Evaluation of prehistoric land use intensity in the Rhenish Loessboerde by canonical correspondence analysis—A contribution to LUCIFS

Abstract

Almost every agricultural activity has an effect on vegetation. In fact, human impact is the most important and continuous factor in the vegetational development of landscapes that have been settled since prehistoric times. Hence vegetational changes are the key to the evaluation of past human impact. Human impact in the pollen record can be assessed in two ways: positively by so-called cultural indicators—pollen of cultivated plants such as cereals and of plants that tolerate human impact; and negatively by the disappearance of pollen from plants that do not tolerate human impact. The percentage values of cultural indicator pollen can serve as measure for the intensity of human impact. This approach, however, neglects negative indicators of human impact which provide information on the response of the natural vegetation to anthropogenic influences. Here, we introduce first results obtained by applying a multivariate statistical technique to extract a proxy for human impact from pollen data. We use canonical correspondence analysis, which has been applied successfully for the connection and spatial analysis of pollen data from the Rhenish Loessboerde. The long-term objective is to develop land-use models derived from pollen data which allow diachronic comparison of the intensity and character of human impact for different landscapes of the Rhine catchment. As a result, maps of land-use intensity can be evaluated by maps of archaeological settlement density, which are developed by an archaeological working group in Cologne in the LUCIFS program.