| Cite this article: | 王城城,叶文伟,赵从举,等.热带桉树树干液流的时滞效应分析[J].灌溉排水学报,0,():-. |
| WangChengCheng,YeWenWei,ZhaoCongJu,et al.热带桉树树干液流的时滞效应分析[J].灌溉排水学报,0,():-. |
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| Time Lag Effect of Stem Sap Flow of Eucalyptus in Tropical Hainan, China |
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WangChengCheng, YeWenWei, ZhaoCongJu, ChenLiYan
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Hainan Normal University
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| Abstract: |
| Abstract: 【Objective】In this study, the time lag effect of Eucalyptus trunk sap flow were test in the growing season. The response of time lag in Eucalyptus to environmental factors was analyzed. 【Method】The sap flow of 6-year-old Eucalyptus trees at Danzhou Forest Farm, Hainan, China, was monitored for 6 months by using a Granier-type thermal dissipation probe (TDP). Photosynthetically active radiation (PAR), vapor pressure deficit (VPD), soil water content (SWC) at a depth of 0-60 cm were monitored simultaneously.The time lags between sap flow density and PAR, VPD was estimated by the cross-correlation analysis.【Result】The results showed that the diurnal courses of sap flow density were “double peak” curve, and there was a photosynthesis depression at midday. The peaking time of sap flow density was ahead of PAR and VPD for 60 min in typical sunny days. Partical correlation analysis showed that there was a significant positive correlation between sap flow density and PAR, VPD (P < 0.001). There were obvious time lags between sap flow density and environmental factors (PAR, VPD) in growing season, which was ahead of PAR and VPD for 30 min and 50 min, respectively. The effect of soil water content (SWC) on the time lag between sap flow density and PAR/VPD reached a significant level(P＜0.05), and when SWC was higher (15.42%), sap flow density was ahead of PAR and VPD for 60 min and 30 min, respectively, while sap flow density was ahead of PAR and VPD for 0 min and 60 min when SWC was lower (10.45%). The time lag between sap flow and PAR/VPD had no significant correlation with the diameter grade (P＞0.05).【Conclusion】There are obvious time lags between Eucalyptus sap density and environmental factors, which is ahead of PAR and VPD. The main factor affecting the time lag is SWC.Comprehensive consideration of the differences between environmental factors can promote the research of Eucalyptus time lag effect. |
| Key words: Eucalyptus; sap flow; environmental factor; time lag; soil water content |
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