Ing. Lies Leewis MSc

Introduction

Lies Leewis has a background in nature management, agricultural analysis, animal ecology and systems ecology. She is a now a PhD student (2006 onward) specialising in coastal ecology and management.

PhD project: Ecology of the Dutch sandy coast

In the coming years, the Dutch coast will be under increasing pressure due to the predicted sea level rise and an increased claim on land for urbanisation and recreation. Protection against coastal erosion will become a key issue in coastal management. In order to be able to cope with current and future laws on nature- and environmental protection (i.e. E.U. Bird- and Habitat Directives, Water Directive) and to maintain and strive towards the most natural ecosystem, a sustainable management of the coastal zone is necessary. This will require ecological knowledge on the sandy coast ecosystem. Especially knowledge on the Dutch sandy beaches and the interactions between the different parts of the coastal zone (i.e. shallow coastal waters, surf zone, beach, and dunes) is relatively poor and will have to be developed. Also, the ecological effects of human activities in the coastal zone will be investigated, particularly sand nourishments to counteract beach erosion, and recreation.
 
In this project, the two main Dutch beach types are compared. First, the relatively natural beach of the Wadden island of Schiermonnikoog has not been affected by beach nourishments and recreation is relatively low. The beach is accreting, very broad and dissipative. In response to geomorphological processes, there is a continuous successional vegetation change. More than half of the beach has now turned into a “green beach”, with species typical of salt marshes, foredunes and dune slacks. The other location is the coast of the province of North Holland, which is much more influenced by human activities such as beach nourishments, recreation and mechanical beach cleaning. Here, the coast is highly erosion-prone and less dissipative with narrow and steep beaches. Vegetation development is limited to pioneer dune species.

On the beaches, from the low water line to the foredunes, macroinvertebrate fauna and vegetation (lower and higher plants, algae, diatoms) are described. Central themes of the research are the presence of the species and the influence of biotic, abiotic, physical and anthropogenic factors. Key processes in the functioning of the sandy beach ecosystem will be investigated. Moreover, processes and species that connect the marine and terrestrial parts of the beach are being investigated. These investigations include both field sampling and purpose-designed experimental work.

Prof Dr Jelte Rozema
Ing Rob Broekman