Riparian vegetation is known to affect floodplain/river ecosystem process and have an important role as primary producers fixing carbon which is then moved thorough the food webs. Variations in seasonal flow timing, duration and depth affect riparian vegetation production and community composition and potentially the partitioning of above to below ground primary production which will have significant effects on energy stores/flow through floodplain ecosystems. Understanding this response to inundation is critical to understanding energy flow.
It has been predicted that macrophyte production at the landscape scale will be dependent on the floodplain habitat type as a result of different flow condition in each habitat type, with macrophyte production greater in wetlands than in red gum woodlands followed by black box woodlands. Using a mesocosm approach we have shown that riparian vegetation production is incredibly complex and no single variable (season, flood duration, depth or habitat type-Red Gum, Black Box or Open water wetland) can be used to predict biomass production after inundation. Results have shown significant differences in biomass, the number of seedling germinating (abundance) and species richness between habitats at different depths over time occurring. The duration of flooding and season greatly affects the biomass, partitioning of above to below ground biomass, abundance and richness. In summer germination and establishment required greater than four weeks growing time, while after 12 weeks changes were less pronounced. However in winter there was significantly lower biomass, abundance and species richness than that recorded in summer, regardless of duration, depth or habitat type.