Ökolgische Feldstudie zur Bewertung einer Low-input-Strategie

Im Rahmen des Reduktionsprogramms Chemischer Pflanzenschutz wird die Wirkung von Pflanzenschutzintensitäten auf Diversität, Aktivität und Dominanzstruktur epigäischer Spinnen untersucht. Aranaen besitzen in Agro-Ökosystemen wichtige Regulationsfunktionen. Es wird geprüft, ob durch reduzierte Aufwandmengen Akkumulationseffekte bei den Spinnen auftreten, die für den guten ökologischen Zustand der Produktionsflächen sprechen würden.

Reduction programs are designed to reduce chemical plant protection to a minimum. The intensity of plant protection can be measured by the treatment frequency index (BI). This study is interested in the ecological impact of a long-term reduction of chemical plant protection in commercial crop cultures. It investigates the effects of a 50% reduction on Araneae at three fields in Ochtmers­leben (Saxony-Anhalt). Each field was divided into two halves representing a 100% and a 50% application variant. The analysis was based on qualitative and quantitative parameters such as activity density, species diversity, pattern of dominance as well as other computed parameters. The results indicate that the impact of insecticides on the spider population was the stronger the earlier insecticides were applied. There were no significant shifts in dominance structures between both variants. In summary, a 50% long-term reduction of chemical plant protection did have positive effects on spider coenoses.