Thirty seven old fields were surveyed for above and below ground biomass, soil nitrogen and light penetration. These fields include the ones used in experiment 14 (see E014), field D and 13 succession strips. In the succession strips, samples were taken through each strip every 15m. In the old fields from E014, except fields A, B and C, samples were parallel to the transect lines of E014. The clip strips were halfway up the transects, with 2 outside the transects and 3 in between the transect lines, making 5 strips per field. In fields A, B, C and D, samples were taken from control macroplots (E004). Five sample strips were taken from each field. In field A (29), two sample strips were taken from plots 1 and 6 and 1 strip from plot 9. In field B (22), two samples were taken from plots 2 and 3 and 1 strip from plot 5. In field C (69), three strips were taken from plot 3 and two strips from plot 5. In field D (6), two samples were taken from plots 1 and 4 and 1 strip from plot 5. Five strips, 1m x 10cm, were clipped in each field for above ground biomass. This was sorted to grasses and forbs. Three root cores, down to 30cm, were taken from each of the five strips in each of the 37 fields. These cores were rinsed, dried and weighed. Two light measurements and one pooled (3 cores, down 10cm deep) soil nitrogen sample (for available and total N) were taken per strip.

Thirty five abundant species of known successional status were harvested from the field (usually 15 individuals per species), including roots contained in a core 20cm x 30 cm, dried, sorted to stem, leaf, and root, and weighed. Root cores were taken from microplots in fields A, B, C and D (E001), all treatments. This was an estimate of root biomass.