Optimal LAI

[AlexisRenchon]

Optimal LAI (optimal_lai.jl), after Zhou et al., 2025

• New AbstractLAIModel (not AbstractAreaIndexModel which also gives RAI and SAI)

TO DO:

• currently updates via callback (akin to pmodel). We may want to update in Y instead. (let's discuss)
• This currently stores LAI in p.canopy.lai_model.LAI, which means there are two LAIs: the prescribed one p.canopy.biomass.area_index.leaf, and the modeled one. (this is intentional for now - so we can compare them). Maybe we want to do this differently. (and maybe we want to use biomass and not a new lai_model). let's discuss.
• Currently, optimal LAI is computed, but the LAI used for photosynthesis etc. is still the prescribed LAI.
• To go global, how do we get, at all (lon, lat):
• annual precip
• annual gpp
• growing season mean VPD
• growing season length
• daily GPP

--> we could start by reading them and have them constant (except daily gpp), and later, store in Y starting year 2?

Ozark, with

Ao_annual = FT(100.0), # mol CO2 m-2 y-1, for an average forest
P_annual = FT(60000.0), # ~ 1000 mm precipitation per year,
D_growing = FT(1000.0), # mean VPD growing season (Pa) - also some average value,
GSL = FT(180.0), # days, growing season length