Area Types: Four new tree types for use in CMIP7

[martinjuckes]

Proposee: Martin Juckes, Daniele Peano

Date : 2024-09024

For each term please try to give the following:

- Terms

• broadleaf_deciduous_trees
• broadleaf_evergreen_trees
• needleleaf_deciduous_trees
• needleleaf_evergreen_trees

- Description

The distinction broadleaf vs needleleaf and deciduous vs. evergreen have important implications for the carbon cycle. The four categories have been used in the CMIP6 without the blessing of CF. They are likely to be used more extensively in CMIP7, so it would be very helpful to have them added to the Area Types table.

[github-actions]

Thank you for your proposal. These terms will be added to the cfeditor (http://cfeditor.ceda.ac.uk/proposals/1) shortly. Your proposal will then be reviewed and commented on by the community and Standard Names moderator.

[JonathanGregory]

I agree that these four tree types are sensible additions. I notice that the existing deciduous/evergreen tree area types are also distinguished as primary/secondary. Do CMIP6 and CMIP7 use that distinction?

[martinjuckes]

Those four area types (combinations of deciduous/evergreen and primary/secondary) were used in CMIP6, but appear to have had significantly lower usage than the broad-/narrow-leaf and evergreen/deciduous combinations. The deciduous/evergreen and primary/secondary variants have not yet been requested for CMIP7.

[daniele-peano]

The original request of
Broadleaf Deciduous
Broadleaf Evergreen
Needleleaf Deciduous
Needleleaf Evergreen
derives from a proposed opportunity to study plant phenology.
In that case, the distinction between deciduous and evergreen plants is more relevant than the primary/secondary one.

[JonathanGregory]

@martinjuckes @daniele-peano Thanks for explaining. That satisfies my curiosity!