Although an understanding of wetland processes and their vulnerability to anthropogenic stressors is fundamental for predicting future impacts, the limited evidence to date suggests that biological processes usually respond only weakly and slowly to stressors in wetlands. In contrast to changes in community structure which tend to occur gradually, changes in processes, when they ultimately occur, may occur suddenly and catastrophically. Perhaps with further testing and development of new ways to measure and quantify biological processes, their utility to regulatory monitoring programs will increase. The effects of enrichment on annual productivity, decomposition and denitrification have been studied primarily in cypress dome and northern bog wetlands. Differing conclusions may be due to differences in current velocity, leaf type, temperature, fertilizer type, ambient water quality, and other factors.
Enrichment commonly increases secondary production.
The effects of severe organic loading, e.g., from wastewater outfalls, on annual productivity have been studied primarily in cypress dome and northern bog wetlands, and results were similar to the above. With regard to decomposition, Brinson et al. The effects of metals on primary and secondary production, and the effects of other contaminants on other processes, have not been widely studied in wetlands. The effects of acidification on biological processes have generally not been studied in inland wetlands. The effects of salinization, e.g., from irrigation return water and oil drilling wastes, on biological processes have generally not been studied in inland wetlands.