Spruce
Not RecommendedField testing showed the sensor cannot hold a reliable reading here, usually because the wounding response floods the install site and it reads zero.
Performance
Not recommended. Field trials in Norway spruce (Picea abies) showed sensors consistently exhibit shifted diurnal patterns (minimum SWP between 6 PM and 6 AM instead of midday) and sustained positive readings inconsistent with pressure chamber measurements of -15 to -30 bar. The conifer wounding/resin response floods the installation site and breaks the hydraulic connection to the xylem. Some installations produce reasonable data for roughly a month before the response sets in, and reinstalling the sensor in a fresh location can restore another short window of valid data — but this is impractical for long-term monitoring or research.
Installation Tips
- Will need to use thick-bark install method.
- For short-term experiments, plan for periodic reinstallation into fresh locations as the resin response disables each site.
Known Issues
- Resin production floods the sensor interface, causing readings to drift positive or show inverted diurnal patterns.
- Readings can diverge sharply from pressure chamber measurements (near-zero or positive SWP while the chamber reads -15 to -30 bar).
- Freezing temperatures may damage the sensor.
References
- Field trials incl. Natural Resources Canada / Laurentian Forestry Centre (2026), Norway spruce.