Biomechanics of plant growth forms: The trouble with fossil plants
Biomechanics of plant growth forms: The trouble with fossil plants
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DOI：
10.1016/s0034-6667(98)00013-x
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发表时间：
1998-07-01
影响因子：
1.9
通讯作者：
Speck, T
中科院分区：
文献类型：
--
作者：
Rowe, NP;Speck, T
在活的植物中，从草本植物到灌木和大型树木和藤本植物的广泛的生长形式可以通过基于个体发育期间的结构杨氏模量（E-str）和弯曲刚度（EI）的变化来识别不同的机械信号来表征。近年来，这种“个体发生的方法”已被采用来推断化石植物的生长形式，通过处理的化石茎和它们的组织作为复合材料，并使用适当的中心对称模型来计算EI和E-str的值。面临的主要困难之一的化石植物的机械重建和一个自信的评估的生长形式，结果从脱节的茎部分。观察植物活体和化石力学数据的两种方法是：（1）将基于不同个体发育阶段的力学数据作为“一般数据”来观察，而与植物体上的相对位置无关（适用于活植物，特别是孤立的化石茎部分）;（2）将力学数据视为“位置数据”，其中可以观察到茎部分的相对位置及其力学参数（在化石植物中很少）。现存植物之间的一般和位置数据集的比较表明，这两个是信息量大的增长形式，包括自立的树木和非自立的藤本植物，显示出可观的变化，在个体发育过程中的茎直径。在所测试的小体型植物如Lycopodiella cernua中，仅从位置数据集产生信息性机械信号。将这种方法扩展到化石植物中得出的结论是，在生长过程中显示出广泛的基于茎直径的个体发育阶段的大型化石植物可能会从孤立的片段中产生信息丰富的模式，但小型植物可能需要相互关联的位置数据，以获得明确的机械生长形式信号。(C)1998 Elsevier Science B. V.保留所有权利。
Among living plants, a wide range of growth forms from herbs to shrubs and large-bodied trees and Lianas can be characterized by identifying different mechanical signals based on changes of structural Young's modulus (E-str) and flexural stiffness (EI) during ontogeny. Over recent years this 'ontogenetic approach' has been adopted to infer growth forms of fossil plants by treating the fossil stems and their tissues as composite materials and using appropriate centrisymmetric models to calculate values of EI and E-str. One of the main difficulties facing mechanical reconstructions of fossil plants and a confident assessment of growth form, result from disarticulated stem parts. Two approaches of viewing mechanical data from both living and fossil plants include: (1) observing mechanical data based on different ontogenetic stages as 'general data', independently of relative position on the plant body (applicable to both living plants and especially isolated fossil stem parts); (2) viewing the mechanical data as 'positional data' where relative positioning of stem parts and their mechanical parameters may be observed (rare in fossil plants). A comparison of general and positional data sets among extant plants indicates that both are informative for large-bodied growth forms including self-supporting trees and non-self-supporting lianas that show appreciable changes in stem diameter during ontogeny. Among the small-bodied plants tested such as Lycopodiella cernua, an informative mechanical signal was generated only from the positional data set. The conclusion reached in extending this approach to fossil plants is that large-bodied fossil plants showing a wide range of stem diameter-based ontogenetic stages during growth may generate an informative pattern from isolated fragments but small-bodied plants may require interconnected positional data for an unequivocal mechanical growth form signal. (C) 1998 Elsevier Science B.V. All rights reserved.