Differential sensitivities of grassland structural components to changes in precipitation mediate productivity response in a desert ecosystem
Article first published online: 19 MAR 2014
© 2014 The Authors. Functional Ecology © 2014 British Ecological Society
Volume 28, Issue 5, pages 1292–1298, October 2014
How to Cite
Reichmann, L. G., Sala, O. E. (2014), Differential sensitivities of grassland structural components to changes in precipitation mediate productivity response in a desert ecosystem. Functional Ecology, 28: 1292–1298. doi: 10.1111/1365-2435.12265
- Issue published online: 18 SEP 2014
- Article first published online: 19 MAR 2014
- Accepted manuscript online: 20 FEB 2014 11:25PM EST
- Manuscript Accepted: 9 FEB 2014
- Manuscript Received: 13 AUG 2013
- National Science Foundation. Grant Numbers: DEB 09-17668, DEB 12-35828, DDIG 09-10027
- axillary buds;
- Bouteloua eriopoda;
- desert grassland;
- meristem bank;
- precipitation legacies;
- vegetative reproduction
In arid and semi-arid ecosystems, there are legacies of previous-year precipitation on current-year above-ground net primary production. We hypothesized that legacies of past precipitation occur through changes in tiller density, stolon density, tiller growth, axillary bud density and percentage of viable axillary buds. We examined the sensitivity to current- and previous-year precipitation of these grassland structural components in Bouteloua eriopoda, the dominant grass in the northern Chihuahuan Desert.
We conducted a rainfall manipulation experiment consisting in −80% reduced precipitation, ambient, +80% increased precipitation treatments that were subjected to one of five precipitation levels in the previous two years (−80% and −50% reduced precipitation, ambient, +50% and +80% increased precipitation). The first two years preconditioned the experimental plots for year three, in which we created wet-to-dry and dry-to-wet transitions. Measurements were taken in year 3.
We found that stolon density was the most sensitive to changes in precipitation and that percent-active buds were insensitive.
We also found that past precipitation had a significant legacy on grassland structural components regardless of the precipitation received in the current year, and that the legacy occurs mostly through changes in stolon density.
Here, we showed that there is a differential sensitivity of structural components to current and past precipitation and supported previous findings that vegetation structure is one of the controls of productivity during precipitation transitions.