A functional approach to assessing plant–arthropod interaction in winter wheat

This paper deals with the effect of the farming system on the arthropod community through its effects on plant community characteristics by comparing organic and conventional winter wheat fields in the Mediterranean region. Arthropods and plants were surveyed sequentially in each plot within each field. Most arthropods were identified to family and each taxon was classified into one of the following feeding groups: chewing-herbivores, flower-consumers, omnivores, saprophages, sucking-herbivores, parasitoids, and predators. Plant species were classified into three functional groups (grasses, forbs and legumes) which represent highly distinct resources for the arthropods. The farming system had a significant impact on the abundance and richness of grasses, forbs and legumes. In turn, the plant community, mainly conditioned by the farming system, affected the entire community of arthropods, indicating that small-scale plant community characteristics must be taken into account in order to achieve a better comprehension of the arthropodʹs response to the farming system. There is still no clear perception of the importance of weeds in arable ecosystems, but the role of legumes in enhancing the richness of saprophages, parasitoids and predators underlines the importance of investigating further cropping systems that combine crop production with the maintenance of essential ecosystem services.