Sampling strategies in a forest environment for the elaboration of Isoscapes

This article introduces a sampling technique especially developed for the field collection of soil and plant samples in a complex forest environment. The technique consists in the definition of a spiders' web georeferenced lattice to be used as a reference frame on the field collection. The web lattice points are equally distributed in polar coordinates, thus providing a finer coverage of the central area, maintaining a good rate up to the boundary. Such a spatial distribution is specially suited to many geostatistical algorithms including the widespread Kriging or Inverse Distance Weighting, which are commonly used in the production of Isoscapes (isotopic abundances maps).