Fig. 3. Mean (plus one standard deviation) denitrification rates in August 2001 under ambient and amended conditions at two sites, BLS and BDO. (Site characteristics are given in Table 1.) Within a site, treatments with different letters are significantly different from each other (p < 0.05, Tukey's pairwise comparisons). AFDM, ash-free dry mass; DOC, dissolved organic carbon.