Fig. 5. Soil N analyses on 1982 soils by Kjeldahl digestion in 1982 (1982 KJN), on 1986 soils by Kjeldahl digestion in 1986 (1986 KJN), on 1986 soils by Perkin-Elmer CHN analyzer in 2000 (1986 CHN-N), and on 2000 soils by Perkin-Elmer CHN analyzer in 2000 (2000 CHN-N) in the loblolly pine site. Error bars denote standard errors and letters denote significant differences (p < 0.05) using Bonferonni post-hoc tests.