Seed mixture strongly affects species-richness and quality of perennial flower strips on fertile soil

• Published in: Basic and applied ecology Vol. 42; pp. 62 - 72
• Main Authors: Schmidt, Annika, Kirmer, Anita, Kiehl, Kathrin, Tischew, Sabine
• Format: Journal Article
• Language: English
• Published: Elsevier GmbH 01.02.2020
• Subjects: agri-environmental policy; Agri-environmental scheme; arable soils; atmospheric precipitation; Biodiversity; Common Agricultural Policy; Cultivars; field experimentation; flowers; foraging; forbs; funding; Germany; habitats; indigenous species; Mulching; Native forb; perennial grasses; Perennial wildflower strip; seed mixtures; soil fertility; species richness; wild flowers; Germany; Agri-environmental scheme; Native forb; Mulching; Biodiversity; Perennial wildflower strip; Cultivars
• DOI: 10.1016/j.baae.2019.11.005
• ISSN: 1439-1791

Within the frame of the EU Common Agricultural Policy, most countries subsidise the establishment and maintenance of perennial flower strips on arable land within Agri-Environmental Schemes to provide foraging habitats and refuges for wildlife. In a replicated field experiment, we studied the effects of different types of seed mixtures on the establishment and maintenance of perennial flower strips on fertile arable land in the federal state of Saxony-Anhalt, Germany over seven years. The seed mixtures were commonly applied within recent Common Agricultural Policy funding periods: (1) a low-diversity cultivar standard seed mixture (CULTIVAR), (2) a high-diversity cultivar and native plant mixture (MIX), and (3) a high-diversity native plant mixture (WILDFLOWER). All plots were mulched every year in March and at the beginning of August. The low success of CULTIVAR triggered the massive encroachment of spontaneously established perennial grasses. In MIX, too, cultivars have disappeared after the first year. Both wildflower variants were successful in maintaining a high cover of sown perennial native forbs and a high ratio of established sown species, even after seven years. WILDFLOWER always tended to show better values than MIX. Furthermore, spontaneously establishing species began to spread their cover in MIX in the fifth year, with a very strongly increasing tendency, whereas in WILDFLOWER cover of spontaneously immigrating species stayed satisfyingly low. Using native wildflowers to establish perennial wildflower strips was very effective in maintaining high species diversity within the Agri-Environmental Schemes funding period of five years and beyond. WILDFLOWER was especially successful. On the other hand, CULTIVAR failed completely. On fertile soils in regions with rather low yearly precipitation, mulching twice a year supported the maintenance of perennial wildflower strips.