Spruce
CautionPerformance
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.