Coastal conversion alters topsoil carbon, nitrogen and phosphorus stocks and stoichiometric balances in subtropical coastal wetlands
Hu, Minjie (Fujian Normal University. School of Geographical Sciences)
Wang, Jingtao (Fujian Normal University. School of Geographical Sciences)
Sardans i Galobart, Jordi (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Wu, Hui (Fujian Normal University. School of Geographical Sciences)
Ni, Ranxu (Fujian Normal University. School of Geographical Sciences)
Guo, Pingping (Fujian Minjiang River Estuary Wetland National Nature Reserve Administrative Office)
Yan, Ruibing (Fujian Normal University. School of Geographical Sciences)
Liao, Haoyu (Fujian Normal University. School of Geographical Sciences)
Liu, Chunya (Fujian Normal University. School of Geographical Sciences)
Peñuelas, Josep (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Tong, Chuan (Fujian Normal University. School of Geographical Sciences)

Date:	2024
Abstract:	The extensive conversion of coastal wetlands into agricultural and aquaculture areas has significant repercussions on soil nutrient balance. However, how coastal conversion specifically influences the dynamics and stoichiometry of topsoil carbon (C), nitrogen (N), and phosphorus (P) remains limited due to the considerable spatial variability and a lack of comprehensive field data. Here, we investigated the concentration and distribution of total C (TC), N (TN) and P (TP), along with their stoichiometric balance in four distinct coastal landscapes, including natural marshes and tidal flats, as well as converted agricultural croplands and ponds. The results revealed that converted croplands and ponds exhibited significantly higher concentrations of soil C, N and P, particularly in comparison to tidal flats. Furthermore, croplands and ponds have higher topsoil C stocks than tidal flats, but little difference or even lose stored C compared to marshes. Cropland soils showed considerably higher levels of available N (NH4+-N and NO3−-N) and available P compared to those in natural marshes and tidal flats. The distribution of soil TC, TN, and TP demonstrated greater spatial heterogeneity in natural marshes and tidal flats, while the converted areas were more uniform and became hotspots for N and P accumulation. Coastal conversion altered soil C:N:P stoichiometry, with cropland soils exhibiting a lower N:P ratio (2. 9 ± 1. 1), indicating that long-term application of N and P fertilizers could decrease the N:P ratio, as P is more retained in the soil than N. Furthermore, it was observed that the dynamics of C, N and P, as well as their stoichiometry, are closely linked to soil physicochemical properties, especially soil organic matter and texture. These findings highlight that coastal conversion and associated management practices markedly affected soil C, N and P dynamics in a representative wetland area of the subtropical regions, leading to a reshaping of their stoichiometric balances, particularly in the topsoil layer.
Grants:	Agencia Estatal de Investigación PID2020-115770RB-I00 Agencia Estatal de Investigación PID2022-140808NB-I00 European Commission 101056844
Note:	Altres ajuts: Fundación Ramón Areces Project CIVP20A6621
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, i la comunicació pública de l'obra, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original. No es permet la creació d'obres derivades.
Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Subject:	Topsoil ; C, N and P dynamics ; Land use change ; Coastal wetlands
Published in:	Science of the Total Environment, Vol. 944 (September 2024) , art. 174011, ISSN 1879-1026

DOI: 10.1016/j.scitotenv.2024.174011

Available from: 2026-09-30 Postprint

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > CREAF (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Articles > Research articles
Articles > Published articles