The fossil cuticle as a skeletal record of environmental change
The fossil cuticle as a skeletal record of environmental change
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DOI：
10.2307/3515247
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发表时间：
1996-08-01
期刊：
影响因子：
1.6
通讯作者：
Chaloner, WG
中科院分区：
文献类型：
--
作者：
McElwain, JC;Chaloner, WG
植物角质层及其气孔代表了植物与其周围环境之间的重要界面。角质层厚度、气孔密度、气孔指数和气孔比率等角质层特征在指示它们生长和发育的环境方面的潜力已经被综述。特别是，来自约克郡中侏罗世的三种物种（Brachyphyllum crucis Kendall、Brachyphyllum mamillare Lindley and Hutton 和 Ginkgo huttonii (Sternberg) Heer）的新气孔数据与选定的两种最近活体等效 (NLE) 物种 Athrotaxis cupressoides 和 Ginkgo biloba 的气孔数据进行了比较，试图推断大气中的碳 从那时起的二氧化碳浓度，厚角质层的发育似乎可以代表对多种环境限制的适应，并且显然是某些分类群的特征。因此得出的结论是，角质层厚度本身并不是一个合适的古生态指标。相反，化石植物的气孔参数似乎具有作为二氧化碳古大气指标的巨大潜力，并在这个意义上作为“古生态变化的骨骼证据”。侏罗纪物种的气孔密度和指数结果显着低于（P < 0.0001）。 他们选择的 NLE 物种，因此表明中侏罗世大气中二氧化碳浓度升高。此外，侏罗纪物种的气孔比率与先前泥盆纪和石炭纪的气孔比率结果一致。这些结果与碳循环模型和碳同位素数据的证据一致，后者推断中侏罗世大气中二氧化碳浓度分别是目前大气水平的 4 至 5 倍和 6 至 10 倍。
The plant cuticle with its stomatal pores represents an important interface between the plant and its surrounding environment. The potential of cuticular features such as cuticle thickness, stomatal density, stomatal index and stomatal ratio to signal the environment in which they grew and developed have been reviewed. In particular new stomatal data from three Yorkshire Middle Jurassic species, Brachyphyllum crucis Kendall, Brachyphyllum mamillare Lindley and Hutton and Ginkgo huttonii (Sternberg) Heer, have been compared with those of two selected nearest living equivalent (NLE) species Athrotaxis cupressoides and Ginkgo biloba, in an attempt to deduce the atmospheric carbon dioxide concentration from that time, It appears that the development of a thick cuticle can represent an adaptation to more than one kind of environmental constraint and evidently is a feature of certain taxonomic groups. It was concluded therefore that cuticle thickness, taken on its own was nor a suitable palaeo-ecological indicator In contrast however stomatal parameters of fossil plants seem to have great potential as palaeo-atmospheric indicators of carbon dioxide and in this sense as ''skeletal evidence of palaeo-ecological change.'' The stomatal density and index results of the Jurassic species were significantly lower (P < 0.0001) than those of their selected NLE species, therefore indicating elevated atmospheric CO2 concentrations for the Middle Jurassic. In addition the stomatal ratios of the Jurassic species were in agreement with those of previous Devonian and Carboniferous stomatal ratio results. These results are consistent with the evidence from carbon cycle modelling and carbon isotopic data which infer elevated atmospheric CO2 concentrations curing the Middle Jurassic of 4 to 5 times and 6 to 10 times the present atmospheric level respectively.