Improved thermal method of continual recording the transpiration flow rate dynamics

Ktjčera, J.; Čermák, Jan; Penka, Miroslav

doi:10.1007/bf02922976

Cited by 135 publications

(48 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…After numerous experiments on hundreds of plants and more than 60 species it was inferred that the same empirical formula could be applied for different species. Whenever it was possible, sap flow measurements using the HFD were compared with measurements simultaneously conducted with known recognized methods such as tissue heat balance (THB -Cermák et al 1973, Kučera et al 1977, thermal dissipation (TD -Granier 1985) or Heat-Ratio Method (HRM - Burgess et al 2001) and results were in a close range.…”

Section: Calculation Of Sap Flow Per Sectionmentioning

confidence: 99%

Revisiting the Heat Field Deformation (HFD) method for measuring sap flow

Nadezhdina¹

2018

iForest

View full text Add to dashboard Cite

The Heat Field Deformation (HFD) technique is a thermodynamic method for measuring sap flow. Based on continuous heating the HFD method allows for high time resolution measurements which are highly important when studying plant responses to abrupt environmental changes. This work provides a succinct review of previously described features of the HFD methodology. Analyzing symmetrical and asymmetrical temperature differences around a measured linear heater (dTsym and dTas) relative to their ratio dTsym/dTas (so called a K-diagram) is at the heart of this methodology. This key concept, however, has to date only been generally described in previous works on the HFD technique. My objective here is to provide a comprehensive overview describing different types of K-diagrams, their interpretation and application for determining Kvalues or dTas for a zero flow condition. The K-value is a measured parameter which is particularly important for objectively characterizing heat conducting properties at the sensor insertion point under specific local measurement conditions. Correctly determining the K-value is critical for accurately calculating sap flow based on recorded temperature measurements. I have included in this review several examples demonstrating how the K-value is dependent upon changes to the environment and its important role in sap flow estimation. Keywords: K-diagram, K/R-diagram, K-value, Sap Flow per Section, Sap Flux Density, Sensor IntroductionThermodynamic methods for measuring sap flow are widely used in forestry, hydrology, agronomy and eco-physiological studies to accurately estimate tree water use, to identify specific drought stress conditions or to understand plant functionality. These methods which depend on heat transfer, however, differ fairly widely in their capabilities and limitations, notably in their sensitivity to low, zero and reverse flow rates. Reverse sap flow is particularly important for understanding the whole plant physiology and tree architecture, and acts as an indicator of hydraulic redistribution (Nadezhdina 1999, 2010, Burgess et al. 1998. In thermodynamic methods, thermometers are commonly used to gauge temperature changes of the heat field around a heater in response to sap movement. Thermometers may be arranged around the heater either symmetrically or asymmetrically. For symmetrical measurements, they are placed above and below and at equal distance from the heater in the axial direction (Daum 1967, Vieweg & Ziegler 1960, Sakuratani 1981, Tikhov 1979, Nadezhdina 1989, 1999, Burgess et al. 2001, while for asymmetrical measurements, the above thermometer is substituted by one placed together with the heater. (Ittner 1968, Cermák et al. 1973, Granier 1985.The majority of methods using thermometers arranged symmetrically around a heater produce accurate sap flow measurement with good dynamic resolution with the true sap flow under low flow conditions (Vieweg & Ziegler 1960, Leyton 1970, Saddler & Pitman 1970, Nadezhdina 1999. The situation can be different, however, under hig...

show abstract

Section: Calculation Of Sap Flow Per Sectionmentioning

confidence: 99%

Revisiting the Heat Field Deformation (HFD) method for measuring sap flow

Nadezhdina¹

2018

iForest

View full text Add to dashboard Cite

show abstract

“…Transpiration was monitored by means of a continuous measuring of sap flow in 10-minute interval. The EMS 62 system (EMS, Brno) uses the SHB method (Kučera et al, 1977) was used. Sap flow (Q, kg.h −1 ) was measured on two plants per pot from heading (BBCH 50) to full maturity (BBCH 89).…”

Section: Methodsmentioning

confidence: 99%

“…The "thermal dissipation method" is related to the correlation between the temperature of a heated sensor and flow density (Granier, 1985). The "stem heat balance method" (SHB) (Kučera et al, 1977;Ishida et al, 1991;Lindroth et al, 1995) and the "trunk sector heat balance method" (Smith and Allen, 1996) employ direct electrical heating of tissue and inner heat monitoring. The outcomes completed with meteorological and physiological characteristics can be used to assess individual subjects as well as forest stands and field crops canopies.…”

Section: Introductionmentioning

confidence: 99%

Maize transpiration in response to meteorological conditions

Klimešová

Středová

Středa

2013

Contributions to Geophysics and Geodesy

View full text Add to dashboard Cite

Differences in transpiration of maize (Zea mays L.) plants in four soil moisture regimes were quantified in a pot experiment. The transpiration was measured by the "Stem Heat Balance" method. The dependence of transpiration on air temperature, air humidity, global solar radiation, soil moisture, wind speed and leaf surface temperature were quantified. Significant relationships among transpiration, global radiation and air temperature (in the first vegetation period in the drought non-stressed variant, r = 0.881**, r = 0.934**) were found. Conclusive dependence of transpiration on leaf temperature (r = 0.820**) and wind speed (r = 0.710**) was found. Transpiration was significantly influenced by soil moisture (r = 0.395**, r = 0.528**) under moderate and severe drought stress. The dependence of transpiration on meteorological factors decreased with increasing deficiency of water. Correlation between transpiration and plant dry matter weight (r = 0.997**), plant height (r = 0.973**) and weight of corn cob (r = 0.987**) was found. The results of instrumental measuring of field crops transpiration under diverse moisture conditions at a concurrent monitoring of the meteorological elements spectra are rather unique. These results will be utilized in the effort to make calculations of the evapotranspiration in computing models more accurate.

show abstract

“…Sap flow rates for particular trees were estimated applying the tree-trunk heat balance method (Kučera et al 1977). Results of continuous measurements since August 1 to September 30 performed on the spruce and large sample trees are given in this paper.…”

Section: Site Description and Plant Materialsmentioning

confidence: 99%

Canopy transpiration of mountain mixed forest as a function of environmental conditions in boundary layer

Střelcová

Kučera²,

Fleischer

et al. 2009

Biologia

View full text Add to dashboard Cite

Abstract:The canopy transpiration of mountain mixed forest was investigated during summer 2006 at research plot Smrekovec in Tatra National Park in Slovakia after heavy windstorm in November 2004 on the area of 12,000 hectares. The research plot is situated in untouched forest at altitude 1249 m on the southern-east oriented slope. The forest is mixed with 80% of spruce trees and 20% of larch trees with rich under storey vegetation, 120 years old, 7th altitudinal vegetation stage. Whole tree sap flow based on up to dated stem tissue heat balance method was continuously measured in nine 120-years old larch and spruce trees. Stem basal area was used for tree-canopy up-scaling. Meteorological parameters were measured on the top of eddy stuff tower above investigated forest. Two virtual monocultures were assumed for characterizing of both species. The sap flow and tree transpiration were calculated for the whole measured period for both spruce and larch virtual forests.

show abstract

Improved thermal method of continual recording the transpiration flow rate dynamics

Cited by 135 publications

References 11 publications

Revisiting the Heat Field Deformation (HFD) method for measuring sap flow

Revisiting the Heat Field Deformation (HFD) method for measuring sap flow

Maize transpiration in response to meteorological conditions

Canopy transpiration of mountain mixed forest as a function of environmental conditions in boundary layer

Contact Info

Product

Resources

About