Research
Coastal ecosystems are shaped by the interaction between tides and waves determining sediment transport patterns and the presence of organisms. My research focuses on the importance of ecosystem engineering organisms shaping back barrier-, coastal- and estuarine systems linking ecologic and morphologic processes. Ecosystem engineering organisms (such as plants or worms) are ubiquitous, whether in mud or sand dominated systems, on top or within sediment, or in the water column, and contribute to the morphodynamic development and the functioning of the ecosystem. Understanding interactions between organisms and their abiotic environment is crucial for protecting and managing present and future coastal development.
Remote sensing helps us to understand how ecological (e.g. plant cover) as well as morphological parameters (e.g. channel width) of coastal ecosystems change over space and time. It moreover allows us to study the impact of extreme events, on coastal ecosystems such as Hurricane Sandy which hit Atlantic Coast of the United States in October 2012 causing >68 billion of dollars of damage.
Field experiments and measurements are crucial to quantify processes shaping coastal ecology and morphological development.
Laboratory measurements and experiment are a valuable tool to gain a deeper understanding of coastal ecosystems. They enable us to remove confounding factors and investigate specific processes of interest.
Numerical modeling needs input from remote sensing, field measurements and laboratory experiments and enables us to make predictions on how coastal ecosystems will develop under different environmental scenarios, able to support planing and management decisions.
Salt Marsh Research
Salt marshes, a specific type of coastal ecosystems, are among the most productive ecosystems on earth, which can also function as ecosystem based flood defenses. Salt marshes are threatened by land use changes, wave erosion and sea level rise leading to marsh losses around the globe . This makes restoration projects gaining increased importance, for the sake of biodiversity conservation and coastal protection. However restoration success it tightly linked to our mechanistic knowledge on processes shaping salt marshes which is still lacking.
The interaction between plant characteristics, flowing water and the transport of sand and silt play a dominant role in the creation of the landscapes typical of coastal areas. In a recent study together with a team of international scientists from Utrecht University, the Royal Netherlands Institute for Sea Research (NIOZ), and the University of Antwerp, we could show that although physical characteristics of the plants (the thickness of their roots and stems, size, etc.) are important factors, the manner in which the plants settle and spread (their colonisation behaviour) is even more important in determining the appearance of the landscape. This research is interesting not only to biologists and physical geographers, but is also highly valuable to coastal managers and hydrological engineers who want to build with nature as a means of coastal defence.
Would you like to know more?
The study on the interaction between plant colonisation and landscape formation: Christian Schwarz et al., ‘Self-organization of a bio-geomorphic landscape controlled by plant life history traits’ has been published on the Nature Geoscience (https://www.nature.com/articles/s41561-018-0180-y)
In an illustration of my 2018 Nature Geoscience publication I showcase how organisms can shape their environment:
