Phytocenoses at Environments Contact Sites as Proxies of Climate Dynamics with Time (East Siberia, Russia)

Usage of methods for determination of long-term trends of the dynamics of vegetation formation on the background of climate changes becomes more and more important at modern stage of the assessment of natural systems development. This causes to researchers a series of problems from choice of conceptual base to notions and terms of the processes identified and of state of vegetation of different environments. Solution of such a task results inevitably in necessity to correct the understanding of existing processes occurring in the vegetation cover. It allows establishing a direction of their development in the system of natural factors of any territory. As a result, we have base for determination of age, site and role of current state of phytocenoses in successional systems. It is necessary for this to reveal the peculiarities of phytocenoses composition and formation due to climate dynamics and to determine a period of ecosystems homeostasis, especially for phytocenoses of contact natural conditions. Optimal values of phytocenoses diversity, like one of whole biosystems, depend on the amount of resource in the environment, on stability degree and on evolutional development of cenoses due to ecological, micro-evolutional and evolutional processes.

The structure of the plant communities in the different environment contact sites on the base of the soil-geobotanic profiling in the changing climate of Lake Baikal region

The results of studies of the peculiarities of formation of phytocenoses in environments contact sites of the western and eastern coasts of the Lake Baikal has been showed in this paper. On the base of geobotanic profiling combined with soil one, the structure and dynamics of phytocenoses forming under the conditions of mutual development of light-coniferous taiga forest and of extra zonal steppes. Edaphic conditions and placement of phytocenoses are main trigger factors determining the ways of plant cover development in this part of Lake Baikal basin. We discuss the characteristics properties inherent in the linkage of the dynamics and spatial variability of the vegetation with the change of climate in the Baikal region. The regional conditions of the physiogeographic environment had given rise to structurally highly contrasting plant communities in this region. The increase in yearly mean summertime amounts of rainfall, combined with the rise of yearly mean winter temperatures over the last years were conducive to changes in the spatial structure of vegetation. The boundary between the types of vegetation undergoes smoothing. The upper boundary of forest is altered because of changes of the environment that are responsible for the zonality and properties of vertical zonality of the vegetation on the mountains surrounding Lake Baikal. Changes in the vegetation serve as indicators of climate change as well as providing diagnostic tools for the genesis of the Baikal region’s natural environment.

Paragenese of the vegetation in ecosystems contact zones (in Lake Baikal basin)

Phytocenoses in the ecosystems contact zones are characterized by a rather complex structural and dynamical more than one features and by specific development characters under definite physical and geographical conditions. Unlike zonal vegetation, such phytocenoses respond to all environment changes more rapidly. The structure of such phytocenoses allows to determine the way this or that scenarios of climate change would develop at any level of more than one ecosystems. A possibility to use the notion “paragenese” for characterization of phytocenoses under contrast conditions is considered. Paragenese is the development of phytocenoses which are not related to zonal vegetation types by their composition and structure. Probably, the communities from ecosystems contact zones are to be related to a particular “type” of vegetation. Phytocenoses in the contact of light coniferous taiga and extrazonal steppes, as well as relations between zonal forest-steppe at main areas of Lake Baikal basin served as examples for justification of use of the notion “paragenese” to characterize the development of such communities.