The diverse landscapes and climates of Armenia support a wide
diversity of micro-organisms, and these have been relatively
well studied compared to other countries. In particular, the
distributions and ecological relations of different micro-organism
groups and the altitudinal zonation in soil micro-organisms
have been studied. Much if this work has been done by a number
of institutes focusing on microbiology (Institute of Microbiology
of the National Academy of Science, Republican Centre for Micro-organisms,
and the Institute of Biotechnology, Ministry of Industry). A
range of micro-organisms are important in maintaining ecological
balance, soil quality and human health. Of particular interest
are the micro-organisms used in food production (cheese, yoghurt,
wine and bread), and there is a long history of selection of
strains of yeast and lacto-bacteria in Armenia. The need to
preserve a wide range of commercially important micro-organisms
represents an important issue relating to the conservation of
agrobiodiversity. The breadth of knowledge about micro-organism
diversity is illustrated below.
· Nitrogen-fixing micro-organisms, (including nitrogen-bacter)
are the best studied group of soil microflora. Distributions
of different species have been described from various soil types,
and from the root systems of plants; a new species (Azotobacter
nigricans) has also been described. Tuber bacteria have been
described widely within Armenia, and species recorded from different
plant groups include Rhizobium simplex, R. leguminosarum, R.
meliloti, R. phaseoli, R. lupinus, and R. trifoli.
· Sulphate-removing bacteria have been studied in saline
areas of the Ararat valley, where they occur in damp soils with
high levels of sulphate and organic matter. Soil treatment (sulphur
acid washing) resulted in a decline in these bacteria and affected
their role in sulphate removal.
· Bacteria which favour extreme conditions (of heat,
cold, salinity, and alkalinity) have been extensively studied,
including their biological components. About 1000 species of
such bacteria are maintained at the State Micro-organism Bank.
· Sulphide-oxidising bacteria, and other groups with
similar oxidation capabilities, are well studied. A number of
new species (and sub-species) have been described, including
Leptospirillum feroxidans, Thiobacillus organoparus and Sulfobacillus
thermosulfidooxidans asporogenes Such micro-organisms are used
in bacteria leaching, and in bacteria washing of metals and
in copper refining.
· Photosynthetic bacteria are common in the mineral waters
of Armenia. These include both sulphur bacteria (such as Chromatium
buderi and C. vinosum) and the more widely spread non-sulphur
bacteria such as Rhodopseudomonas (Rhodobacter) palustris, R.
spheroides, R. acidophilus, R. capsulatus, and Rhodospirillum
rubrum. In saline waters photosythetic, alkaline-tolerant species
are found (Ectothiorhodospira, Thiospira and Thiocystis).
· Lactic-acid bacteria, used in fermentation of dairy
products, have been well studied in Armenia, and the results
from such studies have been applied to a selection of new strains
for use in the dairy industry. A wide range of species, including
heat- and saline-tolerant forms, have been described. A number
of cultures are found in milk only in Armenia, and are not used
in neighbouring countries (e.g. Lactobacillus xylosus, Streptococcus
uberis, Leuconostoc parameseneroides). Specific lactic-acid
bacteria have long been used in the production of yoghurt, where
the main species used are Lactobacillus bulgaricus, L.helveticus,
L fermentum, Streptococcus faecalis, Str. bovis, and Str.cremoris.
Similarly, the bacteria used in cheese making differ from those
elsewhere in the Former Soviet Union.
· Yeasts have been studied in relation to the production
of wine and bread. Yeast strains used in baking (Saccharomyces
cerevisiae) have been isolated, including cultures of heat-
and salt-tolerent strains. In wine production, naturally occurring
yeasts and those used in fermentation have been well studied.
Many of these have been shown to be very productive, including
Saccharomyces cheresienis (var. armeniensis), an alcohol-tolerant
culture used in sherry production.
The enormous diversity of plants in Armenia has been described
based both in terms of classification (algae, fungi, moss and
higher plants), and by ecosystem. The botanic diversity of the
country reflects its position between major floristic regions,
with both Mediterranean and Boreal (Caucasian) floras being
recorded. The extent of knowledge of different floristic groups
(particularly fungi and higher plants) is described below, and
the numbers of species described in different floristic groups
is summarised in Table 2.1.
Table 2.1. Plant diversity in Armenia
|
Croup
|
Number of species recorded
|
|
Algae
|
388
|
|
Fungi
|
4166
|
|
Lichens
|
300
|
|
Mosses
|
430
|
|
Vascular plants
|
c.3555
|
|
TOTAL
|
c.9,800
|
Algae occur both in soil and in water bodies, but are relatively under-studied in
Armenia. In total, 143 species of algae are recorded from soil or other substrates,
mainly including green, yellow-green and blue-green algae, and bacillariophyta (Table
2.2).
A total of 245 species of phytoplankton have been recorded
from the water systems of Armenia. These include representatives
of the following groups: Cyanophyta (69 species); Chlorophyta
(58); Bacillariophyta (101); Charophyta (2); Dinophyta (3);
Xanthophyta (4); Phyrrophyta (1); Rhodophyta (1) and Euglenophyta
(6). Most of these are freshwater species, although some forms
are found in brackish water in the Ararat Valley. Over 97
species have been recorded from Lake Sevan alone, among which
the Chlorophyta are the most diverse (47 species), and Bacillariophyta
are also well represented. Rivers and streams within the Lake
Sevan watershed also show diverse algal communities (125 species),
and which characteristically include species associated with
high altitude, fast-flowing rivers. Other rivers , such as
the Arpa and the Masrik, also show high algal diversity (75
and 67 species respectively).
Table 2.2 Numbers of genera and species of different groups
of soil algae in Armenia
|
Group
|
Genera
|
Species
|
Widely distributed species characteristic
of Armenia
|
|
Cyanophyta
|
27
|
71
|
Gloeocapsa minuta, Merismopodia glauca,
Microcystis pulverea, Anabaena variabilis, Oscillatoria
brevis, Phormidium autumnale
|
|
Bacillariophyta
|
15
|
38
|
Cymbella parva, Diatoma vulgare, Fragilaria
pinnata, Navicula dicephala, Nitzschia amphibia, Pinnularia
borealis
|
|
Xanthophyta
|
12
|
14
|
Botrydiopsis arhiza, Vaucheria pachyderma,
Tribonema elegans
|
|
Chlorophyt
|
11
|
20
|
Chlamydomonas conferta, C. elliptica,
Chlorococcum humicola, Chlorella vulgaris, Ulothrix
variabilis
|
|
TOTAL
|
65
|
143
|
|
Phytoplankton found in Lake Sevan were previously considered
unusual, relative to other large lakes in Western Europe,
being adapted to oligotrophic (nutrient poor) conditions.
However, many of these species disappeared during euthropication
of the lake. Indeed, species such as Anabaena flos-aquae and
A. lemmermanii flourished, and contributed to the algal bloom
which occurred in 1964. By the 1970s species such as Melosira
granulata and M. islandica dominated the phytoplankton community
of the lake, but further eutrophication in the 1980s reduced
their numbers (although a recent upturn in numbers has been
recorded).
|
