Abstract
Ecosystems that are coupled by reciprocal flows of energy and nutrient subsidies can be viewed as a single “meta-ecosystem.” Despite these connections, the reciprocal flow of subsidies is greatly asymmetrical and seasonally pulsed. Here, we synthesize existing literature on stream–riparian meta-ecosystems to quantify global patterns of the amount of subsidy consumption by organisms, known as “allochthony.” These resource flows are important since they can comprise a large portion of consumer diets, but can be disrupted by human modification of streams and riparian zones. Despite asymmetrical subsidy flows, we found stream and riparian consumer allochthony to be equivalent. Although both fish and stream invertebrates rely on seasonally pulsed allochthonous resources, we find allochthony varies seasonally only for fish, being nearly three times greater during the summer and fall than during the winter and spring. We also find that consumer allochthony varies with feeding traits for aquatic invertebrates, fish, and terrestrial arthropods, but not for terrestrial vertebrates. Finally, we find that allochthony varies by climate for aquatic invertebrates, being nearly twice as great in arid climates than in tropical climates, but not for fish. These findings are critical to understanding the consequences of global change, as ecosystem connections are being increasingly disrupted.
Original language | English |
---|---|
Article number | e14401 |
Pages (from-to) | 1-13 |
Number of pages | 13 |
Journal | Ecology Letters |
Volume | 27 |
Issue number | 3 |
DOIs | |
Publication status | Published - Mar 2024 |
Bibliographical note
Funding Information:We thank the U.S. National Science Foundation (NSF) (award DEB 1354867) for funding the Stream Resiliency Research Coordination Network (RCN), which formed this working group. Additional support to DCA was provided by NSF awards DEB 2207232 and DEB 2207680, and the USDA National Institute of Food and Agriculture and Hatch Appropriations under Project #PEN04817 and Accession #700372. AMB was supported by NSF award DEB 2207232, KHT by NSF award DEB 2207680, MHB by NSF award DEB 1754389, and KEA by NSF awards DEB 1553718 and DEB 1655764. Support for JHL was provided by the U.S. Geological Survey's Ecosystem Mission Area. We thank Sean Bailey and Kenna Breckner for assisting in extracting data from the literature. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. government.
Publisher Copyright:
© 2024 The Authors. Ecology Letters published by John Wiley & Sons Ltd.