Food chains in cereal fields

Summary

Correlations between the weed flora and the arthropod fauna of conventionally and organically managed fields were analysed. The results indicate that the abundance of weeds in Danish conventionally grown cereal fields is too low to sustain a population of more or less species specific herbivores, i.e. too low to maintain functioning food chain links between weeds and herbivores. Organically grown fields with a higher abundance of weeds may be capable of sustaining a fauna of arthropods relying on the weeds. The data from extra- weedy areas support this hypothesis, indicating that particularly weed-rich fields can better support herbivorous insects.