DOI: 10.5281/zenodo.15525189
title: PSInet Subdataset: Plant Hydraulics in Two Temperature Central European Forest Ecosystems

description: This data sets contains plant water potential data from Norway spruce (Picea abies) and European beech (Fagus sylvatica) taking from top-canopy twigs in 2023. The data was primarily taken at 6 p.m. local standard time (CET) to overlap with the Sentinel-1 SAR missing for model validation of forest water status. Twice per site, the diurnal cycles was measured. 

Temporal resolution:

Two different schemes:



Seasonal monitoring: April–September, biweekly, evening (6 p.m. local standard time CET)

Dirunal samples: 2x per season, peak-of-season, late season (predawn-morning-midday-afternoon-eventing)


Sites:



Wetzstein: Monospecific managed evergreen needleleaf forest (ENF), Norway spruce (Picea abies) with stand age > 100 years (clear cut in 2024), adjacent to eddy covariance tower (EC) DE-Wet.

Leinefelde: Monospecific managed deciduous broadleaf forest (DBF), European beech (Fagus sylvatica) with stand age > 100 years, adjacent to EC tower DE-Lnf.


Measurment protocol:



Twigs were harvested using a telescope pruner from the eddy covariance tower on the site

Specimen: Top canopy (within 3 m of the top crown), sun exposed

Transport: Bagged in zip-lock and carried to ground

Measured with Scholander pressure chamber model 1505D on the ground (always the same person, project leader)

Sample size: 2-3 replica per tree and sampling time

3-4 trees per site


Variables (Leinefelde):




 
Manual or automated sampling
Unit
Sensor location
Instrument


Plant water potential - pressure chamber
Manual
MPa
 
chamber unbagged


Soil water content - shallow (8 cm)
Automated
cm3 cm3-1 (volumetric)
 
SWC-DeltaT MLx


Soil water content - deep (64 cm)
Automated
cm3 cm3-1 (volumetric)
 
SWC-DeltaT MLx


Precipitation
Automated
mm
Above canopy
Thies tipping bucket, Thies Clima, Göttingen, Germany


Relative humidity
Automated
%
Above canopy
HMP155, Vaisala GmbH, Hamburg, Germany


Vapor pressure deficit
Automated
kPa
Above canopy
HMP155, Vaisala GmbH, Hamburg, Germany


Air temperature
Automated
C
Above canopy
HMP155, Vaisala GmbH, Hamburg, Germany


Photosynthetically active radiation (PPFD)
Automated
µmolPhoton m-2 s-1
Above canopy
PQS1, Kipp&Zonen, OTT HydroMet B.V., Delft, The Netherlands


Incident shortwave radiation
Automated
W m-2
Above canopy
CNR4, Kipp&Zonen, OTT HydroMet B.V., Delft, The Netherlands


Net radiation
Automated
W m-2
Above canopy
CNR4, Kipp&Zonen, OTT HydroMet B.V., Delft, The Netherlands


Windspeed
Automated
m s-1
Above canopy
2D sonic anemometer, Thies Clima, Göttingen, Germany




Variables (Wetzstein):




 
Manual or automated sampling
Unit
Sensor location
Instrument


Plant water potential - pressure chamber
Manual
MPa
 
chamber unbagged


Soil water content - shallow (8 cm)
Automated
cm3 cm3-1 (volumetric)
 
SWC-DeltaT ML2x


Soil water content - deep (64 cm)
Automated
cm3 cm3-1 (volumetric)
 
SWC-DeltaT ML2x


Precipitation
Automated
mm
Above canopy
Tipping bucket rain gauge 5.4032.30.008, Thies Clima, Göttingen, Germany


Relative humidity
Automated
%
Above canopy
CPC1S_5-ME, Mela Sensortechnik GmbH, Mohlsdorf-Teichwolframsdorf, Germany


Vapor pressure deficit
Automated
kPa
Above canopy
CPC1S_5-ME, Mela Sensortechnik GmbH, Mohlsdorf-Teichwolframsdorf, Germany


Air temperature
Automated
C
Above canopy
CPC1S_5-ME, Mela Sensortechnik GmbH, Mohlsdorf-Teichwolframsdorf, Germany


Photosynthetically active radiation (PPFD)
Automated
µmolPhoton m-2 s-1
Above canopy
SKP 215S, Skye Instruments Ltd, Llandrindod Wells, Great Britain


Incident shortwave radiation
Automated
W m-2
Above canopy
CNR1, Kipp&Zonen, Delft, The Netherlands


Net radiation
Automated
W m-2
Above canopy
CNR1, Kipp&Zonen, Delft, The Netherlands


Windspeed
Automated
m s-1
Above canopy
2D sonic anemometer 4.3800.00.140, Thies Clima, Göttingen, Germany