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Development of a novel critical nitrogen concentration-cumulative transpiration curve for optimizing nitrogen management under varying irrigation conditions in winter wheat
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作者 Tianyang Ye Yu Zhang +9 位作者 Jingyan Xuan Xintian Wang Yang Li Junhao Xu Liujun Xiao Leilei Liu Liang Tang Weixing Cao Bing Liu Yan Zhu 《The Crop Journal》 SCIE CSCD 2024年第4期1242-1251,共10页
Accurate nitrogen(N)nutrition diagnosis is essential for improving N use efficiency in crop production.The widely used critical N(Nc)dilution curve traditionally depends solely on agronomic variables,neglecting crop w... Accurate nitrogen(N)nutrition diagnosis is essential for improving N use efficiency in crop production.The widely used critical N(Nc)dilution curve traditionally depends solely on agronomic variables,neglecting crop water status.With three-year field experiments with winter wheat,encompassing two irrigation levels(rainfed and irrigation at jointing and anthesis)and three N levels(0,180,and 270 kg ha1),this study aims to establish a novel approach for determining the Nc dilution curve based on crop cumulative transpiration(T),providing a comprehensive analysis of the interaction between N and water availability.The Nc curves derived from both crop dry matter(DM)and T demonstrated N concentration dilution under different conditions with different parameters.The equation Nc=6.43T0.24 established a consistent relationship across varying irrigation regimes.Independent test results indicated that the nitrogen nutrition index(NNI),calculated from this curve,effectively identifies and quantifies the two sources of N deficiency:insufficient N supply in the soil and insufficient soil water concentration leading to decreased N availability for root absorption.Additionally,the NNI calculated from the Nc-DM and Nc-T curves exhibited a strong negative correlation with accumulated N deficit(Nand)and a positive correlation with relative grain yield(RGY).The NNI derived from the Nc-T curve outperformed the NNI derived from the Nc-DM curve concerning its relationship with Nand and RGY,as indicated by larger R2 values and smaller AIC.The novel Nc curve based on T serves as an effective diagnostic tool for assessing winter wheat N status,predicting grain yield,and optimizing N fertilizer management across varying irrigation conditions.These findings would provide new insights and methods to improve the simulations of water-N interaction relationship in crop growth models. 展开更多
关键词 Crop dry matter Crop cumulative transpiration Bayesian statistical model Critical nitrogen dilution curve Nitrogen nutrition index
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Field Measurement of Cotton Seedling Evapotranspiration 被引量:3
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作者 R. J. Lascano J. L. Duesterhaus +2 位作者 J. D. Booker T. S. Goebel J. T. Baker 《Agricultural Sciences》 2014年第13期1237-1252,共16页
Information on cotton evapotranspiration (ET) during the seedling growth stage and under field conditions is scarce because ET is a difficult parameter to measure. Our objective was to use weighable lysimeters to meas... Information on cotton evapotranspiration (ET) during the seedling growth stage and under field conditions is scarce because ET is a difficult parameter to measure. Our objective was to use weighable lysimeters to measure daily values of cotton seedling ET. We designed and built plastic weighable micro-lysimeters (ML) that were 0.35 m deep with a soil volume of 6300 cm3. The soil core was obtained in-situ by pushing the ML well casing into the soil using a commercial soil sampler. The soil core was weighed with tension and compression type load-cells, where a change in mass of 18 g·d-1 was equivalent to a water evaporation of 1 mm·d-1. We compared load-cell measurements of changes in mass to values measured with a portable field scale by linear regression analysis, and the slope was equal to 1, indicating no statistical difference (P = 0.05) between the two measurements. We measured and compared seedling height, root length and leaf area of cotton plants in the ML with cotton plants in the surrounding area and this comparison showed that the ML used was suitable to measure cotton seedling ET for the first 30 days after seed emergence. The root mean squared error for crop height was 0.09 cm, for leaf area index (LAI) was 0.03 m2·m-2 and 6.5 cm for root length. Also, soil temperature at a 0.1 m depth was statistically (P = 0.05) the same in and outside the ML’s. For two planting dates, we measured daily values of soil water evaporation (E) and cotton seedling ET. The day following an irrigation event, E was ~ 9 mm d-1 and quickly declined the following days. Results showed that ML’s provide an accurate tool to measure water losses from the soil and cotton plants with a LAI of ≤0.2. 展开更多
关键词 COTTON SEEDLING LYSIMETER evapotranspiration transpiration Water Use FIELD Measurement
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Cryosphere evapotranspiration in the Tibetan Plateau:A review 被引量:3
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作者 KunXin Wang YinSheng Zhang +2 位作者 Ning Ma YanHong Guo YaoHui Qiang 《Research in Cold and Arid Regions》 CSCD 2020年第6期355-370,共16页
Land surface actual evapotranspiration is an important process that influences the Earth's energy and water cycles and determines the water and heat transfer in the soil-vegetation-atmosphere system.Meanwhile,the ... Land surface actual evapotranspiration is an important process that influences the Earth's energy and water cycles and determines the water and heat transfer in the soil-vegetation-atmosphere system.Meanwhile,the cryosphere's hydrological process is receiving extensive attention,and its water problem needs to be understood from multiple perspectives.As the main part of the Chinese cryosphere,the Tibetan Plateau faces significant climate and environmental change.There are active interaction and pronounced feedback between the environment and ETa in the cryosphere.This article mainly focuses on the research progress of ETa in the Tibetan Plateau.It first reviews the ETa process,characteristics,and impact factors of typical underlying surfaces in the Tibetan Plateau(alpine meadows,alpine steppes,alpine wetlands,alpine forests,lakes).Then it compares the temporal and spatial variations of ETa at different scales.In addition,considering the current greening of cryosphere vegetation due to climate change,it discusses the relationship between vegetation greening and transpiration to help clarify how vegetation activities are related to the regional water cycle and surface energy budget. 展开更多
关键词 cryosphere evapotranspiration Tibetan Plateau transpiration evapoRATION
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The Impacts of the Interannual Variability of Vegetation on the Interannual Variability of Global Evapotranspiration: A Modeling Study 被引量:1
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作者 CHEN Hao ZENG Xiao-Dong 《Atmospheric and Oceanic Science Letters》 2012年第3期225-230,共6页
The impact of the interannual variability (IAV) of vegetation on the IAV of evapotranspiration is investigated with the Community Land Model (CLM3.0) and modified Dynamic Global Vegetation Model (DGVM). Two sets of 50... The impact of the interannual variability (IAV) of vegetation on the IAV of evapotranspiration is investigated with the Community Land Model (CLM3.0) and modified Dynamic Global Vegetation Model (DGVM). Two sets of 50-year off-line simulations are used in this study. The simulations begin with the same initial surface-water and heat states and are driven by the same atmospheric forcing data. The vegetation exhibits interannual variability in one simulation but not in the other simulation. However, the climatological means for the vegetation are the same. The IAV of the 50-year annual total evapotranspiration and its three partitions (ground evaporation, canopy evaporation, and transpiration) are analyzed. The global distribution of the evapotranspiration IAV and the statistics of evapotranspiration and its components in different ecosystems show that the IAV of ground evaporation is generally large in areas dominated by grass and deciduous trees, whereas the IAV of canopy evaporation and transpiration is large in areas dominated by bare soil and shrubs. For ground evaporation, canopy evaporation, and transpiration, the changes in IAV are larger than the mean state over most grasslands and shrublands. The study of two sites with the same IAV in the leaf area index (LAI) shows that the component with the smaller contribution to the total evapotranspiration is more sensitive to the IAV of vegetation. The IAV of the three components of evapotranspiration increases with the IAV of the fractional coverage (FC) and the LAI. The ground evaporation IAV shows the greatest increase, whereas the canopy evaporation shows the smallest increase. 展开更多
关键词 interannual variability evapotranspiration ground evaporation canopy evaporation transpiration
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Species- and Habitat-variability of Photosynthesis, Transpiration and Water Use Efficiency of Different Plant Species in Maowusu Sand Area 被引量:105
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作者 蒋高明 何维明 《Acta Botanica Sinica》 CSCD 1999年第10期1114-1124,共11页
Photosynthesis ( P n ), transpiration ( E ) and water use efficiency ( WUE ) of more than 66 arid sand species from different environmental habitats, shifting sand dune, fixed sand dune, lowland and wetland in ... Photosynthesis ( P n ), transpiration ( E ) and water use efficiency ( WUE ) of more than 66 arid sand species from different environmental habitats, shifting sand dune, fixed sand dune, lowland and wetland in the Maowusu Sand Area were analyzed and the relation among these characteristics and the resource utilization efficiency, taxonomic categories and growth forms of the species were assessed. The results showed that species from Chenopodiaceae, Gramineae, Leguminosae which possessed the C 4 photosynthesis pathway, or C 3 pathway and also with nitrogen_fixation capacities had higher or the highest P n values, i.e., 20~30 μmol CO 2·m -2 ·s -1 , while that of evergreen shrub of Pinaceae had the lowest P n values, i.e., 0~5 μmol CO 2·m -2 ·s -1 . Those species from Compositae, Scrophulariaceae, and Gramineae with C 3 pathway but no N_fixation capacity had the highest E rates, i.e., 20~30 mmol H 2O·m -2 ·s -1 and again the evergreen shrub together with some species from Salicaceae and Compositae had the lowest E rates, i.e., 0~5 mmol H 2O·m -2 ·s -1 . Species from Leguminosae, Gramineae and Chenopodiaceae with C 4 pathway or C 3 pathway with N_fixation capacity, both shrubs and grasses, generally had higher WUE . However, even the physiological traits of the same species were habitat_ and season_specific. The values of both P n and E in late summer were much higher than those in early summer, with average increases of 26%, 40% respectively in the four habitats. WUE in late summer was, however, 12% lower. Generally, when the environments became drier as a result of habitats changed, i.e., in the order of wetland, lowland, fixed sand dune and shifting sand dune, P n and E decreased but WUE increased. 展开更多
关键词 PHOTOSYNTHESIS transpiration Water use efficiency HABITAT C 4 pathway SHRUBS Grasses Maowusu Sand Area
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SIMULATION OF THE PHYSIOLOGICAL RESPONSES OF C 3 PLANT LEAVES TO ENVIRONMENTAL FACTORS BY A MODEL WHICH COMBINES STOMATAL CONDUCTANCE, PHOTOSYNTHESIS AND TRANSPIRATION 被引量:41
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作者 于强 王天铎 《Acta Botanica Sinica》 CSCD 1998年第8期740-754,共15页
Transpiration element is included in the integrated stomatal conductance photosynthesis model by considering gaseous transfer processes, so the present model is capable to simulate the influence of boundary layer con... Transpiration element is included in the integrated stomatal conductance photosynthesis model by considering gaseous transfer processes, so the present model is capable to simulate the influence of boundary layer conductance. Leuning in his revised Ball's model replaced relative humidity with VPD s (the vapor pressure deficit from stomatal pore to leaf surface) and thereby made the relation with transpiration more straightforward, and made it possible for the regulation of transpiration and the influence of boundary layer conductance to be integrated into the combined model. If the differences in water vapor and CO 2 concentration between leaf and ambient air are considered, VPD s , the evaporative demand, is influenced by stomatal and boundary layer conductance. The physiological responses of photosynthesis, transpiration, and stomatal function, and the changes of intercellular CO 2 and water use efficiency to environmental factors, such as wind speed, photon flux density, leaf temperature and ambient CO 2, are analyzed. It is shown that if the boundary layer conductance drops to a level comparable with stomatal conductance, the results of simulation by the model presented here differ significantly from those by the previous model, and, in some cases, are more realistic than the latter. 展开更多
关键词 PHOTOSYNTHESIS transpiration Stomatal conductance Boundary layer conductance Integrated model
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The Dynamic Study on Transpiration Consumption of Black Locust Forest 被引量:2
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作者 贺康宁 侯振宏 《Forestry Studies in China》 CAS 2001年第2期10-17,共8页
To know the annual water consumption of forest, it is necessary to acquire the annual transpiration value of stands. This paper is based on the data measured in the typical weather of the growth season, from 1998 to 2... To know the annual water consumption of forest, it is necessary to acquire the annual transpiration value of stands. This paper is based on the data measured in the typical weather of the growth season, from 1998 to 2000, with the LI 1600 Steady Porometer and the general weather information. The daily variation of transpiration in black locust forest ( Robinia pesudoacacia L.) is modeled by Penman Monteith equation. As a result of the model, a continuous daily transpiration in the growth season was calculated. The net radiation, intercepted by black locust forest canopy, was acquired from a semi empirical equation of measuring net radiation R n with the extinction coefficient k and leaf area index LAI . The canopy integral stomatic resistance is a mimesis with an empirical equation of measuring data. Compared with measuring data, the relative error of the modeled ones is less than 12% averagely. At last, the total transpiration of black locust forest during the period of 1998 and 2000 in the growth season of May to October, as an average transpiration of the different density stands, were 192 46, 187 07 and 195 59?mm respectively. 展开更多
关键词 black locust transpiration net radiation leaf area index extinction coefficient stomatic resistance water consumption
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The Response of Transpiration Rate of Malus pumila cv.Goldspur to Illumination and Soil Moisture 被引量:1
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作者 王克勤 杨晓晖 《Forestry Studies in China》 CAS 2001年第2期18-25,共8页
We tested the transpiration rate ( Tr ) of seven\|year\|old field and two\|year\|old potted Malus pumila cv.Goldspur under different conditions of illumination and soil water. The results showed that the interre... We tested the transpiration rate ( Tr ) of seven\|year\|old field and two\|year\|old potted Malus pumila cv.Goldspur under different conditions of illumination and soil water. The results showed that the interrelationship between Tr of Malus pumila cv.Goldspur and illumination and soil water content ( SWC ) was quite remarkable. Tr increased with the increase of light intensity and SWC . However, when one of the environmental stresses of illumination and water existed, the improvement of the other condition couldn't make Tr rise greatly. Only when SWC was higher than 11%, which arrived at over 55% of the field content ( FC ), or the photosynthetic active radiation ( PAR ) higher than 400?μmol·s -1 m -2 , Tr could rise greatly with the increase of PAR or SWC . But when SWC was higher than 15%, which reached over 75% of FC or PAR higher than 1?000?μmol·s -1 ·m -2 , Tr would not change a lot with the change of PAR or SWC . That PAR and SWC influenced the magnitude of stomatic resistance( RS ) and leaf water potential ( Ψ l) was the basic reason for the Tr responded to them. Light stress reduced the open degree of stomas, so when severe light stress existed ( PAR <100?μmol·s -1 ·m -2 ), RS was larger ( RS >2 0?s·cm -1 ), which led to the decrease of Tr(Tr <5?μgH 2O·s -1 ·cm -2 ). When severe water stress existed( SWC <11% and<55% of FC and soil water potential Ψ ws <-1 15?MPa), RS was higher than 4 00?s·cm -1 and Ψ l lower than -2 10?MPa, which led to Tr lower than 11?μgH 2O·s -1 ·cm -2 . When soil water was adequate( SWC >15% amd over 75% of FC , and Ψ ws >-0 50?MPa), RS was lower than 2 00?s·cm -1 , Ψ l higher than -1 65?MPa and Tr would be higher than 15?μgH 2O·s -1 ·m -2 . The range of SWC , 11%~15%, which accounted for 55% to 75% of FC , and correspond RS (2 00~4 00?s·cm -1 ) were the turning area, where the variable curve of Tr transited from a variable trend to another variable one. It could be considered as the range to control soil water. 展开更多
关键词 transpiration rate irradiation intensity(photosynthetically active radiance) soil moisture
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Photosynthesis and Transpiration Characters of Alfalfa (Medicago sativa) and Their Relationship with Relevant Factors during Branching Stage
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作者 马宇飞 李红丽 +2 位作者 董智 任国勇 董鲁光 《Animal Husbandry and Feed Science》 CAS 2009年第2期32-35,共4页
[ Objective] The paper presents the diumal changes of photosynthesis and transpiration of different alfalfa varieties and their relationship with the associated physiological and ecological factors during branching st... [ Objective] The paper presents the diumal changes of photosynthesis and transpiration of different alfalfa varieties and their relationship with the associated physiological and ecological factors during branching stage, so as to provide a basis for the development, utilization, and breed- ing of alfalfa. [ Method] Under natural conditions, the diurnal changes of net photosynthetic rate (Pn), transpiration rate (Tr), the relevant physio- logical factors including leaf temperature (TI), stomatal conductance (Gs) and intemal COn concentration (Ci), as well as the relevant physiologi- cal factors including photosynthetic available radiation (PAR), CO2 concentration in field (Ca) and air temperature (Ta) were measured in four al- falfa varieties (Algonguin, WL323 HQ, WL414, and Millionaire). The water use efficiency (WUE) and light use efficiency (LUE) were calculated, and the correlation among them was also analyzed. [Result] The Pn, Tr, PAR and Ta of the four varieties appeared to vary in a single-peak curve; the sequence of WUE was WL323 HQ ~ Algonguin ~ WL414 ~ Millionaire; there was no significant difference in LUE of the four alfalfa varieties; coef- ficient analysis showed that Pn was mainly affected by PAR, Gs, and Ci, while Tr by PAR and Ta. [ Conclusion] WL323 HQ is the variety with high Pn, high WUE and low Tr, and it has strong adaptability to drought. In four alfalfa varieties, PAR, Ta, Gs, and TI are the primary determining fac- tors while Ca and Ci the limiting factors of Tr; Gs is the primary determining factor while Ci the limiting factor of Pn. 展开更多
关键词 Alfalfa Medicago Sativa) Net photosynthesis rate transpiration rate
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Transpiration surface reduction of Kousa Dogwood trees during serious water imbalance
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作者 王斐 山本晴彦 《Journal of Forestry Research》 SCIE CAS CSCD 2009年第4期337-342,I0006,共7页
The response of Kousa dogwood (Cornus kousa Buerg.) to extreme stresses was investigated by RGB image analysis in the hot, dry and windy summer in 2007 in Yamaguch, Japan. Results show that tip and margin leaf scorc... The response of Kousa dogwood (Cornus kousa Buerg.) to extreme stresses was investigated by RGB image analysis in the hot, dry and windy summer in 2007 in Yamaguch, Japan. Results show that tip and margin leaf scorch was observed on many Kousa dogwood trees and clearly dark brown defense barrier appeared on scorched leaves. The defense barrier withdrew back from distal to proximal gradually until successful control of scorching, and left a series of unsuccessful defense traces. By responsive analysis of leaf color homogeneity with RGB image analysis method, a sharp logistic equation was obtained for the relative green/luminance (RGL) value of scorched leaves. By the meteorological analysis, the occurrence of dogwood leaf scorch-back was almost synchronous with the aridity peak period. It sug- gested that during the sudden aridity increment the extreme water stresses induce the defense response of Kousa dogwood tree to shear the excessive transpiration leaf area, and prevent the rest of the trees from further water loss. Image pixet analysis showed that 40.2% leaf area of sampled dogwood trees was reduced through the partial leaf scorch-back by the end of August in 2007. In contrast, only 13.2% leaf area was reduced from the same trees in 2008, for the reason of sufficient precipitation during first half year. In any case, the Kousa dogwood trees indeed reduced their transpiration surface area and appeared a surface reduction pattern differing from those shedding leaves or withering all the aboveground. Based on desiccation process analysis, it is considered that the interaction of the leaf dried back and the self-defense response was the key of the transpiration surface reduction (TSR) of Kousa dogwood during sudden hot and droughty stresses. 展开更多
关键词 aridity peak Kousa dogwood leaf scorch-back logistic responsive function relative G/L transpiration surface reduction
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关于“transpiration ratio”概念的商榷
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作者 李荣生 《植物生理学通讯》 CSCD 北大核心 2003年第6期663-,共1页
关键词 蒸腾系数 定义 需水量 transpiration ratio 植物生理学 TR 概念 思维形式
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Nighttime transpiration of Populus euphratica during different phenophases 被引量:5
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作者 Chunyan Zhao Jianhua Si +3 位作者 Qi Feng Tengfei Yu Peidu Li Michael A.Forster 《Journal of Forestry Research》 SCIE CAS CSCD 2019年第2期435-444,共10页
Evidence exists of nighttime transpiration and its potential impact on plant/water relations for species in a diversity of ecosystems. However, relevant data related to typical desert riparian forest species remains l... Evidence exists of nighttime transpiration and its potential impact on plant/water relations for species in a diversity of ecosystems. However, relevant data related to typical desert riparian forest species remains limited Accordingly, we measured sap flow velocity of Populus euphratica using the heat ratio method between 2012 and2014. Nocturnal stem sap flow was separated into nighttime and stem refilling using the ‘‘forecasted refilling''method. Nighttime transpiration was observed for each phenophase. The highest value was during the full foliation period but lowest during leaf expansion and defoliation periods. The contribution of nighttime transpiration to daytime transpiration was an average of 15% but this was comparatively higher during the defoliation period. Relationships between nighttime transpiration, vapor pressure deficits, and air temperatures were more closely associated than with wind speed in all phenophases. Moreover, we found that nighttime transpiration linearly correlated to vapour pressure deficit during the first and the full foliation periods, but nighttime transpiration showed exponential correlations to air temperatures during the same phenophases. Additionally, environmental drivers of transpiration were significantly different between nighttime and daytime(P \ 0.05). Driving forces behind nighttime transpiration were characterized by many factors, and integrated impacts between these multiple environmental factors were complex. Future studies should focus on these integrated impacts on nighttime transpiration, and the physiological mechanisms of nighttime transpiration should be investigated, given that this could also influence its occurrence and magnitude during different phenophases. 展开更多
关键词 SAP flow NIGHTTIME transpiration PHENOPHASE Heat ratio method POPULUS EUPHRATICA
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Temporal Variation in Sap-Flux-Scaled Transpiration and Cooling Effect of a Subtropical Schima superba Plantation in the Urban Area of Guangzhou 被引量:6
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作者 ZHU Li-wei ZHAO Ping 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2013年第8期1350-1356,共7页
Agriculture could suffer the water stress induced by climate change. Because climate warming affects global hydrological cycles, it is vital to explore the effect of tree transpiration, as an important component of te... Agriculture could suffer the water stress induced by climate change. Because climate warming affects global hydrological cycles, it is vital to explore the effect of tree transpiration, as an important component of terrestrial evapotranspiration, on the environment. Thermal dissipation probes were used to measure xylem sap flux density of a Schima superba plantation in the urban area of Guangzhou City, South China. Stand transpiration was calculated by mean sap flux density times total sapwood area. The occurrence of the maximum sap flux density on the daily scale was later in wet season than in dry season. The peak of daily sap flux density was the highest of 59 g m-2 s^-1 in July and August, and the lowest of 28 g m-2 s-1 in December. In the two periods (November 2007-October 2008 and November 2008-October 2009), the stand transpiration reached 263.2 and 291.6 ram, respectively. During our study period, stand transpiration in wet season (from April to September) could account for about 58.5 and 53.8% of the annual transpiration, respectively. Heat energy absorbed by tree transpiration averaged 1.4×10s and 1.6×10s kJ per month in this Schima superba plantation with the area of 2 885 m2, and temperature was reduced by 4.3 and 4.7℃ s^-1 per 10 m3 air. 展开更多
关键词 Schima superba plantation sap flux density stand transpiration cooling effect
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Comparison of transpiration between different aged black locust(Robinia pseudoacacia)trees on the semi-arid Loess Plateau,China 被引量:3
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作者 JIAOLei LU Nan +6 位作者 FU Bojie GAO Guangyao WANG Shuai JIN Tiantian ZHANG Liwei LIU Jianbo ZHANG Di 《Journal of Arid Land》 SCIE CSCD 2016年第4期604-617,共14页
Black locust (Robinia pseudoacacia) is widely planted throughout the semi-arid Loess Plateau of China. The spatial distribution of this species at different ages is highly heterogeneous due to restoration and manage... Black locust (Robinia pseudoacacia) is widely planted throughout the semi-arid Loess Plateau of China. The spatial distribution of this species at different ages is highly heterogeneous due to restoration and management practices. In this study, we aimed to compare the transpiration levels between different aged black locusts at the tree and stand scales, clarifying the physiological status of this species with different ages. Black locust trees with two representative age classes (12 and 28 years) were selected in the Yangjuangou catchment on the semi-arid Loess Plateau. Sap flux density (Fd) and environmental variables (solar radiation, air temperature, relative humidity and soil water content) were simultaneously monitored throughout the growing season of 2014. Tree transpiration (Et) was the product of Fd and sapwood area (As), and stand transpiration (Ec) was calculated basing on the stand sap flux density (Js) and stand total sapwood area (AsT). Stomatal conductance (gs) was measured in a controlled environment and hydraulic conductance was estimated using the relationship between transpiration rate and vapor pressure deficit (VPD). Our results showed that Et and Ec were higher in the 28-year-old stand than in the 12-year-old stand. The gs and hydraulic conductance of 28-year-old trees were also higher than those of 12-year-old trees, and the two parameters were thus the causes of variations in transpiration between different age classes. After rainfall, mean Fd increased by 9% in 28-year-old trees and by 5% in 12-year-old trees. This study thus suggests that stand age should be considered for estimating transpiration at the catchment and region scales in this area. These results provide ecophysiological evidences that the older black locust trees had more active physiological status than the younger ones in this area. These findings also provide basic information for the management of water resources and forests on the semi-arid Loess Plateau. 展开更多
关键词 SAPFLOW transpiration stand age AFFORESTATION RESTORATION Loess Plateau
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Subtropical Modern Greenhouse Cucumber Canopy Transpiration Under Summer Climate Condition 被引量:3
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作者 LUO Wei-hong, WANG Xiao-han, DING Wei-min, CHEN Yu-qing and DAI Jian-feng(Key Laboratory of Crop Growth Regulation , Ministry of Agriculture/Nanjing Agricultural University ,Nanjing 210095, P.R.China) 《Agricultural Sciences in China》 CAS CSCD 2002年第11期1260-1265,共6页
Greenhouse canopy transpiration not only has effects on greenhouse air temperature and humidity, but also is important for determining the set-point of fertigation. In this study, Penman-Monteith equation was used to ... Greenhouse canopy transpiration not only has effects on greenhouse air temperature and humidity, but also is important for determining the set-point of fertigation. In this study, Penman-Monteith equation was used to calculate the greenhouse cucumber canopy transpiration under summer climate condition. The effects of greenhouse environmental factors on canopy transpiration were analyzed based on the measurements of greenhouse microclimate factors and canopy transpiration. The results showed that Penman-Monteith equation was reliable and robust in estimating greenhouse cucumber canopy transpiration under summer climate condition. Greenhouse cucumber canopy transpiration rate increased linearly with the increase of net radiation and water vapor pressure deficit (VPD) above the canopy. But the maximum value of the canopy transpiration rate occurred at the same time as that of VPD whereas about two hours later than that of net radiation. Based on the results, it was concluded that in addition to radiation, air humidity should also be considered when determine the set-point of fertigation. 展开更多
关键词 CUCUMBER GREENHOUSE transpiration rate
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Impact of time lags on diurnal estimates of canopy transpiration and canopy conductance from sap-flow measurements of Populus cathayana in the Qinghai–Tibetan Plateau 被引量:3
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作者 Hui Wang Kangning He +4 位作者 Runjie Li Zhuping Sheng Yun Tian Jun Wen Bo Chang 《Journal of Forestry Research》 SCIE CAS CSCD 2017年第3期481-490,共10页
Recently, canopy transpiration (Ec) has been often estimated by xylem sap-flow measurements. However, there is a significant time lag between sap flow measured at the base of the stem and canopy transpiration due to... Recently, canopy transpiration (Ec) has been often estimated by xylem sap-flow measurements. However, there is a significant time lag between sap flow measured at the base of the stem and canopy transpiration due to the capacitive exchange between the transpiration stream and stem water storage. Significant errors will be introduced in canopy conductance (gc) and canopy transpiration estimation if the time lag is neglected. In this study, a cross-correlation analysis was used to quantify the time lag, and the sap flowbased transpiration was measured to pararneterize Jarvistype models of gc and thus to simulate Ec of Populus cathayana using the Penman-Monteith equation. The results indicate that solar radiation (Rs) and vapor pressure deficit (VPD) are not fully coincident with sap flow and have an obvious lag effect; the sap flow lags behind Rs and precedes VPD, and there is a 1-h time shift between Eo and sap flow in the 30-min interval data set. A parameterized Jarvis-type gc model is suitable to predict P. cathayana transpiration and explains more than 80% of the variation observed in go, and the relative error was less than 25%, which shows a preferable simulation effect. The root mean square error (RMSEs) between the predicted and measured Ec were 1.91×10^-3 (with the time lag) and 3.12×10^-3cm h^-1 (without the time lag). More importantly, Ec simulation precision that incorporates time lag is improved by 6% compared to the results without the time lag, with the mean relative error (MRE) of only 8.32% and the mean absolute error (MAE) of 1.48 × 10^-3 cm h^-1. 展开更多
关键词 Canopy transpiration Model - Populuscathayana Qinghai-Tibetan Plateau Sap flow Time lags
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Estimating plant crown transpiration and water use efficiency by vegetative reflectance indices associated with chlorophyll fluorescence 被引量:2
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作者 Hidenori Furuuchi Michael W. Jenkins +2 位作者 Randy S. Senock James L. J. Houpis James C. Pushnik 《Open Journal of Ecology》 2013年第2期122-132,共11页
This research developed estimates of plant crown transpiration and water-use-efficiency using reflectance and derivative indices extracted from remotely sensed chlorophyll fluorescence measurements under natural condi... This research developed estimates of plant crown transpiration and water-use-efficiency using reflectance and derivative indices extracted from remotely sensed chlorophyll fluorescence measurements under natural conditions. Diurnal changes of leaf-level gas exchange (carbon assimilation rate (A), stomatal conductance (gs), transpiration rate (E)), chlorophyll fluorescence and canopy-scale remote sensing were measured on top crown of valley oak (Quercus lobata) in the foothills of central California, USA. The results indicated Q. lobata experienced saturating irradiance (PAR), which induced photoinhibition indicated by a decrease in the quantum efficiency of photosystem II (r2 = 0.648 with Fv ′/Fm′ and r2 = 0.73 with FPSII) and open reaction centers (qP;r2 = 0.699). The excess absorbed quantum energy was dissipated as heat through the Xanthophyll cycle and other processes (photorespiration and the water-water cycle) rather than energy emission as steady state chlorophyll fluorescence (Fs). An increase in leaf temperature caused by the activity of Xanthophyll cycle was correlated to a decrease in Fs (r2 = 0.381) and an increase in evaporative cooling through E (r2 = 0.800) and water use efficiency (WUE;r2 = 0.872). 展开更多
关键词 CROWN transpiration Remote Sensing CHLOROPHYLL Fluorescence Reflectance QUERCUS lobata
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Partitioning tree water usage into storage and transpiration in a mixed forest 被引量:4
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作者 Ziqiang Liu Qianqian Liu +3 位作者 Zijun Wei Xinxiao Yu Guodong Jia Jiang Jiang 《Forest Ecosystems》 SCIE CSCD 2021年第4期961-973,共13页
Background:Water migration and use are important processes in trees.However,it is possible to overestimate transpiration by equating the water absorbed through the plant roots to that diffused back to the atmosphere t... Background:Water migration and use are important processes in trees.However,it is possible to overestimate transpiration by equating the water absorbed through the plant roots to that diffused back to the atmosphere through stomatal transpiration.Therefore,it is necessary to quantify the water transpired and stored in plants.Method:The δ^(2)H/δ^(18)O technique and heat ratio method were used to explore the water usage of coniferous and broad-leaved tree species,including the proportions of water used for transpiration and water storage.Results:Platycladus orientalis and Quercus variabilis had strong plasticity in their water usage from different sources.Platycladus orientalis primarily used groundwater(30.5%)and the 60-100-cm soil layer(21.6%)throughout the experimental period and was sensitive to precipitation,absorbing water from the 0-20-cm layer(26.6%)during the rainy season.Quercus variabilis absorbed water from all sources(15.7%-36.5%)except from the 40-60-cm soil layer during the dry season.In addition,it did not change its water source but increased its groundwater uptake during the rainy season.The annual mean water fluxes of P.orientalis and Q.variabilis were 374.69 and 469.50 mm·year−1,with 93.49% and 93.91% of the water used for transpiration,respectively.However,nocturnal sap flow in P.orientalis and Q.variabilis was mainly used for water storage in the trunk rather than transpiration,which effectively alleviated drought stress and facilitated the transport of nutrients.Conclusions:The water stored in both species comprised 6%-7% of the total water fluxes and,therefore,should be considered in water balance models. 展开更多
关键词 Water migration Water uptake Nocturnal sap flow transpiration
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Study on Transpiration and Stomatal Conductance Characteristics of C3 and C4 Plant 被引量:1
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作者 MENG Jinghui LU Yuanchang +1 位作者 Ronald Kohne LIU Gang 《Journal of Northeast Agricultural University(English Edition)》 CAS 2009年第4期1-8,共8页
The transpiration experiment was done under greenhouse conditions with a C3 plant sweet pepper (Capsicum annuum Linn.) and two C4 plants, sorghum (Sorghum bicolor L.Moench) and maize (Zea mays Linn.). Three spec... The transpiration experiment was done under greenhouse conditions with a C3 plant sweet pepper (Capsicum annuum Linn.) and two C4 plants, sorghum (Sorghum bicolor L.Moench) and maize (Zea mays Linn.). Three species were irrigated with three different water treatment levels of 100%, 66% and 33% which gave a comparison of tolerance and adaptation to irrigation and two different levels of water stress. The measurements of transpiration rate and stomatal conductance were done between 8.00 a.m. and 16.00 p.m. with measurements about each 1.5 h with an infrared gas analyzer. The results showed that Z. mays probably due to a higher leaf area had very low values and was significantly different (LSD pairwise comparison) from C. annuum and S. bicolor. The hypotheses that C4 plants and C3 plants have different transpiration rates and stomatal conductance could not be shown with the results. However, the hypotheses that for the same species, the highest values in transpiration rate and stomatal conductance were with the 100% irrigation treatment and the lowest values were with the 33% irrigation treatment could be accepted due to the results of this trial. 展开更多
关键词 transpiration rate stomatal conductance water stress
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Changes in spatial variations of sap flow in Korean pine trees due to environmental factors and their effects on estimates of stand transpiration 被引量:2
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作者 Minkyu MOON Taek-yu KIM +4 位作者 Juhan PARK Sungsik CHO Daun RYU Sanguk SUH Hyun Seok KIM 《Journal of Mountain Science》 SCIE CSCD 2016年第6期1024-1034,共11页
It is difficult to scale up measurements of the sap flux density(J_S) for the characterization of tree or stand transpiration(E) due to spatial variations in J_S and their temporal changes.To assess spatial variations... It is difficult to scale up measurements of the sap flux density(J_S) for the characterization of tree or stand transpiration(E) due to spatial variations in J_S and their temporal changes.To assess spatial variations in the sap flux density of Korean pine(Pinus koraiensis) and their effects on E estimates,we measured the J_S using Granier-type sensors.Within trees,the J_S decreased exponentially with the radial depth,and the J_S of the east aspects were higher than those of the west aspects.Among trees,there was a positive relationship between J_S and the tree diameter at breast height,and this positive relationship became stronger as the transpiration demand increased.The spatial variations that caused large errors in E estimates(i.e.,up to 110.8 % when radial variation was ignored) had varied systematically with environmental factors systematic characteristics in relation to environmental factors.However,changes in these variations did not generate substantial errors in the E estimates.For our study periods,the differences in the daily E(E_D) calculated by ignoring radial,azimuthal and tree-to-tree variations and the measured E_D were fairly constant,especially when the daily vapor pressure deficit(D_D)was higher than 0.6 k Pa.These results imply that the effect of spatial variations changes on sap flow can be a minor source of error compared with spatial variations(radial,azimuthal and tree-to-tree variations) when considering E estimates. 展开更多
关键词 Sap flow Environmental factors Pinuskoraiensis Scale-up Stand transpiration
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