Istruzioni per l'esecuzione dei rilievi al suolo nei boschi di neoformazione

A shift in the traditional land-use system of the Alps resulted in the widespread abandonment of agricultural lands and recovery of secondary woodlands. Our study area, located in the Southern-Central Alps and extended for about 6000 km2, provided the opportunity to study this trend and suggest strategies for restoration ecology and sylviculture. In order to estimate the secondary woodland area, we adopted a two-stages sampling design. In the first stage, 100 cells were randomly selected with replacement in a 4 km regularly spaced grid according to a probability depending on an auxiliary variable; in the second stage, 100 sample points were drawn randomly within each selected cell; the 10000 sampling points were then surveyed on 1973 and 1999 orthophotos to estimate the area of secondary woodlands. These woodlands covered approximately 3% of the study area. The 291 sample points located on naturally or artificially reforested abandoned land were surveyed further on the ground, recording ecological, biometrical, management and landscape attributes. This report concerns the instructions for the field surveys.