Weight and nutrient content of understorey vegetation in biomass subplots in June 2011 at the Biotree site in Kaltenborn, Germany

Usage Rights

This data is Free within projects.

FunDiv-intern

Dataset Abstract

Most of the plant diversity in European forests is found in the understorey, and despite its relatively low biomass compared to the forest overstorey, its functional importance is high (nectar source for pollinators, habitat for small mammals, affects tree regeneration, invasion resistance, decomposition and nutrient cycling (Gilliam 2007). Relationships between overstorey and understorey diversity and composition will be tackled. At the Biotree site in Kaltenborn-Germany, plots of 0.6ha were established in 2004, subdivided in an unmanaged part, a managed part and a managed part with additional species. The desired species mixture was achieved by patch planting (patches of 8mx8m). In the unmanaged part of each plot, 4 permanent vegetation monitoring subplots of 1m x 1m were established (see area maps) and permanently marked. Vegetation was first monitored in 2004 by the team of Michael Scherer-Lorenzen and afterwards in 2010 by the team of Helge Bruehlheide. In June 2011, these plots were relocated by Evy Ampoorter and Kris Ceunen in order to take a biomass sample of each subplot: within a frame of 1m x 1m (placed at the exact location of the permanent monitoring plot) a smaller frame of 0.5m x 0.5m was placed centrally within the bigger frame. All aboveground biomass within this smaller frame was clipped. Dead vegetation was removed from each biomass sample. The biomass sample was further divided into following groups: grass, Leguminosae, Achillea millefolium, other herbs. After removal of death vegetation and division into groups, the biomass samples were dried for 48h at 70°C (samples were quite wet). Then they were weighed and analysed for P, Ca, K, Mg (Forest & Nature Lab, Ghent University) and C and N (Institut für Walbau, Universität Freiburg).

Dataset Design

Set-up was similar to set-up used for vegetation monitoring in 2004 and 2010. In each plot, 4 permanent monitoring subplots of 1m x 1m are marked (see maps). These plots were relocated and a frame of 1m x 1m was placed at the exact location. Within the frame of 1m x 1m a smaller frame of 0.5m x 0.5m was placed at a location where vegetation was relatively abundant and composition was representative for the bigger frame. All aboveground biomass within this smaller frame was clipped. Dead vegetation was removed from each biomass sample. Each biomass sample was also further divided into following groups: grass, Leguminosae, Achillea, other herbs. After removal of death vegetation and division into groups, the biomass samples were dried for 48h at 70°C (samples were quite wet when collecting). Then they were weighed and analysed for P, Ca, K, Mg (Forest & Nature Lab, Ghent University) and C and N (Institut für Walbau, Universität Freiburg).
Preparation of biomass samples for chemical analyses: dried at 70°C, grinded using a sieve of 1mm (for analyses of P, Mg, Ca en K content) and afterwards further grinded with a ball mill (MM301, Retsch, Hahn, Germany) in Freiburg (for analysis of C and N). Before analyses of Ca, Mg, K en P-content, grinded biomass samples are 'destroyed' with HNO3/HClO4, diluted with demineralised water and filtered according to the method of Varian Instruments at work, AA-24 (McKenzie T., 1982. Automated multielement analysis of plant material by flame atomic absorption spectroscopy. Varian Instruments at work, AA-24). Analysis for Ca-content: destruction of biomass sample with the above mentioned method. Then the sample is diluted, 10% CsCI is added as modifer on the AAS (Varian SpectrAA 220) and calibrated to 5mg Ca/l and atomized in a nitrous oxide-acetylene flame, absorption is measured at 422.7nm. The analytical quality of the analysis is verified by repeated measurement of blanco and control samples. Analysis for K-content: destruction of biomass sample with the above mentioned method. Then the sample is diluted, 10% CsCI is added as modifer on the AAS (Varian SpectrAA 220) and calibrated to 1mg K/l and atomized in a air-acetylene flame, absorption is measured at 766.5nm. The analytical quality of the analysis is verified by repeated measurement of blanco and control samples. Analysis for Mg-content: destruction of biomass sample with the above mentioned method. Then the sample is diluted, 10% CsCI is added as modifer on the AAS (Varian SpectrAA 220) and calibrated to 0.5mg Mg/l and atomized in a air-acetylene flame, absorption is measured at 258.2nm. The analytical quality of the analysis is verified by repeated measurement of blanco and control samples. Analysis for P-content: destruction of biomass sample with the above mentioned method, then reaction of the destroyed biomass sample with metholsulphite, ammoniumheptamolybdate and sodiumacetate solution. Finally, measurement of the total P-content with a spectrophotometer type Varian Cary 50 at 700nm (Chemical analysis of plants and soils. Cottenie, Verloo,... Laboratory of analytical and agrochemistry, RUG). Analyses for C and N: C and N analysis is done by dry combustion with an elemental analyzer leco truspec™ (Leco, St. Joseph USA). 100-200 mg finely ground sample is wrapped in tin foil and burned with pure oxygen at 950°C. Tin foil rises temperature additionally throughout the burning process. Carbon is detected as CO2 with an infrared measuring cell, nitrogen is reduced to N2 and detected with a thermal conductivity cell.
For prediction of C and N content with near infrared spectroscopy spectra are taken from finely ground material with a Tensor 37 spectrometer (Bruker, Ettlingen, Germany). The wavenumber range is 12000 to 3800 cm-1, Resolution is 16 cm-1 with 64 scans for each spectrum. Five spectra are measured for each sample. For at least 100 samples the dry combustion reference analysis is done. With Opus 6.5 software (Bruker, Ettlingen, Germany) spectral information is combined with the corresponding reference value and models to predict unknown samples are developed using PLS (partial least square) regression.

Spatial Extent

Kaltenborn, Germany: Biotree site

Temporal Extent

Spring 2011

Taxonomic Extent

understorey vegetation: woody and non-woody vascular species (herbs, seedlings) < 1.3m

Measurement Circumstances

Overall good weather (but a lot of dew in the morning making the biomass samples wet). Until 2008, mowing between rows. Mowing between trees within rows, until trees were higher than grass layer.

Data columns available in the raw data part of this dataset

plot number
unique number ascribed to each plot (see location in sheet 'area maps')
Data group: Kaltenborn plot id
Alert Sample values are not displayed because this column hasn't been approved yet.
subplot number
plot number followed by a, b, c, d to indicate which subplot within the plot is considered (vegetation monitoring subplots are permanently marked in the field in the unmanaged part of the plots; our numbering is in accordance with the experimental set-up of the Biotree site, therefore downwards within the unmanaged plot)
Data group: Kaltenborn sub plot id
Alert Sample values are not displayed because this column hasn't been approved yet.
diversity
Number of tree species present in subplot
Data group: Species richness
Keywords: diversity
Alert Sample values are not displayed because this column hasn't been approved yet.
target Quercus petraea
Absence/presence of Quercus petraea as planted seedling within the plot; Datagroup description: Presence data
Data group: Presence data
Alert Sample values are not displayed because this column hasn't been approved yet.
target Fagus sylvatica
Absence/presence of Fagus sylvatica as planted seedling within the plot; Datagroup description: Presence data
Data group: Presence data
Alert Sample values are not displayed because this column hasn't been approved yet.
target Pseudotsuga menziesii
Absence/presence of Pseudotsuga menziesii as planted seedling within the plot; Datagroup description: Presence data
Data group: Presence data
Alert Sample values are not displayed because this column hasn't been approved yet.
target Picea abies
Absence/presence of Picea abies as planted seedling within the plot; Datagroup description: Presence data
Data group: Presence data
Alert Sample values are not displayed because this column hasn't been approved yet.
surrounding species
Tree species that surrounds the permanent vegetation monitoring subplot (each plot is composed of small monocultures; each subplot is located at the center of such a monoculture, for more information on the monocultures present in a plot: see plot maps in other sheets, e.g. 'plot 1', 'plot 2')
Data group: Tree species
Alert Sample values are not displayed because this column hasn't been approved yet.
Weight total
Weight of total biomass sample
Unit: g
Data group: Biomass
Keywords: process, understorey productivity
Alert Sample values are not displayed because this column hasn't been approved yet.
Weight grass
Weight of grass present in biomass sample
Unit: g
Data group: Biomass
Keywords: process, understorey productivity
Alert Sample values are not displayed because this column hasn't been approved yet.
K grass
K content of grass present in biomass sample
Unit: mg/kg
Data group: Biomass nutrient concentration
Keywords: process, K
Alert Sample values are not displayed because this column hasn't been approved yet.
Ca gras
Ca content of grass present in biomass sample
Unit: mg/kg
Data group: Biomass nutrient concentration
Keywords: process, Ca
Alert Sample values are not displayed because this column hasn't been approved yet.
Mg grass
Mg content of grass present in biomass sample
Unit: mg/kg
Data group: Biomass nutrient concentration
Keywords: process, Mg
Alert Sample values are not displayed because this column hasn't been approved yet.
P grass
P content of grass present in biomass sample
Unit: mg/kg
Data group: Biomass nutrient concentration
Keywords: process, P
Alert Sample values are not displayed because this column hasn't been approved yet.
C grass
C content of grass present in biomass sample
Unit: %
Data group: Biomass nutrient concentration
Keywords: process, C
Alert Sample values are not displayed because this column hasn't been approved yet.
N grass
N content of grass present in biomass sample
Unit: %
Data group: Biomass nutrient concentration
Keywords: process, N
Alert Sample values are not displayed because this column hasn't been approved yet.
Weight leguminosae
Weight leguminosae
Data group: Biomass
Alert Sample values are not displayed because this column hasn't been approved yet.
K leguminosae
K leguminosae
Data group: Biomass nutrient concentration
Alert Sample values are not displayed because this column hasn't been approved yet.
Ca leguminosae
Ca leguminosae
Data group: Biomass nutrient concentration
Alert Sample values are not displayed because this column hasn't been approved yet.
Mg leguminosae
Mg leguminosae
Data group: Biomass nutrient concentration
Alert Sample values are not displayed because this column hasn't been approved yet.
P leguminosae
P leguminosae
Data group: Biomass nutrient concentration
Alert Sample values are not displayed because this column hasn't been approved yet.
C leguminosae
C leguminosae
Data group: Biomass nutrient concentration
Alert Sample values are not displayed because this column hasn't been approved yet.
N leguminsae
N leguminsae
Data group: Biomass nutrient concentration
Alert Sample values are not displayed because this column hasn't been approved yet.
weight Achillea
Weight of Achillea millefolium present in biomass sample
Unit: g
Data group: Biomass
Keywords: process, understorey productivity
Alert Sample values are not displayed because this column hasn't been approved yet.
K Achillea
K content of Achillea millefolium present in biomass sample
Unit: mg/kg
Data group: Biomass nutrient concentration
Keywords: process, K
Alert Sample values are not displayed because this column hasn't been approved yet.
Ca Achillea
Ca content of Achillea millefolium present in biomass sample
Unit: mg/kg
Data group: Biomass nutrient concentration
Keywords: process, Ca
Alert Sample values are not displayed because this column hasn't been approved yet.
Mg Achillea
Mg content of Achillea millefolium present in biomass sample
Unit: mg/kg
Data group: Biomass nutrient concentration
Keywords: process, Mg
Alert Sample values are not displayed because this column hasn't been approved yet.
P Achillea
P content of Achillea millefolium present in biomass sample
Unit: mg/kg
Data group: Biomass nutrient concentration
Keywords: process, P
Alert Sample values are not displayed because this column hasn't been approved yet.
C Achillea
C content of grass present in biomass sample
Unit: %
Data group: Biomass nutrient concentration
Keywords: process, C
Alert Sample values are not displayed because this column hasn't been approved yet.
N Achillea
N content of grass present in biomass sample
Unit: %
Data group: Biomass nutrient concentration
Keywords: process, N
Alert Sample values are not displayed because this column hasn't been approved yet.
Weight other herbs
Weight of other herbs present in biomass sample
Unit: g
Data group: Biomass
Keywords: process, understorey productivity
Alert Sample values are not displayed because this column hasn't been approved yet.
K other herbs
K content of other herbs present in biomass sample
Unit: mg/kg
Data group: Biomass nutrient concentration
Keywords: process, K
Alert Sample values are not displayed because this column hasn't been approved yet.
Ca other herbs
Ca content of other herbs present in biomass sample
Unit: mg/kg
Data group: Biomass nutrient concentration
Keywords: process, Ca
Alert Sample values are not displayed because this column hasn't been approved yet.
Mg other herbs
Mg content of other herbs present in biomass sample
Unit: mg/kg
Data group: Biomass nutrient concentration
Keywords: process, Mg
Alert Sample values are not displayed because this column hasn't been approved yet.
P other herbs
P content of other herbs present in biomass sample
Unit: mg/kg
Data group: Biomass nutrient concentration
Keywords: process, P
Alert Sample values are not displayed because this column hasn't been approved yet.
C other herbs
C content of grass present in biomass sample
Unit: %
Data group: Biomass nutrient concentration
Keywords: process, C
Alert Sample values are not displayed because this column hasn't been approved yet.
N other herbs
N content of grass present in biomass sample
Unit: %
Data group: Biomass nutrient concentration
Keywords: process, N
Alert Sample values are not displayed because this column hasn't been approved yet.