TY - JOUR

T1 - Abundance of spring- and winter-active arthropods declines with warming

AU - Fitzgerald, Jacquelyn L.

AU - Stuble, Katharine L.

AU - Nichols, Lauren M.

AU - Diamond, Sarah E.

AU - Wentworth, Thomas R.

AU - Pelini, Shannon L.

AU - Gotelli, Nicholas J.

AU - Sanders, Nathan J.

AU - Dunn, Robert R.

AU - Penick, Clint A.

N1 - Funding Information: We thank Paul CaraDonna and Amy Iler for their helpful advice on statistical analyses. We thank the Iler‐CaraDonna laboratory group for their helpful feedback on the manuscript. This project was funded by a National Science Foundation Dimensions of Biodiversity grant (NSF‐1136703) awarded to Aaron M. Ellison, NJG, NJS, and RRD; a US Department of Energy PER award (DEFG02‐08ER64510) awarded to NJS and RRD; and a National Science Foundation Career grant (NSF‐0953390) awarded to RRD as well as two undergraduate research fellowships awarded to JLF by the Office of Undergraduate Research at North Carolina State University and the Atlantic Coast Conference Inter‐Institutional Academic Collaborative. Publisher Copyright: © 2021 The Authors.

PY - 2021/4

Y1 - 2021/4

N2 - Because ectotherm activity and metabolism are sensitive to temperature, terrestrial arthropods may be especially responsive to ongoing climatic warming. Here, we quantified responses of arthropod abundance to two years of warming in an outdoor temperature manipulation experiment at Duke Forest, North Carolina, USA. Nine open-top chambers were individually heated year-round from 1.5° to 5.5°C above ambient temperature. From two years of monthly pitfall trapping, we collected and identified 4,468 arthropods representing 24 orders. We initially predicted that arthropods would experience the greatest negative effects of experimental warming during the summer months, when temperatures reach their yearly maximum and arthropods may be close to their maximum thermal tolerance limits. Instead, we found that the strongest negative effects on arthropod abundance occurred during the winter and spring, when ambient temperatures are relatively cooler, whereas the effects of experimental warming on abundance were not significant during the summer or fall. During the spring of 2012, the warmest spring on record for the southeastern USA, total arthropod abundance declined 20% per °C of experimental warming. Abundance declines were driven largely by flies (Diptera), which were the most abundant insect order, representing approximately a third of all arthropods collected. The most abundant arthropod family, Mycetophilidae (fungus gnats), declined 64% per °C of warming during the spring of 2012. Although previous research on climatic warming has focused on the impact of maximum yearly temperatures on organismal performance, our results are more consistent with the cool-season sensitivity hypothesis, which posits that arthropods adapted for cooler conditions are likely to face the strongest negative effects of warming during the cooler seasons.

AB - Because ectotherm activity and metabolism are sensitive to temperature, terrestrial arthropods may be especially responsive to ongoing climatic warming. Here, we quantified responses of arthropod abundance to two years of warming in an outdoor temperature manipulation experiment at Duke Forest, North Carolina, USA. Nine open-top chambers were individually heated year-round from 1.5° to 5.5°C above ambient temperature. From two years of monthly pitfall trapping, we collected and identified 4,468 arthropods representing 24 orders. We initially predicted that arthropods would experience the greatest negative effects of experimental warming during the summer months, when temperatures reach their yearly maximum and arthropods may be close to their maximum thermal tolerance limits. Instead, we found that the strongest negative effects on arthropod abundance occurred during the winter and spring, when ambient temperatures are relatively cooler, whereas the effects of experimental warming on abundance were not significant during the summer or fall. During the spring of 2012, the warmest spring on record for the southeastern USA, total arthropod abundance declined 20% per °C of experimental warming. Abundance declines were driven largely by flies (Diptera), which were the most abundant insect order, representing approximately a third of all arthropods collected. The most abundant arthropod family, Mycetophilidae (fungus gnats), declined 64% per °C of warming during the spring of 2012. Although previous research on climatic warming has focused on the impact of maximum yearly temperatures on organismal performance, our results are more consistent with the cool-season sensitivity hypothesis, which posits that arthropods adapted for cooler conditions are likely to face the strongest negative effects of warming during the cooler seasons.

KW - abundance declines

KW - arthropods

KW - climate change

KW - global warming

KW - insects

KW - seasonality

U2 - 10.1002/ecs2.3473

DO - 10.1002/ecs2.3473

M3 - Journal article

AN - SCOPUS:85105005882

VL - 12

JO - Ecosphere (Washington, D.C.)

JF - Ecosphere (Washington, D.C.)

SN - 2150-8925

IS - 4

M1 - e03473

ER -