Net heterotrophy and carbonate dissolution in two subtropical seagrass meadows
Item
Title (Dublin Core)
Net heterotrophy and carbonate dissolution in two subtropical seagrass meadows
Description (Dublin Core)
<p>The net ecosystem productivity (NEP) of two seagrass
meadows within one of the largest seagrass ecosystems in the world, Florida
Bay, was assessed using direct measurements over consecutive diel cycles
during a short study in the fall of 2018. We report significant differences
between NEP determined by dissolved inorganic carbon (NEP<span class="inline-formula"><sub>DIC</sub></span>) and by
dissolved oxygen (NEP<span class="inline-formula"><sub>DO</sub></span>), likely driven by differences in air–water gas
exchange and contrasting responses to variations in light intensity. We also
acknowledge the impact of advective exchange on metabolic calculations of
NEP and net ecosystem calcification (NEC) using the “open-water” approach
and attempt to quantify this effect. In this first direct determination of
NEP<span class="inline-formula"><sub>DIC</sub></span> in seagrass, we found that both seagrass ecosystems were net
heterotrophic, on average, despite large differences in seagrass net
above-ground primary productivity. NEC was also negative, indicating that
both sites were net dissolving carbonate minerals. We suggest that a
combination of carbonate dissolution and respiration in sediments exceeded
seagrass primary production and calcification, supporting our negative NEP
and NEC measurements. However, given the limited spatial (two sites) and
temporal (8 <span class="inline-formula">d</span>) extent of this study, our results may not be
representative of Florida Bay as a whole and may be season-specific. The
results of this study highlight the need for better temporal resolution,
accurate carbonate chemistry accounting, and an improved understanding of
physical mixing processes in future seagrass metabolism studies.</p>
meadows within one of the largest seagrass ecosystems in the world, Florida
Bay, was assessed using direct measurements over consecutive diel cycles
during a short study in the fall of 2018. We report significant differences
between NEP determined by dissolved inorganic carbon (NEP<span class="inline-formula"><sub>DIC</sub></span>) and by
dissolved oxygen (NEP<span class="inline-formula"><sub>DO</sub></span>), likely driven by differences in air–water gas
exchange and contrasting responses to variations in light intensity. We also
acknowledge the impact of advective exchange on metabolic calculations of
NEP and net ecosystem calcification (NEC) using the “open-water” approach
and attempt to quantify this effect. In this first direct determination of
NEP<span class="inline-formula"><sub>DIC</sub></span> in seagrass, we found that both seagrass ecosystems were net
heterotrophic, on average, despite large differences in seagrass net
above-ground primary productivity. NEC was also negative, indicating that
both sites were net dissolving carbonate minerals. We suggest that a
combination of carbonate dissolution and respiration in sediments exceeded
seagrass primary production and calcification, supporting our negative NEP
and NEC measurements. However, given the limited spatial (two sites) and
temporal (8 <span class="inline-formula">d</span>) extent of this study, our results may not be
representative of Florida Bay as a whole and may be season-specific. The
results of this study highlight the need for better temporal resolution,
accurate carbonate chemistry accounting, and an improved understanding of
physical mixing processes in future seagrass metabolism studies.</p>
Creator (Dublin Core)
B. R. Van Dam
C. Lopes
C. L. Osburn
J. W. Fourqurean
Subject (Dublin Core)
Ecology
QH540-549.5
Life
QH501-531
Geology
QE1-996.5
Publisher (Dublin Core)
Copernicus Publications
Date (Dublin Core)
2019-11-01T00:00:00Z
Type (Dublin Core)
article
Identifier (Dublin Core)
10.5194/bg-16-4411-2019
1726-4170
1726-4189
https://doaj.org/article/3173ce68f8a34c53a467838282636ece
Source (Dublin Core)
Biogeosciences, Vol 16, Pp 4411-4428 (2019)
Language (Dublin Core)
EN
Relation (Dublin Core)
https://www.biogeosciences.net/16/4411/2019/bg-16-4411-2019.pdf
https://doaj.org/toc/1726-4170
https://doaj.org/toc/1726-4189
Provenance (Dublin Core)
Journal Licence: CC BY