Influences of sediment properties and macrophytes on phosphorous speciation in the intertidal marsh

Abstract

Phosphorus (P) in wetlands is mainly bound to sediment in various species, which is essential to predict water column P levels. The purpose of this work is to understand the influences of sediment properties and vegetation types on P speciation. Sediments under four vegetation types in the tidal flat and offshore sandbar in Hangzhou Bay of China were collected seasonally. The rank order of P species in sediment based on concentration was exchangeable P (Exch-P) < iron/aluminum-bound P (Fe/Al-P) < organic P (Org-P) < calcium-bound P (Ca-P). Sediment total phosphorus (TP) and Fe/Al-P concentrations were lower in offshore sandbar than those of tidal flat, reflecting effects of anthropogenic contamination in the latter. Sediment particle size distribution strongly affected P speciation, as indicated by a significant correlation between them. Total phosphorus and Org-P concentrations in vegetated sediments were higher than those of bare mudflat. Additionally, there was a significant negative correlation between Ca-P and Org-P, and Fe/Al-P, indicating the presence of vegetation which may result in P speciation by converting Ca-P to soluble and active P and higher Org-P. Overall, sediment particle size distribution is the most fundamental physical property that affects P speciation, and vegetation types are important factors that influence Org-P concentration.

Geochemical forms and seasonal variations of phosphorus in surface sediments of the East China Sea shelf

“…This indicated that they were mainly of terrestrial origin. Similar conclusion were also drawn in previous studies (Ruban et al, 2001;Yu et al, 2013;Shao et al, 2014;Meng et al, 2015b). The offshore areas of the ECSS with relatively low concentrations of Ads-P, Fe-P and OP in the surface sediments may result from the relatively weak influence of the CDW and the ZFCC but relatively strong influence of the TWC and KC ( Fig.…”

“…It was reported that high primary production could result in high concentrations of particulate OP (Liu et al, 2001;Chai et al, 2006;Yu et al, 2012) and sedimentary OP (Andrieux and Aminot, 1997;Fang, 2000;Dunne et al, 2007;González-Alcaraz et al, 2012;Li et al, 2014;Shao et al, 2014). As a result, relatively high OP concentrations occurred in surface sediments of the northern part of the studied area in spring (Fig.…”

“…Some of OP in surface sediments does not accumulate for long periods (Andrieux and Aminot, 1997) and it can be partially biologically utilized by mineralization and enzymatic hadrolysis (Rydin, 2000;Zhang et al, 2008;Huo et al, 2011;Shao et al, 2014). Besides, the primary production in autumn is low (Rabouille et al, 2008) and therefore low OP can be produced during autumn (Andrieux and Aminot, 1997).…”

“…Ads-P in the sediment can be easily released into water and utilized by phytoplankton Samadi-Maybodi et al, 2013;Shao et al, 2014;Zhuang et al, 2014). Reynolds (1976) indicated that owing to the limited nutrient availability in the surface water after the consumption by phytoplankton during summer, phytoplankton tended to grow in deeper waters where nutrients were relatively abundant due to sediment release.…”

Reclamation Culture Alters Sediment Phosphorus Speciation and Ecological Risk in Coastal Zone of Southeastern China

“…Meanwhile, sediment water content, bulk density, TC, TN, Fe 2+ , Fe 2+ /Fe 3+ , and clay were significantly related to P species (Table ). Previous studies have shown that sediment particle size has significant influence on P species, and clay has a large surface area and P adsorption ability . In this study, relatively higher proportion of clay particles was observed in reclamation culture ponds, which accelerate the P adsorption capacity of sediment, and thus increase the concentration of various P species.…”