GP Ks show changes in time and space, both between and within the parcels, with a different temporal behaviour for the different parcels, and no evident seasonal cycle. Mean and standard deviation of the transformed GP data samples are shown to be linearly related. This allowed the definition of a model of Ks statistical distribution that elucidates the distinct contributions of soil matrix and macropores, and provides a validation of the Morales et al. (2010. J. Hydrol. 393, 29) concept of biologically-driven macropore dynamics.
TI estimations of Ks vary in space in agreement with the soil texture and show a stable seasonal pattern. However, in presence of macropores, they are not representative of the actual values of the saturated conductivity. On the other hand, TI Ks could provide an estimate of the conductivity of the soil matrix. The comparison with the soil matrix conductivity values deriving from the proposed model of Ks statistical distribution seem to support this possibility.
These results, that shall be corroborated by further experiments, support the importance of thoroughly investigating the interactions between soil biota, vegetation and the soil hydraulic properties.