Wetlandscape hydrology and ecosystem services

Wetlands are increasingly considered as nature based solution as they provide valuable services and functions to the society and environment, such as water quality improvement and biodiversity support. However, while land use and climate change have been affecting the functions and service of these ecosystems, it has become important to study the large-scale behaviour of wetlands in the landscape. Consequently, previous studies have suggested studying wetlands within wetlandscapes, defined as catchments containing networks of several wetlands, in order to understand large-scale functions of wetlands and their response to land-use and climate changes. This emphasizes the ecohydrological interactions of wetlands rather than having focus of individual wetlands. As the concept of wetlandscape is new, we have been working on systematically quantifying its governing properties in two different studies.

In the first study, we systematically quantified ecohydrological properties of individual wetlands (e.g. wetland area, wetland catchment area and wetland type) in multiple wetlandscapes that may impact biodiversity and modulate nutrient flows as well as characteristics of the whole wetlandscape in terms of their large-scale processes and functions. Results from this work showed that large wetlandscapes generally contained features to support different ecosystem services compare to smaller wetlandscapes. More specifically, results indicated that small wetlandscapes have a poor ability to route water through their wetlands which was in contrast to large wetlandscapes. This implies that large wetlandscapes have a higher potential for large-scale retention of nutrients and contaminants.

The second study consisted of investigating spatial and temporal wetland storage dynamics for multiple wetlands in the landscape in order to address considerable knowledge gaps regarding hydrological functions of wetlands and wetlandscapes. More specifically, we use high-resolution monitoring of wetland water levels to assess storage patterns and inundation conditions. A key finding of this work is that the position of wetlands is important for storage dynamics and flood buffering. Notably we find that wetlands located in headwater regions showed larger water level variability during the growing season (spring, summer and autumn) and hence were more active in temporal water storage than wetlands located downstream in the wetlandscape. This variability in water level for headwater wetlands was also associated with complex and patchy inundation conditions, while downstream wetlands essentially showed dry-state conditions during the entire summer.

Results from both studies show that ecohydrological properties of wetlandscapes can have implications for ecosystem service delivery (e.g., biodiversity support and water quality) at regional level as well as for using wetlands as nature-based solution. Present results also support the importance of wetlandscape studies and the priority of a wetlandscape focus in future management programs to various regional environmental challenges.