TY  - JOUR
A1  - Bergholz, Kolja
A1  - May, Felix
A1  - Ristow, Michael
A1  - Giladi, Itamar
A1  - Ziv, Yaron
A1  - Jeltsch, Florian
T1  - Two Mediterranean annuals feature high within-population trait variability and respond differently to a precipitation gradient
JF  - Basic and applied ecology : Journal of the Gesellschaft für Ökologie
N2  - Intraspecific trait variability plays an important role in species adaptation to climate change. However, it still remains unclear how plants in semi-arid environments respond to increasing aridity. We investigated the intraspecific trait variability of two common Mediterranean annuals (Geropogon hybridus and Crupina crupinastrum) with similar habitat preferences. They were studied along a steep precipitation gradient in Israel similar to the maximum predicted precipitation changes in the eastern Mediterranean basin (i.e. -30% until 2100). We expected a shift from competitive ability to stress tolerance with decreasing precipitation and tested this expectation by measuring key functional traits (canopy and seed release height, specific leaf area, N-and P-leaf content, seed mass). Further, we evaluated generative bet-hedging strategies by different seed traits. Both species showed different responses along the precipitation gradient. C. crupinastrum exhibited only decreased plant height toward saridity, while G. hybridus showed strong trends of generative adaptation to aridity. Different seed trait indices suggest increased bet-hedging of G. hybridus in arid environments. However, no clear trends along the precipitation gradient were observed in leaf traits (specific leaf area and leaf N-/P-content) in both species. Moreover, variance decomposition revealed that most of the observed trait variation (>> 50%) is found within populations. The findings of our study suggest that responses to increased aridity are highly species-specific and local environmental factors may have a stronger effect on intraspecific trait variation than shifts in annual precipitation. We therefore argue that trait-based analyses should focus on precipitation gradients that are comparable to predicted precipitation changes and compare precipitation effects to effects of local environmental factors. (C) 2017 Gesellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved.
KW  - Climate change
KW  - Functional ecology
KW  - Plant height
KW  - Drought stress
KW  - Rainfall gradient
KW  - Trait-environment relationship
KW  - Local adaptation
KW  - Phenotypic plasticity
Y1  - 2017
U6  - https://doi.org/10.1016/j.baae.2017.11.001
SN  - 1439-1791
SN  - 1618-0089
VL  - 25
SP  - 48
EP  - 58
PB  - Elsevier
CY  - Jena
ER  -