Files and links (2)
Preprint (Author's original)CC BY-NC-ND V4.0, Open Access
Journal article
Comparison of dinitrogen fixation rates in two subtropical seagrass communities
Marine Chemistry, Vol.209, pp.62-69
20/02/2019
Metrics
14 File views/ downloads
30 Record Views
UN Sustainable Development Goals (SDGs)
This output has contributed to the advancement of the following goals:
Source: InCites
Abstract
Seagrass morphology varies greatly between species and can impact their nitrogen (N) cycling capacity, including dinitrogen (N2) fixation. We used a 15N—N2 stable isotope technique to measure N2 fixation rates in different zones of two morphologically diverse seagrass communities, Zostera muelleri and Halophila ovalis in Moreton Bay, Australia. Isotope label additions were made to both the surface and rhizosphere of sediment cores containing whole plants over an artificial diurnal cycle. In both species the highest rates of N2 fixation were found in the leaves (including epiphytes) in the light with areal leaf related N2 fixation rates higher in the Z. muelleri (46 ± 26 μmol N2 m−2 h−1) community compared to H. ovalis (11 ± 7.2 μmol N2 m−2 h−1). There was a switch in the location of N2 fixation from the leaves to the sediments in the dark in the Z. muelleri community which was not observed in H. ovalis. The change in the active site of N2 fixation in the Z. muelleri community is likely related to the reduction in oxygen supply and associated increase in sulphate reducing bacterial activity at night. Overall the Z. muelleri community fixed N2 at ~3 times (~75 μmol N m−2 h−1) the rate of H. ovalis (~25 μmol N m−2 h−1). The results of this study illustrate how plant morphology, and its associated influence on sediment biogeochemistry, can regulate N2 fixation rates in seagrass communities.
Details
- Title
- Comparison of dinitrogen fixation rates in two subtropical seagrass communities
- Creators
- Natasha Carlson-Perret - Southern Cross UniversityDirk V Erler - Southern Cross UniversityBradley D Eyre - Southern Cross University
- Publication Details
- Marine Chemistry, Vol.209, pp.62-69
- Publisher
- Elsevier
- Grant note
- This study was funded by Australian Research Council Discovery Grant DP160100248 awarded to Bradley D Eyre.
- Identifiers
- 4713; 991012821841202368
- Copyright
- © 2019 Elsevier B.V. All rights reserved.
- Academic Unit
- Faculty of Science and Engineering; School of Environment, Science and Engineering; Science; Centre for Coastal Biogeochemistry
- Language
- English
- Resource Type
- Journal article