The nature of and driving forces behind variation among wetland forests in terms of biogeochemistry and vegetation production are not well understood. We suggest that insight in biogeochemical and productivity differences may be gained by examining the degree
which nitrogen and phosphorus are balanced within wetland vegetation. On the basis of examinations of data related to N:P balance and nutrient use efficiencies, vegetation productivity in both depressional and riverine forests appears to be primarily N limited. In contrast to some current theories of wetland biogeochemistry, these data suggest
that when P deficiency occurs at all, it represents a secondary productivity constraint in comparison to N. Similarly, a biogeochemical continuum is suggested for wetland forests based on the relationship between N:P ratios in senesced foliage vs. annual litterfall mass. We theorize that the position of a particular wetland forest on this continuum reflects
the integration of its geomorphic position and biogeochemical history. In addition, the position of a particular system on the continuum may have predictive value with regard to met primary productivity and nutrient transformation capabilities.