Glossary of Terms

Abiotic factors: Factors of the non-living nature – climate, water, rocks, minerals, etc.
Abrasion: Process of destruction or washing away of coastal beaches, lake banks, etc. by the waves or tides.
Abundance: A direct or indirect value for the quantitative participation of a species that occurs in a phytocoenosis.
Acidophillous plant: Plant that grows on acidic soils (pH < 6,7).
Andropogoid steppes: Steppe herbaceous communities dominated by grasses from the subfamily Andropogonidae – in Bulgaria these are Chrysopogon gryllus and Bothriochloa ischaemum (=Dichanthium ischaemum).
Anoxic: Reduction or absence of oxygen.
Anthropophytes: Plants with secondary distribution in the country as a result of unconscious or deliberate human activities. They are archeophytes (spread before the 15th century) and neophytes (after the 15th century).
Anthrosols: soils which are the result of human activities
Apophytes: Plants that are a part of the autochthonous or primary element of the local vegetation cover, which can spread and establish in habitats that are created and maintained by man.
Arctic-Boreal species: Species the main areas of distribution of which cover the border area between tundra and taiga; they also occur in the high parts of some mountains in Europe.
Assectator: Species with permanent presence but with low abundance in the plant communities.
Association: major syntaxonomic category in the vegetation classification.
Atlantic period, Atlantic: The third stage of Holocene (see Holocene) according to the chronological system of Blytt-Sernander. The period is characterized by higher temperatures – also known as the Holocene temperature optimum.
Autenvironment: The environment in which each individual develops.
Benthos: Organisms that live on the bottom of a water body.
Biocoenosis: The total number of all living organisms that occur on a relatively homogenous territory , land or water.
Biogenic aeration: Release of chemical elements (gases), which are part of the living matter, whose accumulation in the water causes eutrophication (see Eutrophication).
Biological drift: Passive transfer of benthic organisms by the water currents.
Biological spectre: Percent ratio between the life forms according to the classification of Raunkier (1904) (phanerophytes, chamephytes, hemicryptophytes, cryptophytes and terrophytes).
Biotic factors: Factors of the living nature (living organisms and the production of their activities).
Boreal species: These species are typical for the taiga and mountains of the central and southern parts of the continents in the northern hemisphere.
Boreal: The second phase of the Holocene according to the chronology of Blytt-Sernander (see Holocene).
Brackish species: Species that occur in brackish water bodies (see below).
Brackish water body: A water body whose salinity varies from 1 to 30 ‰ (lower than that of the ocean) due to the inflow of fresh water.
Calciphil: A plant that grows on alkaline (pH > 7,0) soils with high calcium content or on calcareous rocks.
Central European species: Species which are typical for the deciduous forests of the region.
Chamephyte: Plant the reproduction buds of which are close to the ground (up to 25 cm).
Characteristic species: Species that are related to a certain vegetation syntaxon in which they have relatively high constancy and the conditions for their development are optimal.
Chemicryptophyte: Plant the reproduction buds of which are on the soil surface during the unfavourable vegetation season.
Chemiskiophyte: Plants that develop at direct sun light but can endure strong shading.
Cherry waters: The high spring waters of the rivers in the Danube water catchment area from mid-May to the end of May, resulting from the melting snow in the mountains.
Chloride solonchaks: Saline soils which contain more than 1 % of water soluble salts (mainly chlorides) at pH > 8,5.
Circumlittoral: A border area of distribution of marine algae, at or near the water level.
Cladoceran crustaceans: An order of crustaceans (Cladocera) from class Branchiopoda, also called water fleas.
Climax: Stable community that is in dynamic equilibrium with its abiotic environment.
Closed community: A plant community in an advanced stage of development, with dense vegetation cover and diffuse distribution of the individuals of different species. The penetration of new species is very difficult.
Co-dominant: A plant that, together with other plants, plays a major role in the composition of a certain layer in the phytocoenosis (see Dominant).
Coenopopulation: A group of individuals of a certain species that grow in a certain phytocoenosis and exchange genetic information with each other.
Coenosis makers: Species which play a major part in the formation of a community (see Edificator).
Coenosis: A community of organisms (biocoenosis, phytocoenosis, zoocoenosis, algocoenosis, etc.).
Coluvial deposits: Conical gravel deposits that have been accumulated by the rains temporarily running rivers and streams, etc., when entering the flat areas.
Constancy: Occurrence (respectively constant participation in a community composition), given in a scale.
Constant species: Species with high degree of constancy (see Constancy).
Crenophillous fauna: Animals that live in springs and small, permanently running water bodies.
Cryoclastic material: Rock material that is a result of ice erosion (a long-term impact of the repeating freezing and melting of water).
Cryophyte: Plant that develops at dry and cool climate.
Cryprogamic plants: Plants with spore reproduction – algae, lichens, mosses and pteridophytes.
Cryptophyte: Plant, the reproduction buds of which are in the soil or in the water during the unfavourable living conditions.
Detritophillous invertebrate fauna: Invertebrates that disintegrate or mineralize organic materials.
Detritus: Non-living parts of organic matter usually including the bodies of dead organisms, part of organisms or their excrements.
Diagnostic species: Group of species whose optimal development is possible within a certain syntaxon (see Syntaxon); a group of characteristic species that are typical for a certain phytocoenoses.
Dominants: Species that, as a result of the struggle for existence, have gained a dominant position in the community or the ecosystem; species with large biomass and projective cover (see Projective cover).
Drift zone: The zone in which biological drift occurs (see Biological drift).
Dyke: The main elements of each dyke are: crest, slopes (inside and outside), basis and body.
Dystrophic water body: A water body without nutrients that is in its terminal stage of development.
Ecological niche: The functional position of the species in the ecosystem; the living conditions within an ecosystem that correspond to the needs of the population of a species within one community.
Ecological plant groups: Groups of plants that originate as a result of one dominating ecological factor (humidity, temperature, light, mechanical or chemical composition of the soil, etc.)
Ecosystem: Biocoenosis and ecotope together (see Biocoenosis and Ecotope).
Ecotone: The transitional zone between different types of habitats or communities.
Ecotope: A subsystem within an ecosystem that includes the edaphotope, aerotope, and hydrotope; the climatic, soil and other abiotic factors of the environment.
Edafic humidity: Soil humidity.
Edafotope: The soil environment.
Edificator: A prevailing (dominating) species in the main (structure determining) layer of the plant community.
Endemic species: Species the distribution of which is limited to a certain area (geographical zone, country, sea, etc.).
Eole origin: Origin that is linked to the wind (for deposits, earth shapes, niches, etc. that are created by the wind).
Epibiont: Organism that develops on other animals or plants.
Epifauna: Animals (part of the benthos) that are attached to the ground surface or freely moving on it (see also Zoobenthos)
Epilimnion: The water layer (usually 10-15 m deep) that is stirred by strong air currents in summer and the temperature of which is almost homogeneous.
Epilith: Organism that develops on rocks or stones.
Epizoid: Organism that develops on an animal.
Ericoid species: Evergreen small shrubs or small shrubs from family Ericaceae, mostly with needle-like leaves.
Eutrophic species: Organisms that develop in nutrient-rich substrates.
Eutrophication: High concentration of nutrients that causes high biological productivity; algal “blooming.”
Extrazonal vegetation type: Vegetation that makes patches in one zone and is similar to the vegetation in a different zone.
Flora: The plant species that occur on a certain terrestrial or aquatic area.
Floristic elements, phytogeographic elements, geoelements: Group of species that originate from one geographical region and have had similar direction of distribution and changes in this distribution.
Floristic richness: All plant taxa that comprise a plant community or ecosystem.
Garrigue: open climax vegetation characteristic of the Mediterranean, with low shrubs and trees, on acid or alkaline soils.
Geographical vicariation: Variation of closely related species or plant coenoses in distant areas with similar ecological conditions.
Geophytes: Plants, the reproduction buds of which are in the soil during the unfavourable period (in bulbs, tubers, on rhizomes, etc.).
Grazing degression: A succession process (see Succession) caused by overgrazing that causes a regression in the state and impoverishment of the species composition of a herbaceous community.
Habitat: An area with specific abiotic and biotic conditions that provides for the complete life cycle of an individual, population or a species as a whole.
Halonitrophillous plant: Plant that grows on saline soils rich in nitrogen substances.
Halophyte: Plant that grows in saline soils.
Hasmophyte: Plant growing in the rock crevices.
Hasmophytic community: Plant community on rocks consisting of hasmophytes.
Hekistothermic species: Cold-adapted arctic or high-mountain plants.
Heliophillous organism: Plant or animal that needs much light.
Heliophyte: Plants that need direct sunlight for their optimal development.
Helophyte: Aquatic-terrestrial plant the reproduction buds of which are in the water during the unfavourable vegetation season and the vegetative shoots (stems and branches) are above the water surface.
Heterophototypic complex: A group of heterotrophic organisms.
Heterotrophic organisms: Organisms that, unlike the autotrophic ones, cannot synthesize organic substances from the atmospheric CO₂ and feed on complex organic substances. Heterotrophic organisms are animals, fungi, and many bacteria.
Holarctics: Floristic kingdom that covers the non-tropical parts of Europe, Asia, North America (Palaearctics) and North Africa (Neoarctics).
Holocene: The interglacial period that began 13000 years ago and continues until the present time. It has the following phases: pre-Boreal, Boreal, Atlantic, sub-Boreal, and sub-Atlantic.
Holodynamic water bodies: Water bodies in temperate zones characterised by the temperature dynamics of the water. Twice a year they have temperature stratification of the water – in winter (when the temperature in the bottom layers is much higher than at the surface) and in summer (the temperature of the surface is much higher than that of the bottom layers). In spring and autumn the water temperature is homogeneous throughout the water body (in spring, teperature is lower and in autumn it is higher).
Humid climate: Climate in which the rprecipitation prevails over the evaporation but the temperature is high; the air contains much water vapour (evaporation from plants, soils, etc., after rain, for example).
Hydrophytes: Plants, the reproduction buds of which are in the water and the shoots are covered by water; water plants.
Hygrobiont: Organisms that live in an aquatic environment or which have certain periods of their development which obligatorily take place in such environment.
Hygromesophytes: Mesophytes that are adapted to live on over-wet soils.
Hygrophillous vegetation: Vegetation that develops at high humidity.
Hygrophyte: Terrestrial plant that grows in a constant or temporary surplus of water.
Hygropsychrophytes: plants which like water and cold
Hypersaline species: Plant that grows on strongly saline soils (see Halophyte).
Hypersaline water body: A water body with salinity above 40 ‰.
Hypolimnion: Ecological zone in fresh water basins which are more than 14-20 m deep.
Hypoxy: Reduced quantity of oxygen in the tissues (see Anoxy).
Hyssopus flora: Aromatic perennial plants and semishrubs from the genus Hyssopus (Lamiaceae), occurring in the eastern Mediterranean region and extending to Central Asia.
Infralittoral: See Sublittoral.
Interstitial fauna: Fauna that lives in-between the sand grains on marine beaches (above or below the water level).
Intrazonal group of phytocoenoses: Phytocoenoses that develop in conditions that are not typical for a certain zone and do not make a specific zone. They occur in different zones as patches.
IUCN: International Union for Conservation of Nature and Natural Resources.
Lagoon: Shallow water body (former bay) separated from the sea by a sand strip or coral reef.
Laurous scrub: Hygromesophytic, evergreen shrubs with relatively large, leathery leaves (Rhododendron ponticum, Laurocerasus spp., Ilex spp., Daphne ponticum, etc.).
Liman: A river estuary that is flooded by seawater and is transformed into a stagnant water body.
Limnobiont: Organism that occurs in stagnant, continental water bodies.
Littoral: The tidal zone of lakes, seas and oceans.
Living form: The outer appearance of a plant that corresponds to the environmental conditions.
Malacofauna: Snail and slug fauna.
Mediterranean species: A (plant) species that is typical for the evergreen, hard-leaved forests of the Mediterranean region.
Meso-hygrophytes: Hygrophytes (see Hygrophytes) that can also grow on medium-humid soils.
Meso-oligotrophic peat bogs: Peat bogs that are medium-poor in nutrients.
Mesophytes: Plants that grow on medium-humid soils.
Mesophytic vegetation: Vegetation that is adapted to an average level of humidity.
Mesotrophic species: Species that grow on soils that are medium-rich in nutrients.
Mesoxerophytes: Mesophytes (see Mesophytes), that can endure drought.
Microgroup: Element of the horizontal structure of the phytocoenosis.
Mixohaline water bodies: Semi-saline water bodies (water bodies whose salinity is 0,5-30 ‰).
Monodominant phytocoenoses: Plant communities with one dominant species (see Dominant).
Monoedificator phytocoenoses: Plant communities with one edificator species (see Edificator).
Nanophanerophyte: Phanerophyte (see Phanerophyte) up to 2 m high.
Neophyte: see Anthropophyte.
Neutrophillous forests: Forests that grow on neutral soils or soils close to neutral.
Nitrification: The process of transformation of organic nitrogen-containing substances into nitrites or nitrates.
Nitrophillous plant: Plant that occurs on soils rich in nitrates.
Occurrence: Parameter that corresponds to the distribution of the individuals of the different coenopopulations; it is calculated as a percentage.
Oligotrophic species: A species that develops on soils poor in nutrients.
Open community: A community in its early (or regressive) stage of development in which the plants occur at a certain distance from one another.
Palearctics, Palearctic region: Part of the Holarctic floristic kingdom that covers the neotropic parts of Europe, Asia and North America (see Holarctic).
Pannonic basin: Historically and geographically determined flat area in Central Europe along the Danube, mainly situated in Hungary today.
Parietal fauna: Animals that live on the cave walls.
Pelagic: The open mass of a water body.
Petrophytic communities: Plant communities that occur on stony areas, on poor soils or in places where soils are lacking.
Phanerophyte: Plants, whose reproduction buds are situated at a level higher than 25 cm above the ground.
Photophillous organism: See Heliophillous organism.
Phrygana: Open xerothermic communities dominated by small, mainly evergreen shrubs and semishrubs, with the participation of many ephemeres and occurring in the central and eastern parts of the Mediterranean Area.
Phrygophillous small shrub: Cold-adapted small shrub.
Physical aeration: The adding of air through physical methods.
Phytocoenosis: Plant community.
Phytophage: Animals that feed on plants.
Phytoplankton: Small, often microscopic algae, that float on the water (fresh or marine) or make slow movements.
Pioneer coenoses: Communities that developson primary substrates, poor in nutrients, and constitute the initial stage of the habitat development.
Plestophyte: Plant that develops on the water surface (synonyms Phytopleustone; see Pleustone).
Pleustone: An ecological group of aquatic plants that occur on the water surface as a result of adaptations that make them lighter than the water.
Pre-Boreal: The first, transitional stage of the Holocene, prior to Boreal (see Boreal).
Primary habitat: Natural, unchanged habitat.
Priority communities: Communities in which priority species participate; communities of conservation value.
Priority species: Species that are important for the state of the habitat or protected area; species of conservation value according to the national or international environmental legislation; species from the Red Data Book of Bulgaria; endemic species; relic species.
Projective cover: Percentage of the territory that is covered by the aboveground part of the individuals, coenopopulation or the whole phytocoenoses (total projective cover).
Psammophyte: Plant that lives in sandy areas (dunes, etc.).
Pseudolittoral: The beach zone of continental seas that is without tides.
Psychrophillous plant: Plants that grow at cold and humid climate.
Refugium: Shelter, area of distribution of isolated or relic species that used to be widely distributed in the past.
Relic: Phylogenetically old taxa that used to be more widely distributed in the past.
Reobiont species, potamobionts: Organisms living in running water bodies.
Reocrenic springs: Springs in which the water is under high pressure. They are called also vaucluse springs after the name of the French scientist. There are springs of underground water on karst areas nearby.
Rotifers: (Rotifera): Widely distributed, microscopic invertebrates between 50 and 2000 μm in size, living in different habitats. They are abundant in fresh and saline water bodies and periodically in the humid habitats of soil, sandy beaches, leaves, mosses, etc.
Ruderal: Species with low competition potential for quick seed or vegetative reproduction that occurs in areas under anthropogenic impact – urban places, arable land, etc.
Sclerophillous plant: Xerophyte that has adaptations to limit transpiration, such as thick walls of the epidermal cells, thick cuticle, reduced leaf area, etc.
Semi-succulent plant: see Succulent plant.
Skiophyte: Plants that prefer shady places. They do not endure direct light and the optimum of their development is at lower light intensity.
Stenoxybiont: Organism that can occur only in environment with free oxygen.
Stratification: Process of layering of the water in lakes and oceans, usually due to temperature differences; inverted stratification (the water is cold at the top) and straight stratification (when the water is warm at the top).
Subclimax, disclimax: Relatively stable state of phytocoenoses that have not reached a climax (stable state) as a result of different abiotic or biotic factors (see Climax).
Subdominant: Plant that plays major role in a certain layer of the phytocoenoses but its abundance is lower than that of the dominant (see Dominant and Edificator).
Sublittoral: A coastal part of the sea bed that may coincide with the shelf. It is situated below the tidal zone (littoral) and reaches the border of the distribution of the bottom vegetation (200-500 m depth); the most productive sea zone with extremely rich flora and fauna.
Succession: Changes in the plant communities that result in the replacement of one phytocoenoses by another; development of the ecosystem, replacement of one ecosystem with another one.
Succulent: Xerophyte with strongly developed water-containing tissues in the vegetative organs.
Syndynamics: The dynamics of plant communities.
Syntaxon: Phytocoenoses that belong to a certain syntaxonomic category.
Syntaxonomic category: All syntaxa at a certain level of the hierarchical classification.
Syntaxonomic continuum: The continuity of the vegetation cover (plant continuum), that reflects the vegetation classification when the separate syntaxa are not clearly distinct from one another and many transitions (ecotones) are observed between them.
Synusium: Spatially and ecologically distinct part of the phytocoenosis that belongs to one or several similar life forms.
Synvicariant: Plant community the replaces another similar community in a distant area with similar ecological conditions (see Geographical vicariation).
Taxon: The name of the classification units that identifies its place in the hierarchical identification system; all organisms which are treated as a formal unit at a corresponding level of the classification scheme. The main taxonomic unit is the species.
Temperature fluctuations: Changes in the temperature.
Terrophytes: Annual plants that spend the unfavourable part of the vegetation season as seeds, fruits, spores, etc.
Tertiary relics: Species that used to be more widely distributed during Tertiary period (see Relics).
Tragacanth scrub: Small, spiny shrubs, mainly from the genus Astragalus s.l. or genera systematically close to it and belonging to the Legume family (Fabaceae); they occur in the arid areas of Asia where they dominate the so called tragacanth steppes.
Troglobiont: Organism adapted to live only in caves.
Troglophillous organism: See Troglobiont.
Vegetation fluctuations: Non-targeted, differently oriented or cyclic fluctuations in the phytocoenoses that are caused by biological, climatic or other cyclic impacts at the end of which the initial or close to the initial state is restored
Vegetation: All plant communities (phytocoenoses) found on a certain terrestrial or aquatic area.
Xerophyte: Plant that develops in dry habitats and can survive a long-term atmospheric and soil drought, preserving its physiological activities.
Xerothermic plant: Plant that occurs in dry and warm habitats.
Xerothermophillous plant: See Xerothermic plant.
Zoobenthos: Animals that live on the bottom of a water body (see also Epibenthos).

Marius Dimitrov