Effects of local landscape richness on in-field weed metrics across the Great Britain scale

Weeds sit at the crux of issues of arable biodiversity and productivity. We test whether the effects of a simple local landscape richness score are apparent on in-field data for the predominant weeds, in the seedbank and as standing weeds, across the Great Britain (GB) scale. We test two hypotheses: (H1) that in-field weed species richness is positively related to local landscape richness around arable fields; and (H2) that in-field weed abundance is positively related to local landscape richness. We maintain H1, but find little evidence of a consistent effect of local landscape on the species richness of in-field weeds. Convincing evidence for local landscape richness affecting weed abundance lead us to accept H2 as a working hypothesis for in-field weed abundance. However, we have no mechanism to explain why in-field weed abundance should be linked to off-field landscape features, as expectations for farmer management intensity and local bee abundance affecting weed abundance were not significant.