Do field defects support beneficial arthropods and ecosystem services within arable fields?

KNAPP, MICHAL; GONZÁLEZ, EZEQUIEL; SEIDL, MIROSLAV; STROBL, MARTIN; SASKA, PAVEL; KADLEC, TOMÁS

Olomouc

Conferencia; Zoologické dny 2019 (Zoological days); 2020

Biodiversity has declined globally over the last decades and agricultural intensification is among the main drivers of this process, highlighting the need of conservation measures in agricultural landscapes. In this study, we introduced a novel low-cost conservation measure called artificial field defects, i.e. areas without crop . In collaboration with farmers, we created artificial field defects at the edges and interiors of oilseed rape (OSR) fields and sow half of the defects with a nectar-rich plant (Onobrychis defects). We investigated the effects of artificial field defects on diverse arthropod taxa during OSR flowering and ripening using a combination of several sampling techniques: pitfall traps, pan traps, sweep netting and individual counting. Butterflies, true bugs, bees and wasps were more abundant and species-rich in both types of defects than in OSR controls, whereas only spider abundance showed the same trend. By contrast, carabid beetles and rove beetles had more individuals and species in controls than in defects, and the same was true for myriapods? richness. Arthropod abundance and species richness increased, and field defects become relatively more attractive, during OSR ripening compared to OSR flowering. Only butterfly and spider assemblages were consistently more abundant and species species-rich at field edges compared to field interiors. Surprisingly, Onobrychis sowing has had only negligible effects on arthropod abundance, species richness or speciesand composition, probably because of low seedling recruitment. Field defects can represent a simple tool to support some arthropod groups, although future studies are needed to understand their importance and balance their benefits for farmers.