ACHIEVEMENTS AND GENERAL INFORMATION ABOUT ISLED PROJECT:
The project focuses on identifying,describing and defining the abiotic and biotic processes in salt marsh ecosystems resulting from and counteracting the effect of accelerated sea level rise,i.e. the effect of increased inundation frequencies.On the longterm, salt marshes will only survive if they are able to maintain their elevation relative to mean sea level,otherwise they will be drowned. Without an adequate understanding, of the nature,scale and extent of the counteracts to survive,future management and uses of these areas and resources will be extremely difficult.These countereffects provide stability and robustness,but when their capacities are exceeted they give rise to non-linear responses.Non-linear behaviour of salt marsh ecosystems has been recognised as a major cause for unpredictable changes.
The project involves mechanististic studies and requires a multi-disciplinary approach involving microbiologists,marine biologists,biogeochemists and system ecologists.Firstly,we will determine the historical and current rates of accretion and erosion for predicting the past development and future survival of marshes.We aim to study the ecophysiological processes that lead to changes in competitive abilities of tidal vegetation promoting enhanced trapping of detrital and organic material on the vegetated surface so that long-term changes in the pattern of flooding are counteracted.
Besides these long-term effects of accelerated sea level rise,also short-term effects on the diversity,biomass,distribution and functional behaviour of salt marsh flora and fauna will be examined.
Accelerated sea level rise as a result of global warming is a relatively slow process and difficult to assess in a reasonable length of time. However,civil engineering activities in estuaries may influence the tidal pattern in estuaries and result in changing flooding frequency within a few years time of the adjacent tidal marshes. For example the Westerschelde Estuary will undergo a unique major dredging operation within the next few years,resulting in a major increase in the mean level of the high tide. Although interested in itself, the way by which the marshes changes may be similar to the response to the expected global accelerated sea level rise and therefore enables us with a natural analogue to model the changes caused by long-term global change processes.
The overall aim was to obtain a comprehensive insight into the dynamics of the system counteracting the effects of sea level rise,and will be integrated into mathematical models fit for future management and conservation of salt marshes.