To tie the diffusion results to reality, we can compare ion diffusion coefficients from within our model directly to diffusion coefficients determined from time-lapse X-ray fluorescence microscopy (XFM) experiments . Figure reports the diffusion of ions calculated from MD simulations, replicating information from Figure , and directly compares the measured diffusion with the imputed diffusion coefficients from XFM. The time-lapse XFM ion maps were collected in a preconditioned 2 μm thick section of loblolly pine (Pinus taeda) held at 70%, 75%, or 80% relative humidity, which is 14 -16% equilibrium moisture content . The diffusion determined via simulation is approximately one order of magnitude faster than the experimental references. Multiple factors may contribute to this discrepancy. On the technical side, the selected water model within our simulation system is known to have faster diffusion by roughly a factor of two, with a diffusion coefficient of approximately 4-6 x 10 -5 cm 2 /s depending on temperature rather than 2.3 x 10 -5 cm 2 /s . Likewise, the initial ion distribution is different between the homogenous initial distribution from the simulation compared with the ion wavefront from a single source that was tracked in XFM. Since local charge neutrality needs to be maintained, both cations and anions diffuse at similar rates as measured by XFM , but can move independently in the periodic simulation volume. This is seen mostly explicitly in the Cl anions (Cl -), which diffused as similar rates regardless of counterion in simulation but exhibited diffusion that matched the associated cation measured with XFM . Together, we anticipate that the coupled nature of diffusion in XFM would slow diffusion of the wavefront relative to a tissue already impregnated with ions. Since we recapitulate the key trends found experimentally, that K + diffuses much more rapidly than Cu 2+ (Figure ), with magnitudes that are reasonable given the different conditions seen between the two experiments, our simplified cell wall model recapitulates the essential dynamics of ion permeation into cell walls.