Experimental restoration of the Charophytes Chara aspera and Chara tomentosa in a shallow Baltic Sea bay

This data comprises three different experiments in three different areas to test methods for (A) replanting C. aspera, (B) the effects of harvesting C. aspera on the donor C. aspera meadow and (C) replanting C. tomentosa. The experiment took place over two growing seasons and light, temperature and sediment water and organic matter content data is also available for the experimental areas. Three methods of planting were tested for C. aspera, spade planting, jute band, BESE elements© and natural recolonization and two methods for C. tomentosa, BESE elements and natural recolonization. Additionally, four levels of harvesting were tested in the C. aspera meadow, removal of 0, 0.8%, 1.8% or 2.6 % of the C. aspera coverage. Shoot height, shoot density and coverage of aquatic vegetation species in the plots was measured on 1 June (before treatment), 1 July, 24 August and 29 September 2021 by snorkelling. Follow up measurements of vegetation coverage were made 15 months after initial planting on 14 September 2022 for all the plots.