Heat pulse sap flow measurement (Plantae)

Knowledge graph centered on Heat pulse sap flow measurement (Plantae) with 75 nodes and 215 connections. Top connected: Rocky Mountain Biological Laboratory, Gothic, Beetles, Engelmann Spruce, Populus tremuloides.

Method synopsis

Continuous measurement of tree water transport using thermal dissipation sensors with temperature measurements at multiple depths in sapwood to calculate sap velocity via heat pulse methodology.

Synthesized from method descriptions across 5 papers using this protocol.

Procedure from a recent peer-reviewed implementation

Steps below were extracted from the most recent peer-reviewed implementation of this protocol in the corpus — Canopy structure modulates the sensitivity of subalpine forest stands to interannual snowpack and precipitation variability (2025), Hydrology and Earth System Science. Implementations in other papers (listed below) may differ.

1. Install sap velocity sensor network
   Installed sap velocity sensors at six sites across a hillslope transect spanning 500m elevation range. At each site, selected two mature and visibly healthy trees of each species present for instrumentation. Each sensor includes three stainless-steel probes of 1.3mm diameter and 35mm length inserted in the tree by removing outer bark and drilling three parallel holes spaced precisely 5mm apart using a drill guide.
   Quantities: 6 sites, 2-6 instrumented trees per site, 3 probes per sensor, 1.3mm diameter probes, 35mm length probes, 5mm spacing between holesDuration: Installation conducted in June 2019 and repositioned on the same tree each spring through 2022Conditions: Excluded 2020 when fieldwork was unable to be conducted due to COVID-19
   Equipment: sap velocity sensors manufactured by ICT International, drill guide, methyl orange stain
2. Measure sapwood depth and tree characteristics
   Determined sapwood depth on two cores with a 5mm diameter taken on the northern and southern sides of the tree at 1.2m height using an increment borer and stained with methyl orange to indicate active sapwood. Measured bark depth, sapwood depth, sapwood density and moisture content. Also determined wound diameter following reinstallation.
   Quantities: 2 cores per tree, 5mm diameter cores, measurements at 1.2m heightDuration: Measured each year when probes were reinstalledConditions: Measurements taken in July 2019
   increment borer, Haglöf increment borer, methyl orange stain

Typical Equipment

• sap velocity sensors manufactured by ICT International
• drill guide
• thermistors
• solar panels

Output Measurements

• sap velocity
• transpiration rates

Papers Using This Protocol (5)

Species Studied With This Protocol

Places Where Used