Update aboveground biomass allometry parameters for extratropical trees

[JessicaNeedham]

There was a small typo in the script I used to estimate AGB parameters from BAAD data. With this fixed there are changes to the AGB parameters for extratropical trees (for tropical PFTs we use Chave et al. parameters). The differences in the allometries are fairly minor, especially over the range of usual DBH values but will be answer changing.

Collaborators:

Thanks to Henrique Ferro Duarte for spotting the typo

Expectation of Answer Changes:

This will be answer changing for any simulations using extratropical tree PFTs. See figure below.

Checklist

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All checklist items must be checked to enable merging this pull request:

Contributor

• The in-code documentation has been updated with descriptive comments
• The documentation has been assessed to determine if updates are necessary

Integrator

• FATES PASS/FAIL regression tests were run
• Evaluation of test results for answer changes was performed and results provided
• FATES-CLM6 Code Freeze: satellite phenology regression tests are b4b

If satellite phenology regressions are not b4b, please hold merge and notify the FATES development team.

Documentation

• Technical Note update:
• User's Guide update:

Test Results:

Results below are from100 year simulations comparing old and updated parameter files using the latest NorESM-FATES tags and parameter files. The differences might be larger once this has run longer, since it mostly impacts large trees.

[JessicaNeedham]

Looking more closely at the extratropical needleleaf evergreen tree, there are a couple of really large trees which skew the AGB curve at smaller sizes.

Full size distribution:

Zoomed in on smaller size classes:

All of these trees with massive dbhs are Sequoia sempervirens from a single site in Northern California. I think there is an argument to be made for removing them since they are not representative of the NEET PFT over most of its global distribution. We might need a separate Sequoia PFT at some point.

With Sequoias removed this is the new curve:

I'm updating the NEET AGB parameters accordingly.

[glemieux]

Thanks for this @JessicaNeedham. I'm assuming that @rosiealice is using this in the current calibration effort? I.e. I'm assuming we should integrate this prior to the freeze?

[JessicaNeedham]

Thanks for this @JessicaNeedham. I'm assuming that @rosiealice is using this in the current calibration effort? I.e. I'm assuming we should integrate this prior to the freeze?

It is not in the NorESM-FATES version yet, but I think the plan is to get it in there shortly.