Author Identifier

Oscar Serrano Orcid: https://orcid.org/0000-0002-5973-0046 Paul Lavery Orcid: https://orcid.org/0000-0001-5162-273X Miguel Mateo Orcid: https://orcid.org/0000-0001-7567-0277

Document Type

Journal Article

Publication Title

Journal of Geophysical Research: Biogeosciences

Publisher

Wiley

School

School of Science / Centre for Marine Ecosystems Research

RAS ID

30384

Funders

Australian Research Council.

Deutscher Akademischer Austauschdienst (DAAD).

Spanish National Parks and State Research Schemes.

Grant Number

ARC Number : DE170101524

Comments

Belshe, E. F., Sanjuan, J., Leiva‐Dueñas, C., Piñeiro‐Juncal, N., Serrano, O., Lavery, P., & Mateo, M. A. (2019). Modeling organic carbon accumulation rates and residence times in coastal vegetated ecosystems. Journal of Geophysical Research: Biogeosciences, 124(11), 3652-3671. Available here

Abstract

Coastal vegetated “blue carbon” ecosystems can store large quantities of organic carbon (OC) within their soils; however, the importance of these sinks for climate change mitigation depends on the OC accumulation rate (CAR) and residence time. Here we evaluate how two modeling approaches, a Bayesian age-depth model alone or in combination with a two-pool OC model, aid in our understanding of the time lines of OC within seagrass soils. Fitting these models to data from Posidonia oceanica soil cores, we show that age-depth models provided reasonable CAR estimates but resulted in a 22% higher estimation of OC burial rates when ephemeral rhizosphere OC was not subtracted. This illustrates the need to standardize CAR estimation to match the research target and time frames under consideration. Using a two-pool model in tandem with an age-depth model also yielded reasonable, albeit lower, CAR estimates with lower estimate uncertainty, which increased our ability to detect among-site differences and seascape-level trends. Moreover, the two-pool model provided several other useful soil OC diagnostics, including OC inputs, decay rates, and transit times. At our sites, soil OC decayed quite slowly both within fast cycling (0.028 ± 0.014 yr−1) and slow cycling (0.0007 ± 0.0003 yr−1) soil pools, resulting in OC taking between 146 and 825 yr to transit the soil system. Further, an estimated 85% to 93% of OC inputs enter slow-cycling soil pools, with transit times ranging from 891 to 3,115 yr, substantiating the importance of P. oceanica soils as natural, long-term OC sinks.

DOI

10.1029/2019JG005233

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

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