Two Mediterranean annuals feature high within-population trait variability and respond differently to a precipitation gradient
Two Mediterranean annuals feature high within-population trait variability and respond differently to a precipitation gradient
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DOI：
10.1016/j.baae.2017.11.001
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发表时间：
2017-12-01
影响因子：
3.8
通讯作者：
Jeltsch, Florian
中科院分区：
文献类型：
--
作者：
Bergholz, Kolja;May, Felix;Jeltsch, Florian
种内性状变异在物种适应气候变化中起着重要作用。然而，目前尚不清楚半干旱环境中的植物如何应对日益严重的干旱。我们调查了两种常见的地中海一年生植物（Geropogon hybridus和Crupina crupinastrum）具有相似的栖息地偏好的种内性状变异。他们被研究沿着一个陡峭的降水梯度在以色列类似的最大预测降水量变化在地中海东部盆地（即-30%，直到2100年）。我们预计从竞争能力的变化，以减少降水胁迫耐受性和测试这种期望通过测量关键功能性状（冠层和种子释放高度，比叶面积，N-和P-叶含量，种子质量）。此外，我们评估了不同的种子性状的生成下注对冲策略。两个物种表现出不同的响应沿着降水梯度。C. crupinastrum只表现出株高降低的趋势，而G.杂种对干旱表现出强烈的生殖适应趋势。不同的种子性状指标表明，增加了赌注对冲G。在干旱的环境中杂交。然而，没有明显的趋势，沿沿着降水梯度观察叶性状（比叶面积和叶片N-/P-含量）在这两个物种。方差分解结果表明，大部分性状变异（>> 50%）存在于群体内。我们的研究结果表明，干旱增加的反应是高度物种特异性和当地的环境因素可能有更强的影响种内性状的变化比年降水量的变化。因此，我们认为，基于性状的分析应侧重于降水梯度，预测降水变化和比较降水的影响，当地环境因素的影响。(C)2017 Gesellschaft fur Okologie.由爱思唯尔有限公司出版。All rights reserved.
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.