Restoration of riparian forest cover increases carbon stocks in the Pacific Northwest

Bibliographic Data

ID15548985
AuthorsRegina O’Kelley (0009-0005-0639-8237, University of Oregon, corresponding author), Rose A Graves (0000-0002-3405-0212, The Nature Conservancy, corresponding author), Holly Amer (0009-0002-8516-2078, University of Oregon, corresponding author), Lucas C R Silva (0000-0002-4838-327X, University of Oregon, corresponding author)
Year2025
Volume20
Issue8
Pages084003-084003
Publication date2025-06-18
Peer ReviewedYes
Open AccessYes
TypeARTICLE
VenueEnvironmental Research Letters (JOURNAL)
Journal identifiersISSN: 1748-9326 • E-ISSN: 1748-9326
PublisherIOP Publishing (PUBLISHER • GB)
DOI10.1088/1748-9326/ade5bb
OpenAlexW4411405973
LanguageEN
References cited108

Reforestation of degraded riparian areas provides climate mitigation benefits through increased carbon (C) storage. However, the magnitude of this potential natural climate solution (NCS) remains uncertain across ecoregions. Few studies have evaluated riparian planting C sequestration and storage, particularly in highly productive wet riparian ecosystems. In recent decades, riparian reforestation has accelerated in the Pacific Northwest (PNW) of the United States, primarily aiming to restore ecosystem functions and associated benefits. Using these plantings as a ‘natural experiment’, we assessed C storage in woody vegetation (trees and shrubs) and soils across a chronosequence of PNW riparian reforestation sites. Our study evaluated changes in C storage with planting age and identified key covariates affecting C storage in plants and soils and their relationship with planting age across a ∼430 km latitudinal gradient in western Oregon, USA. We found that woody and soil C stocks increase with planting age, averaging 24% and 1% per year, respectively. Increases in tree C were strongly driven by increasing planting age and tree stem density. Understory C was weakly related to stand characteristics and geomorphic properties, and strongly related to planting age. Soil C gains were positively driven by precipitation. We find that riparian reforestation can result in increased C storage, with woody vegetation comprising most of the increase. Our results highlight the importance of including both trees and shrubs in plantings to realize C accumulation gains in the earlier years. Because C accumulation is gradual, yet compounding (i.e. 10+ and 15+ years for total C stocks to increase by 1.95, and 19.2 Mg C ha −1 , respectively), riparian reforestation projects implemented today could take over a decade to deliver high NCS benefits, emphasizing the urgency to implement these projects to limit the worst of climate change impacts

Agroforestry · Biology · Carbon dioxide · Carbon sequestration · Carbon stock · Climate change · Cover (algebra · Forest cover · Geography · Riparian forest · Riparian zone · Environmental Science · Fire effects on ecosystems · Forest ecology and management · Remote Sensing and LiDAR Applications · Ecology · Forestry · Geology · Oceanography

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