Temporal trends in species composition and plant traits in natural grasslands of Uruguay
Article first published online: 24 FEB 2009
2003 IAVS - the International Association of Vegetation Science
Journal of Vegetation Science
Volume 14, Issue 3, pages 433–440, June 2003
How to Cite
Rodríguez, C., Leoni, E., Lezama, F. and Altesor, A. (2003), Temporal trends in species composition and plant traits in natural grasslands of Uruguay. Journal of Vegetation Science, 14: 433–440. doi: 10.1111/j.1654-1103.2003.tb02169.x
- Issue published online: 24 FEB 2009
- Article first published online: 24 FEB 2009
- Received 21 January 2002; Revision received 22 October 2002; Final version received 3 December 2002; Accepted 13 December 2002.
- Grazing exclosure;
- Plant functional type;
- Cabrera (1970)
Abstract. We report the successional trends of the major life-forms (graminoids and forbs) in natural grasslands of Uruguay over a 9-yr period after the removal of domestic herbivores. For the whole community, species richness and diversity decreased over the successional period. In graminoids we observed clear temporal trajectories in floristic composition; the rate of floristic change decreased with time and was associated with a shift in plant traits. The exclusion of large herbivores promoted erect and tall grasses with narrow leaves and greater seed length, vegetative growth constrained to the cool season and increased frequency of annual species. Forbs did not show a clear temporal trend in species composition, but there was, nevertheless, a plot-specific species turnover of this functional group that was reflected in their attributes. Species spreading by means of rhizomes, with vegetative growth restricted to the warm season. Species with larger seeds increased under grazing exclusion, as did annual and nitrogen-fixing forbs. The floristic changes induced by cattle exclusion occurred early in the succession. This early high rate of change has practical implications for management and conservation programs of the natural grasslands of Uruguay. Additionally, the shift in plant traits may be helpful in devising simple indicators of grazing impact.