TY - JOUR
T1 - Herbicide drift can affect plant and arthropod communities
AU - Egan, J. Franklin
AU - Bohnenblust, Eric
AU - Goslee, Sarah
AU - Mortensen, David
AU - Tooker, John
N1 - Funding Information:
We thank Brian Macafee, Scott Smiles, and David Biddinger for assistance establishing and managing field sites for this research. Dwight Lingenfelter and Art Gover provided recommendations on herbicide application methods. Bethany Carter, Ian Graham, and Kathryn Barlow provided assistance with plant censuses, and Allie Shoffner, Curtis London, Glenden Taylor, and Andrew Aschwanden assisted with insect sampling and sorting. This work was supported through US EPA Science to Achieve Results fellowships awarded to J. F. Egan (FP917131012) and E. Bohnenblust (FP917431). Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture. USDA is an equal opportunity provider and employer.
PY - 2014/3/1
Y1 - 2014/3/1
N2 - Field edges, old fields, and other semi-natural habitats in agricultural landscapes support diverse plant communities that help sustain pollinators, predators, and other beneficial arthropods. These plant and arthropod communities may be at significant ecotoxicological risk from herbicides applied to nearby crop fields. Recent innovations in herbicide-resistant crop biotechnology may lead to major increases in the use of the herbicides dicamba and 2,4-D. These herbicides selectively affect broadleaf plants, and non-target exposures may therefore lead to a net reduction in the functional diversity and floral resources provided by semi-natural habitats. In multi-year experiments at two sites (a field edge and an old field), we exposed replicated plots to low doses of dicamba designed to simulate herbicide drift and monitored changes in plant and arthropod communities. At the field edge site, we observed a significant decline in forb cover (but not floral resources) in plots treated at doses (~1% of the field application rate) that are substantially lower than those that have been documented to affect plant communities in previous research. We also observed declines in three herbivorous pest species (pea aphids, spotted alfalfa aphid, and potato leaf hopper), increases in one pest species (clover root curculio), and increases in beneficial seed predators (crickets) associated with dicamba exposure. In contrast, at the old field site, drift-level doses did not affect plant community structure but reduced flowering of a key species (Monarda fistulosa). Variability across sites and taxonomic groups makes it difficult to offer general conclusions about the risks of dicamba drift to plant and arthropod biodiversity. Factors including the successional age of the plant community and water stress at the time of herbicide exposure likely explain the differing responses at the two sites to simulated drift.
AB - Field edges, old fields, and other semi-natural habitats in agricultural landscapes support diverse plant communities that help sustain pollinators, predators, and other beneficial arthropods. These plant and arthropod communities may be at significant ecotoxicological risk from herbicides applied to nearby crop fields. Recent innovations in herbicide-resistant crop biotechnology may lead to major increases in the use of the herbicides dicamba and 2,4-D. These herbicides selectively affect broadleaf plants, and non-target exposures may therefore lead to a net reduction in the functional diversity and floral resources provided by semi-natural habitats. In multi-year experiments at two sites (a field edge and an old field), we exposed replicated plots to low doses of dicamba designed to simulate herbicide drift and monitored changes in plant and arthropod communities. At the field edge site, we observed a significant decline in forb cover (but not floral resources) in plots treated at doses (~1% of the field application rate) that are substantially lower than those that have been documented to affect plant communities in previous research. We also observed declines in three herbivorous pest species (pea aphids, spotted alfalfa aphid, and potato leaf hopper), increases in one pest species (clover root curculio), and increases in beneficial seed predators (crickets) associated with dicamba exposure. In contrast, at the old field site, drift-level doses did not affect plant community structure but reduced flowering of a key species (Monarda fistulosa). Variability across sites and taxonomic groups makes it difficult to offer general conclusions about the risks of dicamba drift to plant and arthropod biodiversity. Factors including the successional age of the plant community and water stress at the time of herbicide exposure likely explain the differing responses at the two sites to simulated drift.
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U2 - 10.1016/j.agee.2013.12.017
DO - 10.1016/j.agee.2013.12.017
M3 - Article
AN - SCOPUS:84891635799
SN - 0167-8809
VL - 185
SP - 77
EP - 87
JO - Agriculture, Ecosystems and Environment
JF - Agriculture, Ecosystems and Environment
ER -