scholarly journals Nocturnal sap flow of Hedysarum scoparium and its response to meteorological factors in semiarid Northwest China

2018 ◽  
Vol 186 ◽  
pp. 012022
Author(s):  
Jifeng Deng ◽  
Hangyong Zhu
Keyword(s):  
Sap Flow ◽  
Meteorological Factors ◽  
Northwest China

scholarly journals Radial profile of sap flow velocity in mature Xinjiang poplar (Populus alba L. var. pyramidalis) in Northwest China

2014 ◽  
Vol 6 (5) ◽  
pp. 612-627 ◽  
Author(s):  
HongZhong Dang ◽  
TianShan Zha ◽  
JinSong Zhang ◽  
Wei Li ◽  
ShiZeng Liu
Keyword(s):  
Flow Velocity ◽  
Sap Flow ◽  
Radial Profile ◽  
Northwest China ◽  
Populus Alba ◽  
Sap Flow Velocity

scholarly journals Time-Lag Effect Between Sap Flow and Environmental Factors of Larix principis-rupprechtii Mayr

Forests ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 971 ◽  
Author(s):  
Liu Hong ◽  
Jianbin Guo ◽  
Zebin Liu ◽  
Yanhui Wang ◽  
Jing Ma ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Meteorological Factors ◽  
Time Lag ◽  
Weather Conditions ◽  
Experimental Period ◽  
Northwest China ◽  
Thermal Dissipation ◽  
Time Lags ◽  
Sap Flux Density ◽  
Water Limitations

A time lag between sap flux density (Js) and meteorological factors has been widely reported, but the controlling factors of the time lag are poorly understood. To interpret the time lag phenomenon systematically, thermal dissipation probes were placed into each of eight trees to measure the Js of Larix principis-rupprechtii Mayr. in the Liupan Mountains in Northwest China. Meteorological factors, including vapor pressure deficit (VPD), solar radiation (Rs) and air temperature (Ta), were synchronously measured with Js, and the dislocation contrast method was used to analyze the time lag between Js and the meteorological factors. The analysis indicated the following for the whole experimental period. (1) The time lag between Js and VPD (TLV) and the time lag between Js and Rs (TLR) both exhibited different patterns under different weather conditions, and Js could precede Rs on dry days. (2) Both TLV and TLR varied with the day of the year (DOY) throughout the experimental period; namely, both exhibited a decreasing tendency in September. (3) Reference crop evapotranspiration (ETref) had a greater influence on the time lag than the other meteorological factors and directly controlled the length and direction of TLV and TLR; relative extractable water (REW) modified the relationship between ETref and time lag. (4) The regression analysis results showed differences between the time lags and the environmental factors (ETref and REW) within different ranges of REW. Namely, TLR was better determined by ETref and REW when REW < 0.38, while TLV was better correlated with ETref and REW in the absence of soil water limitations (REW > 0.38). This project provided an important opportunity to advance the understanding of the interaction between plant transpiration and meteorological factors in a changing climate.

Characteristic of Sap Flow of Poplar and Response to Meteorological Factors in Coastal Region

2014 ◽  
Vol 1010-1012 ◽  
pp. 1055-1058
Author(s):  
Qing Yun Zhou ◽  
Yang Ren Wang ◽  
Shu Hong Sun
Keyword(s):  
Solar Radiation ◽  
Regression Model ◽  
Flow Rate ◽  
Sap Flow ◽  
Meteorological Factors ◽  
Pearson Correlation ◽  
Coastal Region ◽  
Meteorological Factor ◽  
Thermal Dissipation ◽  
Determination Coefficient

Thermal dissipation sap flow rate probe was used to measure trunk sap flow dynamic of Poplar during the growing season from September 2011 to May 2012 in coastal region of China. The relationship of trunk sap flow rate and meteorological factors was analyzed. The results showed that the process of sap flow rate of Poplar presented an obvious day and night alternate phenomenon. The diurnal variation of sap flow was a single-peak curve in sunny day and a multi-peak curve in rainy day. According to Pearson correlation analysis, the diurnal sap flow rate of Poplar was positively correlated with solar radiation and atmospheric temperature, and negatively correlated with air relative humidity. The regression analysis showed that there was a significant correlation between multi-day sap flow rate and solar radiation, and the determination coefficient was 0.287 and 0.778 in summer and autumn, respectively. The linear regression model of multi-day sap flow with meteorological multi-factor was remarkable correlation, and the determination coefficient was 0.577 and 0.791 in summer and autumn, respectively. The regression model of multi-day sap flow with meteorological multi-factor was better than with single meteorological factor.

scholarly journals Influence of Water and Nitrogen Stress on Stem Sap Flow of Tomato Grown in a Solar Greenhouse

2015 ◽  
Vol 140 (2) ◽  
pp. 111-119 ◽  
Author(s):  
Rangjian Qiu ◽  
Taisheng Du ◽  
Shaozhong Kang ◽  
Renqiang Chen ◽  
Laosheng Wu
Keyword(s):  
Water Supply ◽  
Water Content ◽  
Sap Flow ◽  
Northwest China ◽  
Application Rate ◽  
Irrigation Scheduling ◽  
Regression Equations ◽  
Solar Greenhouse ◽  
Influence Of Water ◽  
Water Treatments

Accurate measurement of crop water use under different water and nitrogen (N) conditions is of great importance for irrigation scheduling and N management. This research investigated the effect of water and N status on stem sap flow of tomato (Solanum lycopersicum) grown in an unheated solar greenhouse in northwest China. A water experiment included sufficient water supply (T1) based on in situ water content measurement, two-thirds T1 (T2) and half T1 (T3) under a typical N application rate (N1); i.e., 57.4 g·m−2 N. The N experiment included N1, two-thirds N1 (N2), and half N1 (N3) under T2 irrigation. Results showed that deficit water supply reduced the stem sap flow by 22.1% and 42.8% in T2 and T3, respectively, compared with T1. The average daily stem sap flow between N1 and N2 was similar, and both were higher than that of N3. Significant differences between N1 or N2 and N3 were only observed on four dates (totally 34 days). Nighttime stem sap flow accounted for 6.0% to 6.9% of the daily value for the water treatments and 5.7% to 8.5% of the daily value for the N treatments. No significant differences for nighttime stem sap flow were found among water and N treatments. The daily stem sap flow was significantly and positively correlated with solar radiation, air temperature, vapor pressure deficit, and reference evapotranspiration under the water and N experiments. The slopes of the regression equations between the daily stem sap flow and these parameters were lower when soil water availability was limited, whereas the slopes of the regressions had no significant differences among N treatments. A parabolic relationship between the ratio of the daily stem sap flow of water deficit treatments to that of T1 and soil relative extractable water content was observed.

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