Elution of dissolved Fe from mangrove soil by tannin solution

作者:Matsutani Tatsuma; Nagai Takashi; Kinjyo Kazutoshi; Nakanishi Yasuhiro*
来源:Wetlands Ecology and Management, 2013, 21(2): 107-115.
DOI:10.1007/s11273-013-9282-x

摘要

To reveal the role of tannins in mangroves, tannins in mangrove leaves and the Fe eluted from mangrove soil by adding tannin solutions of different salinity levels was investigated. Leaves of six mangrove and 16 non-mangrove species, and samples of a mangrove floor, Andosol and dark red soil were collected. Results were: (1) Increasing tannic acid concentration to similar to 50 mM, increased the Fe eluted from mangrove soil to similar to 20 mu gg(-1). (2) When a 100 mM tannic acid solution was added, the Fe eluted from mangrove soil was 5.5 times higher than dark red soil. (3) Although elution of Fe from mangrove soil was higher than in Andosol one day after submersion in a 10 mM tannic acid solution, the difference was stable after 2 days. (4) The elution of Fe from all soils significantly decreased with increasing salinity of a 10 mM tannic acid solution. However, the amount from mangrove soil was 6.1 times higher than dark red soil even with 35 % salinity. (5) The tannin content in the mangrove leaves was 99 +/- 16 mgg(-1) and nonmangrove leaves was 76 +/- 19 mgg(-1). (6) The Fe eluted from mangrove soil had a positive correlation with the tannin concentrations in the added leaf solution. Tannins in mangrove species promote the elution of Fe from mangrove floor soil even in saline water. Fe complexes were formed when mangrove soil was mixed with leaf tannins suggesting that Fe produced by tannins in mangrove leaves growing in land/sea interfaces likely plays a direct role in marine ecosystems.

  • 出版日期2013-4

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