Endure – standardised invertebrate sampling in coastal blond dunes from the 2-seas region

Study Extent

To understand the drivers behind the community structure of invertebrates associated with marram grass -the dominant dune-building ecosystem engineer in European coastal dunes-, we set up a stratified sampling scheme in six biogeographic regions along the North Sea. We studied to which degree local invertebrate species composition is affected by the spatial organisation of marram grass tussocks, and whether biodiversity aligns with coastal protection services.

Sampling

In each sampling area, transects parallel to the coastline and within 100m from the driftline were drawn in locations with sandy coasts and marram-dominated, blond dunes (Natura 2000 habitat 2120, CORINE biotope 16.21). Transect lengths were variable and chosen on site to incorporate the available variation in marram grass cover (average length: 1212 ± 786 m). Given the strong fragmentation of the dune areas into separated entities due to recent urbanisation (usually a reserve in between coastal villages or cities), one entity was sampled by a single transect. The number of samples along each transect depended on the length of the transect, with individual samples separated by at least 20 m. Each sample was centred on a marram grass (Calamagrostis arenaria (L.) Roth) tussock surrounded by only marram grass vegetation and bare sand (e.g., no shrubs, trees, or large quantities of other species) in a radius of 5 m. A total of 638 tussocks were sampled across all regions during the summers of 2017-2019. At each sampled marram grass tussock, aboveground invertebrates were sampled by sweep netting in and above the tussock for 15 seconds. Afterwards, ground-dwelling invertebrates were collected manually at the base of the tussock for 5 minutes. Sampling was only performed on relatively sunny days so flying insects would be active. All specimens were stored in 70% ethanol, before being counted and identified using a stereomicroscope.

Quality Control

Data are collected using a predefined sampling protocol, all identifications were checked by specialists in the taxonomic groups.

Method steps

1. Researchers from UGent and the Endure consortium drafted the EU project to investigate marram dune health with respect to biodiversity and coastal protection.
2. Fieldwork is planned and coordinated by UGent.
3. Data are collected in the field by Ruben Van De Walle, PhD student on the project.
4. Identifications performed by Ruben Van De Walle, Pieter Vantieghem, Dries Bonte, Martijn Vandegehuchte – all members of the Terrestrial Ecology Unit (TEREC) research group.
5. A custom SQL view is created by Hans Matheve to map the original data to Darwin Core as an event core and occurrence extension.
6. The Darwin Core views are connected to the IPT of the Belgian Biodiversity Platform and documented with metadata by Stijn Cooleman.
7. The dataset is published and registered with GBIF.

1. Animalia
   rank: kingdom
2. Arthropoda
   rank: phylum
3. Mollusca
   rank: phylum

N-France, Belgium, Netherlands and UK; coastline of the North-Sea-Channel