1.5. Landscape and biologic diversity
1.5.1. Flora and fauna
The flora of the Republic of Moldova is rich and includes about 5513 species of plants (superior plants – 1989 species, inferior plants – 3524 species).
The forest ecosystems have the richest floristic composition (over 850 species): the steppecommunities, over 600 species, the meadow communities, about 650 species, the petricolous communities, about 250 species, and aquatic and paludous ecosystems, about 160 plant species. The diversity of species and ecological groups is determined both by biotop variability, providing a variety of ecological conditions due to different combinations of temperature, humidity, soil reaction and other environmental factors, and by the fact that the territory of Moldova is situated at the interference of three bio-geographic zones: Central-European, represented by the Central Moldavian Heights (54% of the country’s territory); Euro-Asiatic, represented by the forest steppes and steppes (30% of the territory); and Mediterranean, represented by the xerophyte forest steppes in the South of Moldova (16%).
The general tendency of the last decades consistsin the gradual withdrawal of the plant populations specificfor natural ecosystemsalong with the accelerated expansion of adventitious and ruderalspecies in all ecosystems.
The forest ecosystems of the Republic of Moldovaaremainly representedbydeciduous forests. Oak forests predominate.In the North of Moldova there are two types of oak woods: English oakwith cherry tree (dominant community), and English oakwith birch. The lattercan be found in the forest sectors “Rososeni” and “Mestecanis” of the Ocnita forest district, it indicates the South-western area limit of birch in Eastern Europe.
Beech forests, Fagus sylvatica L, can be found in the Northwest part of the Central Moldavian Hights (Codrii), at the altitude of 200-400m, on the northern and north eastern slopes.This is the eastern limit of the beech area in Europe. The slopes exposed to the south of the Codrii region are occupied by durmast oak (Quercus petraea) and durmast oak with hornbeam (Carpinus betulus L.).
Forested communities of Mediterranean types with pubescent oak (Quercus pubescens) as well as English oak groves (Quercus robur L.) can be found in the forest ecosystems from the southern part of Moldova. The former indicate the Northeaster limit of the area of that species.The floristic structure of the pubescent oak forests includes about 400 species, the most representative being the steppe species. A significant number from these are Mediterranean and Balkan species, most of them are at the limit of their area.
The Prut and Dniesterrivers floodplains present areas with meadowforests of white poplar (Populus alba L.), English oak, elm (Ulmus laevis Pall.), various species of willow (Salix). Meadow forests constitute 4.7% from the total area of Moldavian forests.
Steppe ecosystems.Only spots of steppe herbaceous communities have remained in the BaltiPlain (in the North) and in the hilly Plain of Bugeac (in the South).The latter is much more xerophytic and has a poorer floristic composition.The most representative are the Asteraceae, Papilionaceae, Poaceae and Lamiaceae families.
As a result of the anthropic impact (development of fallow lands, intensive grazing, reclamation works, gathering of medical and adornment plants) the native steppe communities have practically disappeared. They are represented by spots of primary and secondary vegetation, which are encountered in the oak-wood clearings, among agriculture lands and on eroded steep slopes.
Out of the total number of steppe species, 18 are included in the Red Book of the Republic of Moldova, and 9 of these (Astragalus dasyanthus Pall., Belevallia sarmatica (Georgi) Woronow, Bulbocodium versicolor (Ker.-Gawl.) Spreng., Colchicum triphyllum G.Kunze, C. Fominii Bordz., Galanthus elwesii Hook. fil., Ornithogalum amphibolum Zahar., O. oreoides Zahar., Stembergia colchiciflora Waldst. et Kit.) also appear in the Red Book of Ukraine (1996) and the Red List of Superior Plant of Romania (1994).
Apart from the destruction of specific biotopes, an essential factor endangering the populations of rare species is the collection and marketing of some ornamental plants, especially ephemeroids,e.g.Ornithogalum, cocrus (Crocus), adonis (Adonis), snowdrop(Galanthus), hyacinth (Hyacinthella), colchicum (Colchicum), Stipa etc.
Paludous and aquatic ecosystems. Duringla last decades, the network of Moldavian surface waters has been essentially modified.The heavy impact of anthropic factors (deforestation, draining the wetlands, canalisation of rivers, excessive grazing, etc.) on the aquatic and paludous ecosystems reduced significantly the areas covered by natural vegetation and leaded to the erosion of the specific genetic diversity.
The floristic outline of vascular plants from aquatic and paludous ecosystems includes 52 aquatic speciesfrom 26 genera and 19 families and 165 paludous species from 71 genera and 32 families. The most representative genera are: sedge (Carex), 16 species, water spike (Potamogeton), 15 species, rush (Juncus), 14 species, knot grass (Polygonum), 8 species, Cyperus and Eleocharis, 5 species each.
Petricolous ecosystems can befound on calcareous rocks (toltres) in the northern part of the Prutriver catchment (from Lipcani to Braniste), representing a unique element of the landscape. Calcareous biotopes also appear along the Dniesterriver course (from Naslavcea to Tighina).
According to the researches carried out by Simonov (1980, 1987) the petricolous flora of the Republic of Moldovacomprise 20 species of lichens and 53 species of bryophytes.
Researches onpetricolous vegetation were carried out by Gheideman (1980), Postolache (1975, 1993), Panzaru (1991). The list of the rocky plants includes 252 species belonging to 153 genera and 55 families. The most representative families are: Asteraceae, Caryophyllaceae, Brassicaceae, Poaceae, Rosaceae, Papilionaceae and Lamiaceae, gathering altogether over 60% of the rocky flora.
The rocky habitats are very specific; the aridity and inaccessibility of the groundwater for plants reduce the diversity of petricolous communities. About half of the rocky flora is constituted of hemicryptophytes – 47.2%, and terrophytes (annual and biannual) – 27.3%.
In the composition of rocky flora 25% is represented by diverse species of steppe – xerophytes and mesoxerophytes. An endemic species,Poa versicolor, was identifiedin these communities.
The study of petricolous flora emphasised the presence of 18 species included in the Red Book of the Republic of Moldova and a number of species that needs protection.
From this category,a number of forest communities can bedistinguished:English oak(Quercus robur); durmast oak(Q. petraea); and pubescent oak groves (Q. pubescens).
Fauna.Moldavianfauna has a transition character with elements of European forest steppes and Asiatic continental steppes fauna. The territory between the Dniester and Prutrivers represents the Western or Eastern area limit for many species of animals and this makes themparticularly vulnerable. The intensive land use led to the disjunction of biotopes and habitats of animal speciesand to their increased isolation, particularly important during reproduction period, and, consequently, to the reduction of existing populations.
The animal diversityin Moldova comprises about 15,000 species, out of which 462 species are vertebrateanimals and 14,500, invertebrates. Among vertebrate animals the most numerous is the class of birds (281 species and subspecies) and among invertebrates,the insects (over 12,000 species).
The degradation of natural ecosystems implicitly has a negative impact on the animal species. The first issue of the Red Book of the Republic of Moldova (1978) included 29 species of vertebrate terrestrial animals (mammals, birds, reptiles), while in the second issue of the Red Book (2001) this number increased twice (mammals 14, birds 39, reptiles 8). Moreover, there were introduced 12 fish species, one amphibian, one Cyclostomatae and one crustacean species, 37 insect species, and 3 molluscs. All in all 116 vertebrate and invertebrate species are in danger and vulnerable. Besides, a relatively large number of rare animal species was not introducedin the Red Book.
Analysing the specific diversity from different natural and anthropicecosystems, it has been concluded that on the territory of the republic there are several complexes of adjacent forest, aquatic, paludous ecosystems where 10 and more species of terrestrial vertebrate animals included in the Red Book of Moldova, live. Five of these complexes are represented by the scientific reserves and the adjacent zones (“Codru”, “Plaiul Fagului”(Beech Country), “Padurea Domneasca”(Regal Forest), “Prutul de Jos”(The Lower Prut), “Iagorlac”), Baltile Talmaz (Talmaz Swamps), the complex of forest ecosystems “Caracuseni-Tabani-Balasinesti-Sirauti” and the complex of forest ecosystems “Rudi-Arionesti-Calarasovca” plus the rocky habitats and the Dniesterriver.
In table 1.16 the specific diversity of the terrestrial vertebrates in 8 natural ecological complexes is presented. The data show that almost all natural ecological complexes create favourable conditions for at least half of the terrestrial vertebrate species registered on the territory of Moldova.
Table 1.16
Specific diversity of terrestrial vertebrates in natural ecosystems
No / Name /Number of species
/Total number of
species
Mammals / Birds / Reptiles / Amphibians1. /
“Codru” scientific reserve
/ 45 / 138 / 10 / 10 / 2032. / “Plaiul Fagului” scientificreserve / 42 / 138 / 7 / 10 / 197
3. / “Padurea Domneasca” scientificreserve / 45 / 150 / 7 / 8 / 210
4. / “Prutul de Jos” scientificreserve / 34 / 189 / 7 / 11 / 241
5. / “Iagorlac” scientificreserve / 22 / 122 / 8 / 6 / 158
6. / Talmaz swamps / 45 / 142 / 6 / 6 / 199
7. / Caracuseni-Tabani-Balasinesti-Sirauti complex / 43 / 140 / 7 / 7 / 197
8. / Rudi-Arionesti- Calarasovca complex / 38 / 140 / 7 / 7 / 192
Table 1.17 presents the number of terrestrial vertebrate species included in the Red Book of Moldova (2nd issue, 2001), which populate the mentioned ecologic complexes. Mammals, reptiles and amphibians are represented by sedentary species and the bird species include the migratory birds. The number of nesting birds is 6-7 species.
Table 1.17
Terrestrial vertebrate species from complexes of natural ecosystems included in the Red Book of the Republic of Moldova
N. / Name /Number of species
/Total number of
species
Mammals / Birds / Reptiles / Amphibians1. /
“Codru” scientificreserve
/ 2 / 12 / 2 / 1 / 172. / “Plaiul Fagului” scientificreserve / 3 / 14 / 2 / 1 / 19
3. / “Padurea Domneasca” scientificreserve / 6 / 19 / 2 / 1 / 28
4. / “Prutul de Jos” scientificreserve / 5 / 21 / 2 / 1 / 29
5. / “Iagorlac” scientificreserve / 2 / 10 / 3 / 1 / 16
6. / Talmaz swamps / 5 / 21 / 3 / 1 / 30
7. / Caracuseni-Tabani-Balasinesti-Sirauti complex / 5 / 15 / 2 / 1 / 23
8. / Rudi-Arionesti- Calarasovca complex / 3 / 14 / 3 / 1 / 21
Comparing the present state of specific diversity with the past one (in the 1970s) one can mention that it became poorer, firstly due to the disappearance of several predatory animals from the reproduction sites and the reduction of the number of other terrestrial vertebrate species.