Towards a physically based model of CO2 -induced stomatal frequency response.
Towards a physically based model of CO2 -induced stomatal frequency response.
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DOI：
10.1046/j.1469-8137.2003.00702.x
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发表时间：
2003-03
期刊：
影响因子：
--
通讯作者：
J. Wynn
中科院分区：
文献类型：
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作者：
J. Wynn
最近的CO2浓度的古大气重建利用了观察到的大气CO2和气孔频率之间的生理关系（可以报告为SI，气孔指数，或SD，气孔密度;图1; Kurschner埃塔尔1996;瓦格纳埃塔尔，1999; Retallack，2001; Royer埃塔尔，2001; Beerling & Royer，2002; Beerling埃塔尔，2002; Beerling，2002;瓦格纳埃塔尔，2002年）。在相对较小的pCO 2范围内，例如大气增加的历史范围，SI的响应近似为线性和负（瓦格纳等人，1996; Royer埃塔尔，2001; Beerling，2002）。大多数工人已经开始认识到一个“非线性响应”在最近的观测SI在较高的CO2浓度，并应用经验非线性校准化石叶数据。在一些这样的研究中，化石数据被外推到测量的CO2范围之外，或者到相对较少的现代观测所代表的CO2浓度（表1）。为了描述这种关系，已经使用桦属和栎属的S形回归函数对在可变CO2浓度下生长的现代叶子的SI测量进行了几次非线性校准（Kiirschner等人，1997）、银杏的二阶多项式（Retallack，2001）以及银杏和水杉的逆表达式（Royer埃塔尔，2001年）。外推法包括来自古土壤稳定同位素测量的数据，对银杏使用对数函数（Beerling & Royer，2002）。气体通过气孔扩散的非线性响应是直观的基本规律控制扩散的理解。这里提出的一个新的模型，基于气孔的一般扩散方程的解决方案，提供了一个物理为基础的SI和大气CO2之间的关系，遵循逆幂函数。
Recent paleoatmospheric reconstructions of CO2 concentration have utilized the observed physiological relationship between atmospheric CO2 and stomatal frequency (which can be reported as SI, stomatal index, or as SD, stomatal density; Fig. 1; Kurschner etal. 1996; Wagner etal., 1999; Retallack, 2001; Royer etal., 2001; Beerling & Royer, 2002; Beerling etal., 2002; Beerling, 2002; Wagner etal., 2002). Over relatively small ranges of pCO2 such as the historical range of atmospheric increase, the response of SI is approximately linear and negative (Wagner et al., 1996; Royer etal., 2001; Beerling, 2002). Most workers have begun to recognize a'nonlinear response'in more recent observations of SI at higher CO2 concentrations, and applied empirical nonlinear calibrations to fossil leaf data. In some such studies, fossil data have been extrapolated beyond the range of CO2 measured, or to CO2 concentrations represented by relatively few modern observations (Table 1). In efforts to describe this relationship, several nonlinear calibrations of SI measurements of modern leaves grown at variable CO2 concentrations have been made using a sigmoidal regression function for Betula and Quercus (Kiirschner et al., 1997), a second-order polynomial for Ginkgo (Retallack, 2001), and an inverse expression for Ginkgo and Metasequoia (Royer etal., 2001). Extrapolations to include data derived from paleosol stable isotopic measurements have used a logarithmic function for Ginkgo (Beerling & Royer, 2002). A nonlinear response of gaseous diffusion through stomatal pores is intuitive with an understanding of the fundamental laws governing diffusion. A new model presented here, based on the solution to the general diffusion equation for stomatal pores, provides a physically based relationship between SI and atmospheric CO2 that follows an inverse power function.