• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Causes and consequences of prolonged dormancy: Why stay belowground?
【24h】

Causes and consequences of prolonged dormancy: Why stay belowground?

机译：长时间休眠的原因和后果：为什么要留在地下？

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Prolonged dormancy is a stage in which mature plants fail to resprout during the growing season and instead remain alive belowground. Though it is relatively common, the causes and consequences of this intriguing stage have remained elusive. In this dissertation, I investigate the causes and consequences of prolonged dormancy in a long lived perennial herb, Astragalus scaphoides.;First, I use a combination of demography and ecophysiology to study the proximate mechanisms associated with prolonged dormancy. Analysis of a long-term demographic dataset indicates that both endogenous factors (e.g. age, condition, and history) and exogenous factors (e.g. climate and spatial variation) are associated with dormancy. I then investigate the association between stored resources and dormancy. My results indicate that individual plants with low levels of stored available carbon are more likely to enter prolonged dormancy. Surprisingly, individuals increased their mobile carbon concentrations while dormant, presumably by remobilizing structural carbon into mobile forms. Since stored resources integrate past conditions and performance with current state, these results can explain why some individuals remain belowground while others emerge to grow and reproduce.;I used matrix models to examine the ultimate causes and consequences of prolonged dormancy. I found evidence that prolonged dormancy acts as a conservative strategy that allows plants to avoid the risk of a variable environment. Further, my results demonstrate that intermediate levels of dormancy result in the highest fitness advantage. Finally, I measured the trade-offs associated with emerging during times of environmental stress. Although plants showed remarkable physiological tolerance to stress, stress led to demographic costs. Therefore, prolonged dormancy is shown to be a beneficial strategy in a variable environment.;Together, my research identifies both the proximate causes of prolonged dormancy, as well as the ultimate consequences of remaining belowground during the growing season. Therefore, my research not only identifies why some plants go dormant while others emerge, but also explains the prevalence of this intriguing life stage in the life histories of so many perennial plants.
机译：长期休眠是成熟植物无法在生长季节重新萌发，而是在地下存活的阶段。尽管这是相对普遍的，但是这个有趣阶段的原因和后果仍然难以捉摸。本论文研究了多年生多年生草本黄芪的长期休眠的原因和后果。首先，我结合人口统计学和生态生理学研究了长期休眠的相关机制。对长期人口统计学数据集的分析表明，内源性因素（例如年龄，状况和历史）和外源性因素（例如气候和空间变化）均与休眠相关。然后，我研究存储的资源和休眠之间的关联。我的结果表明，储存的可用碳水平较低的单个植物更有可能进入长期休眠状态。出人意料的是，人们在休眠时增加了其活动碳的浓度，大概是通过将结构碳迁移为活动形式而实现的。由于存储的资源将过去的条件和性能与当前状态结合在一起，因此这些结果可以解释为什么有些人仍然处于地下，而另一些人则要生长和繁殖。我使用矩阵模型来研究长时间休眠的最终原因和后果。我发现有证据表明，延长休眠期是一种保守的策略，可使植物避免环境变化的风险。此外，我的结果表明，中等水平的休眠会带来最高的健身优势。最后，我测量了在环境压力时期与新兴相关的权衡。尽管植物对胁迫表现出显着的生理耐受性，但是胁迫导致人口统计学损失。因此，在多变的环境中，延长休眠期被证明是一种有益的策略。；总体而言，我的研究既确定了延长休眠期的直接原因，又指出了在生长季节保持地下休眠的最终结果。因此，我的研究不仅确定了为什么有些植物休眠而另一些则出现休眠，还解释了这么多多年生植物生命史中这种有趣的生命阶段的普遍性。

著录项

  • 作者

    Gremer, Jennifer Robin.;

  • 作者单位

    University of Montana.;

  • 授予单位 University of Montana.;
  • 学科 Biology Botany.;Biology Ecology.
  • 学位 Ph.D.
  • 年度 2010
  • 页码 141 p.
  • 总页数 141
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

  • 入库时间 2022-08-17 11:36:56

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号