Does sexual dimorphism predispose dioecious riparian trees to sex ratio imbalances under climate change?
Does sexual dimorphism predispose dioecious riparian trees to sex ratio imbalances under climate change?
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DOI：
10.1007/s00442-018-4190-7
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发表时间：
2018-06
期刊：
影响因子：
2.7
通讯作者：
K. Hultine;S. Bush;J. Ward;T. Dawson
中科院分区：
文献类型：
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作者：
K. Hultine;S. Bush;J. Ward;T. Dawson
环境的变化导致了大部分由雌雄异株树木组成的原生河岸森林的显著下降，包括Boxelder和标志性的棉白杨/杨柳画廊森林。雌雄异株物种可能特别容易受到气候变化的影响，因为它们往往表现出性别比例失衡，而每种性别在生理和形态上对特定微生境的专门化又加剧了这种失衡。一个全面的数据综合表明，雄性个体的boxelder和棉白杨类群有较高的代表性，在干燥的微生境比女性和生理敏感性增加的干旱比共同发生的女性。因此，在未来的气候条件下，极端的男性偏见性别比例是可能的，这可能会使人口适应度降低到可持续的阈值以下。而河岸柳树在生境选择和生理干旱敏感性上一般不表现出明显的两性异形。因此，目前还不清楚气候变化是否会影响人口结构的柳树的方式，平行于其他雌雄异株的河岸树木类群。未来的河岸树木恢复计划的目标应该是保持未来的性别比例平衡，最大限度地提高人口健身预测水文气候条件下。基因组学的最新进展可能会提供关键的工具，在生殖前树木跨河岸树种的早期性别决定，这样的性别比例的平衡，可以有针对性的恢复的初始阶段，沿着适应耐旱性和其他关键性状，是在未来的条件下生存必不可少的。
Environmental changes have resulted in significant declines in native riparian forests that are comprised largely of dioecious tree taxa, including boxelder and iconic cottonwood/willow gallery forests. Dioecious species may be especially vulnerable to the effects of climate change given that they often exhibit skewed sex ratios that are reinforced by physiological and morphological specialization of each sex to specific microhabitats. A comprehensive data synthesis suggests that male individuals of boxelder and cottonwood taxa have a higher representation on dry microhabitats than females and are less physiologically sensitive to increased aridity than co-occurring females. Consequently, extreme male-biased sex ratios are possible under future climate conditions that could reduce population fitness below a sustainable threshold. Riparian willows, on the other hand, generally do not express obvious sexual dimorphism in habitat preference or physiological sensitivity to aridity. Thus, it is unclear whether climate change will impact population structure of willows in ways that parallel other dioecious riparian tree taxa. Future riparian tree restoration programs should aim to maintain future sex ratio balance that maximizes population fitness under projected hydro-climatological conditions. Recent advances in genomics will likely provide the critical tools for early sex determination in pre-reproductive trees across riparian tree species such that sex ratio balance could be targeted during initial stages of restoration, along with adaptations for drought tolerance and other key traits that are essential for survival under future conditions.