Compensatory growth of Festuca rubra after grazing: can migratory herbivores increase their own harvest during staging?
Article first published online: 19 OCT 2005
Volume 19, Issue 6, pages 961–969, December 2005
How to Cite
VAN DER GRAAF, A. J., STAHL, J. and BAKKER, J. P. (2005), Compensatory growth of Festuca rubra after grazing: can migratory herbivores increase their own harvest during staging?. Functional Ecology, 19: 961–969. doi: 10.1111/j.1365-2435.2005.01056.x
- Issue published online: 21 NOV 2005
- Article first published online: 19 OCT 2005
- Received 14 February 2005; revised 30 May 2005 accepted 20 June 2005
- Barnacle Goose;
- carrying capacity;
- forage quality;
- grazing optimization hypothesis;
- 1The grazing optimization hypothesis predicts increased production and quality of plants grazed at intermediate grazing pressures. Following this hypothesis, herbivores will be able to increase their own harvest by repeated grazing. We tested the predictions of this hypothesis for Barnacle Geese, Branta leucopsis.
- 2We manipulated the grazing intensity of Festuca rubra swards through trials with captive geese in early spring. Levels on experimental grazing matched levels of natural grazing pressure. The growth response of individually marked tillers was measured over 6 weeks.
- 3Above-ground biomass production of individual tillers was not different among different grazing intensities. Lost biomass in grazed tillers was compensated by a lower rate of senescence.
- 4Grazing affected sward characteristics significantly: the proportion of dead biomass in the vegetation was reduced, and production of additional axillary tillers increased.
- 5When extrapolating the experimental findings to foraging opportunities for staging geese, we calculate an increase in potential harvest for grazed compared with ungrazed swards at levels of natural spring grazing.
- 6This experiment demonstrates an increase in the carrying capacity of the staging site for migratory geese through grazing. When comparing the experiment with grazing levels of wild Barnacle Geese, it is clear that current goose densities maximize potential harvest.