Incorporating wood thinning forest management bugfixes from UM_v7 into the main CABLE branch for CABLE3 in ESM1.6

[tammasloughran]

While testing on ESM1.5 and ESM1.6 with CABLE3 is still ongoing, we would like to bring the wood thinning changes from the ACCESS_NRI/UM7 repository into the CABLE-LSM repository so that it's ready to go before the code is frozen for spinup.

Wood thinning issue on UM7

Wood thinning branch on UM7

I will create a branch for this here also in preparation to merge sometime in the future.

[tammasloughran]

Rachel warned me that some files have C preprocessor ifdef statements that may interfere with what is/is not compiled.
src/coupled/ESM1.5/casa_landuse.F90 has these C preprocessor sentinels. I have removed them in the thinning branch here. Hope that's okay.

[tammasloughran]

The bug fixes are:

1. thinning ratio variable should not be initialized to 0
2. thinned biomass should be added to the wood_flux output variable.
3. the newlitter_thin routine only aggregated root carbon and not leaf carbon to be redistributed to the litter pools.
4. The newlitter_thin could possibly edit non-forest tiles, when it shouldn't.

[access-hive-bot]

This issue has been mentioned on ACCESS Hive Community Forum. There might be relevant details there:

https://forum.access-hive.org.au/t/wood-thinning-in-access/1923/1