Stomata in Gigantopteridium marginervum (fossil)

 

 

A new gigantopterid plant with cuticles from the Permian of South China

by Yao Z.-Q., Liu L.-J. (2004)

Zhao-Qi YaoLu-Jun Liu

in Review of Palaeobotany and Palynology 131(1-2): 29-48 – DOI10.1016/j.revpalbo.2004.02.007 – 

https://www.infona.pl/resource/bwmeta1.element.elsevier-ecc615d1-981f-3a7d-a16b-9bc9f17e03be

Abstract

A new species of gigantopterid leaf Gigantopteridium marginervum sp. nov. is described from the uppermost bed of the Kuhfeng Formation (Middle Permian, equivalent to the Wordian of the Guadalupian) of Jiangsu Province, China.

The leaf is apparently simple with pinnately organized venation similar to that of Gigantopteridium americanum (White) Koidzumi in which the tertiary venation forms sutural veins between adjacent pairs of secondaries. A distinct intramarginal vein is also present.

The cuticle is well preserved with cyclocytic stomata on both surfaces. Subsidiary cell of stomata on the adaxial surface form a ring of thickened cuticle surrounding each stomatal pore, while subsidiary cells of stomata on the abaxial surface are papillate with each stomatal pore surrounded or partially overarched by two to seven papillae.

Gigantopteridium marginervum sp. nov. exhibits some superficial similarities both in venation and cuticular structure to the leaves of Aipteris (=Scytophyllum). The thick cuticle of G. marginervum makes it unlikely that these leaves were produced by true ferns and indicates instead that the fossil leaves assigned to G. marginervum sp. nov. were produced by some kind of seed plant.

Based on cuticular characters the systematic position and the palaeoecological implications of the new species are discussed.

 

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Early land plants could actively control stomata

 

 

Stomata: Active Portals for Flourishing on Land

Bowman J. L. (2011)

John L. Bowman

in Current Biology 21(14): R540-R541 – DOI10.1016/j.cub.2011.06.021 –

https://www.infona.pl/resource/bwmeta1.element.elsevier-30ed66d7-875e-3268-bd9f-edf4c55b60da

Abstract

Two studies suggest early land plants could actively control stomata, facilitating gas exchange while limiting water loss, a critical adaption to life on land.

Identification of conifer stomata in fossil pollen samples

 

 

Identification of conifer stomata in pollen samples from western North America

bij Lacourse T., Beer K. W., Hoffman E. H. (2016)

Terri LacourseKyle W. BeerElizabeth H. Hoffman

in Review of Palaeobotany and Palynology 232: 140-150 – DOI10.1016/j.revpalbo.2016.05.005 –

https://www.infona.pl/resource/bwmeta1.element.elsevier-5fe5c0a0-08b2-36e3-9359-19c33b713a5c

Abstract

Conifer stomata provide important paleoecological information for determining the composition of past plant communities, particularly at the local scale and when plant macrofossils are absent.

To aid efforts to identify conifer stomata in fossil pollen samples from western North America, we describe the stomatal morphology of 19 conifer species that occur in the region, with emphasis on species that are present in the conifer-dominated forests along the northwest Pacific coast.

We measured 10 morphological traits in a total of 315 stomata from these species. Morphological variability within species and the degree of morphological overlap among species precludes reliable identification to the species level; however, stomatal morphology is relatively consistent within genera and sufficiently unique to permit identification to genus.

We used classification and regression trees to identify the critical morphological features for stomata identification and to build classification models. We then used these classification models as the basis for dichotomous identification keys for complete and incomplete conifer stomata.

Identification of conifer stomata in fossil pollen samples from western North America should enhance paleoecological records from the region by providing evidence of local conifer presence and potentially clarifying their arrival times. Conifer stomata also provide a possible avenue for increasing taxonomic resolution in some paleoecological records: Pseudotsuga and Larix as well as members of the Cupressaceae family have indistinguishable pollen morphologies, but our results show that their stomata can be differentiated in most instances.

Vegetation history and stomata records

 

 

The potential of stomata analysis in conifers to estimate presence of conifer trees: examples from the Alps

by Ammann B., van der Knaap W. O., Lang G., Gaillard M.-J., Kaltenrieder P., Rösch M., Finsinger W., Wright H. E., Tinner W. (2014)

Brigitta AmmannWillem O. van der KnaapGerhard LangMarie-José GaillardPetra KaltenriederManfred RöschWalter FinsingerHerbert E. WrightWilly Tinner

Brigitta Ammann, University of Bern, Institute of Plant Sciences and Oeschger Centre for Climate Change Research, Bern, Switzerland

in Vegetation History and Archaeobotany 23(3): 249-264 – DOI10.1007/s00334-014-0431-9 –

https://www.infona.pl/resource/bwmeta1.element.springer-11d09098-6ac7-3882-9153-74a68b692ec8

Abstract

To estimate whether or not a plant taxon found in the fossil record was locally present may be difficult if only pollen is analyzed. Plant macrofossils, in contrast, provide a clear indication of a taxon’s local presence, although in some lake sediments or peats, macrofossils may be rare or degraded.

For conifers, the stomata found on pollen slides are derived from needles and thus provide a valuable proxy for local presence and they can be identified to genus level.

From previously published studies, a transect across the Alps based on 13 sites is presented. For basal samples in sandy silt above the till with high pollen values of Pinus, for example, we may distinguish pine pollen from distant sources (samples with no stomata), from reworked pollen (samples with stomata present).

The first apparent local presence of most conifer genera based on stomata often but not always occurs together with the phase of rapid pollen increase (rational limit). An exception is Larix, with its annual deposition of needles and heavy poorly dispersed pollen, for it often shows the first stomata earlier, at the empirical pollen limit.

The decline and potential local extinction of a conifer can sometimes be shown in the stomata record. The decline may have been caused by climatic change, competition, or human impact.

In situations where conifers form the timberline, the stomata record may indicate timberline fluctuations. In the discussion of immigration or migration of taxa we advocate the use of the cautious term “apparent local presence” to include some uncertainties. Absence of a taxon is impossible to prove.

 

The Holocene tree limit history and stomata analysis

 

 

Holocene tree limit history in the northern French Alps stomata and pollen evidence

by David F. (1997)

Fernand David

in Review of Palaeobotany and Palynology 97(3-4): 227-237 – ISSN :0034-6667 –

https://www.infona.pl/resource/bwmeta1.element.elsevier-4cc2ec84-1075-3711-8f3f-f6accb544942

Abstract

Certain aspects of the Holocene tree limit history in the northern French Alps are inferred from both pollen and stomata analysis conducted in a subalpine marsh (2080 m a.s.1.). The proposed chronology is based on 1 4 C AMS dating of terrestrial plant macrofossils. In the area, Betula invaded this altitudinal level at the beginning of the Holocene prior to 9100 yr B.P., whereas the first occurrence of Pinus stomata is recorded much later at around 7000 yr B.P.

Afterwards five periods of stomata accumulation are recorded (6480-6130, 5600-4990, 4730-4470, 3200-2870 and 2680-2300 yr B.P.). The low pollen influx in the first four periods and the occurrences of Artemisia at the beginning of these periods indicate that stomata accumulation resulted from a reduction of the tree cover.

The climatic and/or anthropogenic origin of these stomata accumulations is discussed. A good correlation appeared with five of the nine phases of Holocene climatic deterioration described in the Swiss and Austrian Alps.

In this study, the combination of pollen influx and stomata determination proved to be a useful tool for understanding the tree limit history. Moreover, discrepancies in the occurrence of Pinus in an adjacent area imply it is difficult to find universal indicators of tree line fluctuations even in a small area.

This warrants methodological discussion.

—————

L’etude du contenu en pollen et stomates d’un petit site de l’etage subalpin asylvatique de la zone intermediaire des Alpes francaises du nord permet de proposer un schema de l’evolution holocene de la limite superieure des arbres dans cette aire et une chronologie basee sur 8 datations AMS de macrorestes vegetaux terrestres. Le bouleau colonise ce niveau altitudinal des le debut de l’holocene (avant 9100 yr B.P.) et precede les pins dont les premiers stomates sont enregistres autour de 7000 yr B.P. Cinq niveaux d’accumulation de stomates sont ensuite enregistres jusqu’aux deboisements de la periode romaine (6480-6130, 5600-4990, 4730-4470, 3200-2870, 2680-2300 yr B.P.). La diminution des flux polliniques dans 4 de ces niveaux et la reapparition d’Artemisia au debut de ces periodes soulignent la relation entre ouverture du milieu et accumulation de stomates. L’origine climatique ou anthropique de ces phases est discutee et une correlation apparait avec 5 des neuf phases holocenes de pejoration climatique decrites dans les Alpes suisses et autrichiennes. La combinaison des comptages de pollen et de stomates est un bon outil pour decrire les fluctuations de la limite des arbres si l’on considere les flux polliniques et non les seules frequences relatives. Cependant les differences chronologiques entre regions dans l’apparition des pins soulignent la difficulte a definir des indicateurs universels des fluctuations de la limite des arbres.

Stomata in fossils Geinitzia and Sedites

 

 

Geinitzia reichenbachii (Geinitz, 1842) Hollick and Jeffrey, 1909 and Sedites rabenhorstii Geinitz, 1842 (Pinopsida; Late Cretaceous) reconsidered and redescribed

by Kunzmann L. (2010)

Lutz Kunzmann

in Review of Palaeobotany and Palynology 159(1-2): 123-140 – DOI10.1016/j.revpalbo.2009.11.006 –

https://www.infona.pl/resource/bwmeta1.element.elsevier-67b34033-2167-3802-b071-5d94873bbcca

Abstract

Atmospheric pCO2 estimated from the ratios between stomatal indices of fossil cuticles and those from modern analogs

 

 

 

Mid-Cretaceous pCO2 based on stomata of the extinct conifer Pseudofrenelopsis (Cheirolepidiaceae) 

Haworth M., Hesselbo S. P., McElwain J. C., Robinson S. A., Brunt J. W. (2005) 

in Geology 33(9): 749-752 – DOI: https://doi.org/10.1130/G21736.1

Abstract

Stomatal characteristics of an extinct Cretaceous conifer, Pseudofrenelopsis parceramosa (Fontaine) Watson, are used to reconstruct atmospheric carbon dioxide (pCO2) over a time previously inferred to exhibit major fluctuations in this greenhouse gas.

Samples are from non-marine to marine strata of the Wealden and Lower Greensand Groups of England and the Potomac Group of the eastern United States, of Hauterivian to Albian age (136–100 Ma).

Atmospheric pCO2 is estimated from the ratios between stomatal indices of fossil cuticles and those from four modern analogs (nearest living equivalent plants). Using this approach, and two calibration methods to explore ranges, results show relatively low and only slightly varying pCO2 over the Hauterivian–Albian interval: a low of ∼560–960 ppm in the early Barremian and a high of ∼620–1200 ppm in the Albian.

Data from the Barremian Wealden Group yield pCO2 values indistinguishable from a soil-carbonate–based estimate from the same beds. The new pCO2 estimates are compatible with sedimentological and oxygen-isotope evidence for relatively cool mid-Cretaceous climates.