Fluxes of methane and distribution of sulfate as influenced by coastal salt-marsh soil ecosystem of Northern Germany

Abstract

The study was conducted in Schleswig-Holstein at the Wadden sea coast of Northern Germany to evaluate the possible factors controlling methane (CH₄) and sulfate (SO₄) dynamics along a toposequence of daily to seasonally ?ooded coastal salt marsh soils. The soil at the top end  of the salt marsh (with a height of 1.8 m above sea level: a.s.l. and a dense vegetation cover) was salic silty to clayic Typic Sulfaquent, while  the soil at the bottom end (with some salt bushes and a 1.4 m a.s.l.) was sandy to silty Haplic Sulfaquent. The mean (depth: 0-100 cm) values  of pH were around 7, and of redox potentials in the Typic Sulfaquent were ranged from -162 to +104 mV during all the seasons. The annual average emissions of CH₄ were almost 10 fold higher (0.3 g m^-2 a^-1) in Haplic Sulfaquent than that (0.03 g m^-2 a^-1) of the Typic Sulfaquent. In all the pro?les, the concentrations of CH₄ were very low and varied signi?cantly (p?0.05) with the seasons and soil depths. The concentrations of CH₄ showed no dependence to temperature. The SO₄ contents were observed maximum in the Typic Sulfaquent followed by Haplic  Sulfaquent during all the seasons. There is no noticeable correlation was obtained between the SO₄ and CH₄ concentrations. Moreover, even CH₄ was determined at depths where the SO₄ concentration in the soil solution was around 1200 mg SO₄ L^-1.

Bangladesh J. Sci. Ind. Res. 52(3), 177-186, 2017