No net insect abundance and diversity declines across US long term ecological research sites

Authors: CROSSLEY, MICHAEL - University Of Georgia; MEIER, AMANDA - University Of Georgia; BALDWIN, EMILY - Hendrix College; BERRY, LAUREN - Hendrix College; CRENSHAW, LEAH - Hendrix College; Hartman, Glen; Lagos-Kutz, Doris; NICHOLS, DAVID - Hendrix College; PATEL, KRISHNA - Hendrix College; VARRIANO, SOFIA - Hendrix College; SNYDER, WILLIAM - University Of Georgia; MORAN, MATTHEW - Hendrix College

Submitted to: Nature Ecology and Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/30/2020
Publication Date: 8/10/2020
Citation: Crossley, M.S., Meier, A.R., Baldwin, E.M., Berry, L.L., Crenshaw, L.C., Hartman, G.L., Lagos-Kutz, D.M., Nichols, D.H., Patel, K., Varriano, S., Snyder, W.E., Moran, M.D. 2020. No net insect abundance and diversity declines across US long term ecological research sites. Nature Ecology and Evolution. https://doi.org/10.1038/s41559-020-1269-4.
DOI: https://doi.org/10.1038/s41559-020-1269-4

Interpretive Summary: Insects and other arthropods provide critical ecosystem services, including pollination, natural pest control, and decomposition, while influencing plant community structure and providing food to humans and other vertebrates. Recent reports of dramatic declines in insect abundance suggest grave consequences for global ecosystems and human society. We used data representing over 5,300 time series points for insects and other arthropods to search for evidence of declines across the United States. The data were collected over a 4-36-year period at monitoring sites representing 68 different natural and managed areas. Some taxa and sites showed decreases in abundance and diversity while others were increased or unchanged indistinguishable from zero. This lack of overall increase or decline was consistent across arthropod feeding groups and was similar for heavily disturbed versus relatively natural sites. These is a need for continued monitoring to obtain this type of data over more decades to follow changes in species composition. This information is important to the general public, ecologists and other scientists interested in ecosystems.

Technical Abstract: Recent reports of dramatic declines in insect abundance suggest grave consequences for global ecosystems and human society. Most evidence comes from Europe, however, leaving uncertainty about insect population trends worldwide. We used > 5,300 time series for insects and other arthropods, collected over 4-36 years at monitoring sites representing 68 different natural and managed areas, to search for evidence of declines across the United States. Some taxa and sites showed decreases in abundance and diversity while others increased or were unchanged, yielding net abundance and biodiversity trends generally indistinguishable from zero. This lack of overall increase or decline was consistent across arthropod feeding groups and was similar for heavily disturbed versus relatively natural sites. The apparent robustness of U.S. arthropod populations is reassuring. Yet, this result does not diminish the need for continued monitoring and could mask subtler changes in species composition that nonetheless endanger insect-provided ecosystem services.