It would be great to include the diameter at maturity of each species (i.e., diameter at which a tree species start to produce seeds) in the recruitment function, especially in the regional pool configuration. Basically, the idea would be that in the local fecundity term of the recruitment function, the variable logBATOTSP (log of the summed basal area of the species) would be replaced by logBAFecSP (log of the summed basal area of the species above its diameter at maturity). This could potentially prevent exponential population increase by considering that young recruits do not contribute yet to seed production.
To calculate the diameter at maturity, I used an equation from the work (currently in revision) of Journé et al. (@kunstler I don't know if we can make the equation public yet) who predicted the diameter at maturity as a function of its maximum diameter and of the mean temperature across the species distribution. The maximum diameter of each species was calculated as the 10th order statistic in the calibration dataset (i.e., the 10th highest diameter value). To extract the mean temperature in each species distribution, I used the same approach as in Barrere et al. 2023, by averaging the mean temperature extracted from CHELSA across each occurence of the species observed in the GBIF database. The script to extract the mean temperature per species is publicly available here.
The value of diameter at maturity calculated for each species in the IPM is available below:
dbh_mat.csv
It would be great to include the diameter at maturity of each species (i.e., diameter at which a tree species start to produce seeds) in the recruitment function, especially in the regional pool configuration. Basically, the idea would be that in the local fecundity term of the recruitment function, the variable
logBATOTSP(log of the summed basal area of the species) would be replaced bylogBAFecSP(log of the summed basal area of the species above its diameter at maturity). This could potentially prevent exponential population increase by considering that young recruits do not contribute yet to seed production.To calculate the diameter at maturity, I used an equation from the work (currently in revision) of Journé et al. (@kunstler I don't know if we can make the equation public yet) who predicted the diameter at maturity as a function of its maximum diameter and of the mean temperature across the species distribution. The maximum diameter of each species was calculated as the 10th order statistic in the calibration dataset (i.e., the 10th highest diameter value). To extract the mean temperature in each species distribution, I used the same approach as in Barrere et al. 2023, by averaging the mean temperature extracted from CHELSA across each occurence of the species observed in the GBIF database. The script to extract the mean temperature per species is publicly available here.
The value of diameter at maturity calculated for each species in the IPM is available below: dbh_mat.csv