Changes of SAP flow of Pinus sylvestris var.mongolica and its response to environmental factors before and after dormancy
[Objective]The aims of this study are to explore the water consumption rule of Pinus sylvestris var.mongolica in different periods in Mu Us Sandy land,to elucidate its response to various environmental factors,and to reveal the change process of SAP flow rate from growth period to resting period.[Methods]From September 1 to December 21,2023,the thermal diffusion probe technology was used to continuously monitor the change of SAP flow of Pinus sylvestris var.mongolica,and to simultaneously measure atmospheric temperature,solar radiation,saturated water vapor pressure deficit and other environmental factors.[Results](1)Atmospheric temperature,solar radiation and saturated water vapor pressure difference showed a significant seasonal trend of decreasing gradually with the approach of dormancy season during the whole observation period.(2)On the daily scale,there was a significant unimodal curve of SAP flow with day high and night low before November 4,and there was no obvious pattern of diurnal variation of SAP flow after November 4,so it was defined that the pine forest in the test site began to enter a dormant period around November 4.(3)In the early dormancy period,the daily accumulation of liquid flow showed an'S'pattern,and the total daily accumulation of liquid flow was significantly different with different DBH.(4)The response degree of pine to environmental factors was different in the early and dormant periods.After entering the dormant period,the SAP flow was relatively stable,and the factors affecting the flow rate were significantly reduced.[Conclusion]SAP flow in the Mu Us area began to enter the resting period in early November,and the SAP flow rate in the early dormant period was mainly affected by atmospheric temperature,air relative humidity and saturated water vapor pressure difference.The SAP flow rate showed a significant trend of'first increasing and then decreasing'.The factors affecting SAP flow significantly decreased with the arrival of the resting period,and the flow variation trend tended to be stable.
万方数据
维普
