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)