McLaren, J.R. (corresponding author: email@example.com) & Turkington, R. (firstname.lastname@example.org): Department of Botany & Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada.
Biomass compensation and plant responses to 7 years of plant functional group removals
Article first published online: 17 FEB 2011
© 2011 International Association for Vegetation Science
Journal of Vegetation Science
Volume 22, Issue 3, pages 503–515, June 2011
How to Cite
McLaren, J. R. and Turkington, R. (2011), Biomass compensation and plant responses to 7 years of plant functional group removals. Journal of Vegetation Science, 22: 503–515. doi: 10.1111/j.1654-1103.2011.01263.x
Current Address: Jennie R. McLaren, Department of Biology, University of Texas at Arlington, Arlington, TX, USA.
Co-ordinating Editor: Norman Mason
- Issue published online: 20 APR 2011
- Article first published online: 17 FEB 2011
- Received 3 May 2010, Accepted 13 January 2011
- Context dependence;
- Ecosystem function;
- Rare species;
- Removal experiment
Question: What is the role of functional group identity in determining community composition and dynamics?
Location: A natural grassland in Yukon Territory, Canada.
Methods: We selectively removed single plant functional groups (graminoids, forbs, legumes) to examine their effects on biomass compensation, the distribution of biomass among common and rare colonizing species, and plant species richness and diversity. Removals were conducted across two environmental treatments (fertilization and fungicide) to test if biomass compensation was context-dependent. Biomass was estimated non-destructively using point-intercept sampling.
Results: When graminoids or legumes were continuously removed, there was full biomass compensation by the remaining functional groups after 5 years, but only partial compensation when forbs were removed. Biomass compensation depended on the colonizing functional group; forbs showed no increase in biomass until 5 years after the removal of any functional group, but graminoids colonized quickly after removals. After any removal, the dominant species within each remaining functional group showed no compensatory growth, whereas the first subdominant forb and graminoid both increased in biomass. Rare species had a delayed response to removals; rare species biomass only increased beginning 5 years after removals. Context dependence was observed only in the response of subdominant species to removals, and these responses did not translate into context-dependent effects on total estimated biomass.
Conclusion: We show that the effects of losing a plant functional group depends both on the identity of the group removed and on the species remaining. In this northern grassland, most compensatory growth was by the subdominant species, which may determine the direction of community development in the long term.