VEGETATION OF GEORGIA
Kvachakidze, Revaz
Kvachakidze, Revaz
The structure and change of the Georgian vegetation have been considered throughout the geological history of the territory of the country from the Carbon period of the Paleozoi to this day.The avialable paleogeographical and paleobotanical sources have been used.
In the II part of the book phytocenological characteristic of the principal vegetation types of Georgia – Forests, Scrub, Meadows,Steppes, Semi-Deserts, Wetland vegetation.
Summary
The history of the vegetational cover of Georgia runs to 300 million years. From the Carbon period of the Paleozoic era to the end of the Mezozoic era the islands of the Tetis Ocean (the initial stage of the mountains of the Greater and Minor Caucasus) were covered with the rich vegetation of a tropical type. The ancient plants, representatives of Lepidodendraceae, Sigillariaceae, Calamitaceae, Cordiataceae, Bennettitaceae, Caytoniaceae, Cicadaceae, Ginkgoaceae, Araucariaceae and other families took part in its formation.
In the Oligocene when the active processes of formation of folded mountains of the Greater and Minor Caucasus took place, the representatives of the Turgai fl ora – coniferous and leaf-shedding species took root in the local subtropical evergreens.
In Western Georgia (Kolkheti) the forest vegetation still had the plant species which nowadays are not naturally found in Georgia (the plants, having their related forms spread in East-Asian, Himalayan, North-American and Mediterranean subregions of Golarctic), specifi cally the species of the genera of Sequoia, Metasequoia, Cryptomeria, Cunninghamia, Cedrus, Libocedrus, Taxodium, Tsuga, Thuja, Magnolia, Liquidambar, Carya, Mahonia, Cinnamomum, Aesculus, Platanus, Robinia and others. Some of them were the dominants of forest associations. On the slopes of the Caucasian mountains vertical belts were developed: the lower belt was formed by subtropic (mainly evergreen) forests and the upper belt – by coniferous and leaf-shedding forests. In Eastern Georgia with the climate being comparatively dry and more continental the evergreen species were not numerous. The lower part of the mountain slopes and the plain were partly covered by arid forests (the dominants – Pistacia mutica, Celtis caucasica, Juniperus foetidissima, J.polycarpos) and hemixerophyl forests (the dominants – the species of Quercus etc.). In the same place a big territory was already covered by the steppe vegetation (the dominants – the species of Artemisia, Botriochloa, Stipa, Festuca etc.).
In the Pleistocene (the last one million years) especially in its glacial epochs the vegetation of Georgia lost a great number of thermophilic species of the Tertiary forest fl ora. In Western Georgia (Kolkheti - due to its comparatively warm an humid climate several species of evergreens survived: Laurus nobilis, Laurocerasus offi cinalis, Rhodo¬dendron ponticum, Rh. ungernii, Rh.smirnowii, Ilex colchica, Buxus colchica, Ruscus ponticus, R.colchicus, Hedera colchica etc. These species remain the dominants of local relict forest cenoses to this day. Of the coniferous tertiary species survived Abies nordmanniana, Picea orientalis, Pinus pithyusa, Taxus baccata. They are also the dominants of the local relict coniferous forests. In Western Georgia the tertiary forests (coniferous and leaf-shedding) enlarged the area and strengthened their positions. They settled on the territory of the Iori Upland, formed in the period.
The majority of tertiary heat-loving leaf-shedding species also became extinct. Only few species survived – Castanea sativa, Zelkova carpinifolia, Quercus hartwissiana, Q.imeretina, Q.pedunculifl ora, Q.pontica, Betula medwedewii, Alnus barbata, Populus canescens, Pterocarya pterocarpa, Rhododendron luteum, Vaccinium arctostaphylos, Hypericum androsaemum, H.inodorum etc. These dominating relict species and the young Caucasian leaf-shedding plants (Fagus orientalis, Carpinus caucasica, Quercus iberica, Betula litwinowii etc.) formed in the Pleistocene the modern leaf-shedding forests of Georgia. From the local (Caucasian) and immigrated herbaceous species the meadow vegetation of Georgia was formed, which occupied vast space in subalpine and alpine belts of the Greater and Minor Caucasus. On the plain of Western Georgia the steppe area got expanded. Its phytocenoses were formed of the local tertiary and immigrated to Georgia species in the Pleistocene (from arid neighbour regions).
The phytocenotic variety of forest formations is not identical. Fagus orientalis forests is characterized by the highest phytocenotic variety – 52 associations, which makes up almost half of the Georgian forests having wide altitudinal and horizontal prevalence (area). Other forest formations are represented by the following number of associations.
In Holocene (the last 12-10 thousand years) the structure of the local vegetation underwent a considerable change due to a periodical change in the climate.
In the Middle Holocene the natural structure of the vegetation and the character of distribution of the vegetation syntaxons of Georgia was finally developed (except for the forests; the natural vegetation is formed by shrubs, meadows, steppes, substeppes and marsh types of vegetation).
After the Middle Holocene the vegetation of Georgia underwent a change due to human economic activities. The scale of anthropogenic changes of the natural (virgin) vegetation kept increasing. The results of these changes consist in the following:
1. A quantity of forests decreased (nowadays the forests cover 35-38% of the total territory of Georgia, mainly the slopes of the Greater and Minor Caucasus);
2. A quantity of virgin forests greatly declined making up 18-20% of all forests (about 400000 hectares).
3. The structure of the economic vegetation (forests, meadows, steppes, substeppes) is more or less disturbed, badly decreased is the productiveness of phytocenoses.
In the II part of the book phytocenological characteristic of the principal vegetation types of Georgia – Forests, Scrub, Meadows, Steppes, Semi-Deserts, Wetland vegetation. In the vegetation of Georgia forests are dominated. 98% of them are mountain forests, located on the slopes of the Greater and Lesser Caucasus ranges, 100 (400) – 2300 (2600) m above sea level. In the plain (Kakheti Lowland, Iberian plain, plateaux) natural forests remain in small areas, locally, most part of which are protected nowadays (nature reserves and national parks).
Abies nordmanniana forests – 32 associations, Carpinus caucasica – forests – 28 associations, Quercus iberica forests – 25 associations, Pinus sosnowskyi forests – 18 associations, Picea orientalis forests – 17 associations, Batula litwinowii forests – 16 associations, Castanea sativa forests – 15 associations, Quercus macranthera forests – 8 associations, Acer trautvetteri forests – 8 associations, Alnus barbata, A.incana forests – 8 associations, Juniperus foetidissima, J.polycarpos forests – 11 associations, Zelkova carpinifolia forests – 6 associations, Quercus pedunculi flora forests – 6 associations, Pistacia mutica forests – 5 associations, Quercus imeretina forests – 4 associations, Pinus pithyusa forests – 4 associations, Fraxinus excelsior forests – 4 associations, Populus tremula forests – 3 associations, Populus canescens, P. nigra forests – 3 associations, Quercus dschorochensis forests – 2 associations, Taxus baccata forests – 1 association, Salix excelsa forests – 1 association.
A brief characteristics (diagnostics) of forest associations given in the work embraces dominants and characteristic species (according to layers), structure (layer structure, density of canopy, understorey and grass cover), habitat conditions (altitude, slope exposition and inclination, soil capacity and humidity). Other vegetation types of Georgia are characterized – Scrub, Meadows vegetation, Steppe vegetation, Semi-Deserts vegetation, Wetland vegetation. The phytocenotic diversity of the Georgian forests is high showing itself in the forests typologic variety. 277 associations of 23 formations have been registered in all.
Type of material: | Book (Print, Microform, Electronic, etc.) |
Personal name: | Kvachakidze, Revaz |
Author: | Kvachakidze, Revaz |
Main title: | Vegetation of Georgia |
Title/Heading: | Saqartvelos mcenareuloba [geo] |
Abbreviated Title: | Saq. mcen. [geo] |
Alternate Title: | |
Similar Titles: | |
Tags: | |
Published/Created: | Tbilisi |
The Georgian National Academy of Sciences , 2009 | |
Related names: | Kakha Jashagashvili |
Description: | 154 p. ; 21 cm. |
Includes bibliographical References (p. 146 - 154) | |
Subjects: | Forests / Plants / Vegetation / Phytocenoses |
Subject Headings: | Phytocenotic diversity / phytocenological characteristic |
Kolkheti / Georgia / The Greater and Minor Caucasus | |
Subject/Content: | The structure and change of the Georgian vegetation |
Have been considered throughout the geological | |
History of the territory of the country from the Carbon | |
Period of the Paleozoi to this day.The available | |
Paleogeographical and paleobotanical sources have | |
Been used. In the II part of the book phytocenological | |
Characteristic of the principal vegetation types of | |
Georgia – Forests, Scrub, Meadows,Steppes, Semi- | |
Deserts, Wetland vegetation. | |
ISBN: | 978-9941-0-1206-8 |
Dewey class no.: | 581.9(479.22)+ 581.524+582.382.4+582.382.8 |
Language code: | geo [Georgian] |
eng [English] | |
Country code: | gs [Georgia (Republic)] |
Geographic area code: | gs [Georgia (Republic)] |
Statement of | |
Responsibility: | Prof. Revaz Kvachakidze; |
Tbilisi Botanical Garden And Institute Of Botany | |
Abstract/Summary: | The history of the vegetational cover of Georgia runs |
To 300 million years. From the Carbon period of the | |
Paleozoic era to the end of the Mezozoic era the islands | |
Of the Tetis Ocean (the initial stage of the mountains | |
Of the Greater and Minor Caucasus) were covered | |
With the rich vegetation of a tropical type. The ancient | |
Plants, representatives of Lepidodendraceae, | |
Sigillariaceae, Calamitaceae, Cordiataceae, | |
Bennettitaceae, Caytoniaceae, Cicadaceae, | |
Ginkgoaceae, Araucariaceae and other families | |
Took part in its formation. | |
Notes: | Softcover |
The Georgian National Academy of Sciences | |
Saqartvelos mecnierebata erovnuli academia | |
DDC/UDC Subject: | Forests / Plants / Vegetation / Phytocenoses |
Biology / Life sciences / Geobotany | |
UDC Class Number: | 582.382.4 |
Description: | Lepidodendraceae |
UDC Class Number: | 582.382.8 |
Description: | Sigillariaceae |
Total Copies: | 2 |
Available: | 2 |
Call Number: | |
Request in: | Scientific Library of Institute of Botany of Ilia State University |
Status: | Available |
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