A global synthesis reveals biodiversity-mediated benefits for crop production

Abstract

Human land use threatens global biodiversity and compromises multiple ecosystem functions critical to food production. Whether crop yield–related ecosystem services can be maintained by a few dominant species or rely on high richness remains unclear. Using a global database from 89 studies (with 1475 locations), we partition the relative importance of species richness, abundance, and dominance for pollination; biological pest control; and final yields in the context of ongoing land-use change. Pollinator and enemy richness directly supported ecosystem services in addition to and independent of abundance and dominance. Up to 50% of the negative effects of landscape simplification on ecosystem services was due to richness losses of service-providing organisms, with negative consequences for crop yields. Maintaining the biodiversity of ecosystem service providers is therefore vital to sustain the flow of key agroecosystem benefits to society.

A review of models of natural pest control: toward predictions across agricultural landscapes

“…Analyses of recent large-scale correlative models corroborate the inconsistent nature of natural pest control responses to landscape characteristics. These studies identified system-specific (Karp et al, 2018) 7 and trait-mediated differences in responses (Martin et al, 2019) as a major underlying cause of discrepancies.…”

“…The derivation of archetypes of heterogeneous real-world systems requires that multiple cases be similar with respect to defining features of the studied phenomenon and that these cases share some key attributes (Oberlack et al, 2019). Natural pest control seems to respond idiosyncratically to land-use gradients across different systems, but cases show similar responses when grouped according to system characteristics and functional traits (Karp et al, 2018;Martin et al, 2019). For instance, dietary, dispersal and overwintering traits of pests and their enemies mediate these organisms' responses to landscape characteristics (Martin et al, 2019), while other traits, such as invasiveness, contribute under certain conditions (Tamburini et al, in prep.…”

“…Trait-based correlative models contribute general understanding of potentially important processes behind pest control responses to landscape characteristics (Martin et al, 2019). Multivariate statistical techniques help reduce complex socioecological systems to the fewest possible elements that describe the identified processes across systems (Sietz et al, 2017).…”

“…We focus on shared qualitative and quantitative model predictions, in order to increase predictive robustness. For model verification, predictions are compared with the responses of organisms with the respective trait values to changes in landscape characteristics, as revealed by the analysis of observations across Europe (Martin et al, 2019).…”

“…Crop-pest-enemy combinations that feature in recently compiled large-scale datasets (Karp et al, 2018;Martin et al, 2019;Dainese et al, 2019) can provide a pertinent 23 collection of systems. The identified features should be linked explicitly to specific processes that are known to underlie the behaviour of a system, based on ecological theory and expert knowledge.…”