Succession dynamics of aquatic lake vegetation after restoration measures: increased stability after 6 years of development

For 7 years, development of submerged vegetation was monitored after fish stock removal during the final phase of a restoration program in the shallow, 2.1 km² Lake Loenderveen (The Netherlands). The lake shifted from a turbid, phytoplankton-dominated state, to a clear, macrophyte-dominated state. Vegetation development was very dynamic during years 1–5. Dominance of Elodea nuttallii (Planchon) St. John and Najas marina L. alternated in the initial few years and separate development of Chara species was recorded locally. Elodea nuttallii achieved the highest coverage in the 5th year, but part of the vegetation collapsed in the 6th year. In year 7, the system had recovered and became more stable. The dynamic developments, and spatial differences, are possibly explained by waterfowl interactions, soil nutrient status, and differences in growth form strategies of the species. It was concluded that the trophic level of the lake water was low enough for lake vegetation to recover following removal of most of the fish stock, but stability of the clear water state has increased considerably only after 6 years of development.