The study area, heterogeneous in terms of different landscape types, consisted mainly of forest 37.05%, arable 34.75%, housing 6.37% and water 2.41%. The study area, a 20 km * 20 km square, was divided into 400 grid squares, each grid square was 1 km². One large oak was selected, if given a choice, the one closest to the middle of each grid square was selected. Not all grid squares contained trees of suitable size. All large oaks between 3.1m and 4.1m were measured.

Moreover, five land use type including arable fields, forest, housing and water for each tree were also collected within twenty eight different scales at (radii of 28-1225m). For each target three, two variables were collected describing the near surrounding: sun exposure and density of trees of shrubs near the oak.