Palms: A Model System for Evaluating Hydraulic Costs of Plant Size

获奖摘要Nathan G.菲利普斯棕榈树：一个评估植物大小水力成本的模型系统树高的限制是什么？这个问题既是生物学家的基本兴趣，也是那些对林业和碳封存管理感兴趣的人的基本兴趣。这项研究将集中在水分运输，这是几个关键因素之一，可能会限制树高。树高水力成本的物理学和生物学基础是复杂的，因此还没有很好地理解，因为大多数树种的分支结构将水流分支成无数的流动路径。 此外，复杂的分支将树叶分布在多面层中，进一步增加了复杂性。本研究的目的是简化问题的评估树高的水力成本，通过使用柱状棕榈作为一个简单的模型的水力树结构。棕榈树的研究将在厄瓜多尔的Tiputini研究站进行。 柱状棕榈树的结构特征允许分析没有树枝的树木的水分利用。棕榈树由一个单独的管道，供水到一个独特的和紧凑的树冠的叶子。测量将表征通过高度不同的棕榈的水流，直到它们的最大值。 在为期三年的研究项目中，水分限制对生长的综合影响的建模将澄清对六种特定机制的相对优势的理解，这些机制会产生水运输成本，并可能限制树木的垂直高度生长。在这项研究中，将检查水运输的基本生物物理过程，从而提高对大多数树种用水的理解。该项目包括更广泛的影响，促进厄瓜多尔和美国本科生之间的国际科学合作和交流。 此外，该项目为整个亚马逊地区棕榈的经济和社会用途提供了科学依据，据估计，棕榈在经济上的重要性仅次于草。最后，该项目将有助于国家科学基金会继续支持蒂普蒂尼生物多样性站的本科教育活动和研究培训。

Award Abstract for Nathan G. Phillips Palms: A Model System for Evaluating Hydraulic Costs of Plant Size What are the limits to tree height? This question is both of fundamental interest to biologists, and to those interested in the management of forestry and carbon sequestration. This research will focus on water transport that is one of several key factors that may constrain tree height. The physics and biology underlying hydraulic costs of tree height are complex, and therefore not well understood, because the branching architecture in most tree species ramifies the water stream into innumerable flow paths. In addition, complex branching distributes foliage in multi-faceted layers adding further complexity. The goal of this research is to simplify the problem of assessing hydraulic costs of tree height by using the columnar palm as a simple model of hydraulic tree structure. The research with palms will take place at the Tiputini Research Station in Ecuador. The structural traits of the columnar palms allow analysis of water use in trees without branches. Palm trees consist of a solitary pipeline that supplies water to a distinct and compact crown of leaves. Measurements will characterize water flow through palms that vary in height, up to their maximum. Modeling of integrated impacts of water limitation on growth during the three-year research project will clarify understanding of the relative strengths of six specific mechanisms that incur costs for water transport and potentially limit vertical height growth in trees. Fundamental biophysical processes of the water transport will be examined in this research, resulting in the project improving understanding of water use by most tree species. The project includes broader impacts that promote international scientific cooperation and exchange between Ecuadorian and U.S. undergraduate students. In addition, the project provides a scientific basis for the economic and social use of the palms throughout Amazonia, which are estimated to be second only to grasses in economic importance. Finally, the project will contribute to continuing NSF support for undergraduate educational activities and research training at the Tiputini Biodiversity Station.