Dynamik und Konstanz an naturnahen Flussufern – 27 Jahre Dauerflächenuntersuchungen am Oderufer (Harzvorland)

Since 1981 permanent plots in riparian areas aside the Oder river have been established. High hydroand morphodynamics of the river result in a high diversity of plant species and communities. Three plots on different levels above the river water have been investigated: A (since 1981), B (since 1986), and C (since 2000), with special emphasis (vegetation table) to B. While on the amphibic bank of the river (C) a permanent pioneer community with a high plant diversity has established, in A and B a progressive succession took place on newly accumulated gravel, from a Chenopodium polyspermum- Persicaria lapathifolia phase (similar to C) over a Carduus crispus-Artemisia vulgaris phase to an Aegopodium podagraria-Petasites hybridus phase. The first and second phase were rather short (1–2 respectively 4–5 years) whereas the third forms a rather stable tall-forb fringe community (Phalarido- Petasitetum hybridi). – Special attention is given to Impatiens glandulifera which has been detected first in 1987 and has spread afterwards very quickly. Finally the dynamics and constancy of riparian areas are discussed, also the spread of Impatiens glandulifera in northern Central Europe.