Abstract
Context: Seagrass meadows act as efficient natural carbon sinks by sequestering atmospheric CO and through trapping of allochthonous organic material, thereby preserving organic carbon (C ) in their sediments. Less understood is the influence of landscape configuration and transformation (land-use change) on carbon sequestration dynamics in coastal seascapes across the land–sea interface. Objectives: We explored the influence of landscape configuration and degradation of adjacent mangroves on the dynamics and fate of C in seagrass habitats. Methods: Through predictive modelling, we assessed sedimentary C content, stocks and source composition in multiple seascapes (km-wide buffer zones) dominated by different seagrass communities in northwest Madagascar. The study area encompassed seagrass meadows adjacent to intact and deforested mangroves. Results: The sedimentary C content was influenced by a combination of landscape metrics and inherent habitat plant- and sediment-properties. We found a strong land-to-sea gradient, likely driven by hydrodynamic forces, generating distinct patterns in sedimentary C levels in seagrass seascapes. There was higher C content and a mangrove signal in seagrass surface sediments closer to the deforested mangrove area, possibly due to an escalated export of C from deforested mangrove soils. Seascapes comprising large continuous seagrass meadows had higher sedimentary C levels in comparison to more diverse and patchy seascapes. Conclusion: Our results emphasize the benefit to consider the influence of seascape configuration and connectivity to accurately assess C content in coastal habitats. Understanding spatial patterns of variability and what is driving the observed patterns is useful for identifying carbon sink hotspots and develop management prioritizations. 2 org org org org org org org org org
Keywords
Land–sea interface, Mangrove deforestation, Seagrass meadows, Seascape connectivity, Sedimentary carbon storage
Document Type
Journal Article
Date of Publication
2021
Publication Title
Landscape Ecology
Publisher
Springer
School
School of Science / Centre for Marine Ecosystems Research
RAS ID
36856
Funders
Australian Research Council
Funding details : https://link.springer.com/article/10.1007%2Fs10980-021-01216-8
Grant Number
ARC Number : 170100219
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Comments
Asplund, M. E., Dahl, M., Ismail, R. O., Arias-Ortiz, A., Deyanova, D., Franco, J. N., ... Gullström, M. (2021). Dynamics and fate of blue carbon in a mangrove–seagrass seascape: Influence of landscape configuration and land-use change. Landscape Ecology, 36(5), 1489-1509. https://doi.org/10.1007/s10980-021-01216-8