,
(2)
with * indicating the measurement at the beginning of the time series,
taken as a reference. Once the predicted elastic changes in bark
thickness obtained via Eqn. (1) are subtracted from observed bark
thickness changes, D G is obtained using the
differential-evolution minimization algorithm described in Mencucciniet al. (2017). This final step separates irreversible growthD G from the remaining component of elastic
changes, i.e., local changes in bark osmotic pressure that are caused by
shifts in the balance between phloem carbohydrate supply and radial
growth. For clarity, we introduce the term D G+to indicate the novel capacity of our model to isolate not only
vertical, but also small, yet physiologically important radial processes
related to hydraulic and osmotic adjustments that impact the reversible
expansion dynamics in live bark and xylem. D G+supersedes D G. Cumulative daily increments ofD Gempir andD G+ were calculated to assess the fit between
our empirical dendrometer measurements with model predictions for
irreversible stem growth.