Vegetation Patterns and Ecological Gradients: From Forest to Dry Steppes

Abstract

Vegetation patterns and plant communities associated with them are determined on the regional scale based on an analysis of remote sensing data and ground information. Three main vegetation patterns are described in dependence on ecological factors: geological substrate (loess vs. sand), relief, precipitation and warmness. The first two patterns are characterized by the same substrate (loess) but different relief and consist of dry grasslands in combination with birch forests. The first pattern on elevated plains with extensive gully systems looks at forest patches in the form of dendritic or amoeba-like contours in a matrix of steppes and arable land. The second pattern on low-lying plains with poor drainage is patchy with numerous rounded forest groves, locally called `kolok' forests, embedded in a steppe matrix. The third one differs mostly by substrate (sand) and is represented by pine forests in combination with psammophytic steppes. Each pattern is composed of different vegetation types (forests and grasslands) and distributed more or less throughout all of the Kulunda area. Nine types of forest ecosystems and four types of grasslands could be distinguished by species composition and their ecological demands. Depending on local climate conditions, combinations of plant communities in each pattern change from west to east on the precipitation gradient and from south to north along the warmness gradient.