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Steppe of Tbilisi environs (East Georgia, South Caucasus)
Annals of Agrarian Science 15 (2017) 332e338
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Steppe of Tbilisi environs (East Georgia, South Caucasus) N.J. Lachashvili a, *, M.N. Khachidze a, N.V. Eradze b, L.D. Khetsuriani a a b
Ilia State University, Institute of Botany, 1, Botanikuri Str., Tbilisi, 0114, Georgia Georgian National Botanical Garden, 1, Botanikuri Str., Tbilisi, 0114, Tbilisi, Georgia
a r t i c l e i n f o
a b s t r a c t
Article history: Received 12 March 2017 Accepted 12 June 2017 Available online 12 August 2017
Steppes of Tbilisi environs are studied. In the Tbilisi surroundings the steppe vegetation is either of primary or secondary origin. Steppe vegetation in the Tbilisi environs are represented by 4 formations: (1) Bothriochloeta ischaemum, (2) Festuceta valesiaci, (3) Stipeta pennatae and (4) GraminoMixtoherbeta. From them Bothriochloeta ischaemum and Festuceta valesiaci formations have more area covering and characterized by the comparatively rich typological composition. Typological composition of each formation is established. For each separated plant communities the basic structural characteristics (general projective coverage, sodding degree, dominant-edificatory plant, characteristic species, number of species, moss cover, litter, species richness, spectrum of life forms), distribution area in the Tbilisi environs and main physical-geographical conditions (altitude, exposure, inclination, soil type) are given. © 2017 Agricultural University of Georgia. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Keywords: Tbilisi environs Steppe Typological composition Plant community Distribution area Structural chatracteristics
Introduction The part of basin of the river Mtkvari, which is spread from the vil. Dzegvi to the section between Ponichala and Rustavi, is considered in the environs of Tbilisi. Endings of the thick geographic units of various origins and geographic age are gathered in the vicinities of Tbilisi that makes its relief considerably complicated. Privately, they are involved in the environs of Tbilisi: (1) extreme southern branching of Caucasian range e SaguramoIalno ridge, (2) Eastern part of Kvernaki low range (Skhaltba low range), (3) Eastern endings of Trialeti ridge (the ranges of Satskepela and Armazi, Mskhaldidi and Lisi, Mtatsminda, Narikala, Tabori, Telet-Sakharaulo), (4) Western and extremee north-western part of Iori upland (Samgori, Vaziani, Tbilisi Sea and its adjacent territory, etc.), (5) Extreme north-western ending of Mtkvari-Arax lowland (plains of Ponichala and Kumisi-Tsalaskuri). Hypsometrical amplitude of the Tbilisi vicinity is from 350 m to 1875 m above s.l.. Types of low and middle-height mountain-gorge and stepped plain relief are highlighted in the relief [1e5]. In the environs of Tbilisi, two types of climate with the appropriate two zones of the climate are apportioned [2,3]: (1) The climate with insufficient humidity, dry and hot summer and mild
* Corresponding author. E-mail address: [email protected] (N.J. Lachashvili). Peer review under responsibility of Journal Annals of Agrarian Science.
but well expressed winter, (2) moderately humid climate with moderately warm summer and moderately cold snowy winter. The first zone of the climate contains the whole left side of the river Mtkvari, plains of Ponichala and Kumisi-Tsalaskuri and the river floodplain as well. The secondary climate zone contains the mountainous part of the right side and the main part of SaguramoIalno range. Mainly, grey cinnamonic soil is developed on the western ending of the Iori upland and on the slopes of middle-height low range, which is of skeletal in most cases. Just of the same types, but light saline soil is on the plains of Ponichala and Kumisi-Tsalaskuri, where the solonets and solonchak is speckled. Mainly, different modifications of cinnamonic soil (cinnamonic leached, cinnamonic calcareous, cinnamonic light) are spread on the slopes of eastern endings of Trialeti range, on the slopes of southern exposure of Saguramo-Ialno ringe and partly on the Skhaltba low range. And, brown forest soil of various modifications are met in the upper parts of these ringes. Alluvial soils remained on the terraces of the rivers. Thin primitive skeletal soil and scree-stony are widely spread in the grey cinnamonic soil areal. Rocky bareness of groundless soil covering is also met. The section of clay and claysand badlands is met on the southern slope of Skhaltba low range [2,3,5e8]. Variety of relief-edaphic conditions, geographical location and muster of several geographic units those are different from each other, existence of different climate zones, geological past, modern geophysical and geochemical processes and etc. conditions
http://dx.doi.org/10.1016/j.aasci.2017.06.003 1512-1887/© 2017 Agricultural University of Georgia. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).
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significant biodiversity of Tbilisi environs. From the point of landscapes creation and taken space, forests, shrubberies and steppes are the most important, which are represented by diverse modifications [9]. Steppes are the main pastures in the Tbilisi environs and their floristic-geobotanical and ecological study is important as from an angle of agricultural, as from an angle of conserve of ecological balance and biodiversity. Though, the literature data about steppe vegetation of Tbilisis surroundings are scanty [10e12].
Objectives and methods The object of research is steppe vegetation of Tbilisi environs. The main aim of the research was to establish area, typological composition and distribution regularities of steppe vegetation in the Tbilisi environs; determination of area and main physicalgeographical conditions of identified syntaxa (plant communities); study their geo-botanical structure and evaluation of ecological situation. Geo-botanical data were obtained by the route method. Geobotanical descriptions were carrying out on 1 m2 and 25 m2 plots. During the geo-botanical descriptions, studying the structure of phytocoenoses and identification of syntaxa, we were guided the traditional geo-botanical methods [13e19]. On the each plots were registration general projective cover (in %) of plant communities, sodding degree (in %), floristic composition, coenotic role of each species (projective cover in %), height of layers, as well physical-geographical characteristics (relief, exposure, inclination, soli type, altitude). In the process of cameral work for each plant community were established frequency of occurrence of each species and were determined constant (typical) species, were calculated species richness on 1 m2 and 25 m2 and spectra of life forms.
Results and analysis Steppe vegetation is fragmentary developed almost all over the territory of Tbilisi environs, on the both sides of the river Mtkvari. Its altitude range is in foothills and lower mountain belt, approximately 450e900 (1000) m above s.l.. Plant communities of steppe are developed on slopes with various exposure and inclination, mainly on the grey-cinnamonic and also on cinnamonic soils. Soils are thin or middle depth. In the Tbilisi environs the steppe vegetation is either primary or secondary origin. Nowadays, to draw the line between the primary and the secondary coenoses is impossible in most cases. Spreading of primary steppe vegetation is linked with first climate zone (the climate with insufficient humidity, dry and hot summer and mild but well expressed winter) and various modifications of greycinnamonic soils which are developed in this zone. Plant communities of secondary steppe were formed by digressive succession processes of post-forest vegetation. Their area is outside of first climate zone. They are spread on second climate type zone (the climate with insufficient humidity, dry and hot summer and mild but well expressed winter). Accordingly, secondary plant communities of steppe are included in the area of forests and shrubberies of foothill and lower mountain belt [9,20]. Steppe vegetation in the Tbilisi environs is represented by several formations: (1) yellow bluestem formation (Bothriochloeta ischaemum), (2) fescue formation (Festuceta valesiaci), (3) feather grass formation (Stipeta pennatae) and (4) grass-forbs formation (Gramino-Mixtoherbeta).
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Yellow bluestem formation (Bothriochloeta ischaemum) Yellow bluestem formation (Bothriochloeta ischaemum) is one of the characteristic formations of vegetation of Tbilisi environs. Their plant communities are fragmentary developed almost all over the territory of Tbilisi environs, on the both sides of the river Mtkvari. Altitude range of formation is in foothills and lower mountain belt, approximately 450e900 (1000) m above s.l.. Yellow bluestem plant communities are developed on slopes with various exposure and inclination, mainly on the grey-cinnamonic and also on cinnamonic soils. In the Tbilisi environs they are either primary or secondary origin. Yellow bluestem plant communities of secondary origin are formed by deforest and cutting of shrubberies [9,12,20]. On the one hand, relief-edaphic and climatic factors and, on the other hand, different origin of communities, determine typological diversity of yellow bluestem formation in the Tbilisi environs. The following plant communities are identified by us: (1) Bothriochloetum gramino-mixtoherbosum, (2) Botriochloetum festucoso gramino-mixtoherbosum, (3) Bothriochloetum festucosum, (4) Bothriochloetum ephemerosum, (5) Bothriochloetum stiposum arabici, (6) Bothriocholoetum astracanthosum caucasici. Short geo-botanical characteristic of identified plant communities is given bellow. (1) Bothriochloetum gramino-mixtoherbosum Area in the Tbilisi environs: foothills of Armazi range (on the territory of surroundings of Mukhatgverdi cemetery) & Skhaltba range; Altitude (m): 600e700; Exposure (macro): E, W, S-W; Exposure (micro): N-E, E, W, S-W, W; Inclination: from 2-3 to 20e22 ; Soil: skeletal cinnamonic & grey-cinnamonic, middle depth; General projective coverage: 80e95% (rarely, 60e75%, 100%); Sodding degree: 20e25% (rarely, 10%, 28e32%); Dominant-edificatory: Bothriochloa ischaemum (projective coverage 25e35%, rarely, 15e20%, 50%); Characterized species: Perennial plants e Festuca valesiaca (frequency of occurence 93%), Koeleria cristata (89%), Salvia nemorosa (82%), Medicago caerulea (78%), Eryngium campestre (70%), Polygala transcaucasica, Potentilla recta (67-67%), Galium verum, (63%), Plantago lanceolata (59.3%), Onobrychis cyri (56%), Potentilla adenophylla (58%), Falcaria vulgaris (48-48%), Cleistogenes serotina (44%), Phleum pratense, Stipa capillata (41-41%); Annual plants e Trifolium campestre (frequency of occurence 70%), Linum corymbulosum (59%), Carthamus lanatus (52%), Scabiosa micrantha (48%), Helianthemum salicifolium (44%), Helianthemum lasiocarpum, Brachypodium distachyon (41-41%); Semi-shrubs & dwarf semi-shrubs e Thymus coriifolius (frequency of occurrence 63%), Teucrium polium (48%); Number of species: 140; Moss cover: þ (rarely); Litter: from 1-2% to 20e22%; Species richness on 1 m2: 31 species; Species richness on 25 m2: 42,8 species. Spectrum of life forms: Phanerophytes e 3 species (2,1%), Chamaephytes e 5 (3,6%), Hemicryptophytes (with biannual plants) e 83 (59,3%), Geophytes e 7 (5,0%), Therophytes e 42 (30,0%).
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(2) Botriochloetum festucoso gramino-mixtoherbosum Area in the Tbilisi environs: foothills of Armazi range (on the territory of surroundings of Mukhatgverdi cemetery); Altitud (m): 650e750; Exposure (macro): E, W; Exposure (micro): W, N-W; Inclination: from 7-8 to 17e18 Soil: cinnamonic, skeletal; General projective coverage: from 62-65% to 85e95%; Sodding degree: 25e30% (rarely, 40e42%); Dominant-edificatory: Bothriochloa ischaemum (projective coverage 25e40%, rarely, 60%, 15e20%); Subdominant-edificatory: Festuca valesiaca (projective coverage from 8-9% to 15e17%); Characterized species: Perennial plants e Koeleria cristata (frequency of occurence 86%), Eryngium campestre, Medicago caerulea (71-71%), Stipa capillata (64%), Plantago lanceolata, Potentilla adenophylla (5757%), Onobrychis cyri (50%), Potentilla recta, Poterium polygamum (43-43%); Annual plants e Galium tenuissimum (frequency of occurence 50%), Helianthemum salicifolium, Carthamus lanatus, Brachypodium distachyon (43-43%), Aegilops tauschii, Trifolium campestre, Petrorhagia prolifera (36-36%); Semi-shrubs & dwarf semi-shrubs e Thymus coriifolius (frequency of occurence 71%), Teucrium polium (57%), Teucrium nuchense (36%); Number of species: 128; Moss cover: þ - 5%; Litter: from 1-2% to 5e7% (Rarely, 15e20%); Species richness on 1 m2: 32,5; Species richness on 25 m2: 42,4; Spectrum of life forms: Phanerophytes e 3 species (2,3%), Chamaephytes e 4 (3,1%), Hemicryptophytes (with biannual plants) e 76 (59,4%), Geophytes e 6 (4,7%), Therophytes e 39 (30,5%). (3) Bothriochloetum festucosum Area in the Tbilisi environs: eastern part of Teleti range; Altitude (m): 700e800; Exposure (macro): S; Exposure (micro): S, S-E, E; Inclination: 3e8 ; Soil: dry, grey-cinnamonic, skeletal, thin or middle depth; General projective coverage: 80e98%; Sodding degree: 25e40%; Dominant-edificatory: Bothriochloa ischaemum (projective coverage 30e40%); Subdominant-edificatory: Festuca valesiaca (projective coverage 15e20%, rarely 10e15%); Characterized species: Perennial plants e Achillea nobilis subsp. neilreichii, Eryngium campestre, Euphorbia seguieriana, Medicago caerulea, Potentilla recta (frequency of occurence 100-100%), Falcaria vulgaris (8080%), Galium verum, Onobrychis cyri, Plantago lanceolata (6060%); Biannual plants e Carduus hamulosus (frequency of occurence 100%); Annual plants e Aegilops tauschii, Trifolium arvense, Trifolium campestre, Helianthemum salicifolium (frequency of occurence 100-100%), Brachypodium distachyon (80%), Bromus squarrosus,
Carthamus lanatus, Helianthemum lasiocarpum, Petrorhagia prolifera, Medicago minima, Xeranthemum squarrosum (60-60%); Semi-shrubs & dwarf semi-shrubs e Teucrium polium, Thymus coriifolius (frequency of occurence 100-100%); Number of species: 45; Moss cover: Litter: Species richness on 1 m2: 16,7 species; Species richness on 25 m2: 25,4 species; Spectrum of life forms: Chamaephytes e 2 species (4,5%), Hemicryptophytes (with biannual plants) e 15 (33,3%), Geophytes e 1 (2,2%), Therophytes e 27 (60%). (4) Bothriochloetum ephemerosum Area in the Tbilisi environs: western endings of Iori upland, surroundings of Tbilisi Sea; Altitude (m): 580e630; Exposure (macro): S; Exposure (micro): S-E, S-W, S; Inclination: 15 e25 ; Soil: dry, grey-cinnamonic, skeletal, thin or middle depth; General projective coverage: 70e85%; Sodding degree: 35e45% (rarely, 55%); Dominant-edificatory: Bothriochloa ischaemum (projective coverage 60e70%); Characterized species: Perennial plants e Achillea biebersteinii, Allium pseudoflavum (frequency of occurence 80-80%), Agropyron cristatum subsp. pectinatum, Astragalus bungeanus, Medicago caerulea, Tragopogon graminifolius (60-60%); Biannual plants e Carduus hamulosus (frequency of occurence 100-100%); Annual plants e Erodium cicutarium, Filago pyramidata, Helianthemum salicifolium, Petrorhagia prolifera, Scabiosa micrantha, Brachypodium distachyon (frequency of occurence 100-100%), Consolida divaricata, Glaucium corniculatum, Hirschfeldia incana, Crepis sancta, Medicago minima, Salvia viridis, Xeranthemum squarrosum (80-80%), Alyssum desertorum, Astragalus hamosus, Bromus japonicus, Daucus carota, Linum corymbulosum, Lolium rigidum (60-60%); Semi-shrubs & dwarf semi-shrubs e Artemisia fragrans, Teucrium polium (frequency of occurence 60-60%); Number of species: 52; Moss cover: Litter: Species richness on 1 m2: 15,4 species; Species richness on 25 m2: 28,6 species; Spectrum of life forms: Chamaephytes e 2 species (3,8%), Hemicryptophytes (with biannual plants) e 11 (21,2%), Geophytes e 1 (1,9%), Therophytes e 38 (73,1%). (5) Bothriochloetum stiposum arabici Area in the Tbilisi environs: Mamadaviti range, left slope of Varaziskhevi gorge; Altitud (m): 820e850; Exposure (macro): S; Exposure (micro): S; Inclination: 15-25 ; Soil: dry, grey-cinnamonic, very skeletal, thin depth; surface is with scree-stony, sometimes there is observed the exposure to the
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mother rocks; General projective coverage: 40e50%; Sodding degree: 15e25%; Dominant-edificatory: Bothriochloa ischaemum (projective coverage 22e28%) Subdominant-edificatory: Stipa arabica (projective coverage 5e10%) Characterized species: Perennial plants e Galium verum (frequency of occurence 95%), Scorzonera biebersteinii (90%), Medicago caerulea, Petrorhagia saxifraga (85-85%), Cleistogenes serotina (70%), Festuca valesiaca (55-55%), Astragalus bungeanus, Convolvulus cantabrica (4545%); Biannual plants e Picris strigosa (frequency of occurence 100100%); Annual plants e Bromus japonicus, Helianthemum salicifolium (frequency of occurence 95-95%), Sedum pallidum (85%), Lolium rigidum, Alyssum linifolium, Crepis sancta, Sideritis montana (8080%), Filago arvensis (70%), Papaver arenarium, Xeranthemum squarrosum (60-60%), Alyssum desertorum, Gypsophila elegans (55-55%), Melilotus neapolitanus, Queria hispanica (45-45%), Arenaria serpyllifolia, Salvia viridis (40-40%). Semi-shrubs & dwarf semi-shrubs e Teucrium polium (frequency of occurrence 55%), Thymus coriifolius (50%); Number of species: 95; Moss cover: Litter: Species richness on 1 m2: 29,4 species; Species richness on 25 m2: 54,3 species; Spectrum of life forms: Chamaephytes e 8 species (8,4%), Hemicryptophytes (with biannual plants) e 38 (40%), Geophytes e 3 (3,2%), Therophytes e 46 (48,4%). (6) Bothriocholoetum astracanthosum caucasici Area in the Tbilisi environs: foothills of Ialno range, vicinity of village Martkopi; Altitude (m): 880e930; Exposure (macro): S; Exposure (micro): S, S-E, E; Inclination: from (2e3 )7-8 to 15e17 ; Soil: grey-cinnamonic, skeletal; General projective coverage: 80e90%; Sodding degree: 35e45(50)%; Dominant-edificatory: Bothriochloa ischaemum (projective coverage 60%); Subdominant-edificatory: Astracantha caucasica (projective coverage 5e7%); Characterized species: Perennial plants e Potentilla adenophylla, Plantago lanceolata, Thesium arvense, Lotus caucasicus, Festuca valesiaca (frequency of occurence 100-100%), Linum tenuifolium, Medicago caerulea, Galium verum, Eryngium campestre, Carex humilis, Astragalus brachycarpus (67-67%). Semi-shrubs & dwarf semi-shrubs e Thymus coriifolius (frequency of occurence 100%), Teucrium polium, Teucrium nuchense (67-67%). Number of species: 42; Moss cover: -; Litter: -
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Species richness on 1 m2: 15 species; Species richness on 25 m2: 25,3 species. Spectrum of life forms: Phanerophytes e 1 species (2,4%), Chamaephytes e 4 (9,5%), Hemicryptophytes (with biannual plants) e 35 (83,3?%), Therophytes e 2 (4,8%). Fescue formation (Festuceta valesiaci) Fescue formation (Festuceta valesiaci) is one of the characteristic formations of vegetation of Tbilisi environs. Their plant communities are fragmentary distributed almost all over the territory of Tbilisi environs, on the both sides of the river Mtkvari. Altitude range of formation is in foothills and lower mountain belt, approximately 450e900 (100) m above s.l.. Plant communities are developed on slopes with various exposure and inclination and mainly linked with thin, dry skeletal grey-cinnamonic soils. Comparative is rarely met on middle depth soils. In the Tbilisi environs fescue plant communities are either primary or secondary origin. Fescue plant communities of secondary origin were formed by subsequently of digressive successive processes of hemixerophilous shrubberies of shibliak type and yellow bluestem formation. In the Tbilisi environs within fescue formation we separated 3 plant communities: (1) Festuceum bothriochloosomixtoherbosum, (2) Festucetum mixtoherbosum and (3) Festucetum bothriochloosum. From them first plant community is most widspread. Short geo-botanical characteristic of identified plant communities is given bellow. (1) Festucetum bothriochlooso-mixtoherbosum Area in the Tbilisi environs: almost on the whole territory, on both sides of the riv. Mtkvari; Altitud (m): 550e800 (900); Exposure (macro): various; Exposure (micro): N, N-E, N-W, E, S, S-E, S-W; Inclination: from 5e7 to 20e22 ; Soil: dry, grey-cinnamonic, skeletal, thin or middle depth; General projective coverage: 85e95% (rarely, 65e75%); Sodding degree: 25e40% (rarely, 50e55%); Dominant-edificatory: Festuca valesiaca (projective coverage 35e55%, rarely, 60e65%); Subdominant-edificatory: Bothriochloa ischaemum (projective coverage from 7-8% to 25e30%); Characterized species: Perennial plants e Koeleria cristata (frequency of occurence 100%), Medicago caerulea (93%), Eryngium campestre, Onobrychis cyri (85-85%), Euphorbia seguieriana, Potentilla recta (68-68%), Ranunculus illyricus (66%), Astragalus bungeanus, Potentilla adenophylla (56-56%); Annual plants e Alyssum alyssoides, Arenaria serpyllifolia (frequency of occurence 93-93%), Cerastium glutinosum (85%), Crepis sancta (80%), Erodium cicutarium (73%), Medicago minima (66%), Astragalus hamosus (61%); Semi-shrubs & dwarf semi-shrubs e Thymus coriifolius (frequency of occurence 93%), Teucrium polium (78%); Number of species: 135. Moss cover: þ (rarely); Litter: þ (rarely); Species richness on 1 m2: 28,2 species; Species richness on 25 m2: 41,5 species.
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Spectrum of life forms: Phanerophytes e 2 species (1,5%), Chamaephytes e 4 (3,0%), Hemicryptophytes (with biannual plants) e 65 (48,1%), Geophytes e 9 (6,7%), Therophytes e 55 (40,7%). (2) Festucetum mixtoherbosum Area in the Tbilisi environs: rarely, almost on the whole territory, on both sides of the riv. Mtkvari; Altitude (m): 550e800 (900); Exposure (macro): various; Exposure (micro): N, N-E, N-W, E, S, S-E, S-W; Inclination: from 5-7 to 20e22 ; Soil: dry, grey-cinnamonic, skeletal, thin or middle depth; General projective coverage: 75e85% (rarely, 93e95%); Sodding degree: 35e45% (rarely, 20e22%, 50e55%); Dominant-edificatory: Festuca valesiaca (projective coverage from 35-40% to 65e70%); Characterized species: Perennial plants e Koeleria cristata (frequency of occurence 100%), Medicago caerulea (94%), Eryngium campestre, Onobrychis cyri (75-75%), Euphorbia seguieriana, Potentilla recta, Ranunculus illyricus (63-63%); Annual plants e Alyssum alyssoides, Arenaria serpyllifolia, Cerastium glutinosum, (frequency of occurence 94-94%), Crepis sancta (81%), Erodium cicutarium (75%), Medicago minima (69%), Astragalus hamosus (56%); Semi-shrubs & dwarf semi-shrubs e Thymus coriifolius (frequency of occurence 88%), Teucrium polium (63%); Number of species: 112; Moss cover: þ (rarely); Litter: þ (rarely); Species richness on 1 m2: 25,7 species; Species richness on 25 m2: 46,1 species. Spectrum of life forms: Phanerophytes e 1 species (0,9%), Chamaephytes e 5 (4,5%), Hemicryptophytes (with biannual plants) e 54 (48,2%), Geophytes e 9 (8,0%), Therophytes e 42 (38,4%). (3) Festucetum bothriochloosum Area in the Tbilisi environs: almost on the whole territory, on both sides of the riv. Mtkvari; Altitud (m): 550e800 (900); Exposure (macro): S, rarely N & N-E; Exposure (micro): S, S-E, S-W, rarely N & N-E; Inclination: from 2-3 to 10e12 ; Soil: dry, grey-cinnamonic, skeletal, thin depth; General projective coverage: from 60-65% to 90e95%; Sodding degree: 25e45%; Dominant-edificatory: Festuca valesiaca (projective coverage 35e40%, rarely, 25e30%, 60e65%); Subdominant-edificatory: Bothriochloa ischaemum (projective coverage from 5-7% to 15e20%); Characterized species: Perennial plants e Potentilla recta (frequency of occurence 100%), Eryngium campestre, Euophorbia seguieriana (78-78%), Achillea biebersteinii (67%); Biannual plants e Carduus hamulosus (frequency of occurence 89%);
Annual plants e Helianthemum salicifolium, Medicago minima, Brachypodium distachyon (frequency of occurence 89-89%), Petrorhagia prolifera (78-78%), Alyssum desertorum, Helianthemum lasiocarpum, Scabiosa micrantha, Xeranthemum squarrosum (6767%); Semi-shrubs & dwarf semi-shrubs e Teucrium polium (frequency of occurence 89%), Thymus coriifolius (78%); Number of species: 73; Moss cover: -; Litter: -; Species richness on 1 m2: 16,5 species; Species richness on 25 m2: 27,8 species; Spectrum of life forms: Chamaephytes e 2 species (2,8%), Hemicryptophytes (with biannual plants) e 29 (39,7%), Geophytes e 3 (4,1%), Therophytes e 39 (53,4%). Feather grass formation (Stipeta pennatae) Feather grass formation (Stipeta pennatae) is fragmentary distributed on the foothills and in the lower mountain belt eastern endings of Trialeti ridge and Saguramo ridge, 470e900 m above s.l.. Their plant communities are developed on slopes with various exposure (west, south-west, northern, northern-eastern, northernwestern, eastern) and inclination (10 e40 ). Soils are greycinnamonic or cinnamonic, frequently are thin and skeletal. In the Tbilisi environs feather grass plant communities are either primary or secondary origin. Plant communities of secondary origin were formed from Spirea formation (Spiraeta hypericifoliae) on the one hand and, from plant communities of grass-forbs (GraminetoMixtoherbeta) steppe on the other hand. Unlike from yellow bluestem and fescue formations in the Tbilisi environs plant communities of feather grass formation are characterized by limited area and are comparative rare. As various space plots, they are included in the area of Spirea formation (Spiraeta hypericifoliae) and derivatives of oak forest (Querceta iberici) and in some cases are developed side by side of plant communities of other formations of steppe. In the Tbilisi environs feather grass formation are represented by 2 plant communities: (1) Stipetum gramino-mixtoherbosum and (2) Stipetum festucosum. Second plant community is developed on more thin soils than first community. Short geo-botanical characteristic of identified plant communities is given bellow. (1) Stipetum gramino-mixtoherbosum Area in the Tbilisi environs: Tabori range (environs of vill. Shindisi and National Botanical Garden of Georgia), Mamadaviti range (surroundings of lake Kustba), Saguramo ranges; Altitud (m): 475e900; Exposure (macro): N, W, S-W; Exposure (micro): N, W, S-W; Inclination: from 20 -25 to 30 35 (rarely, 5 -10 ); Soil: dry, grey-cinnamonic, cinnamonic, in many cases skeletal, thin or middle depth; General projective coverage: in many cases 55e70% (rarely, 92e95%, 30e35%); Sodding degree: in many cases 15e25% (rarely, 5e10%, 40e45%); Dominant-edificatory: Stipa pennata (projective coverage 25e45%, rarely 15e20% and 50e55%); Characterized species:
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Perennial plants e Rumex tuberosus (frequency of occurence 73%), Galium verum (71%), Koeleria cristata (65%), Phleum phleoides (55%), Scorzonera biebersteinii (52%), Bothriochloa ischaemum (47%), Medicago caerulea, Onobrychis cyri (45-45%), Potentilla recta (39%); Annual plants e Crepis sancta (frequency of occurence 50%), Viola kitaibeliana (41%), Helianthemum salicifolium, Alyssum alyssoides, Arabidopsis thaliana (39-39%); Semi-shrubs & dwarf semi-shrubs e Teucrium polium (frequency of occurence 33%); Number of species: 203; Moss cover: in the different sections of area is very dissimilar: from þ to 75%; Litter: in the different sections of area is very dissimilar: from þ to 75%; Species richness on 1 m2: in the different sections of area is very dissimilar: from 16 species to 32,5 species; Species richness on 25 m2: in the different sections of area is very dissimilar: from 27,5 species to 54,3 species; Spectrum of life forms: Phanerophytes e 9 species (4,4%), Chamaephytes e 10 (4,9%), Hemicryptophytes (with biannual plants) e 99 (48,8%), Geophytes e 15 (7,4%), Therophytes e 70 (34,5%). (2) Stipetum festucosum Area in the Tbilisi environs: surroundings of lake Lisi, Mamadaviti range (surroundings of lake Kustba); Altitud (m): 650e730; Exposure (macro): N; Exposure (micro): N, N-E; Inclination: 30 35 (40 ); Soil: dry, grey-cinnamonic, cinnamonic, skeletal, thin or middle depth; General projective coverage: 60e85% (reraly, 90e95%); Sodding degree: 20e30%(40%); Dominant-edificatory: Stipa pennata (projective coverage from 20-25% to 30e40%); Subdominant-edificatory: Festuca valesiaca (projective coverage 15e25%, rarely, 8e12%); Characterized species: Perennial plants e Galium verum, Koeleria cristata (frequency of occurrence 100-100%), Medicago caerulea (92%), Veronica multifida (85%), Onobrychis cyri, Potentilla recta, Ranunculus illyricus (77-77%), Bothriochloa ischaemum, Carex liparocarpos subsp. bordzilowskii, Potentilla adenophylla (69-69%), Achillea nobilis subsp. neilreichii (62%), Allium rotundum, Filipendula vulgaris, Stipa capillata (54-54%). Annual plants e Trifolium arvense (frequency of occurrence 85%), Alyssum alyssoides, Trifolium campestre (77%), Cerastium glutinosum, Galium tenuissimum, Crepis sancta (69-69%), Helianthemum lasiocarpum (62%), Silene conica (54%), Arenaria serpyllifolia (46%); Semi-shrubs & dwarf semi-shrubs e Thymus coriifolius (frequency of occurrence 69%), Teucrium polium (46%);
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plants) e 62 (55,4%), Geophytes e 6 (5,4%), Therophytes e 32 (28,5%). Grass-forbs formation (Gramineto-Mixtoherbeta) In form of the small plots grass-forbs plant communities fragmentary distributed on the foothills and in the low mountain belt of eastern endings of Saguramo ridge. Plant communities are developed on slopes and plain places with various exposure and inclination. Soils are cinnanmonic and grey-cinnamonic, not infrequently skeletal. In the Tbilisi environs plant communities of grass-forbs steppe for the most part are of secondary origin. Their formation came by cutting of xeromezophilous and hemixerophilous shrubberies [20]. Plant communities of grass-forbs steppe are not characterized by the stable and shaped structure. Floristic composition of plant communities is changeable. Participation and coenetic role of the individual species are strongly varying. They do not belong to the plant communities in the stage of climax. Accordingly, grass-herb steppe is represented by coenoses of various modifications. Depending on origin, they are represented by less and more xerophilous variants. Short geo-botanical characteristic of plant communities is given bellow. Area in the Tbilisi environs: Eastern endings of Trialeti ridge; Altitud (m): 630e750(800); Exposure (macro): N, N-E, E; Exposure (micro): N, N-E, E; Inclination: from 10 -12 to 22 e23 (rarely, 5e6 , 30e32 ); Soil: cinnamonic, grey-cinnamonic, middle or thin depth; General projective coverage: from 75e to 80% to 95e98(100)%; Sodding degree: from 10-12% to 30e32% (rarely, 4e7%, 35e38%) Dominant-edificatory: various species are dominated on different locations; Characterized species: Perennial plants e Koeleria cristata, Potentilla recta (frequency of occurrence 100-100%), Festuca valesiaca (88%), Falcaria vulgaris, Onobrychis cyri (75-75%), Medicago caerulea, Salvia nemorosa (69-69%), Dactylis glomerata, Galium verum, Rumex tuberosus, Stipa capillata (63-63%), Bothriochloa ischaemum (56%), Elymus repens, Stipa pennata (50-50%); Annual plants e Medicago minima, Scabiosa micrantha (frequency of occurrence 44-44%); Semi-shrubs & dwarf semi-shrubs e Thymus coriifolius (frequency of occurrence 50%) Number of species: 97; Moss cover: 15e45%; Litter: from 15-20% to 65e70%; Species richness on 1 m2: 25 species; Species richness on 25 m2: 50 species. Spectrum of life forms: Phanerophytes e 1%, Chamaephytes e 4,1%, Hemicryptophytes (with biannual plants) e 56,7%, Geophytes e 9,3%, Therophytes e 28,9%. Conclusion
Number of species: 112; Moss cover: from þ to 45e50%; Litter: 12e15% (rarely, 25e35%); Species richness on 1 m2: 29 species; Species richness on 25 m2: 45 species; Spectrum of life forms: Phanerophytes e 5 species (4,5%), Chamaephytes e 7 (6,2%), Hemicryptophytes (with biannual
Area of steppe vegetation in the Tbilisi environs is in foothills and lower mountain belt, approximately 450e900 (100) m above s.l.. Plant communities of steppe are developed on slopes with various exposure and inclination, mainly on the grey-cinnamonic and also on cinnamonic soils. In the Tbilisi environs, the steppe vegetation is either primary or secondary origin. Plant
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communities of secondary steppe vegetation were formed by digressive succession processes of deciduous forests and shrubberies of various types of foothills and lower mountain belt. Steppe vegetation in the Tbilisi environs are represented by 4 formations: (1) Yellow bluestem formation (Bothriochloeta ischaemum), (2) Fescue formation (Festuceta valesiaci), (3) Feather grass formation (Stipeta pennatae) and (4) Grass-forbs formation (Gramino-Mixtoherbeta). From them Bothriochloeta ischaemum and Festuceta valesiaci formations have more area covering and characterized by the comparatively rich typological composition. Stipeta pennatae and Gramino-Mixtoherbeta has limited area. Typological composition of steppe vegetation of Tbilisi environs is such: Yellow bluestem formation (Bothriochloeta ischaemum): 1. 2. 3. 4. 5. 6.
Bothriochloetum gramino-mixtoherbosum Botriochloetum festucoso gramino-mixtoherbosum Bothriochloetum festucosum Bothriochloetum ephemerosum Bothriochloetum stiposum arabici Bothriocholoetum astracanthosum caucasici Fescue formation (Festuceta valesiaci):
1. Festuceum bothriochlooso-mixtoherbosum 2. Festucetum mixtoherbosum 3. Festucetum bothriochloosum. Feather grass formation (Stipeta pennatae): 1. Stipetum gramino-mixtoherbosum 2. Stipetum festucosum Grass-forbs formation (Gramineto-Mixtoherbeta): 1. Gramineto-Mixtoherbeta.
References [1] M. Maruashvili, Physical Geography of Georgia, Tsodna, Tbilisi, 1964 (in Georgian). [2] K.V. Kavrishvili, Physical-geographical Characteristics of Tbilisi Surroundings, Metsniereba, Tbilisi, 1964 (in Russian). [3] D. Ukleba, Physical-geographical Zoning of East Georgia, Metsniereba, Tbilisi, 1968 (in Georgian). [4] D. Ukleba, Landscapes and Physical-geographical Districts of Mountain Regions of East Georgia, Metsniereba, Tbilisi, 1974 (in Georgian). [5] Z. Tatashidze, Tbilisi, in: Z. Tatashidze (Ed.), Geography of Georgia, Part I, Metsniereba, Tbilisi, 2000, pp. 200e207 (in Georgian). [6] M. Sabashvili, Soils of Georgian SSR, Metsniereba, Tbilisi, 1965 (in Georgian). [7] T. Urushadze (Ed.), Soil Map of Georgia, Cartography, Tbilisi, 1999. [8] T.F. Urushadze, V. Blum, Soils of Georgia, Mtsignobari, Tbilisi, 2014 (in Russian). [9] N.J. Lachashvili, M.N. Khachidze, L.D. Khetsuriani, N.V. Eradze, Typology and distribution regularities of the vegetation of Tbilisi environs (East Georgia, South Caucasus), J.Ann. Agrar. Sci. 13 (3) (2013) 55e62. [10] N. Lachashvili, M. Khachidze, N. Eradze, L. Khetsuriani, Natural feather grass steppes (Stipeta pennatae) on the territory of National Botanical Gargen of Georgia, Proc. Georg. Acad. Sci. Biol. Ser. B 9 (1e4) (2011) 28e36. [11] N. Lachashvili, L. Khetsuriani, K. Batsatsashvili, Effects of grazing on some communities of Botriochloeta ischaemum in Shida Kartli (East Georgia), Proc. Georg. Acad. Sci. Biol. Ser. B 8 (1e2) (2010) 20e25. [12] N. Lachashvili, M. Khachidze, N. Eradze, L. Khetsuriani, Yelow blustem formation (Bothriochloeta ischaemum) of Tbilisi environs, Nat. Bot. Gard. Geo. Proc. 100 (2014) 62e72 (in Georgian). [13] A.A. Korchagin, Species (floristic) composition of plant communities and the methods of its investigation, in: E.M. Lavrenko, A.A. Korchagin (Eds.), Field Geobotany, III, Nauka, Moscow-Leningrad, 1964, pp. 39e62 (in Russian). [14] V.M. Ponyatovskaya, Estimation of abundace and distribution of species in natural plant communities, in: E.M. Lavrenko, A.A. Korchagin (Eds.), Field Geobotany, III, Nauka, Moscow-Leningrad, 1964, pp. 209e299 (in Russian). [15] A.A. Yunatov, The types and the scope of geobotanical investigations, the selection of sample areas and the construction of ecological profiles, in: E.M. Lavrenko, A.A. Korchagin (Eds.), Field Geobotany, III, Nauka, MoscowLeningrad, 1964, pp. 9e36 (in Russian). [16] A.P. Shennikov, Introduction to Geobotany, Publishing House of the Leningrad University, Leningrad, 1964 (in Russian). [17] J. Braun-Blanquet, Pflanzensoziologie. Grundzüge der Vegetationskunde. 3 Aufl, Springer, Wien, New-York, 1964. [18] T.A. Rabotnov, Phytocenology, Publishing House of the Moscow University, Moscow, 1983 (in Russian). [19] V. Ch Vasilevich, Concerning methods of vegetation classification, Bot. J. 70 (12) (1985) 1596e1604 (in Russian). [20] N. Lachashvili, M. Khachidze, L. Khetsuriani, Successions of Tbilisi Environs Post-Forest Vegetation, Univrersal, Tbilisi, 2015 (in Georgian).
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Steppe of Tbilisi environs (East Georgia, South Caucasus) N.J. Lachashvili a, *, M.N. Khachidze a, N.V. Eradze b, L.D. Khetsuriani a a b
Ilia State University, Institute of Botany, 1, Botanikuri Str., Tbilisi, 0114, Georgia Georgian National Botanical Garden, 1, Botanikuri Str., Tbilisi, 0114, Tbilisi, Georgia
a r t i c l e i n f o
a b s t r a c t
Article history: Received 12 March 2017 Accepted 12 June 2017 Available online 12 August 2017
Steppes of Tbilisi environs are studied. In the Tbilisi surroundings the steppe vegetation is either of primary or secondary origin. Steppe vegetation in the Tbilisi environs are represented by 4 formations: (1) Bothriochloeta ischaemum, (2) Festuceta valesiaci, (3) Stipeta pennatae and (4) GraminoMixtoherbeta. From them Bothriochloeta ischaemum and Festuceta valesiaci formations have more area covering and characterized by the comparatively rich typological composition. Typological composition of each formation is established. For each separated plant communities the basic structural characteristics (general projective coverage, sodding degree, dominant-edificatory plant, characteristic species, number of species, moss cover, litter, species richness, spectrum of life forms), distribution area in the Tbilisi environs and main physical-geographical conditions (altitude, exposure, inclination, soil type) are given. © 2017 Agricultural University of Georgia. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Keywords: Tbilisi environs Steppe Typological composition Plant community Distribution area Structural chatracteristics
Introduction The part of basin of the river Mtkvari, which is spread from the vil. Dzegvi to the section between Ponichala and Rustavi, is considered in the environs of Tbilisi. Endings of the thick geographic units of various origins and geographic age are gathered in the vicinities of Tbilisi that makes its relief considerably complicated. Privately, they are involved in the environs of Tbilisi: (1) extreme southern branching of Caucasian range e SaguramoIalno ridge, (2) Eastern part of Kvernaki low range (Skhaltba low range), (3) Eastern endings of Trialeti ridge (the ranges of Satskepela and Armazi, Mskhaldidi and Lisi, Mtatsminda, Narikala, Tabori, Telet-Sakharaulo), (4) Western and extremee north-western part of Iori upland (Samgori, Vaziani, Tbilisi Sea and its adjacent territory, etc.), (5) Extreme north-western ending of Mtkvari-Arax lowland (plains of Ponichala and Kumisi-Tsalaskuri). Hypsometrical amplitude of the Tbilisi vicinity is from 350 m to 1875 m above s.l.. Types of low and middle-height mountain-gorge and stepped plain relief are highlighted in the relief [1e5]. In the environs of Tbilisi, two types of climate with the appropriate two zones of the climate are apportioned [2,3]: (1) The climate with insufficient humidity, dry and hot summer and mild
* Corresponding author. E-mail address: [email protected] (N.J. Lachashvili). Peer review under responsibility of Journal Annals of Agrarian Science.
but well expressed winter, (2) moderately humid climate with moderately warm summer and moderately cold snowy winter. The first zone of the climate contains the whole left side of the river Mtkvari, plains of Ponichala and Kumisi-Tsalaskuri and the river floodplain as well. The secondary climate zone contains the mountainous part of the right side and the main part of SaguramoIalno range. Mainly, grey cinnamonic soil is developed on the western ending of the Iori upland and on the slopes of middle-height low range, which is of skeletal in most cases. Just of the same types, but light saline soil is on the plains of Ponichala and Kumisi-Tsalaskuri, where the solonets and solonchak is speckled. Mainly, different modifications of cinnamonic soil (cinnamonic leached, cinnamonic calcareous, cinnamonic light) are spread on the slopes of eastern endings of Trialeti range, on the slopes of southern exposure of Saguramo-Ialno ringe and partly on the Skhaltba low range. And, brown forest soil of various modifications are met in the upper parts of these ringes. Alluvial soils remained on the terraces of the rivers. Thin primitive skeletal soil and scree-stony are widely spread in the grey cinnamonic soil areal. Rocky bareness of groundless soil covering is also met. The section of clay and claysand badlands is met on the southern slope of Skhaltba low range [2,3,5e8]. Variety of relief-edaphic conditions, geographical location and muster of several geographic units those are different from each other, existence of different climate zones, geological past, modern geophysical and geochemical processes and etc. conditions
http://dx.doi.org/10.1016/j.aasci.2017.06.003 1512-1887/© 2017 Agricultural University of Georgia. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).
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significant biodiversity of Tbilisi environs. From the point of landscapes creation and taken space, forests, shrubberies and steppes are the most important, which are represented by diverse modifications [9]. Steppes are the main pastures in the Tbilisi environs and their floristic-geobotanical and ecological study is important as from an angle of agricultural, as from an angle of conserve of ecological balance and biodiversity. Though, the literature data about steppe vegetation of Tbilisis surroundings are scanty [10e12].
Objectives and methods The object of research is steppe vegetation of Tbilisi environs. The main aim of the research was to establish area, typological composition and distribution regularities of steppe vegetation in the Tbilisi environs; determination of area and main physicalgeographical conditions of identified syntaxa (plant communities); study their geo-botanical structure and evaluation of ecological situation. Geo-botanical data were obtained by the route method. Geobotanical descriptions were carrying out on 1 m2 and 25 m2 plots. During the geo-botanical descriptions, studying the structure of phytocoenoses and identification of syntaxa, we were guided the traditional geo-botanical methods [13e19]. On the each plots were registration general projective cover (in %) of plant communities, sodding degree (in %), floristic composition, coenotic role of each species (projective cover in %), height of layers, as well physical-geographical characteristics (relief, exposure, inclination, soli type, altitude). In the process of cameral work for each plant community were established frequency of occurrence of each species and were determined constant (typical) species, were calculated species richness on 1 m2 and 25 m2 and spectra of life forms.
Results and analysis Steppe vegetation is fragmentary developed almost all over the territory of Tbilisi environs, on the both sides of the river Mtkvari. Its altitude range is in foothills and lower mountain belt, approximately 450e900 (1000) m above s.l.. Plant communities of steppe are developed on slopes with various exposure and inclination, mainly on the grey-cinnamonic and also on cinnamonic soils. Soils are thin or middle depth. In the Tbilisi environs the steppe vegetation is either primary or secondary origin. Nowadays, to draw the line between the primary and the secondary coenoses is impossible in most cases. Spreading of primary steppe vegetation is linked with first climate zone (the climate with insufficient humidity, dry and hot summer and mild but well expressed winter) and various modifications of greycinnamonic soils which are developed in this zone. Plant communities of secondary steppe were formed by digressive succession processes of post-forest vegetation. Their area is outside of first climate zone. They are spread on second climate type zone (the climate with insufficient humidity, dry and hot summer and mild but well expressed winter). Accordingly, secondary plant communities of steppe are included in the area of forests and shrubberies of foothill and lower mountain belt [9,20]. Steppe vegetation in the Tbilisi environs is represented by several formations: (1) yellow bluestem formation (Bothriochloeta ischaemum), (2) fescue formation (Festuceta valesiaci), (3) feather grass formation (Stipeta pennatae) and (4) grass-forbs formation (Gramino-Mixtoherbeta).
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Yellow bluestem formation (Bothriochloeta ischaemum) Yellow bluestem formation (Bothriochloeta ischaemum) is one of the characteristic formations of vegetation of Tbilisi environs. Their plant communities are fragmentary developed almost all over the territory of Tbilisi environs, on the both sides of the river Mtkvari. Altitude range of formation is in foothills and lower mountain belt, approximately 450e900 (1000) m above s.l.. Yellow bluestem plant communities are developed on slopes with various exposure and inclination, mainly on the grey-cinnamonic and also on cinnamonic soils. In the Tbilisi environs they are either primary or secondary origin. Yellow bluestem plant communities of secondary origin are formed by deforest and cutting of shrubberies [9,12,20]. On the one hand, relief-edaphic and climatic factors and, on the other hand, different origin of communities, determine typological diversity of yellow bluestem formation in the Tbilisi environs. The following plant communities are identified by us: (1) Bothriochloetum gramino-mixtoherbosum, (2) Botriochloetum festucoso gramino-mixtoherbosum, (3) Bothriochloetum festucosum, (4) Bothriochloetum ephemerosum, (5) Bothriochloetum stiposum arabici, (6) Bothriocholoetum astracanthosum caucasici. Short geo-botanical characteristic of identified plant communities is given bellow. (1) Bothriochloetum gramino-mixtoherbosum Area in the Tbilisi environs: foothills of Armazi range (on the territory of surroundings of Mukhatgverdi cemetery) & Skhaltba range; Altitude (m): 600e700; Exposure (macro): E, W, S-W; Exposure (micro): N-E, E, W, S-W, W; Inclination: from 2-3 to 20e22 ; Soil: skeletal cinnamonic & grey-cinnamonic, middle depth; General projective coverage: 80e95% (rarely, 60e75%, 100%); Sodding degree: 20e25% (rarely, 10%, 28e32%); Dominant-edificatory: Bothriochloa ischaemum (projective coverage 25e35%, rarely, 15e20%, 50%); Characterized species: Perennial plants e Festuca valesiaca (frequency of occurence 93%), Koeleria cristata (89%), Salvia nemorosa (82%), Medicago caerulea (78%), Eryngium campestre (70%), Polygala transcaucasica, Potentilla recta (67-67%), Galium verum, (63%), Plantago lanceolata (59.3%), Onobrychis cyri (56%), Potentilla adenophylla (58%), Falcaria vulgaris (48-48%), Cleistogenes serotina (44%), Phleum pratense, Stipa capillata (41-41%); Annual plants e Trifolium campestre (frequency of occurence 70%), Linum corymbulosum (59%), Carthamus lanatus (52%), Scabiosa micrantha (48%), Helianthemum salicifolium (44%), Helianthemum lasiocarpum, Brachypodium distachyon (41-41%); Semi-shrubs & dwarf semi-shrubs e Thymus coriifolius (frequency of occurrence 63%), Teucrium polium (48%); Number of species: 140; Moss cover: þ (rarely); Litter: from 1-2% to 20e22%; Species richness on 1 m2: 31 species; Species richness on 25 m2: 42,8 species. Spectrum of life forms: Phanerophytes e 3 species (2,1%), Chamaephytes e 5 (3,6%), Hemicryptophytes (with biannual plants) e 83 (59,3%), Geophytes e 7 (5,0%), Therophytes e 42 (30,0%).
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(2) Botriochloetum festucoso gramino-mixtoherbosum Area in the Tbilisi environs: foothills of Armazi range (on the territory of surroundings of Mukhatgverdi cemetery); Altitud (m): 650e750; Exposure (macro): E, W; Exposure (micro): W, N-W; Inclination: from 7-8 to 17e18 Soil: cinnamonic, skeletal; General projective coverage: from 62-65% to 85e95%; Sodding degree: 25e30% (rarely, 40e42%); Dominant-edificatory: Bothriochloa ischaemum (projective coverage 25e40%, rarely, 60%, 15e20%); Subdominant-edificatory: Festuca valesiaca (projective coverage from 8-9% to 15e17%); Characterized species: Perennial plants e Koeleria cristata (frequency of occurence 86%), Eryngium campestre, Medicago caerulea (71-71%), Stipa capillata (64%), Plantago lanceolata, Potentilla adenophylla (5757%), Onobrychis cyri (50%), Potentilla recta, Poterium polygamum (43-43%); Annual plants e Galium tenuissimum (frequency of occurence 50%), Helianthemum salicifolium, Carthamus lanatus, Brachypodium distachyon (43-43%), Aegilops tauschii, Trifolium campestre, Petrorhagia prolifera (36-36%); Semi-shrubs & dwarf semi-shrubs e Thymus coriifolius (frequency of occurence 71%), Teucrium polium (57%), Teucrium nuchense (36%); Number of species: 128; Moss cover: þ - 5%; Litter: from 1-2% to 5e7% (Rarely, 15e20%); Species richness on 1 m2: 32,5; Species richness on 25 m2: 42,4; Spectrum of life forms: Phanerophytes e 3 species (2,3%), Chamaephytes e 4 (3,1%), Hemicryptophytes (with biannual plants) e 76 (59,4%), Geophytes e 6 (4,7%), Therophytes e 39 (30,5%). (3) Bothriochloetum festucosum Area in the Tbilisi environs: eastern part of Teleti range; Altitude (m): 700e800; Exposure (macro): S; Exposure (micro): S, S-E, E; Inclination: 3e8 ; Soil: dry, grey-cinnamonic, skeletal, thin or middle depth; General projective coverage: 80e98%; Sodding degree: 25e40%; Dominant-edificatory: Bothriochloa ischaemum (projective coverage 30e40%); Subdominant-edificatory: Festuca valesiaca (projective coverage 15e20%, rarely 10e15%); Characterized species: Perennial plants e Achillea nobilis subsp. neilreichii, Eryngium campestre, Euphorbia seguieriana, Medicago caerulea, Potentilla recta (frequency of occurence 100-100%), Falcaria vulgaris (8080%), Galium verum, Onobrychis cyri, Plantago lanceolata (6060%); Biannual plants e Carduus hamulosus (frequency of occurence 100%); Annual plants e Aegilops tauschii, Trifolium arvense, Trifolium campestre, Helianthemum salicifolium (frequency of occurence 100-100%), Brachypodium distachyon (80%), Bromus squarrosus,
Carthamus lanatus, Helianthemum lasiocarpum, Petrorhagia prolifera, Medicago minima, Xeranthemum squarrosum (60-60%); Semi-shrubs & dwarf semi-shrubs e Teucrium polium, Thymus coriifolius (frequency of occurence 100-100%); Number of species: 45; Moss cover: Litter: Species richness on 1 m2: 16,7 species; Species richness on 25 m2: 25,4 species; Spectrum of life forms: Chamaephytes e 2 species (4,5%), Hemicryptophytes (with biannual plants) e 15 (33,3%), Geophytes e 1 (2,2%), Therophytes e 27 (60%). (4) Bothriochloetum ephemerosum Area in the Tbilisi environs: western endings of Iori upland, surroundings of Tbilisi Sea; Altitude (m): 580e630; Exposure (macro): S; Exposure (micro): S-E, S-W, S; Inclination: 15 e25 ; Soil: dry, grey-cinnamonic, skeletal, thin or middle depth; General projective coverage: 70e85%; Sodding degree: 35e45% (rarely, 55%); Dominant-edificatory: Bothriochloa ischaemum (projective coverage 60e70%); Characterized species: Perennial plants e Achillea biebersteinii, Allium pseudoflavum (frequency of occurence 80-80%), Agropyron cristatum subsp. pectinatum, Astragalus bungeanus, Medicago caerulea, Tragopogon graminifolius (60-60%); Biannual plants e Carduus hamulosus (frequency of occurence 100-100%); Annual plants e Erodium cicutarium, Filago pyramidata, Helianthemum salicifolium, Petrorhagia prolifera, Scabiosa micrantha, Brachypodium distachyon (frequency of occurence 100-100%), Consolida divaricata, Glaucium corniculatum, Hirschfeldia incana, Crepis sancta, Medicago minima, Salvia viridis, Xeranthemum squarrosum (80-80%), Alyssum desertorum, Astragalus hamosus, Bromus japonicus, Daucus carota, Linum corymbulosum, Lolium rigidum (60-60%); Semi-shrubs & dwarf semi-shrubs e Artemisia fragrans, Teucrium polium (frequency of occurence 60-60%); Number of species: 52; Moss cover: Litter: Species richness on 1 m2: 15,4 species; Species richness on 25 m2: 28,6 species; Spectrum of life forms: Chamaephytes e 2 species (3,8%), Hemicryptophytes (with biannual plants) e 11 (21,2%), Geophytes e 1 (1,9%), Therophytes e 38 (73,1%). (5) Bothriochloetum stiposum arabici Area in the Tbilisi environs: Mamadaviti range, left slope of Varaziskhevi gorge; Altitud (m): 820e850; Exposure (macro): S; Exposure (micro): S; Inclination: 15-25 ; Soil: dry, grey-cinnamonic, very skeletal, thin depth; surface is with scree-stony, sometimes there is observed the exposure to the
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mother rocks; General projective coverage: 40e50%; Sodding degree: 15e25%; Dominant-edificatory: Bothriochloa ischaemum (projective coverage 22e28%) Subdominant-edificatory: Stipa arabica (projective coverage 5e10%) Characterized species: Perennial plants e Galium verum (frequency of occurence 95%), Scorzonera biebersteinii (90%), Medicago caerulea, Petrorhagia saxifraga (85-85%), Cleistogenes serotina (70%), Festuca valesiaca (55-55%), Astragalus bungeanus, Convolvulus cantabrica (4545%); Biannual plants e Picris strigosa (frequency of occurence 100100%); Annual plants e Bromus japonicus, Helianthemum salicifolium (frequency of occurence 95-95%), Sedum pallidum (85%), Lolium rigidum, Alyssum linifolium, Crepis sancta, Sideritis montana (8080%), Filago arvensis (70%), Papaver arenarium, Xeranthemum squarrosum (60-60%), Alyssum desertorum, Gypsophila elegans (55-55%), Melilotus neapolitanus, Queria hispanica (45-45%), Arenaria serpyllifolia, Salvia viridis (40-40%). Semi-shrubs & dwarf semi-shrubs e Teucrium polium (frequency of occurrence 55%), Thymus coriifolius (50%); Number of species: 95; Moss cover: Litter: Species richness on 1 m2: 29,4 species; Species richness on 25 m2: 54,3 species; Spectrum of life forms: Chamaephytes e 8 species (8,4%), Hemicryptophytes (with biannual plants) e 38 (40%), Geophytes e 3 (3,2%), Therophytes e 46 (48,4%). (6) Bothriocholoetum astracanthosum caucasici Area in the Tbilisi environs: foothills of Ialno range, vicinity of village Martkopi; Altitude (m): 880e930; Exposure (macro): S; Exposure (micro): S, S-E, E; Inclination: from (2e3 )7-8 to 15e17 ; Soil: grey-cinnamonic, skeletal; General projective coverage: 80e90%; Sodding degree: 35e45(50)%; Dominant-edificatory: Bothriochloa ischaemum (projective coverage 60%); Subdominant-edificatory: Astracantha caucasica (projective coverage 5e7%); Characterized species: Perennial plants e Potentilla adenophylla, Plantago lanceolata, Thesium arvense, Lotus caucasicus, Festuca valesiaca (frequency of occurence 100-100%), Linum tenuifolium, Medicago caerulea, Galium verum, Eryngium campestre, Carex humilis, Astragalus brachycarpus (67-67%). Semi-shrubs & dwarf semi-shrubs e Thymus coriifolius (frequency of occurence 100%), Teucrium polium, Teucrium nuchense (67-67%). Number of species: 42; Moss cover: -; Litter: -
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Species richness on 1 m2: 15 species; Species richness on 25 m2: 25,3 species. Spectrum of life forms: Phanerophytes e 1 species (2,4%), Chamaephytes e 4 (9,5%), Hemicryptophytes (with biannual plants) e 35 (83,3?%), Therophytes e 2 (4,8%). Fescue formation (Festuceta valesiaci) Fescue formation (Festuceta valesiaci) is one of the characteristic formations of vegetation of Tbilisi environs. Their plant communities are fragmentary distributed almost all over the territory of Tbilisi environs, on the both sides of the river Mtkvari. Altitude range of formation is in foothills and lower mountain belt, approximately 450e900 (100) m above s.l.. Plant communities are developed on slopes with various exposure and inclination and mainly linked with thin, dry skeletal grey-cinnamonic soils. Comparative is rarely met on middle depth soils. In the Tbilisi environs fescue plant communities are either primary or secondary origin. Fescue plant communities of secondary origin were formed by subsequently of digressive successive processes of hemixerophilous shrubberies of shibliak type and yellow bluestem formation. In the Tbilisi environs within fescue formation we separated 3 plant communities: (1) Festuceum bothriochloosomixtoherbosum, (2) Festucetum mixtoherbosum and (3) Festucetum bothriochloosum. From them first plant community is most widspread. Short geo-botanical characteristic of identified plant communities is given bellow. (1) Festucetum bothriochlooso-mixtoherbosum Area in the Tbilisi environs: almost on the whole territory, on both sides of the riv. Mtkvari; Altitud (m): 550e800 (900); Exposure (macro): various; Exposure (micro): N, N-E, N-W, E, S, S-E, S-W; Inclination: from 5e7 to 20e22 ; Soil: dry, grey-cinnamonic, skeletal, thin or middle depth; General projective coverage: 85e95% (rarely, 65e75%); Sodding degree: 25e40% (rarely, 50e55%); Dominant-edificatory: Festuca valesiaca (projective coverage 35e55%, rarely, 60e65%); Subdominant-edificatory: Bothriochloa ischaemum (projective coverage from 7-8% to 25e30%); Characterized species: Perennial plants e Koeleria cristata (frequency of occurence 100%), Medicago caerulea (93%), Eryngium campestre, Onobrychis cyri (85-85%), Euphorbia seguieriana, Potentilla recta (68-68%), Ranunculus illyricus (66%), Astragalus bungeanus, Potentilla adenophylla (56-56%); Annual plants e Alyssum alyssoides, Arenaria serpyllifolia (frequency of occurence 93-93%), Cerastium glutinosum (85%), Crepis sancta (80%), Erodium cicutarium (73%), Medicago minima (66%), Astragalus hamosus (61%); Semi-shrubs & dwarf semi-shrubs e Thymus coriifolius (frequency of occurence 93%), Teucrium polium (78%); Number of species: 135. Moss cover: þ (rarely); Litter: þ (rarely); Species richness on 1 m2: 28,2 species; Species richness on 25 m2: 41,5 species.
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Spectrum of life forms: Phanerophytes e 2 species (1,5%), Chamaephytes e 4 (3,0%), Hemicryptophytes (with biannual plants) e 65 (48,1%), Geophytes e 9 (6,7%), Therophytes e 55 (40,7%). (2) Festucetum mixtoherbosum Area in the Tbilisi environs: rarely, almost on the whole territory, on both sides of the riv. Mtkvari; Altitude (m): 550e800 (900); Exposure (macro): various; Exposure (micro): N, N-E, N-W, E, S, S-E, S-W; Inclination: from 5-7 to 20e22 ; Soil: dry, grey-cinnamonic, skeletal, thin or middle depth; General projective coverage: 75e85% (rarely, 93e95%); Sodding degree: 35e45% (rarely, 20e22%, 50e55%); Dominant-edificatory: Festuca valesiaca (projective coverage from 35-40% to 65e70%); Characterized species: Perennial plants e Koeleria cristata (frequency of occurence 100%), Medicago caerulea (94%), Eryngium campestre, Onobrychis cyri (75-75%), Euphorbia seguieriana, Potentilla recta, Ranunculus illyricus (63-63%); Annual plants e Alyssum alyssoides, Arenaria serpyllifolia, Cerastium glutinosum, (frequency of occurence 94-94%), Crepis sancta (81%), Erodium cicutarium (75%), Medicago minima (69%), Astragalus hamosus (56%); Semi-shrubs & dwarf semi-shrubs e Thymus coriifolius (frequency of occurence 88%), Teucrium polium (63%); Number of species: 112; Moss cover: þ (rarely); Litter: þ (rarely); Species richness on 1 m2: 25,7 species; Species richness on 25 m2: 46,1 species. Spectrum of life forms: Phanerophytes e 1 species (0,9%), Chamaephytes e 5 (4,5%), Hemicryptophytes (with biannual plants) e 54 (48,2%), Geophytes e 9 (8,0%), Therophytes e 42 (38,4%). (3) Festucetum bothriochloosum Area in the Tbilisi environs: almost on the whole territory, on both sides of the riv. Mtkvari; Altitud (m): 550e800 (900); Exposure (macro): S, rarely N & N-E; Exposure (micro): S, S-E, S-W, rarely N & N-E; Inclination: from 2-3 to 10e12 ; Soil: dry, grey-cinnamonic, skeletal, thin depth; General projective coverage: from 60-65% to 90e95%; Sodding degree: 25e45%; Dominant-edificatory: Festuca valesiaca (projective coverage 35e40%, rarely, 25e30%, 60e65%); Subdominant-edificatory: Bothriochloa ischaemum (projective coverage from 5-7% to 15e20%); Characterized species: Perennial plants e Potentilla recta (frequency of occurence 100%), Eryngium campestre, Euophorbia seguieriana (78-78%), Achillea biebersteinii (67%); Biannual plants e Carduus hamulosus (frequency of occurence 89%);
Annual plants e Helianthemum salicifolium, Medicago minima, Brachypodium distachyon (frequency of occurence 89-89%), Petrorhagia prolifera (78-78%), Alyssum desertorum, Helianthemum lasiocarpum, Scabiosa micrantha, Xeranthemum squarrosum (6767%); Semi-shrubs & dwarf semi-shrubs e Teucrium polium (frequency of occurence 89%), Thymus coriifolius (78%); Number of species: 73; Moss cover: -; Litter: -; Species richness on 1 m2: 16,5 species; Species richness on 25 m2: 27,8 species; Spectrum of life forms: Chamaephytes e 2 species (2,8%), Hemicryptophytes (with biannual plants) e 29 (39,7%), Geophytes e 3 (4,1%), Therophytes e 39 (53,4%). Feather grass formation (Stipeta pennatae) Feather grass formation (Stipeta pennatae) is fragmentary distributed on the foothills and in the lower mountain belt eastern endings of Trialeti ridge and Saguramo ridge, 470e900 m above s.l.. Their plant communities are developed on slopes with various exposure (west, south-west, northern, northern-eastern, northernwestern, eastern) and inclination (10 e40 ). Soils are greycinnamonic or cinnamonic, frequently are thin and skeletal. In the Tbilisi environs feather grass plant communities are either primary or secondary origin. Plant communities of secondary origin were formed from Spirea formation (Spiraeta hypericifoliae) on the one hand and, from plant communities of grass-forbs (GraminetoMixtoherbeta) steppe on the other hand. Unlike from yellow bluestem and fescue formations in the Tbilisi environs plant communities of feather grass formation are characterized by limited area and are comparative rare. As various space plots, they are included in the area of Spirea formation (Spiraeta hypericifoliae) and derivatives of oak forest (Querceta iberici) and in some cases are developed side by side of plant communities of other formations of steppe. In the Tbilisi environs feather grass formation are represented by 2 plant communities: (1) Stipetum gramino-mixtoherbosum and (2) Stipetum festucosum. Second plant community is developed on more thin soils than first community. Short geo-botanical characteristic of identified plant communities is given bellow. (1) Stipetum gramino-mixtoherbosum Area in the Tbilisi environs: Tabori range (environs of vill. Shindisi and National Botanical Garden of Georgia), Mamadaviti range (surroundings of lake Kustba), Saguramo ranges; Altitud (m): 475e900; Exposure (macro): N, W, S-W; Exposure (micro): N, W, S-W; Inclination: from 20 -25 to 30 35 (rarely, 5 -10 ); Soil: dry, grey-cinnamonic, cinnamonic, in many cases skeletal, thin or middle depth; General projective coverage: in many cases 55e70% (rarely, 92e95%, 30e35%); Sodding degree: in many cases 15e25% (rarely, 5e10%, 40e45%); Dominant-edificatory: Stipa pennata (projective coverage 25e45%, rarely 15e20% and 50e55%); Characterized species:
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Perennial plants e Rumex tuberosus (frequency of occurence 73%), Galium verum (71%), Koeleria cristata (65%), Phleum phleoides (55%), Scorzonera biebersteinii (52%), Bothriochloa ischaemum (47%), Medicago caerulea, Onobrychis cyri (45-45%), Potentilla recta (39%); Annual plants e Crepis sancta (frequency of occurence 50%), Viola kitaibeliana (41%), Helianthemum salicifolium, Alyssum alyssoides, Arabidopsis thaliana (39-39%); Semi-shrubs & dwarf semi-shrubs e Teucrium polium (frequency of occurence 33%); Number of species: 203; Moss cover: in the different sections of area is very dissimilar: from þ to 75%; Litter: in the different sections of area is very dissimilar: from þ to 75%; Species richness on 1 m2: in the different sections of area is very dissimilar: from 16 species to 32,5 species; Species richness on 25 m2: in the different sections of area is very dissimilar: from 27,5 species to 54,3 species; Spectrum of life forms: Phanerophytes e 9 species (4,4%), Chamaephytes e 10 (4,9%), Hemicryptophytes (with biannual plants) e 99 (48,8%), Geophytes e 15 (7,4%), Therophytes e 70 (34,5%). (2) Stipetum festucosum Area in the Tbilisi environs: surroundings of lake Lisi, Mamadaviti range (surroundings of lake Kustba); Altitud (m): 650e730; Exposure (macro): N; Exposure (micro): N, N-E; Inclination: 30 35 (40 ); Soil: dry, grey-cinnamonic, cinnamonic, skeletal, thin or middle depth; General projective coverage: 60e85% (reraly, 90e95%); Sodding degree: 20e30%(40%); Dominant-edificatory: Stipa pennata (projective coverage from 20-25% to 30e40%); Subdominant-edificatory: Festuca valesiaca (projective coverage 15e25%, rarely, 8e12%); Characterized species: Perennial plants e Galium verum, Koeleria cristata (frequency of occurrence 100-100%), Medicago caerulea (92%), Veronica multifida (85%), Onobrychis cyri, Potentilla recta, Ranunculus illyricus (77-77%), Bothriochloa ischaemum, Carex liparocarpos subsp. bordzilowskii, Potentilla adenophylla (69-69%), Achillea nobilis subsp. neilreichii (62%), Allium rotundum, Filipendula vulgaris, Stipa capillata (54-54%). Annual plants e Trifolium arvense (frequency of occurrence 85%), Alyssum alyssoides, Trifolium campestre (77%), Cerastium glutinosum, Galium tenuissimum, Crepis sancta (69-69%), Helianthemum lasiocarpum (62%), Silene conica (54%), Arenaria serpyllifolia (46%); Semi-shrubs & dwarf semi-shrubs e Thymus coriifolius (frequency of occurrence 69%), Teucrium polium (46%);
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plants) e 62 (55,4%), Geophytes e 6 (5,4%), Therophytes e 32 (28,5%). Grass-forbs formation (Gramineto-Mixtoherbeta) In form of the small plots grass-forbs plant communities fragmentary distributed on the foothills and in the low mountain belt of eastern endings of Saguramo ridge. Plant communities are developed on slopes and plain places with various exposure and inclination. Soils are cinnanmonic and grey-cinnamonic, not infrequently skeletal. In the Tbilisi environs plant communities of grass-forbs steppe for the most part are of secondary origin. Their formation came by cutting of xeromezophilous and hemixerophilous shrubberies [20]. Plant communities of grass-forbs steppe are not characterized by the stable and shaped structure. Floristic composition of plant communities is changeable. Participation and coenetic role of the individual species are strongly varying. They do not belong to the plant communities in the stage of climax. Accordingly, grass-herb steppe is represented by coenoses of various modifications. Depending on origin, they are represented by less and more xerophilous variants. Short geo-botanical characteristic of plant communities is given bellow. Area in the Tbilisi environs: Eastern endings of Trialeti ridge; Altitud (m): 630e750(800); Exposure (macro): N, N-E, E; Exposure (micro): N, N-E, E; Inclination: from 10 -12 to 22 e23 (rarely, 5e6 , 30e32 ); Soil: cinnamonic, grey-cinnamonic, middle or thin depth; General projective coverage: from 75e to 80% to 95e98(100)%; Sodding degree: from 10-12% to 30e32% (rarely, 4e7%, 35e38%) Dominant-edificatory: various species are dominated on different locations; Characterized species: Perennial plants e Koeleria cristata, Potentilla recta (frequency of occurrence 100-100%), Festuca valesiaca (88%), Falcaria vulgaris, Onobrychis cyri (75-75%), Medicago caerulea, Salvia nemorosa (69-69%), Dactylis glomerata, Galium verum, Rumex tuberosus, Stipa capillata (63-63%), Bothriochloa ischaemum (56%), Elymus repens, Stipa pennata (50-50%); Annual plants e Medicago minima, Scabiosa micrantha (frequency of occurrence 44-44%); Semi-shrubs & dwarf semi-shrubs e Thymus coriifolius (frequency of occurrence 50%) Number of species: 97; Moss cover: 15e45%; Litter: from 15-20% to 65e70%; Species richness on 1 m2: 25 species; Species richness on 25 m2: 50 species. Spectrum of life forms: Phanerophytes e 1%, Chamaephytes e 4,1%, Hemicryptophytes (with biannual plants) e 56,7%, Geophytes e 9,3%, Therophytes e 28,9%. Conclusion
Number of species: 112; Moss cover: from þ to 45e50%; Litter: 12e15% (rarely, 25e35%); Species richness on 1 m2: 29 species; Species richness on 25 m2: 45 species; Spectrum of life forms: Phanerophytes e 5 species (4,5%), Chamaephytes e 7 (6,2%), Hemicryptophytes (with biannual
Area of steppe vegetation in the Tbilisi environs is in foothills and lower mountain belt, approximately 450e900 (100) m above s.l.. Plant communities of steppe are developed on slopes with various exposure and inclination, mainly on the grey-cinnamonic and also on cinnamonic soils. In the Tbilisi environs, the steppe vegetation is either primary or secondary origin. Plant
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communities of secondary steppe vegetation were formed by digressive succession processes of deciduous forests and shrubberies of various types of foothills and lower mountain belt. Steppe vegetation in the Tbilisi environs are represented by 4 formations: (1) Yellow bluestem formation (Bothriochloeta ischaemum), (2) Fescue formation (Festuceta valesiaci), (3) Feather grass formation (Stipeta pennatae) and (4) Grass-forbs formation (Gramino-Mixtoherbeta). From them Bothriochloeta ischaemum and Festuceta valesiaci formations have more area covering and characterized by the comparatively rich typological composition. Stipeta pennatae and Gramino-Mixtoherbeta has limited area. Typological composition of steppe vegetation of Tbilisi environs is such: Yellow bluestem formation (Bothriochloeta ischaemum): 1. 2. 3. 4. 5. 6.
Bothriochloetum gramino-mixtoherbosum Botriochloetum festucoso gramino-mixtoherbosum Bothriochloetum festucosum Bothriochloetum ephemerosum Bothriochloetum stiposum arabici Bothriocholoetum astracanthosum caucasici Fescue formation (Festuceta valesiaci):
1. Festuceum bothriochlooso-mixtoherbosum 2. Festucetum mixtoherbosum 3. Festucetum bothriochloosum. Feather grass formation (Stipeta pennatae): 1. Stipetum gramino-mixtoherbosum 2. Stipetum festucosum Grass-forbs formation (Gramineto-Mixtoherbeta): 1. Gramineto-Mixtoherbeta.
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