sap flow methods & data analysis techniques

part one: the thermal conductance and convection equation

Every heat pulse velocity method is derived from the thermal conductance and convection equation developed by Marshall (1958). In part one, the thermal conductance and convection equation is explained in detail.

 

part two: heat pulse velocity methods

Heat pulse velocity methods explained including compensation heat pulse, T-max method, and the Marshall-Hogg slow rates of flow or heat ratio method.

 

part three: the accuracy of heat pulse velocity methods

How accurate are sap flow methods? This video shows the minimum and maximum range limits of various sap flow methods as well as their accuracy and precision.

 

part four: how to measure high, slow and reverse rates of flow

Scientific equipment to measure reverse, zero, slow and high rates of sap flow.

 

part five: analysing sap flow data

Sap flow data analysis techniques to improve your publication success!

 

related equipment

 

references

Barrett, DJ. et al. 1995. Evaluation of the heat pulse velocity technique for measurement of sap flow in rainforest and eucalypt forest species of south-eastern Australia. Plant, Cell and Environment, 18: 463-469.

Burgess, SSO. et al. 1998. The redistribution of soil water by tree root systems. Oecologia, 115: 306-311.

Burgess, SSO. et al. 2001. An improved heat pulse method to measure low and reverse rates of sap flow in woody plants. Tree Physiology, 21: 589-598.

Choudhary, S. et al. 2014. Hydraulic conductance differences among sorghum genotypes to explain variation in restricted transpiration rates. Functional Plant Biology, 41: 270-275.

Closs, RL. 1958. The heat pulse method for measuring rate of sap flow in a plant stem. New Zealand Journal of Science, 1: 281-288.

Cohen, Y., et al. 1981. Improvement of the heat pulse method for determining sap flow in trees. Plant, Cell and Environment 4:391-397.

Cohen, Y. et al. 1993. Accuracy of sap flow measurement using heat balance and heat pulse methods. Agronomy Journal, 85: 1080-1086.

Doronila, AI. and Forster, MA. 2015. Performance Measurement Via Sap Flow Monitoring of Three Eucalyptus Species for Mine Site and Dryland Salinity Phytoremediation. International Journal of Phytoremediation, 17: 101-108.

Duursma, RA. et al. 2011. Rooting depth explains [CO2] × drought interaction in Eucalyptus saligna. Tree Physiology, 31: 922-931.

Forster, MA. 2012. Quantifying water use in a plant-fungal interaction. Fungal Ecology, 5: 702-709.

Gholipoor, M. et al. 2013. Transpiration Response of Maize Hybrids to Atmospheric Vapour Pressure Deficit. Journal of Agronomy and Crop Science, 199; 155-160.

Hogg, EH. et al. 1997. A comparison of sap flow and eddy fluxes of water vapor from a boreal deciduous forest. Journal of Geophysical Research, 102: 28929-28937.

Hultine, KR. et al. 2003. Contrasting patterns of hydraulic redistribution in three desert phreatophytes. Oecologia, 135: 167-175.

Intrigliolo, DS. et al. 2009. Using the Heat Pulse “Tmax” Procedure to Estimate Grapevine Water Use in a Humid Climate. Acta Hort., 846: 177-184.

Marshall, DC. 1958. Measurement of sap flow in conifers by heat transport. Plant Physiology, 33: 385-396.

Morton, DH. et al. 2016. Sensors and instrumentation to measure sap flow in small stem plants. IEEE, 7520519.

Pearsall, KR. et al. 2014. Evaluating the potential of a novel dual heat-pulse sensor to measure volumetric water use in grapevines under a range of flow conditions. Functional Plant Biology 41: 874-883.

Pfautsch, S. and Adams, MA. 2013. Water flux of Eucalyptus regnans: defying summer drought and a record heatwave in 2009. Oecologia, 172: 317-326.

Pfautsch, S. et al. 2012. Assessing sapwood depth and wood properties in Eucalyptus and Corymbia spp. using visual methods and near infrared spectroscopy (NIR). Trees, 26: 963-974.

Prendergast, PT. et al. 2007. Water Use by a Kiwifruit Vine: Calibration, Measurements and a Model. Acta Hort., 753: 535-538.

Swanson, RH. 1962. An instrument for detecting sap movement in woody plants. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Fort Collins, CC, Station Paper 68, 16 pp.

Swanson, RH. 1994. Significant historical developments in thermal methods for measuring sap flow in trees. Agricultural and Forest Meteorology, 72: 113-132.

Wood, SN. 2006. Generalized additive models: an introduction with R. Texts in statistical science. Chapman & Hall/CRC, Boca Raton, FL.