LANDSCAPE AS A REAL OBJECT OF GEOECOLOGY

Abstract

Emergence of dynamic geoecological models (landscape simulators) drives new attention to the conceptual issues of substantial and spatiotemporal organization of a landscape. We interpret the landscape as a continuum – a terrestrial geoeocological complex, which can be differently disaggregated into ecological (substantial), morphological (spatial), and dynamic (temporal) components in the framework of diverse complementary landscape models – geoecosystems. The landscape encompasses physical, biotic, and social phenomena and therefore is an empirical study object of natural and social geographical and ecological (environmental) sciences. Its ecological organization is represented by an incomprehensible number of substances, which constantly transform into each other in space and time. This affords different ways of disaggregation of the landscape substance into ecological components. The most general landscape features can be represented by the interdisciplinary genetic ecological model, which decomposes the substance into the objects of geographic disciplines – e.g., landforms (object of geomorphology), soil (pedology), biotic communities (botany). This comprehensive, but too general model can be supplemented by other models, which represent e.g., energy cycling, and thus delimits autotrophs and heterotrophs, etc. The morphological organization of a landscape can be distinguished between «horizontal» (geospatial) and «vertical». There are numerous ways of decomposing landscape's spatial continuum into discrete geospatial components. This can be done according to the hierarchy of landforms, peculiarities of substrate, climate, actual land cover, etc. While the horizontal morphology is the subject of geography, the vertical morphology of a landscape is predominantly studied by ecosystem ecologists, who distinguish ecological horizons or layers with different assemblages of ecological components.The dynamic organization of a landscape can be perceived as a synergy of an incomprehensible amount of physical, biotic, and social processes (sequences of changes), which constantly transform landscape substance. Each process has two, more or less distinct, patterns: cyclic (recurring) and unidirectional (trend). The cyclic component of the processes is associated with landscape functioning, while the unidirectional component – with landscape evolution. A retrospective study of landscape evolution affords establishing landscape genesis. The length of a cycling pattern is named the characteristic time of a process. Landscape disturbances are external impacts (natural or social), which alter stable functioning to variable functioning. The time period, during which the landscape remains in a state of variable functioning after a disturbance is named a relaxation time. The amount of disturbance the landscape can withstand without significant changes in its structure and processes characterizes landscape resistance. The ability of the geoecological complex to renew its structure and processes after the disturbance is called landscape resilience. Both resistance and resilience contribute to landscape stability. Landscape resistance and resilience cannot be defined in general, but only for a certain category of disturbances. Landscape dynamics is usually reduced to one or several process, which are singled out as significant. This depends on the study approach. Continuous processes can be disaggregated into discrete landscape states – functional (recurring) and evolutionary (non-recurring). Change of evolutionary states manifests the change of a landscape. The set of fundamental landscape features, which define landscape identity, is named landscape invariant. The scope of a landscape invariant depends on the study approach and can be defined differently.