Xiaoguang Ouyang

Xiaoguang Ouyang
The Chinese University of Hong Kong | CUHK · School of Life Sciences

PhD

About

57
Publications
23,249
Reads
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880
Citations
Introduction
Xiaoguang Ouyang does research in Environmental Engineering, Marine Biology and Ecology. Their current project is 'Partitioning of carbon dioxide efflux in mangrove Avicennia marina.'
Additional affiliations
April 2022 - present
Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou)
Position
  • Professor
March 2018 - April 2022
Simon F.S. Li Marine Science Laboratory
Position
  • PostDoc Position
Description
  • Marine Scientist in the Earth Science Programme
October 2012 - February 2014
Beijing Zhongqi Anxin Environmental Science & Technology Co., Ltd.
Position
  • Project Principal, Senior Engineer
Description
  • Appraise the environmental impact assessment (EIA) and write environmental appraisal reports
Education
February 2014 - August 2017
Griffith University
Field of study
  • Environmental studies
September 2002 - December 2004
Chongqing University
Field of study
  • Environment
September 1998 - July 2002
Anhui Jianzhu University
Field of study
  • Environment

Publications

Publications (57)
Article
This study aims to determine the drivers of root decomposition and its role in carbon (C) budgets in mangroves and saltmarsh. We review the patterns of root decomposition, and its contribution to C budgets, in mangroves and saltmarsh: the impact of climatic (temperature and precipitation), geographic (latitude), temporal (decay period) and biotic (...
Article
Mangroves are blue carbon ecosystems that sequester significant carbon but release CO2 , and to a lesser extent CH4, from the sediment through oxidation of organic carbon or from overlying water when flooded. Previous studies, e.g. Leopold et al. (2015), have investigated sediment organic carbon (SOC) content and CO2 flux separately, but could not...
Article
Full-text available
Carbon dioxide (CO2) flux is a critical component of the global C budget. While CO2 flux has been increasingly studied in mangroves, better partitioning of components contributing to the overall flux will be useful in constraining C budgets. Little information is available on how CO2 flux may vary with forest age and conditions. We used a combinati...
Article
Full-text available
Earth system models are widely used to estimate future changes in wetland extent but do not incorporate surface elevation change (SEC) into predicting wetland's real responses to sea level rise (SLR). A machine learning model (MLM) was used to investigate the impact of multiple drivers on SEC and sediment accretion rate (SAR) in tidal marshes, and...
Book
Carbon Mineralization in Coastal Wetlands fills the current knowledge gap in carbon mineralization, providing a balanced view of the carbon dynamics of coastal wetlands. This book provides a holistic treatment of carbon mineralization, from the contributions of litter/root decomposition pathways to carbon mineralization and the processes and source...
Chapter
Carbon minerelization is significant to studying the whole carbon cycling dynamics and food webs in coastal wetlands. It reflects the fate of carbon from litter decomposition to greenhouse gas emission but is often less emphasized than carbon storage in the management of coastal wetlands. This chapter presents the basic concepts, the unique charact...
Chapter
This chapter discusses factors affecting processes of litter decomposition in coastal wetlands, including biotic, abiotic, as well as anthropogenic factors. A few indicators of litter decomposition are used to describe litter disappearance, including decomposition rate, mass loss percentage, half-life time, and residence time. We examine the variab...
Chapter
This synthesis and conclusion chapter aims to compare the processes and drivers of carbon mineralization in different coastal wetlands and provide recommendations on ‘blue carbon management’ in relation to greenhouse gas (GHG) emission and/or litter decomposition of different coast wetlands. Ecosystem carbon stocks in coastal wetlands almost double...
Chapter
Increasing awareness of the significance of coastal wetlands in global carbon budgets combined with recently developed approaches such as in-situ gas analyzers connected to flux chambers, has led to the wide interests in quantifying greenhouse gas exchange in these ecosystems, for which less attention was paid to than terrestrial ecosystems. Consid...
Chapter
This chapter discusses the influence of climate change on coastal wetland productivity, organic carbon burial, CO2 and CH4 production and their emissions. We reviewed studies that were performed in atmosphere-controlled greenhouses or open-top chambers to quantify the role of climate change on mangrove and saltmarsh productivity, as well as in situ...
Article
1.Overfishing, altered flow regimes, loss of connectivity, pollution and other direct human disturbances have had a significant impact on freshwater fish biodiversity. While direct effects of these disturbances are well documented, some can also lead to changes in the nutritional composition at the base of freshwater food webs and may affect fish g...
Article
Full-text available
Aquaculture, particularly shellfish ponds, have expanded dramatically and become an important cause of mangrove deforestation and 'blue carbon' loss in China. We present the first study to examine CO2 efflux from marine aquaculture/shellfish ponds and that in relation to land use change from mangrove forests in China. Light and dark sediment CO2 ef...
Article
Full-text available
Tidal marshes are not only lost to human disturbance but also face the threat of sea 1 level rise (SLR). However, current earth system models used to estimate future changes in 2 wetland extent omit wetland's real responses to SLR without field observations. We 3 synthesised global data on sediment accretion rate (SAR) and surface elevation change...
Article
The status and potential degradation of an ecosystem is often difficult to identify, quantify, and characterize. Multiple, concurrent drivers of degradation may interact and have cumulative and confounding effects, making mitigation and rehabilitation actions challenging to achieve. Ecosystem status assessments generally emphasize areal change (gai...
Article
Intertidal benthos link tertiary predators and primary producers in marine food webs as well as directly contribute to sediment CO2 emission. However, current methods for studying food sources of marine benthos are time-consuming and does not allow direct estimates on feeding regime-related (including different diets, active versus dormant) CO2 pro...
Article
Full-text available
Intertidal benthos link tertiary predators and primary producers in marine food webs as well as directly contribute to sediment CO2 emission. However, current methods for studying food sources of marine benthos are time-consuming and does not allow direct estimates on feeding regime-related CO2 production. We examined the foods of mangrove crabs an...
Chapter
Global, mangrove forests (mangals) harbor about 80 plant species including hybrids and provide habitats and food for a diversified fauna. Mangrove productivity is high and changes with latitudes. However, there is a lack of systematic knowledge on how mangroves cope with the harsh saline conditions to gain high productivity and provide support for...
Article
Cyclone disturbance results in mangrove foliage loss, tree mortality and other changes in ecosystem processes. However, the impact of cyclones on mangrove sediment nutrient density, sediment-air CO2 and CH4 fluxes and their isotopes remains largely unknown. Super-typhoon Mangkhut (maximum gust 256 km h−1) hit Hong Kong in September 2018. We investi...
Article
Full-text available
Mangrove forests are found along the shorelines of more than 100 countries, and provide a wide range of ecosystem services that support the livelihoods and wellbeing of tens of millions of people. Despite their importance, loss of global mangrove area has been so substantial that twelve years ago academics warned of “a world without mangroves” [1]....
Article
Full-text available
Tidal wetlands are global hotspots of carbon storage but errors exist with current estimates on their carbon density due to the use of factors estimated from other habitats for converting loss-on-ignition (LOI) to organic carbon (OC); and the omission of certain significant carbon pools. Here we show that the widely used conversion factor (LOI/OC =...
Article
Full-text available
Tidal wetlands are global hotspots of carbon storage but errors exist with current estimates on their carbon density due to the use of factors estimated from other habitats for converting loss-on-ignition (LOI) to organic carbon (OC); and the omission of certain significant carbon pools. Here we show that the widely used conversion factor (LOI/OC =...
Conference Paper
Full-text available
Loss-on-ignition (LOI) is widely used to estimate organic carbon (OC) content, and thus carbon stocks, due to easy operation and low costs. The wide use of a conversion factor of 1.724 (LOI:OC) oversimplifies the relationship between LOI and OC, and may lead to significant biases in estimating global sediment carbon stocks in 'blue carbon' ecosyste...
Conference Paper
Full-text available
Mangroves and saltmarshes are 'blue carbon' ecosystems that are significant to climate regulating and global carbon cycling. There is a growing interest in studying greenhouse gas (GHG) emissions from the sediment surfaces. Here, we review the pathways of GHG production and emissions, mechanisms of GHG production, and factors regulating GHG emissio...
Data
Supporting Information Appendix Table A1
Data
Supporting Information Appendix Figures
Article
Full-text available
Aquatic macroinvertebrates play an important functional role in energy transfer in food webs, linking basal food sources to upper trophic levels that include fish, birds, and humans. However, the trophic coupling of nutritional quality between macroinvertebrates and their food sources is still poorly understood. We conducted a field study in subalp...
Article
Full-text available
Coastal wetlands are increasingly recognised for their pivotal role in mitigating the growing threats from cyclones (including hurricanes) in a changing climate. There is, however, insufficient information about the economic value of coastal wetlands for cyclone mitigation, particularly at regional scales. Analysis of data from 1990–2012 shows that...
Thesis
Mangroves and saltmarshes are ‘blue carbon’ ecosystems and studies on their carbon (C) dynamics have become highly topical. In these coastal wetlands, the aboveground biomass sequesters C and allocates C to belowground roots. A significant portion of aboveground biomass is transferred to the sediment as litterfall. Belowground roots and their exuda...
Article
The use of adsorption methods to recover vitamin B12 (VB12) from wastewater has been increasingly studied. However, there is a lack of knowledge on optimization of the methods. This study established a feedback network to evaluate alternatives regarding VB12 adsorption from wastewater. The network comprises environmental, economic and technological...
Conference Paper
Full-text available
Aquaculture, particularly shellfish ponds, has expanded dramatically and become the major cause of mangrove deforestation and ‘blue carbon’ loss in China. We present the first study to examine CO2 efflux from marine aquaculture/shellfish ponds and that in relation to land use change from mangroves in China. Dark and light CO2 efflux from shellfish...
Article
Studies on carbon stock in salt marsh sediments have increased since the review by Chmura et al. (2003). However, uncertainties exist in estimating global carbon stor-age in these vulnerable coastal habitats, thus hindering the as-sessment of their importance. Combining direct data and in-direct estimation, this study compiled studies involving 143...
Article
Full-text available
Hg emissions from coal-fired power plants (CFPPs) in Northern China are the major source of anthropogenic atmospheric mercury (Hg) emissions. The impact of denitrification devices on Hg emission, together with difference in Hg emission from different boilers and specific data of air pollution control devices (APCDs) are critical factors for the est...
Article
Full-text available
Studies on carbon stock in salt marsh sediments are increasing. However, uncertainties exist in estimating global carbon storage in these vulnerable coastal habitats, thus hindering the assessment of their importance. Combining direct data and indirect estimation, this study compiled studies involving 158 sites across the southern and Northern Hemi...
Conference Paper
Full-text available
Vertical accretion rate reflects how coastal sedimentary environment responds to sea level and climate change, and is widely employed to estimate relative sea level rise. This study reviews the methods used to measure and model vertical accretion rate of salt marshes. Measuring methods fall into nine categories on the basis of time scales. The main...
Article
The residential area studied in this paper is situated in the special borderland between Beibei town and Jinyun mountain, which is a national beauty spot and natural conservation region. In order to conserve the ecological environment of Jinyun mountain, prevent the excessive development and promote sustainable progress of the residential area, it...

Questions

Questions (3)
Question
Many protocols suggest to dry biomass in blue carbon ecosystems at 60 degree celsius, such as 'coastal blue carbon-methods for assessing carbon stocks and emissions factors in mangroves, tidal salt marshes, and seagrass meadows'. Does anybody know why 60 rather than 105 degree celsius is suggested? Thank you.
Question
Recently, there is an emerging series of studies querying that organic carbon burial in blue carbon ecosystems is largely offset by calcium carbonate. Is it true? As I know, calcium carbonate can only be decomposed to calcium oxide and carbon dioxide at temperatures above 840 degree celsius. The sediment temperature in sediments of blue carbon ecosystems can not be so high to decompose calcium carbonate. On the other hand, calcium carbonate is generally not dissolved in water. According to Frear & Johnston (1929), the dissolubility of calcium carbonate in water is 9 mmol per kg water at 1 standard atmosphere pressure. With increasing CO2 in the atmosphere and seawater, calcium carbonate in marine waters may react with CO2 to produce calcium bicarbonate. To summary, I think this query is unreasonable. What do you think about it?

Projects

Projects (5)
Project
This project will examine how important functions (e.g. carbon sequestration and coastal protection) of coastal wetlands shift under changing climate and anthropogenic disturbances, to provide suggestions on management of 'blue carbon' ecosystems. The project will also investigate how important processes (e.g. carbon partitioning and root decomposition) respond to global changes, to give insights into the variability of carbon cycling in response to natural and anthropogenic factors.
Archived project
Mangroves and saltmarshes are ‘blue carbon’ ecosystems and studies on their carbon (C) dynamics have become highly topical. In these coastal wetlands, the aboveground biomass sequesters C and allocates C to belowground roots. A significant portion of aboveground biomass is transferred to the sediment as litterfall. Belowground roots and their exudates are ultimately decomposed by microbial communities. As the product of root decomposition, CO2 is released from the sediment surface and organic C (OC) contributes to sediment C burial. In addition, the decomposition of litter and sediment organic material also contributes to CO2 efflux from the sediment surface. The patterns of belowground C dynamics in blue C ecosystems remain unclear, especially sediment C burial, root C decomposition, and the relative contributions of different sources to sediment CO2 efflux. Further, sediment CO2 efflux and C storage have typically been examined separately in past research. Improved understanding of these patterns will help consolidate the theory of C cycling in coastal wetlands and facilitate effective ‘blue C’ management. My thesis aims to fill these gaps via systematic quantitative reviews and synthesis of literature data, field surveys and laboratory microcosm experiments.