Abstract
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 compensation
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.
Key words: plant species diversity; soil erosion;
plant competition; insurance effect; compensation
effect.
| Original language | English |
|---|---|
| Pages (from-to) | 881-888 |
| Journal | Ecosystems |
| Volume | 18 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - 2015 |
Keywords
- biodiversity loss
- productivity
- ecology
- stability
- future
- impact