Calibration of Granier-Type (TDP) Sap Flow Probes by a High Precision Electronic Potometer

Thermal dissipation probe (TDP) method (Granier, 1985) is widely used to estimate tree transpiration (i.e., the water evaporated from the leaves) because it is simple to build, easy to install, and relatively inexpensive. However, the universality of the original calibration has been questioned and, in many cases, proved to be inaccurate. Thus, when the TDP is used in a new species, specific tests should be carried out. Our aim was to propose a new method for improving the accuracy of TDP on trees in the field. Small hazelnut trees (diameter at breast height 5 cm) were used for the experiment. The response of TDP sensors was compared with a reference water uptake measured with an electronic potometer system provided with a high precision liquid flow meter. We equipped three stems where we measured the sap flow density, the sapwood area (by using fuchsine), the total tree water uptake (reference), and the main meteorological parameters during summer 2018. Results confirmed that the original Granier’s calibration underestimated the effective tree transpiration (relative error about −60%). We proposed a new equation for improving the measurement accuracy within an error of about 4%. The system proposed appeared an easier solution compared to potted trees and particularly suitable for orchards, thus contributing to improve the irrigation management worldwide.

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Modeling of plant water uptake in two distinct forest stands using whole-plant capacitance approach

10.5194/egusphere-egu21-2579 ◽

2021 ◽

Author(s):

Veronika Skalova ◽

Michal Dohnal ◽

Jana Votrubova ◽

Tomas Vogel ◽

Miroslav Tesar

Keyword(s):

Soil Water ◽

Water Uptake ◽

Sap Flow ◽

Meteorological Data ◽

Water Pressure ◽

Thermal Dissipation ◽

Richards Equation ◽

Soil Drought ◽

Flow Measurements ◽

Whole Plant

Soil-plant-atmosphere interactions are studied to improve the estimation of actual transpiration &#8211; the key part of the catchment water balance. The one-dimensional soil water flow model S1D, involving vertically distributed macroscopic root water uptake and whole-plant hydraulic capacitance, was used. The model is based on the numerical solution of Richards' equation coupled with a transient transpiration stream algorithm.The study focuses on the catchment Liz located in the Bohemian Forest, Czech Republic. The catchment is covered with Norway spruce (Picea abies) and European beech (Fagus sylvatica). In 2020, sap flow measurements by thermal dissipation probes were conducted at both forest environments. Soil water pressure head, soil water content, and soil temperature data, as well as complete meteorological data from the nearby meteorological station, were also available for the whole period of interest.The registered sap flow and simulated transpiration fluxes are compared with a particular attention to the different behavior of isohydric (spruce) and anisohydric (beech) trees. The model reasonably well reproduces the plant responses caused by both the high midday potential transpiration demand and the occasional soil drought.The research is supported by the Czech Science Foundation Project No. 20-00788S.

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Sap flow in ‘Tommy Atkins’ mango trees under regulated deficit irrigation

Ambiente e Agua - An Interdisciplinary Journal of Applied Science ◽

10.4136/ambi-agua.2316 ◽

2019 ◽

Vol 14 (3) ◽

pp. 1

Author(s):

Carlos Elizio Cotrim ◽

Marcelo Rocha dos Santos ◽

Maurício Antônio Coelho Filho ◽

Eugênio Ferreira Coelho ◽

João Abel da Silva

Keyword(s):

Sap Flow ◽

Deficit Irrigation ◽

Irrigation Management ◽

Thermal Dissipation ◽

Phase Iii ◽

Regulated Deficit Irrigation ◽

Flow Measurements ◽

Mango Tree ◽

Irrigated Perimeter ◽

Sap Flow Measurements

Knowledge of transpiration is of fundamental importance for improving irrigation management. This study measured sap flow of the 'Tommy Atkins' mango tree using Granier’s thermal dissipation probe method under regulated deficit irrigation. The work was conducted in a 10-year-old ‘Tommy Atkins’ mango orchard, irrigated by micro sprinkler, located in the Irrigated Perimeter of Ceraíma, in Guanambi, Bahia, Brazil. Sap flow measurements were carried out on three consecutive days in plants under regulated deficit irrigation, with reductions of 30 and 60% of crop evapotranspiration in three phases of fruit development; beginning of flowering to early fruit growth (Phase I), fruit expansion (Phase II) and physiological maturation of fruits (Phase III). Regulated deficit irrigation led to reduced sap flow in ‘Tommy Atkins’ mango tree.

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African Mahogany transpiration with Granier method and water table lysimeter

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v21n5p322-326 ◽

2017 ◽

Vol 21 (5) ◽

pp. 322-326 ◽

Cited By ~ 2

Author(s):

Ana C. O. Sérvulo ◽

Lucas M. Vellame ◽

Derblai Casaroli ◽

José Alves Júnior ◽

Pedro H. de Souza

Keyword(s):

Water Table ◽

Water Demand ◽

Irrigation Management ◽

Weather Conditions ◽

Thermal Dissipation ◽

Sap Flux ◽

Atmospheric Water ◽

Sapwood Area ◽

African Mahogany ◽

Granier Method

ABSTRACT The thermal dissipation probe (Granier method) is useful in the water deficit monitoring and irrigation management of African Mahogany, but its model needs proper adjustment. This paper aimed to adjust and validate the Granier sap flux model to estimate African Mahogany transpiration, measure transpiration using lysimeter and relate it to atmospheric water demand. Weather conditions, transpiration and sap flux were monitored in three units of 2.5-year-old African Mahogany trees in constant water table lysimeter, in Goiânia, GO. Sapwood area (SA), leaf area (LA), transpiration measured by lysimeter (TLYS) and estimated by sap flux (TSF) were evaluated. The SA comprised 55.24% of the trunk’s transversal section. The LA varied from 11.95 to 10.66 m2. TLYS and TSF varied from 2.94 to 29.31 and from 0.94 to 15.45 L d-1, respectively. The original model underestimated transpiration by 44.4%, being the adjusted equation F = 268.25 . k1.231. SA was significant (F < 0.05). Due the root confinement, the transpiration showed low correlation, but positive, with the atmospheric water demand.

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Assessing water requirement of orange trees using sap flow measurements in Narkhed-Pandhurna critical zone observatory (CZO) in central India

Journal of Agrometeorology ◽

10.54386/jam.v23i1.83 ◽

2021 ◽

Vol 23 (1) ◽

pp. 14-20

Author(s):

ASHUTOSH KUMAR MISHRA ◽

PARAS R. PUJARI ◽

SHALINI DHYANI ◽

PARIKSHIT VERMA ◽

RAMESH JANIPELLA ◽

...

Keyword(s):

Water Uptake ◽

Sap Flow ◽

Short Interval ◽

Central India ◽

Water Requirement ◽

Thermal Dissipation ◽

Sap Flux ◽

Flow Measurements ◽

Sap Flow Measurements ◽

Orange Trees

We used thermal dissipation method for sap flux measurements in orange trees to assess its water requirement in Narkhed-Pandhurna region. Thermal Dissipation Probe (TDP) sensors were installed in 5-year old (young) and 15-year old (mature) orange trees to measure the diurnal sap flux variations in trees during November 21, 2019, to January 31, 2020 (71 days). The results show that the maximum daily water uptake by the 5-year old tree was 1.1 L observed on 39th day of measurement (December 29, 2019) and in the 15-year old tree it was 5.0 L, and it observed on 38th day (December 28, 2019) of measurement. The cumulative water uptake during the study period by the 5-year old tree was 49.0 L, and the 15-year old tree consumed 257.4 L of water. The results were compared with the recommended irrigational values of Indian Horticulture Board (IHB), Government of India (GoI) and Groundwater Survey and Development Agency (GSDA), Government of Maharashtra (GoMH) for orange orchards. The initial investigation shows that recommended guidelines for irrigation of orange trees are exorbitantly high and needs to be revised. The sap flow methods are more precise that can measure sap flow at a very short interval and can generate a time series of data. It can be used to revise the guidelines with the aim to conserve water and propose precision water irrigation for the study area in particular and different agro-climatic zones of the country in general.

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Evaluation of sap flow density of Acacia melanoxylon R. Br. (blackwood) trees in overstocked stands in north-western Iberian Peninsula

European Journal of Forest Research ◽

10.1007/s10342-008-0252-4 ◽

2008 ◽

Vol 129 (1) ◽

pp. 61-72 ◽

Cited By ~ 8

Author(s):

E. Jiménez ◽

J. A. Vega ◽

P. Pérez-Gorostiaga ◽

T. Fonturbel ◽

C. Fernández

Keyword(s):

Iberian Peninsula ◽

Sap Flow ◽

Flow Density ◽

Acacia Melanoxylon ◽

Sap Flow Density ◽

North Western

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Water transport in European Beech roots (<5mm) under drought in the south of Lower Saxony

10.5194/egusphere-egu21-2859 ◽

2021 ◽

Author(s):

Eva Messinger ◽

Heinz Coners ◽

Dietrich Hertel ◽

Christoph Leuschner

Keyword(s):

Soil Moisture ◽

Water Transport ◽

Water Uptake ◽

Sap Flow ◽

Climate Models ◽

European Beech ◽

Root Surface Area ◽

Lower Saxony ◽

Tree Roots ◽

Small Roots

Climate models predict hotter and dryer summers in Germany, with longer periods of extreme droughts like in summer 2018. How does this affect the water uptake and transport in tree roots growing in the top- and subsoil?In summer 2018 and 2019 we measured the water transport in fine roots (<5mm) of European Beech on tertiary sand and triassic sandstone up to 2 m depth. We adapted the well-established HRM technique to enable measurements of very small sap flow rates in small roots. Thus, we measured the water transport as a temperature ratio of a stretching heat pulse.Relating sap flow to root surface area, root depth, anatomy, soil moisture, and VPD allows for interesting insights in tree water uptake rates: Where are the limits of drought intensity and duration, for water uptake and recovery of small roots? Are there differences in the function of top- and subsoil roots? Are roots specialized for water transport or nutrient uptake? The investigated data gives a first hint on how the water transport in Beech roots differs with changes in the soil moisture and VPD under changing climate.

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Stand-Level Transpiration Increases after Eastern Redcedar (Juniperus virginiana L.) Encroachment into the Midstory of Oak Forests

Forests ◽

10.3390/f11090901 ◽

2020 ◽

Vol 11 (9) ◽

pp. 901 ◽

Cited By ~ 2

Author(s):

Patricia R. Torquato ◽

Rodney E. Will ◽

Bo Zhang ◽

Chris B. Zou

Keyword(s):

Water Use ◽

Sap Flow ◽

Structural Equation ◽

Mixed Forest ◽

Flow Density ◽

Juniperus Virginiana ◽

Cross Timbers ◽

Eastern Redcedar ◽

Mixed Species ◽

Mixed Stands

Eastern redcedar (Juniperus virginiana L., redcedar) encroachment is transitioning the oak-dominated Cross-Timbers of the southern Great Plain of the USA into mixed-species forests. However, it remains unknown how the re-assemblage of tree species in a semiarid to sub-humid climate affects species-specific water use and competition, and ultimately the ecosystem-level water budget. We selected three sites representative of oak, redcedar, and oak and redcedar mixed stands with a similar total basal area (BA) in a Cross-Timbers forest near Stillwater, Oklahoma. Sap flow sensors were installed in a subset of trees in each stand representing the distribution of diameter at breast height (DBH). Sap flow of each selected tree was continuously monitored over a period of 20 months, encompassing two growing seasons between May 2017 and December 2018. Results showed that the mean sap flow density (Sd) of redcedar was usually higher than post oaks (Quercus stellata Wangenh.). A structural equation model showed a significant correlation between Sd and shallow soil moisture for redcedar but not for post oak. At the stand level, the annual water use of the mixed species stand was greater than the redcedar or oak stand of similar total BA. The transition of oak-dominated Cross-Timbers to redcedar and oak mixed forest will increase stand-level transpiration, potentially reducing the water available for runoff or recharge to groundwater.

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