characteristics of longleaf pine in coastal wet pine flat communities. We specifically tested our

hypothesis that this group of soil biogeochemical indicators measured along the chronosequence

would follow a pattern similar to the biomass accumulation curve for forest succession (Vitousek

and Reiners, 1975). In response to rapid increase in growth during the early years of stand

establishment, we predicted a similar increase in net nitrogen mineralization rates, microbial

biomass and fungal biomass levels. We hypothesized that these variables would decrease at some

point during the mid-aged stage and reach a threshold steady-state some time during the early

mature stage when the understory reinitiation process of forest succession has begun.

 Nitrogen cycling was dominated by ammonium production during the wet 2005 growing

season when compared to a drier 2002. Nitrification represented 50% of the production during

2002 and less than 25% during 2005. There was ammonium enrichment by nitrate reduction.

This probably indicates that the dissimilatory-nitrate reduction-to-ammonium (DNRA) pathway

was prominent during the flooded 2004-2005 growing seasons. The net nitrogen mineralization

rates, microbial biomass carbon, and fungal biomass carbon increased between the young and

mid-aged classes, then decreased between the mid-aged and mature age classes. The FB-to-MB

ratios increased dramatically up to 60 years, then decreased to 110 years. Finally, soil organic

matter content (SOM), increased with soil moisture. Based upon the results, this group of soil

indicators follows biomass accumulation patterns and will attain biogeochemical equilibrium

after a stand age of approximately 60-70 years. The threshold would be during the mature age

class after the understory reinitiation phase of forest succession has started.

 The obj ective of Chapter 4 was to examine the relationships between key soil chemical and

microbial properties and the overstory and understory characteristics of a wet longleaf pine flat

community in the Gulf Coastal Plain of Florida. We hypothesized stand volume will show a