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VSD+ PROPS
Luc Bonten, Janet Mol, Wieger Wamelink, Gert Jan Reinds, Jan-Cees Voogd
Contents
VSD+, what is new
PROPS
●What is PROPS
●Extension of number of species in PROPS
●Limit number of species in PROPS calculations
VSD+ PROPS
What is new in VSD+
option for calcareous soils●no Ca and Mg weathering●no cation exchange●new parameter: parentCa (<0 for non-calcareous,
1 for CaCO3, 0 for MgCO3)
new organic C model: RothC●N mineralisation linked to C turnover●new parameters:
o rfmiR (also in MetHydo QIlf (0.25 for forest, 0.67 for grassland)
1. What is PROPS
PROPS
model that calculates the chance (probability) that a plant species is present
based on measurable abiotic conditions
Derived from:
relevés with simultaneously measured abiotic conditions (N, pH)
climate data
Relevés with abiotic measurements
4596 relevés in Netherlands, Austria and Ireland
pH and N (N-total, C/N ratio and/or NO3)
519 species that were found ≥ 25 relevés
Relevés with measurements of abiotic conditions
Response functions
2 dimensional response functions:
pH
N (N-total, CN, NO3)
logit(y) = α + β1pH + β2N + γ1pH2 + γ2N2 + δpH·N
probability = 1/(1+exp(-logit(y))
Fitting of response functions
Example: Atriplex prostrata
Example: Calluna vulgaris
Results
Number of plant species with response functions
pH + N-total: 406
pH + CN ratio: 330
pH + NO3: 146
2. Extension number of species
Problem:
only few relevés where abiotic conditions have been measured response functions for few species
how to get abiotic conditions for other relevés?
Datasets:
‘Abiotic’ dataset: ± 4600 relevés with measurements of abiotic conditions
Bioscore dataset: ± 430,000 relevés without abiotic conditions
Bioscore dataset
methodology to include more species in PROPS
2 step approach:
Step 1. estimate abiotic conditions based on presence of plant species with known response functions
Step 2. derive response functions based on estimated abiotic conditions
relevé Sp1Sp6SP20Sp78Sp145Sp221Sp456
estimation of abiotic conditions
‘Abiotic’ dataset(± 400 species, response for pH and N)
Sp1Sp2 | |Spn
Bioscore dataset(430,000 relevés,± 4,000 species)
Sp1Sp2 | |Spx
relevé Sp1Sp6SP20Sp78Sp145Sp221Sp456
species that in Bioscore with response functions in ‘Abiotic’ dataset
estimate pH and N from species with response functions
(at least 5 species from ‘abiotic’ dataset)
estimation of abiotic conditions
Bioscore dataset with abiotic conditions
Validation
Fitting response functions
4 dimensional response functions:
pH
N
temperature
precipitation
Results
Number of plant species with response functions
‘abiotic’ database pH + N-total: 406 pH + CN ratio: 330 pH + NO3: 146
Bioscore database pH + N-total: 2306 pH + CN ratio: 2309 pH + NO3: 1781
3. Preselect species in PROPS calculations
2300 species with response functions
a-priori selection of species is required
EUNIS classification is used in M&M work species selection related to EUNIS
overlay of EUNIS map (level 2; e.g. B1) with Map for the Natural Vegetation for Europe.
this gives per level 2 EUNIS class all possible vegetation types
combine overlay with list of Level 3 EUNIS classes (e.g. B1.1)
Wieger screened the remaining 7000 (!) combinations
Step 1:Overlaying
Step 2: species assignment
For each unit of the EuroVegMap units we got a list of typical/relevant species
These can be linked to the PROPS list
In VSD+Studio it is implemented as follows:
Species options
Summary
PROPS
response functions (pH, N, T, prec.) for 2300 species
a-priori selection of species based on vegetation type
relatively few species for Scandinavia, Iberic peninsula, south-east of Europe
Thanks
(VSD+ PROPS training session on wednesday afternoon)