The map “Ecological site types” 1:750 000 in the “Atlas of the GDR”

Summary

Helga Naumann-Tümpfel explains the theoretical foundations, compilation, cartographic design and interpretation of “Ecological Site Types” at 1:750,000, a map in the second installment of the Atlas of the German Democratic Republic. In keeping with the atlas’s emphasis on model-based representations of complex geographical relationships, the map classifies sites by their potential supply of water, heat and mineral nutrients. The author treats these as physiologically relevant factors whose limitations or excesses affect plant productivity, crop suitability and susceptibility to diseases and pests. Compilation combined the unpublished 1:500,000 soil-map original, climate maps and records, and natural-vegetation maps. Soil units were assessed separately for water and nutrient supply. A modified Walter–Gaussen climate-diagram method used 1901–1950 monthly normals from 120 stations to classify moisture and heat conditions, with particular attention to the growing season above +5 °C. Vegetation helped delimit climatic types; climate and soil assessments were combined to determine potential water supply. Three-digit codes express each site type’s water, heat and nutrient supply, while letters identify important controls on water conditions. The cartographic scheme places types in a relationship triangle and associates water with blue, heat with red and nutrients with yellow. Printing trials required colour revisions, including yellow for the central, relatively favourable types. Structural patterns distinguish excess water, permeable soils and favourable nutrient supply; a tabular analytical legend supplies general climatic and soil information. The author interprets central, inner and outer groups as showing progressively stronger constraints on productivity and cultivation, and discusses amelioration, fertilization and crop selection. She presents the map as a basis for regional agricultural planning and further investigation, while noting that local variation, specific crop suitability and particular disease or pest risks require more detailed study.