Nitrogen-limited mangrove ecosystems conserve N through dissimilatory nitrate reduction to ammonium

Abstract : Earlier observations in mangrove sediments of Goa, India have shown denitrification to be a major pathway for N loss(1). However, percentage of total nitrate transformed through complete denitrification accounted for <0-72% of the pore water nitrate reduced. Here, we show that up to 99% of nitrate removal in mangrove sediments is routed through dissimilatory nitrate reduction to ammonium (DNRA). The DNRA process was 2x higher at the relatively pristine site Tuvem compared to the anthropogenically-influenced Divar mangrove ecosystem. In systems receiving low extraneous nutrient inputs, this mechanism effectively conserves and re-circulates N minimizing nutrient loss that would otherwise occur through denitrification. In a global context, the occurrence of DNRA in mangroves has important implications for maintaining N levels and sustaining ecosystem productivity. For the first time, this study also highlights the significance of DNRA in buffering the climate by modulating the production of the greenhouse gas nitrous oxide.
Document type :
Journal articles
Complete list of metadatas

https://hal.archives-ouvertes.fr/hal-00714213
Contributor : Mio Aigle <>
Submitted on : Tuesday, July 3, 2012 - 4:14:29 PM
Last modification on : Monday, September 23, 2019 - 2:50:06 PM

Links full text

Identifiers

Citation

Sheryl Fernandes, Patricia Bonin, Valerie Michotey, Nicole Garcia, P. A. Lokabharathi. Nitrogen-limited mangrove ecosystems conserve N through dissimilatory nitrate reduction to ammonium. Scientific Reports, Nature Publishing Group, 2012, 2, pp.419. ⟨10.1038/srep00419⟩. ⟨hal-00714213⟩

Share

Metrics

Record views

262