Landscape ecosystem research is a multifactor, holistic approach to identifying, classifying, describing, and mapping terrain ecosystems. Abiotic and biotic factors are integrated in the field to distinguish repeating units similar in ecological structure and function. Landscape ecosystems are identified by simultaneous integration of physiographic, soil, and vegetation information. The more stable components–physiography and soil–largely determine local climate, and water and nutrient relations, and thus the interrelationshps of physiography and soil form the foundation of a landscape ecosystem classification. Vegetation is seen as a phytometer that integrates the many abiotic factors and their interactions, and therefore reflects differences in ecosystem structure and function. When the three main ecosystem factors are analyzed simultaneously, one can perceive interrelationships that result in ecologically meaningful differences among segments of the ecosphere. Landscape ecosystems are spatial; they are volumetric, multi-dimensional segments of earth, whose components include soil, water, atmosphere, solar radiation, and biota. These segments can be identified, classified, described, and mapped at various scales. The ecosphere is the largest ecosystem; within the ecosphere is a nested series of interconnected ecosystems. Therefore, the landscape is conceived as ecosystems–large and small pieces of earthspace, waterspace, and airspace–nested in a hierarchy of spatial scales. At the smaller end of the hierarchy, local landscape ecosystem types are segments of the landscape that have similar physiography, climate, soil, natural disturbance regime, and potential natural vegetation. A landscape ecosystem group, which is the level of landscape ecosystem I have identified for the UMBS lands, is a higher-order level in the hierarchy. Landscape ecosystem groups are differentiated from each other by major differences in climate, physiography, soil, and potential natural vegetation. Nested within landscape ecosystem groups are local landscape ecosystem types that may differ among each other in finer differences of the above components, especially with regard to soil profile characteristics (i.e., amount of textural bands, depth to calcareous or till horizons) and position on the landscape (especially as regards susceptibility to fire). I began landscape ecosystem research at UMBS during the 1988 field season. The general objective of the research were: * To identify, classify, describe, and map the upland landscape ecosystem groups of UMBS. * To utilize the landscape ecosystem classification and map in the analysis of biological diversity. ... Twenty-one upland landscape ecosystem groups, differentiated by physiography (landform, parent material, slope, drainage), soil, natural disturbance regime, and inferred presettlement vegetation, were identified, classified, described, and mapped.