BayCEER Workshop 2016
October 13, 2016
NW III, University of Bayreuth
High turgor loss point promotes the survival of temperate grassland species under drought
O 3.2 in Water and the environment: From biosphere to geosphere
13.10.2016, 11:30-11:45, H36, NW III
Introduction
Understanding the mechanisms of drought resistance of temperate grassland species is crucial to predict the dynamics and composition of grassland communities under global climate change. In woody species, turgor loss point has been suggested to be a main trait for drought resistance that can also be used as a proxy. A new method uses osmometer measurements to infer turgor loss point from osmotic potential at full turgor, and makes turgor loss point measurement considerably faster than the traditional method of pressure-volume curves. However, the validation of this method, and of the importance of this trait for drought resistance of grassland species is still outstanding.
Methods
We therefore compared turgor loss point using from pressure-volume curves and osmometer measurements at full turgor. We also related osmometer measurements to plant survival and midday leaf water potential under experimental drought using 41 temperate grassland species common in Germany.
Results
Our results validated the osmometer method to measure turgor loss point for grassland species. We showed that species with high turgor loss point had higher survival under drought. Moreover, midday leaf water potential under drought was positively related with high turgor loss point and survival under drought. This relation was opposite to the one expected from woody species.
Conclusions
Our results indicate that osmotic potential at full turgor is indicative of turgor loss point, and can be used as a proxy to predict the drought resistance of temperate grassland species. Our results further demonstrate that desiccation avoidance strategies are important for grassland species to deal with drought, and that herbaceous and woody species fundamentally differ in their strategy of drought resistance.
Keywords: drought tolerance, turgor loss point, p-v curves, osmometer
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