Reconstructing atmospheric carbon dioxide with stomata: possibilities and limitations of a botanical pCO2-sensor

Abstract

Stomatal frequency is often observed to vary inversely with atmospheric CO 2 concentration (pCO 2 ). The response is due to (1) individual phenotypic plasticity and (2) evolutionary change, depending on the time scale. Evolutionary responses occur more frequently than individual responses and individual responses are more pronounced under subambient pCO 2 levels than under elevated pCO 2

Paleoecology, Ploidy, Paleoatmospheric Composition, and Developmental Biology: A Review of the Multiple Uses of Fossil Stomata

“…Over the past three decades, since publication of Woodward's (Woodward, 1987) seminal article on the inverse relationship between stomatal density and atmospheric CO 2 concentration, the "uncontrolled variability" in stomatal traits such as stomatal density (SD) and stomatal index (SI) has been seized on by paleobiologists as an opportunity to extract meaningful paleoclimatic and paleoecological information from fossil plant stomata (McElwain et al, 2005;Roth-Nebelsick, 2005;Wagner et al, 2005;Kürschner et al, 2008;Lammertsma et al, 2011;Steinthorsdottir et al, 2011b;Franks et al, 2014;Maxbauer et al, 2014;Bai et al, 2015;Montañez et al, 2016;Steinthorsdottir et al, 2016aSteinthorsdottir et al, , 2016b. This has led to a subtle tension in the field of paleobotany, where at one extreme some studies have focused almost exclusively on the taxonomic and systematic utility of stomata with insufficient consideration of environmentally driven variability, while at the other extreme some reconstructions of paleoatmospheric composition have been undertaken using fossil stomatal traits without due consideration for taxonomic determination of the fossils used.…”

Plant Paleoecology in Deep Time1

“…Aspects of the first two topics have been investigated in various deep-time taxa (e.g., rhyniophytes and zosterophylls, cf. Roth-Nebelsick et al, 2000;Roth-Nebelsick, 2001; angiosperms, cf. Roth-Nebelsick et al, 2001) as well as in universal generalities (e.g., Roth-Nebelsick et al, 1994a, b), with the possibility of applying these results to assemblagelevel communities over the Phanerozoic.…”

“…Application and limitations of the approach have been reviewed elsewhere (e.g., McElwain, 1998;Beerling & Royer, 2002a;Roth-Nebelsick, 2005), and the reader is directed to these contributions. An inverse relationship exists between the pCO 2 and stomatal index (SI; Poole & Kürschner, 1999) such that stomatal indices (the ratio of stomata to epidermal cells) decrease as the concentration of atmospheric CO 2 increases.…”

Variation in stomatal numbers of Glossopteris leaves from the Lower Permian of Paraná Basin, Brazil

“…Different authors pointed out that environmental factors such as temperature and humidity can influence stomatal density by altering the size and/or spacing of the epidermal cells (Salisbury, 1927;Tichá, 1982;Roth-Nebelsick, 2005). However, atmospheric CO 2 is the main factor that influences the development of stomata from epidermal cell initials, thus directly affecting the number of stomatal pores on the leaf surface.…”

“…A transfer function, in which stomatal parameters of extant species calibrated against CO 2 are replaced by those of fossil species (Roth-Nebelsick, 2005), available for Ginkgo was applied to the stomatal measurements in the pteridosperms in order to calculate the corresponding atmospheric CO 2 levels. Vörding & Kerp (2008) analyzed cuticles of the Upper Permian pteridosperm species Peltaspermum martinsii (Germar) Poort & Kerp from different coeval outcrops in the Southern Alps to test its applicability as a paleo-CO 2 proxy.…”