Conifer stomates as indicators of alpine treeline in lake sediments

 

 

Comparison of pollen and conifer stomates as indicators of alpine treeline in northwestern Canadian lake sediments

by Pisaric M. F. J., Szeicz J. M., Karst T., Smol J. P. (2000)

Michael F.J. Pisaric, Julian M. Szeicz, Tammy Karst, John P. Smol,

M.F.J. Pisaric1 and J.M. Szeicz.2 – Department of Geography, Queen’s University, Kingston, ON K7L 3N6, Canada.
T. Karst and J.P. Smol.  – Paleoecological Environmental Assessment and Research Laboratory (PEARL), Department of Biology, Queen’s University, Kingston, ON K7L 3N6, Canada.

==========================

 

in Can. J. Bot. 78: 1180–1186 –

https://www.academia.edu/35335956/Comparison_of_pollen_and_conifer_stomates_as_indicators_of_alpine_treeline_in_northwestern_Canadian_lake_sediments

Abstract:

We compare fossil pollen and stomate assemblages in 29 lake sediment surface samples from mountainous regions in northwestern Canada to characterize the relationship between modern vegetation, and pollen and stomate deposition.

Modern pollen spectra were dominated by arboreal taxa originating from lower elevation sites. Pinus pollen frequently reached 30% of the pollen sum, regardless of elevation. Alpine-tundra vegetation has lower pollen abundance, even in the alpine-tundra zone, where it dominates the sparse vegetation cover.

Fossil stomates were observed in all but one site where trees currently exist in the vicinity of the lake, while no stomates were found in the sediments from alpine-tundra sites.

The highest concentration of stomates occurred in lake sediments from closed-canopy forested areas. Our data suggest that different boreal forest types may be differentiated based on pollen assemblages and that the presence of stomates clearly distinguishes vegetation zones dominated by arboreal vegetation from alpine-tundra zones where trees are not present.

 

Résumé :

Les auteurs ont comparé des ensembles de pollens et de stomates fossiles dans 29 échantillons de sédiments lacustres de surface, provenant de régions montagneuses du nord-ouest canadien, afin de caractériser la relation qui existe entre la végétation contemporaine et les dépôts de pollens et de stomates. Les spectres de pollens contemporains sont dominés par des taxons arborescents provenant de sites de faible élévation. La fréquence du pollen de Pinus at- teint 30 % de la somme des pollens, indépendamment de l’élévation. La végétation de toundra alpine présente une abondance pollinique moindre, même dans la zone de toundra alpine, où elle-ci domine le couvert végétal épars. On observe des stomates fossiles dans tous les sites, sauf un, où il existe présentement des arbres au voisinage du lac, alors qu’on ne trouve pas de stomates dans les sédiments des sites de végétation de toundra alpine. Les plus fortes den- sités de stomates se retrouvent dans les sédiments de lacs voisins de peuplements forestiers à canopée fermée. Les don- nées suggèrent que différents types de forêts boréales peuvent être différenciés en se basant sur les ensembles polliniques, et que la présence de stomates distingue clairement les zones de végétation dominées par de la végétation arborée, des autres zones de toundra alpine où il n’y pas d’arbres.

 

Advertisements

Variation in stomata in Pinus sibirica

 

 

Variability of needle structure in Siberian stone pine in provenance plantations

by Bender O., Rudnik T. I. (2008)

Institute for Monitoring of Climatic and Ecological Systems SP RAS, Russia, 634055, Tomsk, pr. Academicheskij10/3.

========

in Annals of Forest Research 51(1): 165-168 –

http://www.afrjournal.org/index.php/afr/article/view/163

Abstract

Siberian stone pine (Pinus sibirica Du Tour) is one of the most common trees in Siberia. Its natural range is from the Ural Mountains to the Aldan river and from the Arctic Circle to northern Mongolia. The climate in natural Siberian stone pine sites influences the whole plant organism, particularly its needle structure, and the response to this occurs at specific morphological and anatomical levels. The genotypical and environmental effects on needle structure in different Siberian stone pine ecotypes are very little known.

One effective way to examine and to separate genotypical effects from environmental ones is by using a common garden experiment. The purpose is to analyze morphological and anatomical needle variability in Siberian stone pine marginal populations that have been grown in provenance plantations in southern West Siberia, Russia.

The needle samples were collected in the provenance plantation located 30 km south of Tomsk (the southeastern West Siberian Plain, southern limit of the taiga zone, optimum site conditions for Siberian stone pine). We investigated the grafts of mother trees taken from natural sites. Four ecotypes were selected for the study. Three ecotypes originated from northern (Urengoy), western (Neviyansk), and eastern (Severobaikalsk) marginal populations. The fourth, the Tomsk ecotype, was a local control. The local Tomsk ecotype grows on a site where natural conditions are worse due to reduction of mean annual temperature and increase of the humid factor northward, humidity reduction eastward and its rise westward. Variability of 10 needle morphological and anatomical characteristics was studied.

The northern ecotype had smaller needle length (28%), leaf cross-section area (21%), mesophyll area (29%), mesophyll cell size (27%), and conducting bundle area (16%) but the number of stomata per unit leaf area increased by 16% over the local Tomsk ecotype. The resin canal area, epidermal and hypodermal cell thickness, and stomata size were equal to both the northern and local ecotypes.

The leaf cross-section and mesophyll area in the western ecotypes decreased by 20% and 23%, respectively, but stomata size increased by 12%. The needle length, mesophyll
cell size, conducting bundle area, resin canal area, the number of stomata per unit leaf area, and epidermal and hypodermal cell thickness did not differ significantly from the same characteristics in the Tomsk ecotype.

The leaf cross-section area, mesophyll area, and mesophyll cell size in the eastern ecotype decreased by 22%, 37% and 20% respectively, as compared with the local ecotype. All other studied needle characteristics did not differ from the local ecotype. The common morphological and anatomical parameters did not change from south to north and from west to east (resin canal area and hypodermal cell thickness) and parameters varied in each ecotype. For example, needle length, conducting bundle area, and the number of stomata per unit leaf area changed along latitude but did not change
along longitude.

Conversely, stomata size and epidermal cell thickness changed along longitude but did not change along latitude. Thus the morphological and anatomical characteristics were specific for each ecotype. The parameter variability of the needle structure is hypothesized to relate to graft geographical provenance that depends on genotype and adaptation properties of mother trees.

Stomata in Welwitschia (Gymnospermae)

Photo credi: Google

View the 2,000 Year Old Welwitschia mirabilis plants

Some points in the anatomy of leaves of Welwitschia mirabilis

Takeda H. (1913b)

in Ann. of Bot. 27: 347-375 – https://doi.org/10.1093/oxfordjournals.aob.a089462 –

https://academic.oup.com/aob/article-abstract/os-27/2/347/177421/Some-Points-in-the-Anatomy-of-the-Leaf-of?redirectedFrom=PDF

Screen Shot 2017-09-16 at 17.13.52

Stomata in Podocarpus (Gymnospermae)

Photo credit: Google

Podocarpus macrophylla – This is the foliage and blue female cones of the yew pine Podocarpus macrophyllus ‘Maki’. The foliage of the species is shown in the inset.

Cutical micromorphology of Podocarpus, subgenus Podocarpus, section Scytopodium (Podocarpaceae) of Madagascar and South Africa.

by Stockey R. A., Frevel B. J., Woltz P. (1998)

Ruth A. Stockey, Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada

Brenda J. Frevel, Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada

Philippe Woltz, Laboratoire de Morphogenèse Végétale, I.M.E.P. CNRS‐URA 1152, Université d’Aix, Marseille III, Centre St. Jérôme, France

in Int. J. Plant Sci. 159: 923-940 – DOI: 10.1086/297613

http://www.journals.uchicago.edu/doi/abs/10.1086/314089

 

Cuticle micromorphology of leaves from seven species and three varieties of the conifer genus Podocarpus subgenus Podocarpus section Scytopodium from South Africa and Madagascar was studied with scanning electron microscopy.

External and internal features of abaxial and adaxial cuticles are characterized for all taxa and are compared with other known Podocarpus species. External cuticles exhibit Florin rings and stomatal plugs with underlying epidermal cell outlines usually visible.

Leaves are hypostomatic and stomata occur in discontinuous but fairly regular rows in most species. Stomata are oriented parallel to the long axis of the leaf and usually lack polar subsidiary cells. From two to six subsidiary cells occur, with two or three being the most common.

Internal cuticle on subsidiary cell surfaces is granular to rugose, usually with a deep groove corresponding to the external Florin ring. Cuticle on guard cell surfaces is granular or rugose to pitted, and prominent polar extensions are present in all species.

Epidermal cell outlines are undulating and cuticle on epidermal cell surfaces is granular to rugose and pitted.

The most useful characters to distinguish species of this section are the micromorphology of cuticle on the guard cell and subsidiary cell surfaces, epidermal cell shapes, and sometimes the length of polar extensions.

Stomata in Dacrydium (Podocarpaceae)

Photo credit: Google

Rimu Dacrydium cupressinum

Cutical micromorphology of Dacrydium (Podocarpaceae) from New Caledonia.

by Stockey R. A., Ko H.  (1990)

Ruth A. Stockey,

Helen Ko,

in Bot. Gazette 151: 138-149 – (ISSN: 0006-8071) – DOI : 10.1086/337813

http://www.journals.uchicago.edu/doi/abs/10.1086/337813

 

Cuticle micromorphology of herbarium and of preserved leaves of four species of the genus Dacrydium was studied with scanning electron microscopy.

Dacrydium araucarioides, D. balansae, D. guillauminii, and D. lycopodioides from New Caledonia are all representatives of the tropical subgroup of the genus.

External and internal features of abaxial and adaxial cuticles are characterized for all taxa. External cuticle surfaces of all species lack the Florin rings present in other members of the Podocarpaceae.

Sunken stomata in discontinuous rows characterize all taxa. Subsidiary cell number varies from two to five. Epidermal cell outlines are very sinuous, and cuticle from cell surfaces is smooth to slightly pitted.

Cuticle on guard cell surfaces distinguishes the taxa. Micromorphological features are compared with other previously studied genera in the Podocarpaceae. The New Caledonian species of the genus Dacrydium show a close similarity to each other in micromorphological features of leaf cuticle and are easily distinguishable from other podocarp genera.

The stomatal regions of Picea glauca and Pinus divaricata

 

 

A close up of the stomatal regions of white spruce and jack pine

provides a possible clue to their differing response to foliar herbicides

Lehela A. R., Day R. J., Koran Z. (1972)

in For. Chron. Feb. 1972: 32-34 –

http://pubs.cif-ifc.org/doi/pdf/10.5558/tfc48032-1

Screen Shot 2017-09-15 at 19.38.17


 

Screen Shot 2017-09-15 at 19.38.32

Screen Shot 2017-09-15 at 19.40.14

Screen Shot 2017-09-15 at 19.39.32  Screen Shot 2017-09-15 at 19.40.40

Screen Shot 2017-09-15 at 19.40.24

Wax-filled stomatal antechambers are excellent antitranspirants.

 

 

Epicuticular wax in the stomatal antechamber of sitka spruce and its effect on the diffusion of water vapour and carbon dioxide

by Jeffree C. E., Johnson R. P. C., Jarvis P. G. (1971)

Department of Botany, University of Aberdeen, Aberdeen, Scotland

in Planta 98: 1-10 – DOI: 10.1007/BF00387018

https://link.springer.com/article/10.1007/BF00387018

Screen Shot 2017-09-15 at 19.28.26

Summary

The distribution of wax tubes on the leaf surfaces is described, especially the presence of wax tubes in the antechambers of the stomata.

The extra resistances which the wax-filled antechambers add to the other resistances in the pathway for diffusion of water vapour and of carbon dioxide are calculated. We conclude that the wax-filled stomatal antechambers reduce the rate of transpiration by about two thirds but reduce the rate of photosynthesis by only about one third. Thus wax-filled stomatal antechambers are excellent antitranspirants.