetation growth is adversely impacted by multiple climate extremes related to the water and thermal stress over the Tibetan Plateau(TP).However,it remains unknown at which stress level these climate extremes can trigger the abrupt shifts of vegetation response to climate extremes and result in the maximum vegetation response across TP.To fill this knowledge gap,we combined the hydrometeorological data and the satellite-derived vegetation index to detect two critical thresholds that determine the response of vegetation productivity to droughts,high-temperature extremes,and low-temperature extremes,respectively,during 2001-2018.Our results show that the response of vegetation productivity to droughts rapidly increases once crossing -1.41±0.6 standard deviation(σ)below the normal conditions of soil moisture.When crossing-2.98σ±0.9σ,vegetation productivity is maximum damaged by droughts.High-temperature extremes,which have the two thresholds of 1.34σ±0.4σand 2.31σ±0.4σover TP,are suggested to trigger the strong response of vegetation productivity at a milder stress level than low-temperature extremes(two thresholds:-1.44σ±0.5σand-2.53σ±0.8σ).Moreover,we found the compounded effects of soil moisture deficit in reducing the threshold values of both high-and low-temperature extremes.Based on the derived thresholds of climate extremes that impact vegetation productivity,Earth System Models project that southwestern TP and part of the northeastern TP will become the hotspots with a high exposure risk to climate extremes by 2100.This study deciphers the high-impact extreme climates using two important thresholds across TP,which advances the understanding of the vegetation response to different climate extremes and provides a paradigm for assessing the impacts of climate extremes on regional ecosystems. 展开更多
关键词 Tibetan Plateau Climate extremes Thresholds Vegetation productivity
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气候变化和物候变动对东北黑土区农业生产的协同作用及未来粮食生产风险
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作者 高江波 刘路路 +4 位作者 郭灵辉 孙东琪 刘婉露 侯文娟 吴绍洪 《Journal of Geographical Sciences》 SCIE CSCD 2023年第1期37-58,共22页
The black soil region of northeast China is a vital food base and is one of the most sensitive regions to climate change in China.However,the characteristics of the crop phenological response and the integrated impact... The black soil region of northeast China is a vital food base and is one of the most sensitive regions to climate change in China.However,the characteristics of the crop phenological response and the integrated impact of climate and phenological changes on agricultural productivity in the region under the background of climate change are not clear.The future agricultural risk assessment has been insufficiently quantified and the existing risk level formulation lacks a sound basis.Based on remote sensing products,climate data,and model simulations,this study integrated a logistic function fitting curvature derivation,multiple linear regression,and scenario simulation to investigate crop phenology dynamics and their climate response characteristics in the black soil region.Additionally,the compound effects of climate and phenology changes on agricultural production and possible future risks were identified.The key results were as follows:(1)From 2000 to 2017,29.76%of the black soil region of northeast China experienced a significant delay in the start of the growing season(SOS)and 16.71%of the total area displayed a trend for the end of the growing season(EOS)to arrive earlier.The time lagged effects of the SOS in terms of the crop response to climatic factors were site and climatic parameter dependent.The influence of temperature was widespread and its effect had a longer lag time in general;(2)Both climatic and phenological changes have had a significant effect on the inter-annual variability of crop production,and the predictive ability of both increased by 70.23%,while the predictive area expanded by 85.04%,as compared to that of climate change in the same period of the growing season;(3)Under the RCP8.5 scenario,there was a risk that the future crop yield would decrease in the north and increase in the south,and the risk area was constantly expanding.With a 2.0℃rise in global temperature,the crop yield of the southern Songnen black soil sub-region would reduce by almost 10%.This finding will improve our understanding of the mechanisms underlying climate change and vegetation productivity dynamics,and is also helpful in the promotion of the risk management of agrometeorological disasters. 展开更多
关键词 black soil region of northeast China vegetation phenology vegetation productivity lag effect future risk
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Satellite-based Studies on Large-Scale Vegetation Changes in China 被引量:17
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作者 Xia Zhao Daojing Zhou Jingyun Fang 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2012年第10期713-728,共16页
Remotely-sensed vegetation indices, which indicate the density and photosynthetic capacity of vegetation, have been widely used to monitor vegetation dynamics over broad areas. In this paper, we reviewed satellite-bas... Remotely-sensed vegetation indices, which indicate the density and photosynthetic capacity of vegetation, have been widely used to monitor vegetation dynamics over broad areas. In this paper, we reviewed satellite-based studies on vegetation cover changes, biomass and productivity variations, phenological dynamics, desertification, and grassland degradation in China that occurred over the past 2-3 decades. Our review shows that the satellite-derived index (Normalized Difference Vegetation Index, NDVI) during growing season and the vegetation net primary productivity in major terrestrial ecosystems (for example forests, grasslands, shrubs, and croplands) have significantly increased, while the number of fresh lakes and vegetation coverage in urban regions have experienced a substantial decline. The start of the growing season continually advanced in China's temperate regions until the 1990s, with a large spatial heterogeneity. We also found that the coverage of sparsely-vegetated areas declined, and the NDVI per unit in vegetated areas increased in arid and semi-arid regions because of increased vegetation activity in grassland and oasis areas. However, these results depend strongly not only on the periods chosen for investigation, but also on factors such as data sources, changes in detection methods, and geospatial heterogeneity. Therefore, we should be cautious when applying remote sensing techniques to monitor vegetation structures, functions, and changes. 展开更多
关键词 Normalized Difference Vegetation Index (NDVI) PHENOLOGY remote sensing vegetation coverage vegetation degradation vegetation productivity
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