Loss of Plant Species Diversity Reduces Soil Erosion Resistance

• Published in: Ecosystems (New York) Vol. 18; no. 5; pp. 881 - 888
• Main Authors: Berendse, Frank, van Ruijven, Jasper, Jongejans, Eelke, Keesstra, Saskia
• Format: Journal Article
• Language: English
• Published: New York Springer Science+Business Media 01.08.2015; Springer US; Springer; Springer Nature B.V
• Subjects: Analysis; Biodiversity; biodiversity loss; Biological diversity; Biomedical and Life Sciences; Brackish; Dikes; Dikes (Engineering); Ecology; Embankments; Environmental conditions; environmental factors; Environmental Management; Environmental quality; Extinct species; field experimentation; floods; Flowers & plants; future; Geoecology/Natural Processes; humans; Hydrology/Water Resources; impact; insurance; Life Sciences; Plant communities; Plant diversity; Plant Sciences; Plant species; Population density; productivity; Protection and preservation; Resistance to control; Rivers; Slopes; soil; Soil erosion; Species diversity; stability; Storm tides; storms; tides; vegetation; Zoology; plant competition; compensation effect; insurance effect; soil erosion; plant species diversity
• ISSN: 1432-9840; 1435-0629
• DOI: 10.1007/s10021-015-9869-6

In many estuarine areas around the world, the safety of human societies depends on the functioning of embankments (dikes) that provide protection against river floods and storm tides. Vegetation on land-side slopes protects these embankments from erosion by heavy rains or overtopping waves. We carried out a field experiment to investigate the effect of plant species diversity on soil loss through erosion on a simulated dike. The experiment included four diversity treatments (1, 2, 4, and 8 species). In the third year of the experiment, we measured net annual soil loss by measuring erosion losses every 2 weeks. We show that loss of plant species diversity reduces erosion resistance on these slopes: net annual soil loss increased twofold when diversity declines fourfold. The different plant species had strongly diverging effects on soil erosion, both in the single-species and in the multi-species plots. Analysis of the dynamics of the individual species revealed that the main mechanism explaining the strong effects of plant species diversity on soil erosion is the com pensation or insurance effect, that is, the capacity of diverse communities to supply species to take over the functions of species that went extinct as a consequence of fluctuating environmental conditions. We conclude that the protection and restoration of diverse plant communities on embankments and other vegetated slopes are essential to minimize soil erosion, and can contribute to greater safety in the most densely populated areas of the world.