(Yang et al. 2006; SAS, 2002). These trends were enhanced by incorporating moving average

smoothing (MA model) as a data filter to reduce seasonal variations found in the datasets for a

number of the indicators affected by climate (Platt and Denman 1975; Kumar et al. 2001; Ittig,

2004). The trend analysis was followed by loglo data transformations where necessary.

 Results

Nitrifying Bacteria and Nitrogen Mineralization

 Young forest soils at one of the reference sites, St. Marks, had numbers of ammonium

oxidizing bacteria (AOB) that were 34 times greater (14,690 / g soil) than that found in soils

from the mature sites (427 / g soil) (Table 4-1). The higher AOB numbers in the young forest

soils corresponded to lower ammonium production (0.14 mg NH4+ / kg soil/month) and higher

nitrate production (Table 4-2). Topsail Hill State Preserve also had numbers of ammonium

oxidizing bacteria that were 60 times greater in the young forested soils (240 / g soil) than found

in soils from the mature sites (4 / g soil) (Table 4-1). However, the young wet pine savanna had

very high ammonium production compared to nitrification (Table 4-2). The mesic mature forest

soils at Topsail had lower ammonium levels than the wet young forest soils (Table 4-2). The

numbers of AOB at St. Marks (14,690) were significantly larger compared to the numbers

measured at Topsail Hill (240). The higher AOB numbers in the soil under the young forest at St.

Marks resulted in lower ammonification 0.14 mg NH4+ / kg soil/month compared to the soil from

the young forest at Topsail Hill 17.9 mg NH4' / kg soil/month. St. Marks had larger numbers of

AOB in the old forest soils (427 vs. 4.0), but the level of ammonium production was smaller 2.98

vs. 4.98 mg NH4' / kg soil/month when compared with the soils from the Topsail old forest site

(Table 4-2). The numbers of nitrite oxidizing bacteria (NOB) showed differences between the

age groups (427 / g -1 soil, in young soil vs. 4 / g-l soil, in old soil), but not between the sites