Effects of farming management at the landscape scale on pollinators and natural enemies and associated crop pests. A review.

Farming management and alterations in land cover play crucial roles in driving changes in biodiversity, altering ecosystem functioning and the provision of ecosystem services. Whereas land cover corresponds to the identity of cultivated/non-cultivated ecosystems in the landscape, farming management describes all the components of farming activities within crops and grassland (i.e., farming practices, crop successions, and farming systems). Despite extensive research on the relationship between land cover and arthropod biodiversity at the landscape scale, there is a surprising scarcity of studies examining the impacts of farming management on arthropods at the same scale. This is unexpected given the already recognized field-scale impact on arthropods and related ecosystem services (such as pollination and biological control), and the fact that most species move or supplement their resources in multiple patches across agricultural landscapes. We conducted a comprehensive literature review that aimed at answering two fundamental questions: 1) What components of farming management are considered at the landscape scale? 2) Does farming management at the landscape scale impact arthropod biodiversity and associated ecosystem functions and services? We performed a query on the Web of Science, on original studies published from January 2005 to December 2021 and addressing the broad notion of farming management at the landscape scale on arthropods. The key findings are as follows: 1) The effect of farming management components at the landscape scale on arthropods was tackled in only 30 studies that highlighted that its response was highly taxon dependent. We have reported positive effects of organic farming on pollinators, as well as positive effects of extensification of farming practices on natural enemies and biocontrol. 2) Most studies focused on the effect of organic farming on natural enemies and associated pests, and reported contrasting effects on these taxa. Our study underscores the challenges in quantifying farming management at the landscape scale, and yet its importance in comprehending the dynamics of biodiversity and related ecosystem services. We discuss research perspectives for an improved consideration of farming management on a landscape scale, particularly on arthropods, to attenuate insect decline as well as ecosystem service loss in agroecosystems.