scholarly journals Autotrophic carbon budget in coral tissue: a new 13C-based model of photosynthate translocation

2012 ◽  
Vol 215 (8) ◽  
pp. 1384-1393 ◽  
Author(s):  
P. Tremblay ◽  
R. Grover ◽  
J. F. Maguer ◽  
L. Legendre ◽  
C. Ferrier-Pages
Keyword(s):  
Carbon Budget ◽  
Coral Tissue ◽  
Photosynthate Translocation

scholarly journals Effect of temperature and feeding on carbon budgets and O2 dynamics in Pocillopora damicornis

2020 ◽  
Vol 652 ◽  
pp. 49-62 ◽  
Author(s):  
NH Lyndby ◽  
JB Holm ◽  
D Wangpraseurt ◽  
R Grover ◽  
C Rottier ◽  
...  
Keyword(s):  
Photosynthetic Activity ◽  
Coral Tissue ◽  
Effect Of Temperature ◽  
Pocillopora Damicornis ◽  
Fixed Carbon ◽  
High Loss ◽  
Coral Holobiont ◽  
Essential Knowledge ◽  
Nutritional Strategies ◽  
Photosynthate Translocation

Studying carbon dynamics in the coral holobiont provides essential knowledge of nutritional strategies and is thus central to understanding coral ecophysiology. In this study, we assessed the carbon budget in Pocillopora damicornis (using H13CO3) as a function of feeding status and temperature stress. We also compared dissolved oxygen (O2) fluxes measured at the colony scale and at the polyp scale. At both scales, O2 production rates were enhanced for fed vs. unfed corals, and unfed corals exhibited higher bleaching and reduced photosynthetic activity at high temperature. Unfed corals exclusively respired autotrophically acquired carbon, while fed corals mostly respired heterotrophically acquired carbon. As a consequence, fed corals excreted on average >5 times more organic carbon than unfed corals. Photosynthate translocation was higher under thermal stress, but most of the carbon was lost via respiration and/or mucus release (42-46% and 57-75% of the fixed carbon for unfed and fed corals, respectively). Such high loss of translocated carbon, coupled to low assimilation rates in the coral tissue and symbionts, suggests that P. damicornis was nitrogen and/or phosphorus limited. Heterotrophy might thus cover a larger portion of the nutritional demand for P. damicornis than previously assumed. Our results suggest that active feeding plays a fundamental role in metabolic dynamics and bleaching susceptibility of corals.

Predicting cold-water bleaching in corals: role of temperature, and potential integration of light exposure

2020 ◽  
Vol 642 ◽  
pp. 133-146
Author(s):  
PC González-Espinosa ◽  
SD Donner
Keyword(s):  
Coral Bleaching ◽  
Cold Water ◽  
Light Exposure ◽  
Light Attenuation ◽  
Florida Keys ◽  
Cold Temperature ◽  
Warm Water ◽  
Coral Tissue ◽  
Effect Of Temperature ◽  
Type I

Warm-water growth and survival of corals are constrained by a set of environmental conditions such as temperature, light, nutrient levels and salinity. Water temperatures of 1 to 2°C above the usual summer maximum can trigger a phenomenon known as coral bleaching, whereby disruption of the symbiosis between coral and dinoflagellate micro-algae, living within the coral tissue, reveals the white skeleton of coral. Anomalously cold water can also lead to coral bleaching but has been the subject of limited research. Although cold-water bleaching events are less common, they can produce similar impacts on coral reefs as warm-water events. In this study, we explored the effect of temperature and light on the likelihood of cold-water coral bleaching from 1998-2017 using available bleaching observations from the Eastern Tropical Pacific and the Florida Keys. Using satellite-derived sea surface temperature, photosynthetically available radiation and light attenuation data, cold temperature and light exposure metrics were developed and then tested against the bleaching observations using logistic regression. The results show that cold-water bleaching can be best predicted with an accumulated cold-temperature metric, i.e. ‘degree cooling weeks’, analogous to the heat stress metric ‘degree heating weeks’, with high accuracy (90%) and fewer Type I and Type II errors in comparison with other models. Although light, when also considered, improved prediction accuracy, we found that the most reliable framework for cold-water bleaching prediction may be based solely on cold-temperature exposure.

Soil respiration and carbon budget in black soils of wheat maize-soybean rotation system

2012 ◽  
Vol 20 (4) ◽  
pp. 395-401 ◽  
Author(s):  
Yao LIANG ◽  
Xiao-Zeng HAN ◽  
Yun-Fa QIAO ◽  
Lu-Jun LI ◽  
Meng-Yang YOU
Keyword(s):  
Soil Respiration ◽  
Carbon Budget ◽  
Rotation System

QUANTIFYING THE ANNUAL CARBON BUDGET FROM A RAPIDLY ERODING COASTAL FRESHWATER WETLAND USING FIELD AND MODEL DATA

2018 ◽  
Author(s):  
Katherine N. Braun ◽  
◽  
Ethan J. Theuerkauf ◽  
Ethan J. Theuerkauf ◽  
Andrew L. Masterson ◽  
...  
Keyword(s):  
Carbon Budget ◽  
Freshwater Wetland ◽  
Model Data ◽  
Annual Carbon

Endolithic community composition of Orbicella faveolata (Scleractinia) underneath the interface between coral tissue and turf algae

Coral Reefs ◽  
2015 ◽  
Vol 34 (2) ◽  
pp. 625-630 ◽  
Author(s):  
N. Gutiérrez-Isaza ◽  
J. Espinoza-Avalos ◽  
H. P. León-Tejera ◽  
D. González-Solís
Keyword(s):  
Community Composition ◽  
Coral Tissue ◽  
Turf Algae ◽  
Orbicella Faveolata ◽  
Endolithic Community

scholarly journals Relationship between physical and biogeochemical parameters and the scenario dependence of the transient climate response to cumulative carbon emissions

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Kaoru Tachiiri
Keyword(s):  
Carbon Emissions ◽  
Carbon Budget ◽  
Extreme Case ◽  
Initial Increase ◽  
Climate Response ◽  
Earth System ◽  
Transient Climate Response ◽  
Large Correlation ◽  
Before And After ◽  
Biogeochemical Parameters

AbstractThe transient climate response to cumulative carbon emissions (TCRE) is a key metric in estimating the remaining carbon budget for given temperature targets. However, the TCRE has a small scenario dependence that can be non-negligible for stringent temperature targets. To investigate the parametric correlations and scenario dependence of the TCRE, the present study uses a 512-member ensemble of an Earth system model of intermediate complexity (EMIC) perturbing 11 physical and biogeochemical parameters under scenarios with steady increases of 0.25%, 0.5%, 1%, 2%, or 4% per annum (ppa) in the atmospheric CO2 concentration (pCO2), or an initial increase of 1% followed by an annual decrease of 1% thereafter. Although a small difference of 5% (on average) in the TCRE is observed between the 1-ppa and 0.5-ppa scenarios, a significant scenario dependence is found for the other scenarios, with a tendency toward large values in gradual or decline-after-a-peak scenarios and small values in rapidly increasing scenarios. For all scenarios, correlation analysis indicates a remarkably large correlation between the equilibrium climate sensitivity (ECS) and the relative change in the TCRE, which is attributed to the longer response time of the high ECS model. However, the correlations of the ECS with the TCRE and its scenario dependence for scenarios with large pCO2 increase rates are slightly smaller, and those of biogeochemical parameters such as plant respiration and the overall pCO2–carbon cycle feedback are larger, than in scenarios with gradual increases. The ratio of the TCREs under the overshooting (i.e., 1-ppa decrease after a 1-ppa increase) and 1-ppa increase only scenarios had a clear positive relation with zero-emission commitments. Considering the scenario dependence of the TCRE, the remaining carbon budget for the 1.5 °C target could be reduced by 17 or 22% (before and after considering the unrepresented Earth system feedback) for the most extreme case (i.e., the 67th percentile when using the 0.25-ppa scenario as compared to the 1-ppa increase scenario). A single ensemble EMIC is also used to indicate that, at least for high ECS (high percentile) cases, the scenario dependence of the TCRE should be considered when estimating the remaining carbon budget.

Organic carbon budget for the Gulf of Bothnia

2006 ◽  
Vol 63 (3-4) ◽  
pp. 155-161 ◽  
Author(s):  
Grete Algesten ◽  
Lars Brydsten ◽  
Per Jonsson ◽  
Pirkko Kortelainen ◽  
Stefan Löfgren ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Carbon Budget ◽  
Gulf Of Bothnia
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