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Biogeosciences An interactive open-access journal of the European Geosciences Union
Biogeosciences, 14, 5533-5549, 2017
https://doi.org/10.5194/bg-14-5533-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
07 Dec 2017
Exploring the contributions of vegetation and dune size to early dune development using unmanned aerial vehicle (UAV) imaging
Marinka E. B. van Puijenbroek1, Corjan Nolet2, Alma V. de Groot3, Juha M. Suomalainen4,5, Michel J. P. M. Riksen2, Frank Berendse1, and Juul Limpens1 1Plant Ecology and Nature Conservation Group (PEN), Wageningen University & Research, Wageningen, P.O. Box 47, 6700 AA, the Netherlands
2Soil Physics and Land Management Group, Wageningen University & Research, Wageningen, P.O. Box 47, 6700 AA, the Netherlands
3Wageningen Marine Research, Wageningen University & Research, Den Helder, Ankerpark 27, 1781 AG, the Netherlands
4Laboratory of Geo-Information and Remote Sensing, Wageningen University & Research, Wageningen, P.O. Box 47, 6700 AA, the Netherlands
5Finnish Geospatial Research Institute, National Land Survey of Finland, Kirkkonummi, Finland
Abstract. Dune development along highly dynamic land–sea boundaries is the result of interaction between vegetation and dune size with sedimentation and erosion processes. Disentangling the contribution of vegetation characteristics from that of dune size would improve predictions of nebkha dune development under a changing climate, but has proven difficult due to the scarcity of spatially continuous monitoring data.

This study explored the contributions of vegetation and dune size to dune development for locations differing in shelter from the sea. We monitored a natural nebkha dune field of 8 ha, along the coast of the island Texel, the Netherlands, for 1 year using an unmanned aerial vehicle (UAV) with camera. After constructing a digital surface model and orthomosaic we derived for each dune (1) vegetation characteristics (species composition, vegetation density, and maximum vegetation height), (2) dune size (dune volume, area, and maximum height), (3) degree of shelter (proximity to other nebkha dunes and the sheltering by the foredune). Changes in dune volume over summer and winter were related to vegetation, dune size and degree of shelter.

We found that a positive change in dune volume (dune growth) was linearly related to initial dune volume over summer but not over winter. Big dunes accumulated more sand than small dunes due to their larger surface area. Exposed dunes increased more in volume (0.81 % per dune per week) than sheltered dunes (0.2 % per dune per week) over summer, while the opposite occurred over winter. Vegetation characteristics did not significantly affect dune growth in summer, but did significantly affect dune growth in winter. Over winter, dunes dominated by Ammophila arenaria, a grass species with high vegetation density throughout the year, increased more in volume than dunes dominated by Elytrigia juncea, a grass species with lower vegetation density (0.43 vs. 0.42 (m3 m−3) week−1). The effect of species was irrespective of dune size or distance to the sea.

Our results show that dune growth in summer is mainly determined by dune size, whereas in winter dune growth was determined by vegetation type. In our study area the growth of exposed dunes was likely restricted by storm erosion, whereas growth of sheltered dunes was restricted by sand supply. Our results can be used to improve models predicting coastal dune development.


Citation: van Puijenbroek, M. E. B., Nolet, C., de Groot, A. V., Suomalainen, J. M., Riksen, M. J. P. M., Berendse, F., and Limpens, J.: Exploring the contributions of vegetation and dune size to early dune development using unmanned aerial vehicle (UAV) imaging, Biogeosciences, 14, 5533-5549, https://doi.org/10.5194/bg-14-5533-2017, 2017.
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Short summary
Understanding the contribution of the vegetation and dune size to nebkha dune growth could improve model predictions on coastal dune development. We monitored a natural nebkha dune field with a drone with camera. Our results show that dune growth in summer is mainly determined by dune size, whereas in winter dune growth was determined by vegetation. In our study area the growth of exposed dunes was restricted by storm erosion, whereas growth of sheltered dunes was restricted by sand supply.
Understanding the contribution of the vegetation and dune size to nebkha dune growth could...
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