The effectiveness of flower strips and hedgerows on pest control, pollination services and crop yield: a quantitative synthesis
Albrechtet al., 2020

Floral plantings are promoted to foster ecological intensification of agriculture through provisioning of ecosystem services. However, a comprehensive assessment of the effectiveness of different floral plantings, their characteristics and consequences for crop yield is lacking. Here we quantified the impacts of flower strips and hedgerows on pest control (18 studies) and pollination services (17 studies) in adjacent crops in North America, Europe and New Zealand. Flower strips, but not hedgerows, enhanced pest control services in adjacent fields by 16% on average. However, effects on crop pollination and yield were more variable. Our synthesis identifies several important drivers of variability in effectiveness of plantings: pollination services declined exponentially with distance from plantings, and perennial and older flower strips with higher flowering plant diversity enhanced pollination more effectively. These findings provide promising pathways to optimise floral plantings to more effectively contribute to ecosystem service delivery and ecological intensification of agriculture in the future.

Forest plot showing effects of flower strips and hedgerows on pollination and pest control service provisioning in adjacent crops compared to control crops without adjacent floral plantings. Squares illustrate predicted mean effects (z‐score estimates), bars show 95% confidence intervals (CIs). On average, pest control services were enhanced by 16% (z‐score: 0.25) in fields with adjacent flower strip compared to control fields.  

Predicted relationships between (a) mean natural pest control service and (b) mean crop pollination service (z‐scores (solid lines) ± 95% CI (dashed lines)) and in‐field distance to field border for field with (red lines; dots) or without adjacent floral planting (black lines, triangles). 

https://onlinelibrary.wiley.com/doi/10.1111/ele.13576

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