[A syntaxonomic analysis of the initial stage effect on secondary autogenous succession of broad-leaved forest].

Using successional system of Stachyo sylvaticae-Tilietum cordatae association as a case study, the possibilities are considered of applying syntaxonomy as developed on the basis of floristic classification principles. Characteristics of restorative successions on cut-over lands have been analysed at strong and weak disturbance of soil cover as well as in plantings of coenotically weak species Pinus sylvestris and coenotically strong species Picea obovata. High self-restoring potential of the association studied is emphasised.

[The contribution of L.G. Ramensky theoretical legacy to modern vegetation science (to the 130 anniversary of the scientist's birth)].

L.G. Ramensky (1884-1953) was an outstanding Soviet geobotanist of the first part of XX century. Considered is his theoretical legacy and its contribution to modern vegetation science. L.G. Ramensky formulated the principle of vegetation continuum based on which the modern paradigm of vegetation science has been put into shape. The scientist made a contribution to the development of such important theoretical conceptions as types of plant strategy, coenosis and coenobiosis (coexistence of species), patterns of interannual variability in plant communities, ecological successions. The unique ecological scales were established by L.G. Ramensky that characterize the distribution of 1400 species over the gradients of soil moistening, richness, and salinization as well as moistening variability, pastoral digression, and alluvial intensity. He came out against mechanistic notions by V.N. Sukachev on a biogeocoenosis structure. The scientist did not offer his own method of plant communities classification but his well-reasoned criticism of dominant classification played a great role in adoption of floristical classification principles (Braun-Blanquet approach) by phytocenology in our country.

[The conception of plants community: the history and the modern state of the art].

After discussion of many years about the nature of plants community, within the science dealing with vegetation the consensus is reached on pragmatic basis. Most researchers consider plants community as conditionally uniform contour marked out of the multi-dimensional continuum of any type of vegetation. Plants community is a generic notion, within the framework of which types with different models of organization are established. With any type of plants community organization model, the main factor of species association remains to be the ecotope which plays the role of an abiotic matrix. The main traits of a plants community are species composition, its structure, species interrelations, and functional parameters. The main types of species interrelations within a plants community appear to be competition and non-competitive formation of environment. The important role in organization of plant communities belongs to heterotrophic organisms such as phytophages, nitrogen-fixing procaryotes, mycorrhizal fungi, pathogens, and others.

[Basic trends in the development of the theory of syntaxonomy and plant communities dynamics].

Considered are trends in the development of two basic parts of phytosociology--syntaxonomy (vegetation classification) and vegetation dynamics. At the end of XX century, the consolidation of researches in the field of syntaxonomy has taken place on the base of Braun-Blanquet approach, as well as the development of syntaxonomy due to studies of vegetation in new regions, and adoption of information technologies. In Russia, Braun-Blanquet approach has being implemented only in 1980s, because before that its spread was impeded by political climate in the country. Presently, syntaxonomy of vegetation in Russia includes 80 classes, 169 orders, and 377 alliances, at that considerable part of them are new for the science. In the theory of vegetation dynamics, the paradigm shift has occurred in XX century--from organicism to the concept of continuum. From the beginning of XXI century, the interest in general theory of successions has being receded and, instead, particular patterns of successions of different type have being revealed.

[Syntaxonomic analysis of restorative successions after cutting down light coniferous forests of South Ural Region].

Discussed are the possibilities of using syntaxa from floristic classification for the analysis of secondary restorative successions after forest cutting in South Ural Region. Peculiarities of secondary forest communities classification that may be viewed as subjects of indigenous vegetation syntaxa forming, sub-associations or could be systematized according to 'deductive' classification introduced by K. Kopecky and S. Heiny are considered. An example is presented of an analysis of communities succession system formed after cutting down hemiboreal pine and birch-pine herbaceous forests of Bupleuro-Pinetum association. Within this system the processes of divergence and convergence of succession series take place. Divergence occur as a result of lifting of the influence caused by dominants edificating role and manifestation of differences in soil humidification, also as a consequence of soil enrichment by mineral elements after burning down the felling debris. The reason behind convergence is grading influence of renewed forest stand. Trends in species richness changes during restorative successions may differ depending on ecotope features. In course of a succession, models of tolerance and inhibition become apparent.

[Contribution of syntaxonomy to the study of vegetation dynamics].

Of late decades, numerous studies on vegetation dynamics have been carried out and the spectrum of studied objects extended. However, syntaxonomy, while is capable to reveal patterns in vegetation changes, is virtually not used in analysis of succession. Prospects of syntaxonomy application to the study of vegetation dynamics are demonstrated by the example of succession analyses of pasture digression, vegetation changes under influence of recreation, progressive succession at the place of deserted settlements. The special role played by the analysis of syntaxonomic spectre of serial plant communities is discussed. The analysis makes it possible to estimate the serial status of communities by the ratio in their floral composition of species from cenofloras of classes that represent different serial stages of vegetation.

[The analysis of the factors determining species richness of Southern Ural forest communities].

There was analyzed the influence of warmth, moisture, and soil fertility on species richness and phytosociological spectrum of phytocenoses of three classes of Southern Ural autochthonous forests: Querco-Fagetea (nemoraloher-bosa), Vaccinio-Peceetea (boreal forests), and Brachypodio-Betuletea (hemiboreal forests). Environmental factors were estimated by Landolt's scales. We studied the changes of syntaxa of association rank by means of gradient phy-tosociological analysis. In phytosociological specter, in addition to the cenoflora of the three investigated classes, we estimated the representation of species from steppes (class Festuco-Brometea), xerothermal forest edges (class Tri-folio-Geranietea), and meadows (class Molinio-Arrhenatheretea). For boreal and hemiboreal forests, the dependence of cenoses species richness on environmental factors is parabolic, with its maximum in the middle of the gradient. With respect to nemoral forests, species richness declines with increase of environmental factors values. Maximum species richness is registered when the proportion of species of the own cenosis class in the community is maximal. The contribution of the ecotone effect (inclusion of other classes' species in the community composition) enhances as species richness reduces.

[Braun-Blanquet method of vegetation classification in Russia].

Under consideration is the history and contemporary state of the vegetation classification based on the ecological-floristic criteria (the Braun-Blanquet approach) in Russia. Analyzed are preconditions of dissemination of this approach in the U.S.S.R. in the 1960s, active development of ecological-floristic classification in the 1980s, and most recent developments in the classification theory. The Braun-Blanquet approach became the principal method of vegetation classification in Russian phytocenology. Due to this, Russian syntaxonomists became associated into international community of the vegetation researchers, which allows them to participate actively in the projects on biodiversity conservation. The journal "Vegetation of Russia" much contributed to these developments. The authors respond to A.M. Ghilyarov's criticisms who considers the Braun-Blanquet approach as a "rudiment of the Natural History" useless for the contemporary ecology.

[Contribution of the Brown-Blanquet method to the explanation of species richness of the plant communities].

A possibility of estimation of factors of formation of species richness of the plant communities by H-function as a measures of complexity of the phyto-sociological spectrum of communities is proved. The phyto-sociological spectrum reflects contribution of those various syntaxa to the coenofloras that indicate ecotope character and the successional status of communities. Analysis of a wide set of grassy vegetation of the South Ural region (from synanthropic to natural) revealed a linear positive correlation between H-function values and species richness. Primary factors of formation of species richness of the vegetation investigated are general favorability of the environment, variability of the moistening regime and successional status reflecting processes of vegetation transformation under influence of internal (regenerative succession) and external (cattle pasture) causes.

[Synanthropic plant communities: models of organization and features of classification].

It is proposed to distinguish between three models of organization in synanthropic plant communities formed under the influence of man: R-modle, communities of segetal weeds in fields of annual crops and at initial stages of restoration successions; R --> CRS-model, serial communities of the later stages of restoration successions; CRS --> S-model, serial communities of allogenic successions under the influence of grazing and other external factors. The higher units of the ecological and faunistic classification (classes and orders) well represent the succession status and the soil and climate conditions under which synanthropic communities are formed. At the same time, the continual character of synanthropic vegetation makes recognition of plant associations inexpedient in some cases. It is preferable to use the deductive classification method of K. Kopecky and S. Hejny.

[The problem of continuum versus discreteness in current ecology].

The problem of continuality versus discreteness of vegetation cover ("biocoenotic cover"--more generally) was the object of heated debates for at least hundred years. The ideas of continuality have been spread in the USSR in the 1970-80s but later the adherents of other approach, that focused on the discreteness of vegetation became more active. The author discussed the views of one of them, A.I. Kafanov (2005), published recently in "Zhurnal Obshchei Biologii". It is claimed that pluralistic approach that is characteristic for present ecology makes unnecessary the search for universal law of relationship between continuum and discreteness of biocoenotic cover. This relationship depends on the particular character of biocoenotic cover and the scale of study.

[Does Darwinism really contribute to ecology]. / Ocheviden li vklad darvinizma v ékologiiu?

The author questions Ghilarov's (2003) claim that Darwinism has high explanatory power in ecology. He is agree with S.V. Meyen who believed that beside synthetic theory of evolution (the popular variant on Darwinism) other explanations of evolution are possible. It is emphasized that several processes (e.g., diversification and unification of species at one trophic level, as well as individual and diffusive coadaptations of species of different levels) can contribute to community evolution. Communities cannot be considered as units of natural selection.

[Importance of S. M. Razumovskií's theories for the vegetation science]. / Znachenie teoreticheskogo naslediia S. M. Razumovskogo dlia nauki o rastitel'nosti.

Publication of S.M. Razumovsky collection works (including some unknown articles) shows his theoretical legacy for current vegetation science. Concepts of S.M. Razumovsky are in the frame of organismic paradigm. He believed that plant communities and associations are natural and continuum concept is only the result of methodical mistakes. Monoclimax (in the meaning of F. Clements) was considered by Razumovsky as the fundamental low of vegetation. Now these statements are very doubtful, but some of his ideas (succession systems, cenophyllous and cenofobous species, the principle and experience of vegetation regionalisation on the base of floristic criteria) are very useful for current vegetation science.

[The vegetation adventivisation through perspective of modern ecological ideas]. / Adventivizatsiia rastitel'nosti v prizme idei sovremennoi ékologii.

Results of study of vegetation adventivisation (increase in proportion of invasive species) correspond to the theory of present ecology that denies general universal laws. Diverse features of invasive species play different role under various ecological conditions and at various time and space scale. The invasibility of communities under various conditions is determined by combination of different biotic and abiotic factors though it is obvious that most of invasive species are characterized with the high seed production, well developed vegetative propagation, windblown pollination, high plasticity and effective use of resources, low consumption by herbivores. The definition of an "ideal invasive species" or an "ideal invasible community" is impossible. The regularities of vegetation adventivisation can be observed clearly only at very large scale.

[The meaning of vegetation classification for modern ecology]. / Znachenie klassifikatsii rastitel'nosti dlia sovremennoi ékologii.

Eco-floristic classification (Brawn-Blanquet system) is useful since in similar manner it can establish ecological units of different level (syntaxons) that have high indicative value. Syntaxons can be used as markers of terrestrial ecosystems of different range. Although this system was proposed by analogy with plant taxonomy it reflects vegetation continuum. The application of this approach is based on certain standards and supported by developed software. The elements of arbitrariness in Brawn-Blanquet method are constrained by rules of strict recommendations. The method is considered as necessary in studies of biodiversity in protected areas.

[The plant cover of Russia in the area of the Braun-Blanquet syntaxonomy: the development of an approach and the results]. / Rastitel'nost' Rossii v areale sintaksonomii Braun-Blanke: razvitie podkhoda i rezul'taty.

Theoretical basis of ecologo-floristic classification according to Braun-Blanquet approach is discussed with the special attention to the contribution of Russian scientists. Principal results concern presentation of vegetation continuum in discrete classification units: polymodal conception of plant communities, principle of plural syntaxonomic decisions, pragmatic approach to classification, method of homological rows of plant communities, etc. Current ecologo-floristic classification of vegetation in Russia consists of 77 classes. This system is a good basement for estimation of rarity of plant communities and biodiversity protection. The first variant of "Red Book" of plant communities of Russia and other eastern European countries is discussed.