Macroscale controls determine the recovery of river ecosystem productivity following flood disturbances.

Autor:	Lowman HE; Department of Natural Resources and Environmental Science, University of Nevada Reno, Reno, NV 89557., Shriver RK; Department of Natural Resources and Environmental Science, University of Nevada Reno, Reno, NV 89557., Hall RO Jr; Division of Biological Sciences, Flathead Lake Biological Station, University of Montana, Polson, MT 59860., Harvey JW; U.S. Geological Survey, Earth System Processes Division, Reston, VA 20192., Savoy P; U.S. Geological Survey, Earth System Processes Division, Reston, VA 20192., Yackulic CB; U.S. Geological Survey, Southwest Biological Science Center, Flagstaff, AZ 86001., Blaszczak JR; Department of Natural Resources and Environmental Science, University of Nevada Reno, Reno, NV 89557.
Jazyk:	angličtina
Zdroj:	Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2024 Jan 30; Vol. 121 (5), pp. e2307065121. Date of Electronic Publication: 2024 Jan 24.
DOI:	10.1073/pnas.2307065121
Abstrakt:	River ecosystem function depends on flow regimes that are increasingly modified by changes in climate, land use, water extraction, and flow regulation. Given the wide range of variation in flow regime modifications and autotrophic communities in rivers, it has been challenging to predict which rivers will be more resilient to flow disturbances. To better understand how river productivity is disturbed by and recovers from high-flow disturbance events, we used a continental-scale dataset of daily gross primary production time series from 143 rivers to estimate growth of autotrophic biomass and ecologically relevant flow disturbance thresholds using a modified population model. We compared biomass recovery rates across hydroclimatic gradients and catchment characteristics to evaluate macroscale controls on ecosystem recovery. Estimated biomass accrual (i.e., recovery) was fastest in wider rivers with less regulated flow regimes and more frequent instances of biomass removal during high flows. Although disturbance flow thresholds routinely fell below the estimated bankfull flood (i.e., the 2-y flood), a direct comparison of disturbance flows estimated by our biomass model and a geomorphic model revealed that biomass disturbance thresholds were usually greater than bed disturbance thresholds. We suggest that primary producers in rivers vary widely in their capacity to recover following flow disturbances, and multiple, interacting macroscale factors control productivity recovery rates, although river width had the strongest overall effect. Biomass disturbance flow thresholds varied as a function of geomorphology, highlighting the need for data such as bed slope and grain size to predict how river ecosystems will respond to changing flow regimes. Competing Interests: Competing interests statement:The authors declare no competing interest.
Databáze:	MEDLINE
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