Flower strips

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A flower strip is a strip of land sown with seeds of mostly colorful flowering plant species, mostly on the edge of a field , which is intended to promote local biodiversity . Flower strips are mostly created by farmers as part of agri-environmental measures , but there are also private initiatives, nature conservation associations or public bodies that can then also be located within settlements (in urban areas). The durability, size and width of flower strips and the respective composition of the seeds are variable and depend on numerous factors, above all the desired goals and the local funding modalities . Flower strips were first introduced in Europe in the 1990s. Flower strips are also used in contractual nature conservation as part of the intervention regulation , as so-called production-integrated compensation measures . They belong to the border biotopes .

Flower strips dominated by cornflowers in the grain field as a field trial on the Mechtenberg

Design

There are countless different forms of flower strips. Some use seeds from annual species, often from the group of arable weeds , while others use partially or fully perennial plants , mostly colorful flowering wild flowers , either with the involvement of grasses or without them. Often, flower strips with nectar or pollen-rich flowers, for example from the butterfly family , are created to encourage bees and other flower-visiting insects in particular . The flower strips are usually mown once a year, but for annuals they are also broken up and re-sown. The exception is Switzerland, where they were often left unprocessed for up to seven years. Regional plants (seeds from local origins ) are preferred ; for most areas of application this will be required by law in Germany from 2020.

Sowing in late summer (August to September) is recommended, and spring (March to April) is also possible. If the flower strip is created in an already established vegetation, for example a grassland or a lawn, the soil should be prepared beforehand by milling, cultivating or plowing. The seeds of the wild plants only germinate after two to three weeks in sufficiently moist soil. Since most species are light germinators, the seeds must not be incorporated into the soil. In most cases, seeds of 2 (1 to 3) grams per square meter are sown, but not infrequently also thinner seeds of 0.4 to 0.5 grams per square meter, often mixed with a filler for practical reasons. A thin layer of mulch is beneficial in dry conditions. In order to push back unwanted, fast-growing weeds such as white goosefoot , a so-called cupping cut is carried out a few weeks after sowing. In order not to damage the rosettes of the desired species, a cutting height of at least 10 to 15 centimeters is maintained.

For the public funding of flower strips in Germany, the conditions in each federal state are slightly different. A minimum width of 6 to 12 meters and a complete waiver of fertilizers and pesticides are required.

species

Seed mixtures for flower strips always contain the most varied possible mixture of different flowering herb species, around 12 to 30 herbs.

Suitable types for flower strips as border biotopes are usually selected from four groups:

Use

The ecological success of flower strips to promote flora and fauna has been studied many times and is now well documented. Flower strips are home to an insect fauna that is far more diverse in species and individuals than agricultural areas. Above all, more common species are funded, while endangered species occur but mostly remain rare. However, in around a third of the studies, no significant improvement was demonstrated without any evidence of reasons for success or failure. Flower strips have also proven to be economically useful in that they promote bees, which are important as pollinators for agriculture, this applies to both wild bees and honeybees .

In the case of perennial flower strips, the abundance of flowers often decreases over the years, as many sown plants gradually fail. A low beneficial effect, due to the high vegetation cover of perennial flower strips compared to other agricultural biotopes, was found in birds in the field landscape. For example, they were ineffective as a species protection measure for the barn owl .

As an agri-environmental measure, flower strips are preferred to other agri-environmental measures, also from agriculture. In a press release , the German Farmers' Association pointed out that Germany's farmers laid out over 200,000 kilometers of flower strips in Germany in 2018.

Influence on pests

The influence of the flower strips on pest species is inconsistent. In a review article, a decrease in pests was found in 13 articles, pests were more frequent in 5 articles, and no impact was measurable in 8 articles. In a comparative study on pest infestation in winter wheat, the density of grain pests in fields adjacent to flower strips was significantly lower than in fields without them. The promotion of natural enemies (beneficial insects) was assumed as a possible reason. In a study in oilseed rape, neither a promotion nor a reduction of pests was found.

criticism

Flower strips are popular with the public and are widely accepted by both conservationists and farmers. Nevertheless, there is criticism of it in individual cases. For example, some conservationists see a competitive situation with unseed strips of field margins to promote the endangered spontaneous wild herb or segetal flora . Some botanical conservationists fear that the flora may be adulterated due to the fact that the seeds are too standardized or not sufficiently locally adapted .

Individual evidence

  1. Anita Kirmer, Klára Řehounková, Anna Müllerová, Sabine Tischew, Lenka Šebelíková, Jana Lipárová, Karel Prach, Kamila Lencová: Guidelines to establish flower-rich structures in urban and rural areas. Research paper. University of České Budějovice and Hochschule Anhalt, 2019. ( restoration-ecology.eu , PDF)
  2. ^ A b c Christine Haland, Russell E. Naisbit, Louis-Félix Bersier: Sown wildflower strips for insect conservation: a review. In: Insect Conservation and Diversity. Volume 4, No. 1, 2011, pp. 60-80.
  3. Juliane Mante, Anett Wagner, Detlef Czybulka, Bärbel Gerowitt: Flower strips as compensation measures in the field - nature conservation assessment and legal assessment using the example of intensively used agricultural regions in three federal states. In: Reports on Agriculture. Volume 88, No. 1, 2010, pp. 37-56.
  4. a b c Sandra Mann, Olaf Loos (editor): Notes on the successful creation and care of perennial flower strips and flowering areas with native wild species (with information on annual flower strips and flowering areas as well as protective strips) Measures to increase biodiversity in Saxony-Anhalt. published by the Ministry of Agriculture and Environment of Saxony-Anhalt, Magdeburg 2015.
  5. a b Anita Kirmer, Daniel Jeschke, Kathrin Kiehl, Sabine Tischew: Practical guidelines for the establishment and upgrading of borders and fields. Research paper. 2nd Edition. Osnabrück University and Anhalt University, 2019, ISBN 978-3-96057-090-5 . ( opus.hs-osnabrueck.de , PDF)
  6. Olaf Zinke: Flower strips and insects - What farmers can do. In: AgrarToday. March 28, 2019. ( agrarheute.com )
  7. Agriculture of North Rhine-Westphalia: agri-environment measures - investment of flowering and conservation headlands. Status: May 12, 2017. ( Landwirtschaftskammer.de , accessed December 11, 2019)
  8. a b Simon Dietzel, Fabian Sauter, Michaela Moosner, Christina Fischer, Johannes Kollmann: Flower strips and flower areas in agricultural practice - a nature conservation evaluation. In: ANL concerns nature. Volume 41, No. 1, 2019, pp. 1-14.
  9. Hans Ramseier, Dominik Füglistaller, Christina Lädrach, Christian Ramseier, Michael Rauch, Franziska Widmer Etter: Flower strips promote honey and wild bees. In: Agricultural Research Switzerland. Volume 7, No. 6, 2016, pp. 276-283.
  10. Pascal Paulen, Michael Trieschmann: Upgrade the agricultural landscape with flower strips. In: RBZ Rheinische Bauernzeitung. Issue 18, 2015, pp. 14-16. ( agrarumwelt.rlp.de , PDF)
  11. Raphaël Arlettaz, Markus Krähenbühl, Bettina Almasi, Alexandre Roulin, Michael Schaub: Wildflower areas within revitalized agricultural matrices boost small mammal populations but not breeding Barn Owls. In: Journal of Ornithology. Volume 151, 2010, pp. 553-564, doi: 10.1007 / s10336-009-0485-0
  12. Farmers protect species - Rukwied: Over 200,000 kilometers of flower strips in Germany. Press release. DBV, May 17, 2019. (presseportal.de)
  13. Roel Uyttenbroeck, Séverin Hatt, Aman Paul, Fanny Boeraeve, Julien Piqueray, Frédéric Francis, Sabine Danthine, Michel Frederich, Marc Dufrêne, Bernard Bodson, Arnaud Monty: Pros and cons of flowers strips for farmers. A review. In: BASE Biotechnology, Agronomy, Society and Environment. Volume 20, No. S1, 2016, pp. 225-235. ( orbi.uliege.be , open access).
  14. Matthias Tschumi, Matthias Albrecht, Martin H. Entling, Katja Jacot: High effectiveness of tailored flower strips in reducing pests and crop plant damage. In: Proceedings of the Royal Society Series B. Volume 282, 2015, S. 20151369. doi: 10.1098 / rspb.2015.1369
  15. Séverin Hatt, Roel Uyttenboeck, Thomas Mendes Lopes, Aman Paul, Sabine Danthine, Bernard Bodson, Julien Piqueray, Arnaud Monty, Frédéric Francis: Do Wildflower Strips Favor Insect Pest Populations at Field Margins? In: Agriculture and Agricultural Science Procedia. Volume 6, 2015, pp. 30-37. doi: 10.1016 / j.aaspro.2015.08.034
  16. Seed flower strips and colored fallow areas - (not) a solution to protect field herbs . Project “100 Acres for Diversity”, last changed on July 9, 2008.
  17. Thomas van Elsen and Holger Loritz (editors): Variety from the seed bag? Position paper on the integration of wild herb protection in sowing flower strip programs developed by the project team “100 fields for diversity!” And the Blooming Landscape Network. published in Nature Conservation and Landscape Planning 45 (5) 2013, 155-157. on-line
  18. Corinne Buch & Armin Jagel (2019): Butterfly meadow, bee feast and bumblebee magnet - insect rescue from the seed bag? Publications of the Bochum Botanical Association 11 (2): 9–24. PDF

literature

  • Peter Meindl, Rudi Schmidt, Thomas Drapela: The 55 most important flower strip plants. FiBL Research Institute for Organic Farming and LFI Rural Training Institute Austria, Vienna 2018. ( shop.fibl.org , pdf)