Impact of different-sized herbivores on recruitment opportunities for subordinate herbs in grasslands
Article first published online: 9 APR 2009
2003 IAVS - the International Association of Vegetation Science
Journal of Vegetation Science
Volume 14, Issue 4, pages 465–474, August 2003
How to Cite
Bakker, E. S. and Olff, H. (2003), Impact of different-sized herbivores on recruitment opportunities for subordinate herbs in grasslands. Journal of Vegetation Science, 14: 465–474. doi: 10.1111/j.1654-1103.2003.tb02173.x
- Issue published online: 9 APR 2009
- Article first published online: 9 APR 2009
- Received 18 September 2002; Revision received 21 November 2002; Final version received 15 January 2003; Accepted 15 January 2003.
- Plant species abundance;
- Species richness
- van der Meijden (1990)
Abstract. Potential effects of herbivores on plant species diversity depend on herbivore size, species and density. In this study we examine the effect of different-sized herbivores (cattle and rabbits) on recruitment of subordinate herbs in grasslands. We show that in a grazed floodplain, grassland plant species richness is mainly determined by the presence of many species of subordinate herbs. These herbs experience high colonization and extinction rates. We conclude that the creation of colonization opportunities for subordinate herbs plays a crucial role in maintaining plant species richness in productive grasslands. We found that cattle disperse large amounts of seeds via their dung, over ten times more than rabbits. Rabbits create more and on average larger bare soil patches than cattle. In a field experiment artificial disturbances improved germination success tremendously for four tested herb species. We found that bare soil is the best regeneration site, while cattle dung gave a too strong nutrient stimulus, resulting in tall vegetation and therefore light limitation. These results can be confirmed with results from field monitoring plots where plant species richness was positively related to the occurrence of bare soil patches. Therefore both large and small herbivores have a major impact on dispersal and colonization, but for different reasons. Cattle are identified as most important for seed dispersal whereas rabbits have a main effect as creators of disturbances. These results emphasize the importance of distinguishing between herbivore species in assessing their (potential) effects.