Response of topsoil Fe-bound organic carbon pool and microbial community to Spartina alterniflora invasion in coastal wetlands

verfasst von: Meifen Lin, Yu Chen, Liwen Cheng, Yi Zheng, Weiqi Wang, Jordi Sardans, Zhaoliang Song, Georg Guggenberger, Yuanchun Zou, Xueli Ding, Akash Tariq, Fanjiang Zeng, Abdulwahed Fahad Alrefaei, Josep Peñuelas
Abstract: Wetland ecosystems have dual functions as both carbon (C) sources and C sinks, playing a vital role in the world's C budget. Wetlands are prone to suffer from plant invasions, and for example, Spartina alterniflora, a well-known invasive species, has rapidly expanded in coastal areas of Asia since 1979 and altered the C cycles in coastal wetland ecosystems. Fe(III) oxides are critical in the OC storage by formation of Fe-bound organic carbon (Fe-OC). But the impact of the invasion by S. alterniflora in coastal wetlands on the formation and stabilization of Fe-OC is poorly known. Herein, we assessed soil Fe species contents, Fe-OC pool, and the microbial communities associated with these processes in seven wetlands dominated by both native (Kandelia obovate, Avicennia marina and Phragmites australis) and invasive (S. alterniflora) plants. Our results showed that organical complexed Fe (Fe_p) concentration and Fe complexing index under S. alterniflora community were lower than that under native communities. Soil Fe-OC concentration and molar OC:Fe ratio decreased (35.9% and 29.3%, respectively) after S. alterniflora invasion in coastal wetlands, while the abundance of FeRB increased by 78.6%. The invasion of S. alterniflora increased soil water content while decreased bulk density, and these changes could have important effects on Fe species and FeRB abundance. Moreover, Fe-OC was positive correlated with soil organic carbon (SOC), Fe_p, and Fe(III), indicating that SOC and Fe(III) concentrations directly affect the formation of Fe-OC. FeRB reacted on the combination of Fe (hydr-) oxides and SOC to indirectly affect Fe-OC through dissimilatory Fe reduction, which further determined the stabilization and mineralization of SOC. Taken together, the invasion of S. alterniflora hindered the generation and accumulation of soil Fe-OC pool weakening the stabilization of SOC in coastal wetlands. Therefore, the conservation and restoration of mangroves and other coastal wetlands provide a promising strategy for SOC sequestration and climate change mitigation.
Organisationseinheit(en): Institut für Bodenkunde
Externe Organisation(en): Fujian Normal University
Center for Ecological Research and Forestry Applications (CREAF)
Tianjin University
Nanjing University of Information Science and Technology
Cele National Station of Observation and Research for Desert-Grassland Ecosystems
King Saud University
Chinese Academy of Sciences (CAS)
Typ: Artikel
Journal: CATENA
Band: 232
ISSN: 0341-8162
Publikationsdatum: 11.2023
Publikationsstatus: Veröffentlicht
Peer-reviewed: Ja
ASJC Scopus Sachgebiete: Erdoberflächenprozesse
Ziele für nachhaltige Entwicklung: SDG 13 – Klimaschutzmaßnahmen
Elektronische Version(en): https://doi.org/10.1016/j.catena.2023.107414 (Zugang: Geschlossen)