Investigating the invisible components of the global carbon budget in mangroves

Impact Postdoctoral Fellowship (March 2019 - Present) works by Dr. Ouyang Xiaoguang

1.

Improved estimates on global carbon stock and carbon pools in tidal wetlands.

This study improved estimates on global carbon stock and carbon pools, in particular provided the first global estimate on sediment inorganic carbon stock in mangroves. We highlighted sediment inorganic carbon as an important component of the total carbon budgets in mangroves. The paper was published in Nature Communications in 2020:

Ouyang, X., Lee, S.Y., 2020. Improved estimates on global carbon stock and carbon pools in tidal wetlands. Nature Communications 11:317.

Link: https://www.nature.com/articles/s41467-019-14120-2

Field sampling sites in Hong Kong

The findings of the Nature Communications paper are reported by CUHK, WN, as well as Ming Pao.

wn.tif
mingpao.tif

2.

Effects of food and feeding regime on CO2 fluxes from mangrove consumers - do marine benthos breathe what they eat?

The study examined the role of bioturbators (crabs and gastropods) on sediment-air CO2 fluxes. This study established the paradigm of ‘You Breathe What You Eat’ by measuring CO2 production and d13C-CO2 respiration of different marine benthos, including crabs and gastropods via cavity-ring down spectroscopy. The study found significant relationships between CO2 production of crabs and carapace width/length. This helps to incorporate their contribution into the overall sediment-atmosphere CO2 fluxes in mangrove forests. The paper has been accepted for publication in Marine Environmental Research.

Conceptual model of the study

P. bidens feeding on yellow mangrove leaves

3.

Coupling between dissolved inorganic carbon and microphytobenthos.

The tidal mesocosm experiment was established to investigate the coupling between dissolved inorganic carbon-gaseous fluxes and mangrove/microphytobenthos using enriched stable isotopes. 

Setup of the mesocosm experiment

Student helpers assisted with sampling at the mesocosms (top) and in the field (left).

4.

The impact of super-typhoon Manghkut on sediment nutrient density and fluxes in a mangrove forest in Hong Kong.

The study investigated the impact of super-typhoon Mankhut on greenhouse gas (CO2 and CH4) fluxes and their isotopes over a period of eight months in the Ting Kok mangrove. This study revealed cyclone disturbance on the fluxes through priming effect and the increase of storm surges. The paper was published in Science of the Total Environment in 2021:

Ouyang, X., Guo, F., Lee, S.Y., 2021. The impact of super-typhoon Mangkhut on sediment nutrient density and fluxes in a mangrove forest in Hong Kong. Science of the Total Environment 766: 142637.

Link: https://www.sciencedirect.com/science/article/abs/pii/S0048969720361660

Conceptual model of the study