In MalditoBarbudo/MedfateValidation: Medfate model validation

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)

General Info

We have used as starting point the SpParamsMED table created by Miquel de Cáceres. We realized that in this table some default values for hydraulic and/or photosynthetic parameters were not really adequate (i.e. $K_{xyl,max} = 0.15$). In order to get more adequate values for some of the parameters used in the Sperry model we have used the HidraTRY database (Rosas et al. in preparation) and the Quercus revision by Robert et al. (in preparation).

HydraTRY database

HydraTRY was used to update/create the values for the following variables:

1. Vmax298
2. Jmax
3. Psi50
4. PItlp
5. xylem_kmax
6. Al2As
7. SLA
8. LeafDuration
9. WoodDens
10. Narea
11. Hmax
12. Zmean

The default values of these variables were substituted by the HydraTRY provided values only for those species present in both tables, SpParamsMED and HydraTRY.

Psi50 and VCstem_d

We use the Psi50 value to calculate the VCstem_d value (as explained in the medfate vignette "Complex model: Hydraulics, stomatal conductance and photosynthesis"), by the following formula:

$$ \Psi_{50} / 0.69314^{1/c} $$

where $c$ is the VCstem_c value.

Default unknown parameters

In order to obtain more "real" values for those parameters in the species not present in HydraTRY database or without values, we perform three different imputations:

1. Quercus genus

Lies et al. book chapter ("The xylem anatomy and function of oaks") was used to impute parameters values for the Quercus species not present in HydraTRY or without values in this database by taking the medians of all the genus.

In these case only four variables were updated:

1. xylem_kmax
2. Psi50
3. Al2As
4. WoodDensity

2. Pinus genus

In this case, all pine species present in HydraTRY database were used to calculate the genus medians for all parameters used from HydraTRY and used to subtitute default values for that parameters in those species without real values.

3. Functional groups

For the rest of the species not included in the previous genus, they were divided in Angyosperms and Gimnosperms and the median value for the hydraulic variables were obtained from HydraTRY database.

MalditoBarbudo/MedfateValidation documentation built on May 7, 2019, 1:22 p.m.