Oxmann, J. F., Pham, Q. H., Schwendenmann, L., Stellman, J. M. and Lara, R. J. (2010) Mangrove reforestation in Vietnam: the effect of sediment physicochemical properties on nutrient cycling. Plant and Soil, 326 (1-2). pp. 225-241. DOI https://doi.org/10.1007/s11104-009-0003-4.

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Abstract

Sediment physicochemical properties most likely control the reforestation success on degraded mangrove sites. Our objectives were (1) to determine the nutritional status of reforested mangrove stands; (2) to investigate the effects of the redox potential (Eh) and pH on phosphorus (P) and nitrogen (N) cycling; and (3) to assess the effect of pH on P speciation. Five transects were studied in replanted stands of the Saigon River Delta, Vietnam. Spatial gradients of sediment Eh and pH were affected by the tidal regime and pyrite oxidation. Sediment Al/Fe-P correlated with Eh or pH, depending on the sediment layer, whereas Ca-P, Morgan-P (available P) and leaf P were influenced by the pH. The highest concentrations of Al/Fe-P were recorded at pH 6.5 probably due to adsorption effects. Sediment Ca-P increased strongly at pH below 4 and above 6, reflecting the different pH-dependent solubilities of individual Ca-P mineral species as shown by a newly developed method for P species quantification. A strong increase of available P and leaf P above pH 6, and positive correlations of available P vs Ca-P (P < 0.001) and leaf P (P = 0.004) suggest that the Morgan’s reagent for available P determination solubilizes mainly thermodynamically less stable Ca-P compounds, which seem to fuel P plant uptake. Since foliar and sediment N:P ratios were influenced mainly by pH, shifts in pH likely cause limitation transitions. Overall, sediment pH rather than Eh was found to control the nutrient status.

Document Type:	Article
Programme Area:	UNSPECIFIED
Research affiliation:	Ecology > Mangrove Ecology Biogeochemistry and Geology
Refereed:	Yes
Open Access Journal?:	No
DOI:	https://doi.org/10.1007/s11104-009-0003-4
ISSN:	0032-079X
Date Deposited:	01 Oct 2019 15:52
Last Modified:	26 Mar 2024 13:29
URI:	http://cris.leibniz-zmt.de/id/eprint/2995

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