[1]WANG Ying,LIU Meijun,GUO Haining,et al.Canopy Stomatal Conductance of Robinia pseudoacacia Under Rainfall Exclusion Treatment[J].Research of Soil and Water Conservation,2023,30(05):209-216.[doi:10.13869/j.cnki.rswc.2023.05.054.]
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Research of Soil and Water Conservation[ISSN 1005-3409/CN 61-1272/P] Volume:
30
Number of periods:
2023 05
Page number:
209-216
Column:
Public date:
2023-08-10
- Title:
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Canopy Stomatal Conductance of Robinia pseudoacacia Under Rainfall Exclusion Treatment
- Author(s):
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WANG Ying1, LIU Meijun1, GUO Haining1, DU Sheng1,2
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(1.State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, China; 2.Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, Shaanxi 712100, China)
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- Keywords:
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Robinia pseudoacacia; rainfall exclusion; meteorological factors; canopy stomatal conductance; sensitivity
- CLC:
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S715.4
- DOI:
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10.13869/j.cnki.rswc.2023.05.054.
- Abstract:
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[Objective] The sensitivity of canopy stomatal conductance to transpiration driving factors and the possible changes with rain reduction treatment were studied in order to provide a theoretical basis for revealing the adaptation strategies of trees to climatic and environmental factors and for reasonably formulating vegetation restoration measures. [Methods] Based on the long-term monitoring of trunk sap flow dynamics of Robinia pseudoacacia by Granier's thermal diffusion probe and the synchronously observed meteorological data, the characteristics of canopy stomatal conductance and its sensitivity of response to transpiration drivers under rain reduction treatment and control environment were compared and analyzed. [Results](1)In the growing season, the diurnal variation of canopy stomatal conductance of R. pseudoacacia maintained the same trend as that of air vapor pressure deficit and solar radiation, but the canopy stomatal conductance of the treated sample plot was generally lower than that of the control plot. At the same time, the canopy stomatal conductance of the two sample plots in July was significantly higher than that of other months.(2)The daily average canopy stomatal conductance of R. pseudoacacia conformed to the fitting relationship of linear and logarithmic curves with daily average solar radiation and air vapor pressure deficit, respectively. The fitting slopes of canopy stomatal conductance and driving factors in the rain reduction sample plots were lower than those in the control plots. Due to the abundant rainfall in the early growth season and the higher average soil water content in the middle and late growth season, the fitting slopes of various plots in the early growth season were relatively high.(3)The sensitivity of canopy stomatal conductance in response to air vapor pressure deficit was linearly correlated with the reference canopy stomatal conductance. The sensitivity of rain reduction treatment sample plot was significantly lower, and the sensitivity of the same plot was also slightly higher in the early growth season with high soil water content. [Conclusion] The peak value difference of stomatal conductance of R. pseudoacacia canopy in different months is related to phenological rhythm such as the change of stand leaf area or environmental factors such as soil moisture. The sensitivity of canopy stomatal conductance to transpiration drivers is different in different plots and different periods. Rainfall reduction treatment will weaken the sensitivity of canopy stomatal conductance to transpiration drivers. In general, R. pseudoacacia stands in this area have a strong ability to respond to the air vapor pressure deficit. After the implementation of rain reduction treatment, the regulation ability has decreased, but maintained at a normal level.