Doctoral Dissertation Research: Human and Climate Influences on Yew (Taxus baccata L.) Population Dynamics in County Cork, Ireland, from 4,000 B.C. to the Present

博士论文研究：人类和气候对公元前 4,000 年爱尔兰科克郡红豆杉 (Taxus baccata L.) 种群动态的影响

• 批准号: 0117693
• 负责人: Michael Binford
• 金额: $ 1万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-15 至 2002-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0117693&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Human; Climate

A critical facet of research on global change has been paleoenvironmental studies aimed at discerning past forms of global climatic and environmental change, especially in time periods since the last continental glaciation. This doctoral dissertation research project will identify factors that influenced yew tree (Taxus baccata L.) populations in the Irish parish of Youghal over the last 6,000 years, when human activity increased in Ireland. The Celts revered the yew tree as 'noble' and considered it a symbol of life and death. The Normans used it as raw material for the longbow. All species in the genus contain taxol, which has cured ovarian cancer. Yew is the longest-lived tree species in Europe. Scotland's Fortinghall yew is reputed to be 3,000 years old. Palynological analyses in Ireland are extensive, but the yew's former distribution and abundance is largely unknown, because its pollen has only recently been recognized. These qualities make it a worthy subject for cultural and paleoecological research. Regrettably, the yew now is not commonly found in Ireland. Youghal (Eo-chaill in Celtic, meaning 'yew forest') has only a few living yews remaining. This study hypothesizes that yew once was abundant in Ireland, as archival mentions of yew forests are common and toponymic analysis has revealed 124 Irish locations named after the tree. Youghal is home to freshwater peatlands (excellent for microfossil analysis), macrofossils (a forest of yew stumps adequate for dendrochronological analysis), and a well-documented history. Paleoecological and historical methods will be applied to identify climatological (temperature and precipitation) and sociological (cultural, economic, and political) factors that caused population fluctuations, and an eventual rarity, of yews in Youghal. These data should help determine whether human interference has been a more significant factor than climate change in the depletion of the yew, with levels of decline directly related to the scale and needs of human enterprise. This paleoecological project will contribute to knowledge of Holocene species declines and multidecadal scale climate reconstructions. Early paleoecological investigators assumed vegetational assemblages were primarily controlled by climate change. It has been realized that human activity may tremendously influence these assemblages. Humans have introduced exotic flora and fauna to compete with indigenous forms and executed further change by exhausting resources via deforestation and overkill. Paul Martin's Blitzkrieg Model suggests that fauna can become extinct as a result of human interference within a few hundred years. This research should help determine whether yew populations were depleted over a similar timespan, thereby providing a test as to whether flora are subject to human-induced rapid extinction. Every case of species decline is unique. In this case it is not believed that the arrival of humans lead to the immediate decline of this species but the arrival of a new cultural group (the Normans) with a different resource perception. The research will also contribute to Holocene climate reconstruction. Concerns about global warming have necessitated Holocene climate research in order to use the data to model future climates. Palynological data will reveal increases/decreases of yew pollen thus indicating changes in climate or human activity. These changes will be cross referenced with global Holocene climate data, analyzed in terms of other arboreal pollen changes, and compared to archival data. Dendrochronological data retrieved from the macrofossils will reveal climate conditions via tree ring anomalies. It will also complement the microfossil data in terms of dating events seen in the pollen profile. As a Doctoral Dissertation Research Improvement award, this award also will provide support to enable a promising student to establish a strong independent research career.

全球变化研究的一个重要方面是古环境研究，旨在辨别过去全球气候和环境变化的形式，特别是在最后一次大陆冰川作用以来的时期。 本博士论文的研究项目将确定影响紫杉树（红豆杉L。）在过去的6,000年里，当人类活动在爱尔兰增加时，爱尔兰尤加尔教区的人口。 凯尔特人将紫杉树视为“高贵”，并认为它是生与死的象征。 诺曼人用它作为长弓的原材料。 该属的所有物种都含有紫杉醇，紫杉醇可以治愈卵巢癌。 红豆杉是欧洲最长寿的树种。 苏格兰的福廷霍尔紫杉据说有3,000年的历史。 爱尔兰的孢粉学分析是广泛的，但紫杉以前的分布和丰富程度在很大程度上是未知的，因为它的花粉只是最近才被承认。 这些品质使其成为文化和古生态学研究的一个有价值的主题。 遗憾的是，紫杉现在在爱尔兰并不常见。 Youghal（凯尔特语中的Eo-chail，意思是“紫杉森林”）只剩下几棵活的紫杉。 这项研究假设，紫杉曾经是丰富的爱尔兰，作为档案提到紫杉森林是常见的和地名分析显示，124爱尔兰地点命名的树。 Youghal是淡水泥炭地（非常适合微体化石分析），宏体化石（紫杉树桩森林足以进行树木年代学分析）和有据可查的历史的家园。 古生态和历史的方法将被应用到确定气候（温度和降水）和社会（文化，经济和政治）的因素，造成人口波动，并最终罕见的，在Youghal红豆杉。 这些数据应该有助于确定人类的干扰是否比气候变化更重要的因素在紫杉的枯竭，下降的水平直接关系到人类企业的规模和需求。这一古生态项目将有助于了解全新世物种减少和几十年尺度的气候重建。 早期的古生态学研究者认为植被组合主要受气候变化的控制。人们已经认识到，人类活动可能会极大地影响这些组合。 人类引进了外来的植物群和动物群来与本土物种竞争，并通过砍伐森林和过度杀戮耗尽资源来执行进一步的变化。 保罗·马丁的闪电战模型表明，动物群可能在几百年内因人类的干扰而灭绝。 这项研究应该有助于确定红豆杉种群是否在类似的时间跨度内被耗尽，从而提供一个测试植物群是否会受到人类引起的快速灭绝。 每一个物种减少的案例都是独一无二的。 在这种情况下，人们不认为人类的到来导致了这个物种的立即衰落，而是一个新的文化群体（诺曼人）的到来，他们对资源有着不同的看法。 该研究也将有助于全新世气候重建。 对全球变暖的担忧使全新世气候研究成为必要，以便利用这些数据来模拟未来的气候。 孢粉学数据将揭示紫杉花粉的增加/减少，从而表明气候或人类活动的变化。 这些变化将与全球全新世气候数据交叉参考，分析其他树木花粉的变化，并与档案数据进行比较。 从大型化石中提取的树木年代学数据将通过树木年轮异常揭示气候条件。 它还将补充微体化石数据，在花粉剖面中看到的日期事件。 作为博士论文研究改进奖，该奖项还将提供支持，使有前途的学生建立一个强大的独立的研究生涯。