Tidal marsh restoration enhances sediment accretion and carbon accumulation in the Stillaguamish River estuary, Washington

Poppe, Katrina L.; Rybczyk, John

doi:10.1371/journal.pone.0257244

Cited by 19 publications

(8 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Conservation of existing carbon stocks in natural marshes is therefore often prioritized as a climate change mitigation strategy over restoration (Macreadie et al, 2017). Recent evidence from the USA, however, found carbon stocks in the top 30 cm of a MR site were only marginally lower than adjacent natural sites in the 4 years following restoration (4.43 and 5.95 kg C m -2 respectively; Poppe and Rybczyk, 2021). The various timescales reported for the development of carbon stocks in restored saltmarshes are highly site-specific -an important consideration for MR as a technique to enhance climate change mitigation.…”

Section: Introductionmentioning

confidence: 99%

Maximizing blue carbon stocks through saltmarsh restoration

et al. 2023

View full text Add to dashboard Cite

Political discourse around coastal wetland restoration and blue carbon management strategies has increased in the past decade, yet carbon storage has neither been a reason for restoration, nor a criterion to measure the success of current saltmarsh restoration schemes in the UK. To maximise climate change mitigation through saltmarsh restoration, knowledge on the key drivers of carbon stock variability is required. We use restored saltmarshes of similar age, paired with adjacent natural marshes as references, to identify drivers of carbon stocks following managed realignment within an estuary in southeastern England. From surficial soil cores (top 30 cm), we measured carbon stock alongside environmental characteristics. Carbon stock between natural and restored sites were similar after ~ 30 years when restored sites were above mean high water neap (MHWN) tidal levels. Elevated marsh platforms likely provide suitable conditions for the development of mature plant communities associated with greater capture and production of organic carbon. The restored site at Tollesbury (Essex, UK) had a 2-fold lower carbon stock than other restored sites in the estuary. We attribute this to the site’s low position in the tidal frame, below MHWN tidal levels, coupled with low sediment supply and the dominance of pioneer plant communities. As blue carbon is anticipated to become an important facet of saltmarsh restoration, we recommend that sites above MHWN tidal levels are selected for managed realignment or that preference is given to coastlines with a high sediment supply that may rapidly elevate realignment sites above MHWN. Alternatively, elevation could be artificially raised prior to realignment. Restoration schemes aiming to maximise climate change mitigation should also encourage the establishment of key plant species (e.g., Atriplex portulacoides in our study) to enhance carbon stocks. However, the overall goal of restoration ought to be carefully considered as trade-offs in ecosystem services may ensue if restoration for climate change mitigation alone is pursued.

show abstract

Section: Introductionmentioning

confidence: 99%

Maximizing blue carbon stocks through saltmarsh restoration

et al. 2023

View full text Add to dashboard Cite

show abstract

“…These factors have been shown to increase the speed of recovery of wetland functions at restored sites (e.g. Moreno‐Mateos et al 2012; Yu et al 2017; Poppe & Rybczyk 2021) and may have promoted the recovery of wetland functions at the passively restored site. Deposits from the Big Creek channel likely elevate burial of allochthonous organic carbon and minerogenic sediments and help preserve autochthonous organic matter in deeper sediment layers (Kemp et al 2019; Spivak et al 2019), in part explaining the high rates of carbon accumulation at the reference and passively restored marshes.…”

Section: Discussionmentioning

confidence: 99%

Controls on organic carbon stocks among restored wetland soils in the Long Point region of southern Ontario, Canada

Loder

Zamaria

Arhonditsis

et al. 2023

Restoration Ecology

View full text Add to dashboard Cite

Freshwater marsh restoration can be a viable natural climate solution; however, the extent to which marsh soils bury and preserve organic carbon within policy‐relevant timescales remains highly uncertain. Here, we compare organic carbon masses and accumulation rates from an undrained reference marsh, a passively restored freshwater marsh (reflooded after 1954) and a chronosequence of actively restored freshwater marshes (<10 years in age) situated in Lake Erie watersheds in the Long Point Biosphere Reserve of Ontario, Canada. The reference site has sustained the highest rates of short‐term organic carbon accumulation (235 g C m−2 yr−1) over the last four decades and has the highest mass of soil organic carbon (122 tC/ha) at 0–30 cm depth. Organic carbon masses are highly variable among all restored wetlands (16–115 tC/ha) at 0–30 cm depth and are not strongly related to time since restoration at least over the last 10 years. Nonetheless, we show that passive wetland restoration generates high rates of organic carbon accumulation (144 g m−2 yr−1) on a multidecadal scale where sites are low‐lying, underlain by alluvial deposits and connected to larger ground and surface water networks. Active restoration measures (e.g. excavation, installation of berms) may promote organic carbon preservation, particularly where fine‐grained soil texture promotes waterlogging. We demonstrate the importance of substrate, topographic gradient, and hydrology in selecting sites for marsh restoration to maximize carbon sequestration, and argue that the presettlement context and reference paleorecords provide necessary baselines for directing successful wetland restoration.

show abstract

“…We note that, within this system, the partitioning between high and low marsh zones appears very closely linked with associated vegetation. Therefore, vegetation composition was recorded as an indicator of "low" vs. "high" marsh zones (Porter, 1982;Weinmann et al, 1984) around each coring spot. Coring spots were considered low marsh if the species Triglochin maritima, Salicornia spp., Fucus ssp., or Distichlis spicata were present and high marsh if it included Plantago maritima, Deschampsia caespitosa, Grindelia integrifolia, Potentilla anserina, Lysimachia maritima, or Eleocharis ssp.…”

Section: Field Samplingmentioning

confidence: 99%

“…Several recent studies have shown substantially higher CARs in restored vs. natural marshes after approximately 10 years (e.g. Poppe and Rybczyk, 2021;Drexler et al, 2019). The causes of these inflated CARs can be very site-specific, depending on the types of colonizing vegetation (Kelleway et al, 2017) and the relative contributions of allochthonous mineral materials (Drexler et al, 2019).…”

Section: Comparison Of Whole-core and 30-year Carsmentioning

confidence: 99%

Quantification of blue carbon in salt marshes of the Pacific coast of Canada

Chastain

Kohfeld²,

Pellatt³

et al. 2022

Biogeosciences

View full text Add to dashboard Cite

Abstract. Tidal salt marshes are known to accumulate “blue carbon” at high rates relative to their surface area, which render these systems among the Earth's most efficient carbon (C) sinks. However, the potential for tidal salt marshes to mitigate global warming remains poorly constrained because of the lack of representative sampling of tidal marshes from around the globe, inadequate areal extent estimations, and inappropriate dating methods for accurately estimating C accumulation rates. Here we provide the first estimates of organic C storage and accumulation rates in salt marshes along the Pacific coast of Canada, within the United Nations Educational, Scientific and Cultural Organization (UNESCO) Clayoquot Sound Biosphere Reserve and Pacific Rim National Park Reserve, a region currently underrepresented in global compilations. Within the context of other sites from the Pacific coast of North America, these young Clayoquot Sound marshes have relatively low C stocks but are accumulating C at rates that are higher than the global average with pronounced differences between high and low marsh habitats. The average C stock calculated during the past 30 years is 54 ± 5 Mg C ha−1 (mean ± standard error), which accounts for 81 % of the C accumulated to the base of the marsh peat layer (67 ± 9 Mg C ha−1). The total C stock is just under one-third of previous global estimates of salt marsh C stocks, likely due to the shallow depth and young age of the marsh. In contrast, the average C accumulation rate (CAR) (184 ± 50 g C m−2 yr−1 to the base of the peat layer) is higher than both CARs from salt marshes along the Pacific coast (112 ± 12 g C m−2 yr−1) and global estimates (91 ± 7 g C m−2 yr−1). This difference was even more pronounced when we considered individual marsh zones: CARs were significantly greater in high marsh (303 ± 45 g C m−2 yr−1) compared to the low marsh sediments (63 ± 6 g C m−2 yr−1), an observation unique to Clayoquot Sound among NE Pacific coast marsh studies. We attribute low CARs in the low marsh zones to shallow-rooting vegetation, reduced terrestrial sediment inputs, negative relative sea level rise in the region, and enhanced erosional processes. Per hectare, CARs in Clayoquot Sound marsh soils are approximately 2–7 times greater than C uptake rates based on net ecosystem productivity in Canadian boreal forests, which highlights their potential importance as C reservoirs and the need to consider their C accumulation capacity as a climate mitigation co-benefit when conserving for other salt marsh ecosystem services.

show abstract

Tidal marsh restoration enhances sediment accretion and carbon accumulation in the Stillaguamish River estuary, Washington

Cited by 19 publications

References 30 publications

Maximizing blue carbon stocks through saltmarsh restoration

Maximizing blue carbon stocks through saltmarsh restoration

Controls on organic carbon stocks among restored wetland soils in the Long Point region of southern Ontario, Canada

Quantification of blue carbon in salt marshes of the Pacific coast of Canada

Contact Info

Product

Resources

About