The frame was designed to provide 25 intercept points in a 25 × 25cm sample surface, in order to balance the need to detect a variety of plants and obtain sufficient sample sizes with the available time for fieldwork. The Jonasson (1988) study successfully used a frame with 5 × 10 cm spacing to model the biomass of dwarf shrub and graminoid plant communities. As the vegetation at Molslaboratoriet is much more diverse and contains many smaller plant species than the vegetation sampled by Jonasson, the spacing was reduced to 5 × 5 cm, allowing for twice the number of points per area. Another consideration was to use as small an area as possible within the research plots, as the sample surface would be harvested after the point-intercept registration in the first period of fieldwork.
The sample surface was systematically placed in alignment with one of the two corner posts of the vegetation monitoring plot facing the outer fence as shown in fig. 6. Out of these two potential sample surfaces, the one with the least amount of scrub was chosen. If no scrub was present, the sample surface was chosen by coin-toss. The sample surfaces for the first period of fieldwork were placed just outside of the vegetation monitoring circle, as they would subsequently be harvested. The sample surfaces for the second period were placed inside the sample surfaces, following the same principles laid out above.