Competition for Light Causes Plant Biodiversity Loss After Eutrophication
Yann Hautier,1,*
Pascal A. Niklaus,1,2
Andy Hector1
Human activities have increased the availability of nutrients
in terrestrial and aquatic ecosystems. In grasslands, this eutrophication
causes loss of plant species diversity, but the mechanism of
this loss has been difficult to determine. Using experimental
grassland plant communities, we found that addition of light
to the grassland understory prevented the loss of biodiversity
caused by eutrophication. There was no detectable role for competition
for soil resources in diversity loss. Thus, competition for
light is a major mechanism of plant diversity loss after eutrophication
and explains the particular threat of eutrophication to plant
diversity. Our conclusions have implications for grassland management
and conservation policy and underscore the need to control nutrient
enrichment if plant diversity is to be preserved.
2 Institute of Plant Sciences, ETH Zürich, Universitätstrasse 2, CH-8092 Zürich, Switzerland.
* To whom correspondence should be addressed. E-mail: yhautier{at}uwinst.uzh.ch
