CAREER: Plant Evolution at Low CO2: Responses of Ice Age Trees

职业：低二氧化碳条件下的植物进化：冰河时代树木的反应

• 批准号: 0746822
• 负责人: Joy Ward
• 金额: $ 84.29万
• 依托单位: University of Kansas Center for Research Inc
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0746822&HistoricalAwards=false
• 关键词: CAREER; Plant; Evolution; Low; CO2

Atmospheric carbon dioxide is the main source of carbon for living organisms and is a critical substrate for plant photosynthesis. This research seeks to determine how plants evolved in response to low carbon dioxide concentrations that occurred during the last ice age (18,000-20,000 years ago). During that period, carbon dioxide concentrations were approximately half of the current value, and these low levels greatly reduce the growth of modern plants. In order to understand how plants evolved in response to low carbon dioxide in the past, the proposed research uses plant specimens from two remarkable collections dating to the last ice age: juniper trees preserved within the La Brea tar pits in southern California and kauri trees preserved within bogs on the North Island, New Zealand. These specimens allow for comparisons between ice age and modern trees for assessing the effects of low carbon dioxide on plant physiology, growth, and evolution. Plant responses to changing carbon dioxide will be measured with annual resolution using carbon isotope analysis of tree rings, along with measurements of leaf morphology and seed size. Broader impacts for this CAREER project will involve the establishment of a SEEDS (Strategies for Ecology Education, Development and Sustainability) chapter at the University of Kansas that will strive to increase the number of students from under-represented groups that enter the field of ecology. This chapter will involve mentoring of undergraduates, student travel to national meetings, and a speaker series with minority scientists. From this research, a more accurate understanding of plant responses to past global changes will be acquired, and from this, insights will be gained into the evolutionary responses of plants to increasing carbon dioxide concentrations that are predicted for the near future.

大气中的二氧化碳是生物体碳的主要来源，也是植物光合作用的关键基质。这项研究旨在确定植物如何进化以应对上一个冰河时代（18，000 - 20，000年前）发生的低二氧化碳浓度。在此期间，二氧化碳浓度约为当前值的一半，这些低水平大大降低了现代植物的生长。为了了解植物如何在过去对低二氧化碳做出反应，拟议的研究使用了两个可追溯到最后一个冰河时代的显着收藏的植物标本：保存在加州南部拉布雷亚焦油坑内的杜松树和保存在新西兰北岛沼泽中的贝壳杉。这些标本允许冰河时代和现代树木之间的比较，以评估低二氧化碳对植物生理，生长和进化的影响。植物对不断变化的二氧化碳的反应将通过对树木年轮的碳同位素分析，沿着对叶片形态和种子大小的测量，以年度分辨率进行测量。更广泛的影响，这个职业项目将涉及建立一个种子（生态教育，发展和可持续性战略）章在堪萨斯大学，将努力增加学生人数从代表性不足的群体进入生态领域。本章将涉及本科生的指导，学生前往国家会议，并与少数民族科学家的演讲系列。从这项研究中，将获得对植物对过去全球变化的反应的更准确的理解，并从中了解植物对预测不久的将来二氧化碳浓度增加的进化反应。