Niko Beruchashvili’s Legacy in Landscape Science
Niko Beruchashvili started as a researcher in 1971-1976 at the Martkophi Physical-Geographic Station (near Tbilisi) where he carried out a unique multi-year program of continuous daily observations of the functioning and dynamics of natural territorial complexes (NTCs). More than 100 parameters of structure and functioning were being registered throughout the day, every day, in each of the typical NTCs. Stationary research of such intensity did not have any analogues anywhere in the world. The acquired data laid the foundation for the new models of functioning of mountain NTCs based on the measurements of the flows of solar energy transformation, the water cycle and the biogeocycle. Subsequently, these models were tested in the various regions of the Caucasus. The studies carried out at the Martkophi Station in the 1970s allowed to identify and quantify intra-annual (seasonal and sub-seasonal) states of elemental NTCs, and within them – ‘nodal’ daily states that are linked to seasonal rhythms, weather conditions, and dynamic trends of the NTC development. Beruchashvili called such nodal states stexes.
Data received from multi-year stationary observations in Martkophi and semistationary observations in various other regions of the Caucasus allowed Dr. Beruchashvili to develop an original concept of landscape geophysics using geomasses and geohorizons as its key notions.
Geomasses are elemental structural-functional parts of an NTC characterized by a mass, a specific functional role, as well as a speed of temporal change and/or spatial movement.
Geohorizons are relatively homogeneous layers of an NTC with a characteristic mix and ratio of geomasses.
According to Beruchashvili, a vertical structure of an elemental NTC is a composition, sequence and interrelationship of its geohorizons. Furthermore, certain geohorizons are sufficiently stable throughout the annual cycle, while others (similarly to certain geomasses) are typical of only specific stexes.
Beruchashvili developed a holistic concept of spatiotemporal landscape synthesis following the algorithm: geomass – geohorizon – NTC vertical structure – stex – NTC (as a sequence of stexes). He introduced the notion of a state of an NTC as certain composition of structural-functional parameters of an NTC within a given period of time when specific input flows (solar radiation, precipitation, etc.) are transformed into specific output functions (runoff, phytomass growth, etc.). He also proposed an original classification of the NTC states by their duration: short-, medium- and long-term. He further identified possible ways of synthesizing daily states of elemental NTCs (stexes) into the states of higher-order landscape units. In his 1982 article about the notion of the ‘state of a geosystem’ in geography, Beruchashvili explored the ways of studying not only the states of natural complexes, but also those of socioeconomic complexes.
Beruchashvili’s theoretic concepts ‘geomass – process’, ‘vertical structure – NTC functioning’ and ‘vertical structure – stex’ were verified against vast empirical data and subsequently became the basis for the methodology of identifying and studying diurnal (daily) states of NTCs in field research.
Intensive stationary, semistationary, expedition and airborne visual studies of the Caucasus resulted in the Landscape Map of the Caucasus (scale 1:1,000,000) prepared under Beruchashvili’s leadership and published in Tbilisi in 1979. The map was accompanied by a four-level classification of landscapes (class – type – subtype – genus). A total of 152 genera of mountain, foothill and plain landscapes were identified for the Caucasus (including adjacent territories of Ciscaucasia, Turkey and Iran). Till today, this map remains the most detailed and systematic spatial model of the Caucasus landscapes.
In the 1980s, Beruchashvili develops a new dimension in landscape science – landscape ethology, which examines patterns of NTC behavior as the changes of their states. He used some of the existing models and approaches of animal ethology to interpret the changes of stexes – as in the notion of inherent pre-readiness of an NTC. In his summary monograph on the subject (1989), Beruchashvili uses the landscapes of the Caucasus to illustrate his newly introduced concepts of a trajectory of states, an ethocycle (a set of trajectories throughout the year), and a landscape-ethological situation (a typical set of stexes within a given territory and within a given time period). Most of these concepts is still being used in landscape science.
In the late 1980s, Beruchashvili initiated the development of a geoinformation system of Georgia based on the previously assembled data bank of the Caucasus landscapes. This included a variety of applied software packages for processing stationary observation data, deriving stex characteristics from hydrometeorological data, computing of the maps of stexes and their individual characteristics (such as snow cover), etc. Starting from 1991, computer simulation covered the entire region, and the so-called general model of landscapes of the Caucasus was created.
The 1995 monograph, ‘Caucasus: Landscapes, Models, Experiments’, summed up the many years of Beruchashvili’s comprehensive studies of the Caucasus landscapes. The book includes the description of the main types of landscapes of the Caucasus based on his original map of landscapes, quantitative data on the main types of their geomasses and characteristics of their most common vertical structures. The second part of the monograph describes the geographic information-heuristic system of the landscapes of the Caucasus and the examples of tasks it can solve (computing geomasses and parameters of their functioning, spatiotemporal extrapolation of hydromet data, etc.). It gives an overview and analysis of the various computer experiments (such as the modeling of landscape changes resulting from changes in air temperature and precipitation, glacial and forest cover).
In the early 2000s, Beruchashvili’s landscape dynamic studies found further practical application in the sustainable forest management planning activities started in Georgia with World Bank support. The scholar and his colleagues developed and successfully tested a new methodology of mountain forest inventory based on a landscape-ecological ‘carcass’ (structure) of a territory, with original techniques for producing maps of landscape sustainability (fragility) (the so-called ‘semaphore maps’) and landscape diversity (the so-called ‘green maps’) that are used in forest management and other spatial planning.
Summarizing the legacy of Niko Beruchashvili’s scientific work, one can highlight its principal pillar. He succeeded in drawing geographers’ serious attention to the ‘fourth dimension’ of a landscape – time – especially, to its most dynamic cycles, the diurnal states of landscapes. The Caucasus Region, with its great spatiotemporal contrasts, like no other region of the world, turned out to fit this task.
Compiled by Dr. Gregory A. Isachenko
Selected Bibliography of Niko Beruchashvili
Beruchashvili, N.L. Explanatory Note to the Landscape Map of the Caucasus. Tbilisi: Tbilisi State University, 1980.
Beruchashvili, N.L. The concept of the state of geosystem in geography // Issues of study of the states of the environment using aerospace methods. Tbilisi: Tbilisi State University, 1982. P. 10-21.
Beruchashvili, N.L. Issues of classification of the states of natural-territorial complexes // Issues of Geography. Vol. 121. Moscow: Mysl, 1982. P. 73-80.
Methods of landscape-geophysical studies and mapping of the states of natural-territorial complexes. / Compiled by N.L. Beruchashvili. Tbilisi: Tbilisi State University, 1983.
Beruchashvili, N.L. Four Dimensions of a Landscape. Moscow: Mysl, 1986.
Beruchashvili, N.L. Landscape Ethology and Mapping of the States of Natural Environment. Tbilisi: Tbilisi State University, 1989.
Beruchashvili, N.L. Landscape Geophysics. Moscow: Vysshaya Shkola, 1990.
Rougerie, G., Beroutchachvili, N. Géosystèmes et Paysages: Bilan et Méthodes. Paris: Armand Colin, 1991.
Beruchashvili, N.L. Caucasus: Landscapes, Models, Experiments. Tbilisi, 1995.
Beruchashvili, N., Shotadze, M., Nikolaishvili, D., Melikidze, V., et al. Main trends of development of the Caucasus environment for the last 30 years // Caucasus Geographical Review. 2002. No. 1. P. 16-27.
Beruchashvili, N.L., Gordeziani, T.P., Jamaspashvili, N.S., Maglakelidze, R.V., Nikolaishvili, D.A. Critical areas in a landscape (Experience of landscape studies in Georgia) // Izvestia RGO. 2007. V. 139, No. 1. P. 22-30.