Soil moisture is a major limiting factor for plant growth on shell ridge islands in the Yellow River Delta. However, it is difficult to carry out situ experiment to study dominant plant photosynthesis physiological on...Soil moisture is a major limiting factor for plant growth on shell ridge islands in the Yellow River Delta. However, it is difficult to carry out situ experiment to study dominant plant photosynthesis physiological on the shell ridge islands under extreme soil water stress. To evaluate the adaptability of plants to light and moisture variations under extreme soil moisture conditions present on these islands, we measured photosynthetic gas exchange process, chlorophyll fluorescence, and stem sap flow variables for 3-year-old trees of Tamarix chinensis Lour, a restoration species on these islands, subjected to three types of soil water levels： waterlogging stress （WS）, alternating dry-wet （WD）, and severe drought stress （SS） to inform decisions on its planting and management on shell ridge islands. Gas exchange, chlorophyll fluorescence, and stem sap flow in T. chinensis were then measured. Net photosynthetic rate （PN）, transpiration rate （E）, and water use efficiency （WUE） were similar under WS and alternating dry-wet conditions, but their mean E and WUE differed significantly （P 〈 0.05）. Under SS, the PN, E and WErE of T. chinensis leaves varied slightly, and mean PN, E and WUE were all low. Apparent quantum efficiency （AQY）, light compensation point （LCP）, light saturation point （LSP）, and maximum net photosynthetic rate （PNmax） of leaves were not significantly different （P 〉 0.05） under WS and dry-wet conditions; however, under extreme drought stress, compared with the dry-wet conditions, LCP was higher, Lsp was lower, and AQy and PNmax were both at the lowest level. Therefore, drought stress weakened light adaptability of leaves, and the efficiency of light transformation was poorer. （3） Maximum photochemical efficiency （Fv/Fm） and the actual photochemical efficiency （ΦPSII） were similar under waterlogged stress and dry-wet conditions, indicating a similar healthy photosynthetic apparatus and photosynthetic reaction cen- ter activity, respectively. Under SS, Fv/Fm was 0.631, and the coefficient of non-photochemical quenching （NpQ） was 0.814, which indicated that while the photosynthetic mechanism was damaged, the absorbed light energy was mainly dissipated in the form of heat, and the potential photosynthetic productivity was significantly reduced. The daily cumulants of sap flow of T. chinensis under drywet alternation and severe drought stress were. 22.25 and 63.97% higher, respectively, than under waterlogging stress. Daily changes in sap flow velocity for T. chinensis differed under the three soil water levels. Stem sap flow was weak at night under severe drought stress. Under drywet alternation, daytime average stem sap flow velocity was the highest, and night stem flow accounted for 10.26% of the day cumulants, while under waterlogged stress, the average nightly stem flow velocity was the highest, accounting for 31.82% of the day cumulants. These results provide important information for regional vegetation restoration and ecological reconstruction.展开更多
The accurate prediction of poverty is critical to efforts of poverty reduction,and high-resolution remote sensing(HRRS)data have shown great promise for facilitating such prediction.Accordingly,the present study used ...The accurate prediction of poverty is critical to efforts of poverty reduction,and high-resolution remote sensing(HRRS)data have shown great promise for facilitating such prediction.Accordingly,the present study used HRRS with 1 m resolution and 238 households data to evaluate the utility and optimal scale of HRRS data for predicting household poverty in a grassland region of Inner Mongolia,China.The prediction of household poverty was improved by using remote sensing indicators at multiple scales,instead of indicators at a single scale,and a model that combined indicators from four scales(building land,household,neighborhood,and regional)provided the most accurate prediction of household poverty,with testing and training accuracies of 48.57%and 70.83%,respectively.Furthermore,building area was the most efficient indicator of household poverty.When compared to conducting household surveys,the analysis of HRRS data is a cheaper and more time-efficient method for predicting household poverty and,in this case study,it reduced study time and cost by about 75%and 90%,respectively.This study provides the first evaluation of HRRS data for the prediction of household poverty in pastoral areas and thus provides technical support for the identification of poverty in pastoral areas around the world.展开更多
The degradation of tilmicosin(TLM),a semi-synthetic 16-membered macrolide antibiotic,has been receiving increasing attention.Conventionally,there are three tilmicosin degradation methods,and among them microbial degra...The degradation of tilmicosin(TLM),a semi-synthetic 16-membered macrolide antibiotic,has been receiving increasing attention.Conventionally,there are three tilmicosin degradation methods,and among them microbial degradation is considered the best due to its high efficiency,eco-friendliness,and low cost.Coincidently,we found a new strain,Glutamicibacter nicotianae sp.AT6,capable of degrading high-concentration TLM at 100 mg/L with a 97%removal efficiency.The role of tryptone was as well investigated,and the results revealed that the loading of tryptone had a significant influence on TLM removals.The toxicity assessment indicated that strain AT6 could efficiently convert TLM into less-toxic substances.Based on the identified intermediates,the degradation of TLM by AT6 processing through two distinct pathways was then proposed.展开更多
In general, coastal habitat conditions are extremely harsh, with the ecological equilibrium inextric- ably related to the plant community. Understanding the natural vegetation features of a coastal zone with little hu...In general, coastal habitat conditions are extremely harsh, with the ecological equilibrium inextric- ably related to the plant community. Understanding the natural vegetation features of a coastal zone with little human disturbance could provide a reference for future vegetation restoration and ecosystem maintenance ser- vices. In this study, the vegetation patterns of Wangzi Shell Ridge Island in the Yellow River Delta were investigated. A total of 35 taxa of vascular plants were documented, representing 15 families and 33 genera （of which most were mono-specific）. Surveys identified only one to eight taxa in each plot. From sea to land, the vegetation showed a typical zonal distribution pattern. There was a correlation between the landform and important factors that influenced the plants including soil factors and distance from the sea. Thus, the taxa distribution and vegetation had a significant correlation with landform. The dune crest, backdune and interdune lowlands were areas with weak storm surges and were the important locations for the taxa to be become established. Plants along the high-tide line formed important defenses from large waves and high winds. The significant protection provided a suitable living environment for many organisms with high medicinal value. Special attention and protection could be provided to this area by reducing the use of the beach road and enclosing the complete section from sea to land with a protective fence. In addition, vegetation protection and restoration on Shell Ridge Island would aid in the formulation and implementation of reintroduction strate- gies for similar vegetation in similar habitats.展开更多
A key step towards the restoration of heavily disturbed fragile coastal wetland ecosystems is determin- ing the composition and characteristics of the plant communities involved. This study determined and char- acteri...A key step towards the restoration of heavily disturbed fragile coastal wetland ecosystems is determin- ing the composition and characteristics of the plant communities involved. This study determined and char- acterized the community of higher plants in the Chenier wetland of Bohai Bay using a combination of field surveys, quadrat approaches, and multivariate statistical analyses. This community was then compared to other adjacent wetlands （Tianjin, Qinhuangdao, Laizhouwan, Jiaozhou- wan, and Yellow River Delta wetland） located near the Huanghai and Bohai Seas using principal coordinate analysis （PCoA）. Results showed a total of 56 higher plant species belonging to 52 genera from 20 families in Chenier wetland, the majority of which were dicotyledons. Single-species families were predominant, while larger families, including Gramineae, Compositae, Leguminosae, and Chenopodiaceae contained a higher number of species （cache〉6 species）. Cosmopolitan species were also dominant with apparent intrazonality. Abundance （number of species） of temperate species was twice that of tropical taxa. Species number of perennial herbs, such as Gramineae and Compositae, was generally higher. Plant diversity in the Chenier wetland, based on the Shannon- Wiener index, was observed to be between the Qinhuang- dao and Laizhouwan indices, while no significant difference was found in other wetlands using the Simpson index. Despite these slight differences in diversity, PCoA based on species abundance and composition of the wetland flora suggest that the Bohai Chenier community was highly similar to the coastal wetlands in Tianjin and Laizhouwan, further suggesting that these two wetlands could be important breeding grounds and resources for the restoration of the plant ecosystem in the Chenier wetland.展开更多
A new state-of-the-art indoor smog chamber facility(CAPS-ZJU) has been constructed and characterized at Zhejiang University,which is designed for chemical mechanism evaluation under well-controlled conditions.A series...A new state-of-the-art indoor smog chamber facility(CAPS-ZJU) has been constructed and characterized at Zhejiang University,which is designed for chemical mechanism evaluation under well-controlled conditions.A series of characterization experiments were performed to validate the well-established experimental protocols,including temperature variation pattern,light spectrum and equivalent intensity(JNO2),injection and mixing performance,as well as gases and particle wall loss.In addition,based on some characterization experiments,the auxiliary wall mechanism has been setup and examined.Fifty chamber experiments were performed across a broad range of experimental scenarios,and we demonstrated the ability to utilize these chamber data for evaluating SAPRC chemical mechanism.It was found that the SAPRC-11 can well predict the 03 formation and NO oxidation for almost all propene runs,with 6 hr △(O3-NO) model error of-3%±7%,while the final O3 was underestimated by-20% for isoprene experiments.As for toluene and p-xylene experiments,it was confirmed that SAPRC-11 has significant improvement on aromatic chemistry than earlier version of SAPRC-07,although the aromatic decay rate was still underestimated to some extent.The model sensitivity test has been carried out,and the most sensitive parameters identified are the initial concentrations of reactants and the light intensity as well as HONO offgasing rate and 03 wall loss rate.All of which demonstrated that CAPS-ZJU smog chamber could derive high quality experimental data,and could provide insights on chamber studies and chemical mechanism development.展开更多
基金supported by the National Natural Science Foundation of China(No.31370702)the Key Project of Natural Science Foundation of Shandong Province(No.ZR2015JL014)+2 种基金the Key Research and Development Project of Shandong Province(No.2015GNC111022)Science and Technology Plan of Universities in Shandong Province(No.J13LC03)Natural Science Foundation of Shandong Province(No.ZR2015CL044)
文摘Soil moisture is a major limiting factor for plant growth on shell ridge islands in the Yellow River Delta. However, it is difficult to carry out situ experiment to study dominant plant photosynthesis physiological on the shell ridge islands under extreme soil water stress. To evaluate the adaptability of plants to light and moisture variations under extreme soil moisture conditions present on these islands, we measured photosynthetic gas exchange process, chlorophyll fluorescence, and stem sap flow variables for 3-year-old trees of Tamarix chinensis Lour, a restoration species on these islands, subjected to three types of soil water levels： waterlogging stress （WS）, alternating dry-wet （WD）, and severe drought stress （SS） to inform decisions on its planting and management on shell ridge islands. Gas exchange, chlorophyll fluorescence, and stem sap flow in T. chinensis were then measured. Net photosynthetic rate （PN）, transpiration rate （E）, and water use efficiency （WUE） were similar under WS and alternating dry-wet conditions, but their mean E and WUE differed significantly （P 〈 0.05）. Under SS, the PN, E and WErE of T. chinensis leaves varied slightly, and mean PN, E and WUE were all low. Apparent quantum efficiency （AQY）, light compensation point （LCP）, light saturation point （LSP）, and maximum net photosynthetic rate （PNmax） of leaves were not significantly different （P 〉 0.05） under WS and dry-wet conditions; however, under extreme drought stress, compared with the dry-wet conditions, LCP was higher, Lsp was lower, and AQy and PNmax were both at the lowest level. Therefore, drought stress weakened light adaptability of leaves, and the efficiency of light transformation was poorer. （3） Maximum photochemical efficiency （Fv/Fm） and the actual photochemical efficiency （ΦPSII） were similar under waterlogged stress and dry-wet conditions, indicating a similar healthy photosynthetic apparatus and photosynthetic reaction cen- ter activity, respectively. Under SS, Fv/Fm was 0.631, and the coefficient of non-photochemical quenching （NpQ） was 0.814, which indicated that while the photosynthetic mechanism was damaged, the absorbed light energy was mainly dissipated in the form of heat, and the potential photosynthetic productivity was significantly reduced. The daily cumulants of sap flow of T. chinensis under drywet alternation and severe drought stress were. 22.25 and 63.97% higher, respectively, than under waterlogging stress. Daily changes in sap flow velocity for T. chinensis differed under the three soil water levels. Stem sap flow was weak at night under severe drought stress. Under drywet alternation, daytime average stem sap flow velocity was the highest, and night stem flow accounted for 10.26% of the day cumulants, while under waterlogged stress, the average nightly stem flow velocity was the highest, accounting for 31.82% of the day cumulants. These results provide important information for regional vegetation restoration and ecological reconstruction.
基金This study was supported by the Key Science and Technology Program of Inner Mongolia(Grant No.ZDZX2018020,2020GG0007,2019GG009)Natural Science Founda-tion of Inner Mongolia(Grant No.2020MS03068)+1 种基金Research Project of China Institute of Water Resources and Hydropower Research(Grant No.MK2019J02)Grassland Talents Program of Inner Mongolia(Grant No.CYYC9013).
文摘The accurate prediction of poverty is critical to efforts of poverty reduction,and high-resolution remote sensing(HRRS)data have shown great promise for facilitating such prediction.Accordingly,the present study used HRRS with 1 m resolution and 238 households data to evaluate the utility and optimal scale of HRRS data for predicting household poverty in a grassland region of Inner Mongolia,China.The prediction of household poverty was improved by using remote sensing indicators at multiple scales,instead of indicators at a single scale,and a model that combined indicators from four scales(building land,household,neighborhood,and regional)provided the most accurate prediction of household poverty,with testing and training accuracies of 48.57%and 70.83%,respectively.Furthermore,building area was the most efficient indicator of household poverty.When compared to conducting household surveys,the analysis of HRRS data is a cheaper and more time-efficient method for predicting household poverty and,in this case study,it reduced study time and cost by about 75%and 90%,respectively.This study provides the first evaluation of HRRS data for the prediction of household poverty in pastoral areas and thus provides technical support for the identification of poverty in pastoral areas around the world.
基金supported by the National Natural Science Foundation of China(Nos.21868011,42106144,42077444)the National Key R&D Program of China(No.2017YFC1103800)the financial support from Shandong University of Science and Technology(No.SKR19-1-012)。
文摘The degradation of tilmicosin(TLM),a semi-synthetic 16-membered macrolide antibiotic,has been receiving increasing attention.Conventionally,there are three tilmicosin degradation methods,and among them microbial degradation is considered the best due to its high efficiency,eco-friendliness,and low cost.Coincidently,we found a new strain,Glutamicibacter nicotianae sp.AT6,capable of degrading high-concentration TLM at 100 mg/L with a 97%removal efficiency.The role of tryptone was as well investigated,and the results revealed that the loading of tryptone had a significant influence on TLM removals.The toxicity assessment indicated that strain AT6 could efficiently convert TLM into less-toxic substances.Based on the identified intermediates,the degradation of TLM by AT6 processing through two distinct pathways was then proposed.
文摘In general, coastal habitat conditions are extremely harsh, with the ecological equilibrium inextric- ably related to the plant community. Understanding the natural vegetation features of a coastal zone with little human disturbance could provide a reference for future vegetation restoration and ecosystem maintenance ser- vices. In this study, the vegetation patterns of Wangzi Shell Ridge Island in the Yellow River Delta were investigated. A total of 35 taxa of vascular plants were documented, representing 15 families and 33 genera （of which most were mono-specific）. Surveys identified only one to eight taxa in each plot. From sea to land, the vegetation showed a typical zonal distribution pattern. There was a correlation between the landform and important factors that influenced the plants including soil factors and distance from the sea. Thus, the taxa distribution and vegetation had a significant correlation with landform. The dune crest, backdune and interdune lowlands were areas with weak storm surges and were the important locations for the taxa to be become established. Plants along the high-tide line formed important defenses from large waves and high winds. The significant protection provided a suitable living environment for many organisms with high medicinal value. Special attention and protection could be provided to this area by reducing the use of the beach road and enclosing the complete section from sea to land with a protective fence. In addition, vegetation protection and restoration on Shell Ridge Island would aid in the formulation and implementation of reintroduction strate- gies for similar vegetation in similar habitats.
文摘A key step towards the restoration of heavily disturbed fragile coastal wetland ecosystems is determin- ing the composition and characteristics of the plant communities involved. This study determined and char- acterized the community of higher plants in the Chenier wetland of Bohai Bay using a combination of field surveys, quadrat approaches, and multivariate statistical analyses. This community was then compared to other adjacent wetlands （Tianjin, Qinhuangdao, Laizhouwan, Jiaozhou- wan, and Yellow River Delta wetland） located near the Huanghai and Bohai Seas using principal coordinate analysis （PCoA）. Results showed a total of 56 higher plant species belonging to 52 genera from 20 families in Chenier wetland, the majority of which were dicotyledons. Single-species families were predominant, while larger families, including Gramineae, Compositae, Leguminosae, and Chenopodiaceae contained a higher number of species （cache〉6 species）. Cosmopolitan species were also dominant with apparent intrazonality. Abundance （number of species） of temperate species was twice that of tropical taxa. Species number of perennial herbs, such as Gramineae and Compositae, was generally higher. Plant diversity in the Chenier wetland, based on the Shannon- Wiener index, was observed to be between the Qinhuang- dao and Laizhouwan indices, while no significant difference was found in other wetlands using the Simpson index. Despite these slight differences in diversity, PCoA based on species abundance and composition of the wetland flora suggest that the Bohai Chenier community was highly similar to the coastal wetlands in Tianjin and Laizhouwan, further suggesting that these two wetlands could be important breeding grounds and resources for the restoration of the plant ecosystem in the Chenier wetland.
基金supported by the Natural Science Founda-tion of China(No.51876190)the Environmental Protection Agency of Hangzhou(No.2017-008)+1 种基金the Innovative Research Groups of the National Natural Science Foundation of China(No.51621005)the program of Introducing Talents of Dis-cipline to University(No.B08026)
文摘A new state-of-the-art indoor smog chamber facility(CAPS-ZJU) has been constructed and characterized at Zhejiang University,which is designed for chemical mechanism evaluation under well-controlled conditions.A series of characterization experiments were performed to validate the well-established experimental protocols,including temperature variation pattern,light spectrum and equivalent intensity(JNO2),injection and mixing performance,as well as gases and particle wall loss.In addition,based on some characterization experiments,the auxiliary wall mechanism has been setup and examined.Fifty chamber experiments were performed across a broad range of experimental scenarios,and we demonstrated the ability to utilize these chamber data for evaluating SAPRC chemical mechanism.It was found that the SAPRC-11 can well predict the 03 formation and NO oxidation for almost all propene runs,with 6 hr △(O3-NO) model error of-3%±7%,while the final O3 was underestimated by-20% for isoprene experiments.As for toluene and p-xylene experiments,it was confirmed that SAPRC-11 has significant improvement on aromatic chemistry than earlier version of SAPRC-07,although the aromatic decay rate was still underestimated to some extent.The model sensitivity test has been carried out,and the most sensitive parameters identified are the initial concentrations of reactants and the light intensity as well as HONO offgasing rate and 03 wall loss rate.All of which demonstrated that CAPS-ZJU smog chamber could derive high quality experimental data,and could provide insights on chamber studies and chemical mechanism development.
