# Evergreen and deciduous forest fractions: inconsistencies? – in #9: CCLM

#### in #9: CCLM

In the EXTPAR v4.0 documentation on page 19 it reads:
Values that depend on the plant cover, such as PLCOV MX, PLCOV MN, LAI MN, LAI MX, RS MIN , FOR E, FOR D, ROOTDP and z0, are weighted with the plant cover maximum in addition to the pixel area.
This would mean that FOR _D and FOR _E are relative to plant cover fraction. In that case the vegetation part of the cell is veg_part = for_e+for_d+veg_low
where veg_low stands for low vegetation which has a snow free albedo of 0.20 in your first equation
For the snow albedo the equation would be then

```zsnow_alb = zsalb_snow*(1._ireals-for_e(i,j)-for_d(i,j)-veg_low(i,j))       &
+ csalb_snow_fe * for_e(i,j)                       &
+ csalb_snow_fd * for_d(i,j)
+ csalb_snow_veg_low * veg_low(i,j)
```

In CCLM it is assumed that low vegetation has the same snow albedo as bare soil. Therefore zsalb_snow=csalb_snow_veg_low. With this assumption you get

```zsnow_alb = zsalb_snow*(1._ireals-for_e(i,j)-for_d(i,j))       &
+ csalb_snow_fe * for_e(i,j)                       &
+ csalb_snow_fd * for_d(i,j)
```