Förderung gefährdeter Flora in Rebbergen

Due to intensive cultivation and the use of chemicals, fields and vineyards are among the most endangered non-aquatic habitats in Switzerland today. The endangered and extinct vascular plant species of Switzerland have a particularly high proportion in fields and vineyards. These include many annual species and bulbous plants, such as the field and meadow yellow star (Gagea villosa and G. pratensis), the dark fumitory (Fumaria schleicheri) and the ray-leaved broadleaf (Orlaya grandiflora). Apart from targeted measures such as the sowing of typical vineyard gardens, it has hardly been possible to date to promote the typical, valuable vine flora in the tramlines of the vineyards. In the “Endangered flora in vineyards” resource project, which has been running since 2020, we are working with the company Agrofutura to test the promotion of bulbous geophytes and annuals as well as valuable meadow plants using various measures on 20 farms in 5 cantons (BE, BL, AG, SH, GE).

As a first measure, the soil in vineyards with remaining stands of bulbous geophytes and annuals is spaded and harrowed annually before the target species flower. In vineyards without residual stands of these species, the second measure is to develop species-rich meadow vegetation by sowing suitable species. The cuttings are removed and the ground vegetation is not disturbed. These measures are carried out in every second vineyard alley on the 20 farms (“flower alleys”), while the remaining vineyard alleys are cultivated conventionally (“cultivation alleys”). Mulch may still be left in these alleys and vine wood may be worked into the soil.

The impact monitoring we planned and optimized in 2024 showed that the numbers of individuals of individual target species and some other typical vine flora species in the vine alleys with measures (“flower alleys”) were higher on average than in the cultivation alleys and thus developed positively as hoped. So far, the increases have mainly been seen in less demanding vineyard species such as vineyard leek (Allium vineale), field lettuce (Valerianella locusta agg.), field helichrysum (Anagallis arvensis) and purple deadnettle (Lamium purpureum). So far, no significant difference in the number of species has been observed between the flower and cultivation alleys.

However, during non-systematic surveys in several vineyards in the canton of Schaffhausen, the specialist responsible for the vine flora found that the yellow stars are increasingly spreading from the understock area into the vine alleys and that the flower alleys have higher populations than the cultivation alleys. This observation makes us confident that the effects of the support measures, which have been rather weak to date, will become more pronounced in the coming years.