The Impact of Sea Embankment Reclamation on Greenhouse Gas GHG Fluxes and Stocks in Invasive <i>Spartina alterniflora</i> and Native <i>Phragmites australis</i> Wetland Marshes of East China
The introduction of embankment seawalls to limit the expansion of the exotic C<sub>4</sub> perennial grass <i>Spartina alteniflora</i> Loisel in eastern China’s coastal wetlands has more than doubled in the past decades. Previous research focused on the impact of sea embankme...
Guardado en:
| Autores principales: | , , , , , , , , |
|---|---|
| Formato: | article |
| Lenguaje: | EN |
| Publicado: |
MDPI AG
2021
|
| Materias: | |
| Acceso en línea: | https://doaj.org/article/fcc1dc8bde30451983eff61869a683da |
| Etiquetas: |
Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
|
| Sumario: | The introduction of embankment seawalls to limit the expansion of the exotic C<sub>4</sub> perennial grass <i>Spartina alteniflora</i> Loisel in eastern China’s coastal wetlands has more than doubled in the past decades. Previous research focused on the impact of sea embankment reclamation on the soil organic carbon (C) and nitrogen (N) stocks in salt marshes, whereas no study attempted to assess the impact of sea embankment reclamation on greenhouse gas (GHG) fluxes in such marshes. Here we examined the impact of sea embankment reclamation on GHG stocks and fluxes of an invasive <i>Spartina alterniflora</i> and native <i>Phragmites australis</i> dominated salt marsh in the Dongtai wetlands of China’s Jiangsu province. Sea embankment reclamation significantly decreased soil total organic C by 54.0% and total organic N by 73.2%, decreasing plant biomass, soil moisture, and soil salinity in both plants’ marsh. It increased CO<sub>2</sub> emissions by 38.2% and 13.5%, and reduced CH<sub>4</sub> emissions by 34.5% and 37.1%, respectively, in the <i>Spartina alterniflora</i> and <i>Phragmites australis</i> marshes. The coastal embankment wall also significantly increased N<sub>2</sub>O emission by 48.9% in the <i>Phragmites australis</i> salt marsh and reduced emissions by 17.2% in the <i>Spartina alterniflora</i> marsh. The fluxes of methane CH<sub>4</sub> and carbon dioxide CO<sub>2</sub> were similar in both restored and unrestored sections, whereas the fluxes of nitrous oxide N<sub>2</sub>O were substantially different owing to increased nitrate as a result of N-loading. Our findings show that sea embankment reclamation significantly alters coastal marsh potential to sequester C and N, particularly in native <i>Phragmites australis</i> salt marshes. As a result, sea embankment reclamation essentially weakens native and invasive saltmarshes’ C and N sinks, potentially depleting C and N sinks in coastal China’s wetlands. Stakeholders and policymakers can utilize this scientific evidence to strike a balance between seawall reclamation and invasive plant expansion in coastal wetlands. |
|---|