Floodplain forests systems are highly valuable to society because of their
potential for water quality improvement and vegetation productivity, among many
other functions. Previous studies have indicated that hydrology influences productivity
but that the relationship between hydroperiod and productivity is a complex
one. Consequently, we compared mutliple indexes of productivity, nutrient circulation,
and hydroperiod among three communities on the Flint River floodplain, Georgia,
that differed in terms of inundation frequency. We hypothesized that (a) the
wettest community would have the lowest net primary production (NPP) values
because of saturated soil conditions; (b) as wetness increases, nutrient circulation
in litterfall would decrease because of the hypothesized lower productivity
in the wetter community; and (c) as wetness increases, internal translocation
would become more efficient. The study site was partitioned into three wetness
types-somewhat poorly drained (SPD), intermediate (I) and poorly drained (PD).
We found that the belowground biomass was greatest on the SPD, litterfall was
similar for all three sites, and that woody biomass current annual increment
(CAI) was greatest in the PD community. However, when the three variables were
totaled for each site, the PD had the greatest NPP, thus disproving hypothesis
(a). For hypothesis (b), we observed that P content in litterfall, although
not significant, followed the predicted trend; nitrogen (N) content displayed
the opposite pattern (PD>I>SPD). As wetness increased, internal translocation
became more efficient for phosphorus (support for hypothesis [c]), but the SPD
community was more efficient at retranslocating N (contradiction of hypothesis
[c]).