Conference presentation
Processing of nitrogen within a subtropical mangrove forest: A whole-ecosystem stable isotope labelling study.
ASLO Aquatic Sciences Meeting (Honolulu, USA, 26/02/2017 - 03/03/2017)
02/03/2017
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Abstract
Human activities are changing the quantity and quality of nitrogen (N) exported from the land to the ocean. Mangrove forests at the land-sea interface are in prime position to intercept these inputs. The rates and pathways for N uptake and processing within mangrove forests are therefore potentially important for determining the ultimate fate of anthropogenic N inputs and the quality and quantity of N that is transported to the open ocean and beyond. In this study, whole-ecosystem stable isotope addition (K15NO3) was used to quantify the uptake, transformation, loss, and retention pathways for N within an intertidal subtropical mangrove forest in Australia. Over 14 days we traced the assimilation of 15N into sediment compartments and its export via surface water and groundwater flow (during the ebbing tide). Substantial assimilation of the added 15N into sediment organic nitrogen (~50% over 0.5 days), indicates that the mangrove forest was N limited and will rapidly incorporate additional N inputs. The export of 15N in forms other than the added NO3- N2, NH4+, PON) at 0.5 days after labelling shows the potential for rapid N processing. Of the 15N assimilated into sediment organic nitrogen, 70% remained after 14 days. The remaining 15N was exported from the mangrove forest as PON, NH4+, NO3- and N2 (decreasing order of importance) in groundwater and surface water flow, or could not be accounted for. Potential explanations for this missing N will be discussed.
Details
- Title
- Processing of nitrogen within a subtropical mangrove forest: A whole-ecosystem stable isotope labelling study.
- Creators
- Joanne M Oakes - Southern Cross UniversityDamien T Maher - Southern Cross UniversityDirk Erler - Southern Cross UniversityPerrine MangionBradley D Eyre - Southern Cross University
- Conference
- ASLO Aquatic Sciences Meeting (Honolulu, USA, 26/02/2017 - 03/03/2017)
- Identifiers
- 991012845997402368
- Academic Unit
- Faculty of Science and Engineering; School of Environment, Science and Engineering; Science
- Resource Type
- Conference presentation