On the creation of the new survey vegetation map of Asia, s. 1 : 4 000 000

Abstract

In September 1995 the First International Workshop on compiling the new survey vegetation map of Asia was held in St.-Petersburg. At this workshop the decision was adopted to create an integrated united cartographic work of survey scale 1 : 4 000 000. The vegetation cover of Asia is most complex. Among its characteristic features are: the unique system of latitudinal zonation; the fullest set of meridional sectors; diverse types of vertical zonation; the widespread reverse zonation (hollow effect); great variety of vegetation types (from desert, poor in species, up to the floristically richest rain tropical forest); diverse ancient flora with high endemism. The full spectrum of natural zones in the northern hemisphere can be observed only in Asia. The concept for creation of the new vegetation map of Asia will be worked out in the process of mapping its separate extensive regions (blocs). In this communication a number of conceptual statements, concerning the general principles and methods of compiling the map, are proposed for discussion. We are of the opinion that the map should reflect the hierarchic multidimension division of vegetation. The survey map s. 1 : 4 000 000 of such an extensive territory should depict first of all the macrostructural regularities of vegetation cover of Asia, connected with the differentiation of environment at the subplanetary level. At the elaboration of map it is necessary first to present: 1) the latitudinal regularities in distribution of vegetation macro- (mega)-complexes from the High Arctic territories down to the tropical ones; 2) the regularities of vertical zonation and variety of its structures, considerably differing in various parts of the continent, belonging to different zones and sectors; 3) the meridional - sectoral regularity of macro-complexes; 4) the regional features of vegetation cover of the territories mapped, its typological composition depending on main ecological factors (lithology, soil variety, humidity, salt accumulation, etc.). In order to mirror the above regularities the hierarchic structure of subtitles will be used in the legend, which will permit to show the vegetation cover in whole its variety and its connection with the environmental factors (Sochava, 1972). In the traditional text form of legend the typological element appears as the leading structure-forming one, since there are survey typological maps for the former USSR and China (i. e. for the greatest part of the continent) in the same scale. Side by side with phytocoenomers (such as group of associations, class of associations, formation) phytocoenochoras, or territorial combinations of phytocoenoses, will be used: types of complexes, of series, of ecological-dynamic series, of mire massifs, of phytocatenas, of combinations, etc. On the vegetation map of Asia the actual vegetation will be shown, including its anthropogenic derivatives. The highest divisions of the legend will be «Northern extratropical vegetation» and «Tropical vegetation», each of them being subdivided into «Vegetation of plains and low plateaus» and «Vegetation of mountains and high plateaus», owing to essential differences in the macrostructures of vegetation cover of these territories. For the macrostructures of northern extratropic vegetation on the plains differentiation into florogenetic complexes may be accepted, taking into account the zonal differentiation of the vegetation cover. As the experience of international cooperation has shown we should aspire to integrated and generalized characteristics of mapping units. The vegetation map of Asia will include the dynamic subject as well. For mountain territories it is necessary to reflect the systems of altitudinal zonation from the arctic and hypoarctic spectra to the tropical ones with further subdivision into the regional groups. In conclusion the authors have emphasized that vegetation map is the fundamental base for better understanding of the ecological processes, first of all of changes in vegetation cover. Compiling the survey map of such variable by natural environments extensive subcontinent, as Asia, is really a challenge, but its significance and urgency are indisputable.