which is for the most recent year for which data are
available, was originally drawn by the Royal Forest
Department based on Landsat 5 remote sensing images of
Thailand (Table 1). Based on the GIS map, all of the
sample grid cells were categorized into a forest group,
which in 2000 had some area of forest within each cell (54
grid cells), and a non-forest group, which had no forest area
within each cells (149 grid cells). Natural forest resources
can be assumed to be easily available to villagers in the
forest group because of their proximity to the forest. On the
other hand, it would be more difficult for villagers in the
non-forest group to gain access to forest resources because
of the greater distances involved. The statistical significance of density differences between the groups was tested
with the two-sided Mann–Whitney U test.