TY - JOUR

T1 - Spatiotemporal changes in landscape crop composition differently affect density and seasonal variability of pests, parasitoids and biological pest control in cabbage

AU - Scheiner, Christine

AU - Martin, Emily A.

N1 - Funding information: This study was funded by the 2013–2014 BiodivERsA/FACCE-JPI joint call for research proposals (project ECODEAL), with the national funders ANR , BMBF , FORMAS , FWF , MINECO , NWO and PT-DLR . The funding sources had no influence on study design, data collection, analysis and interpretation, and writing of the report.

PY - 2020/10/1

Y1 - 2020/10/1

N2 - Declines in functional biodiversity, caused by changing structure and composition of agricultural landscapes, endanger the provision and stability of important ecosystem services, such as biological pest control. Understanding how spatiotemporal landscape changes affect the dynamics of pests, natural enemies and their activity can help safeguard and improve pest control in crops. Here, we tested the influence of spatial and temporal differences in landscape composition of crops (landscape-wide crop rotation diversity and % pest host crops) on the density and seasonal variability of cabbage pests, parasitoids and rates of aphid parasitism and predation. We also tested whether low seasonal variability of pests and parasitoids translates into stable and high pest control, reduced crop damage and higher yields. We show that landscapes with diverse crop rotations increased aphid parasitism, but also leaf-chewing pest density and seasonal stability. Leaf-chewing pest density decreased with increasing % host crops from year to year, suggesting a dilution effect. However, parasitoid density increased in these landscapes. We found no relationship between predation or parasitism and crop damage or yield. Further, stable parasitoid populations led to more stable parasitism rates. These findings highlight that impacts of spatially and temporally changing landscapes are pest- and enemy-specific, and tradeoffs for landscape management may occur. Appropriately managing the diversity and composition of arable crops in farmed landscapes may help influence species occurrences, without converting fertile land to non-crop habitat.

AB - Declines in functional biodiversity, caused by changing structure and composition of agricultural landscapes, endanger the provision and stability of important ecosystem services, such as biological pest control. Understanding how spatiotemporal landscape changes affect the dynamics of pests, natural enemies and their activity can help safeguard and improve pest control in crops. Here, we tested the influence of spatial and temporal differences in landscape composition of crops (landscape-wide crop rotation diversity and % pest host crops) on the density and seasonal variability of cabbage pests, parasitoids and rates of aphid parasitism and predation. We also tested whether low seasonal variability of pests and parasitoids translates into stable and high pest control, reduced crop damage and higher yields. We show that landscapes with diverse crop rotations increased aphid parasitism, but also leaf-chewing pest density and seasonal stability. Leaf-chewing pest density decreased with increasing % host crops from year to year, suggesting a dilution effect. However, parasitoid density increased in these landscapes. We found no relationship between predation or parasitism and crop damage or yield. Further, stable parasitoid populations led to more stable parasitism rates. These findings highlight that impacts of spatially and temporally changing landscapes are pest- and enemy-specific, and tradeoffs for landscape management may occur. Appropriately managing the diversity and composition of arable crops in farmed landscapes may help influence species occurrences, without converting fertile land to non-crop habitat.

KW - Biological pest control

KW - Brassica oleracea var. capitata

KW - Coefficient of variation

KW - Crop rotation

KW - Landscape diversity

KW - Pest damage

UR - http://www.scopus.com/inward/record.url?scp=85086905289&partnerID=8YFLogxK

U2 - 10.1016/j.agee.2020.107051

DO - 10.1016/j.agee.2020.107051

M3 - Article

VL - 301

JO - Agriculture, Ecosystems and Environment

JF - Agriculture, Ecosystems and Environment

SN - 0167-8809

M1 - 107051

ER -