Author(s)

S. Hohensinner, G. Haidvogl, M. Jungwirth, S. Muhar, S. Preis & S. Schmutz

Abstract

Today, natural reference sections are not available for most rivers in the Western world and, consequently, restoration projects increasingly rely on historical references. The 350-km-long Austrian Danube river section has also been changed dramatically by channelisation and hydropower plant construction. Currently, a research project is attempting to reconstruct the former habitat turnover of the alluvial Danube landscape in the Machland (Upper/Lower Austria) based on the analyses of historical sources between 1715 and 1991. The results of this study point to a dynamic equilibrium of both morphological habitat succession and permanent habitat regeneration related to intensive fluvial disturbances. This equilibrium can be referred to as a \“shifting habitat mosaic”. Natural fluvial dynamics not only altered habitat area shares, but also resulted in high habitat age diversities. The reconstructed age distributions point to very short life spans of certain habitat types. Over the long term, the varying intensity of disturbances presumably yielded a range of spatio-temporal patterns of habitat compositions and age distributions typical for the Danube river ecosystem. This balance between destruction, formation and developmental processes contributed to the meta-stability of the overall river-floodplain system and thus represents a primary factor in the ecological integrity of river landscapes. Keywords: Danube River, floodplain, habitat dynamics, turnover, succession, regeneration, age distribution, historical change, channelisation.

Keywords

Danube River, floodplain, habitat dynamics, turnover, succession,regeneration, age distribution, historical change, channelisation.