Mangroves in a changing climate: impacts of elevated carbon dioxide and rising temperatures on mangroves’ carbon and water dynamics (CENTA 2025-B34)

Drought and heat are major contributors to forest mortality, with hydraulic failure being the primary physiological mechanism behind drought-induced tree death. During periods of drought, the xylem —the column responsible for water transport— can rupture, resulting in the formation of air bubbles (known as embolism). These embolisms obstruct water flow through the xylem, leading to reduced water transport and, ultimately, tree mortality (Sperry and Tyree, 1988). In addition to drought, heat and atmospheric water stress severely impact tree physiology, reducing photosynthesis and causing tissue death, which can further disrupt the hydraulic system and increase embolism formation, particularly in the leaf (Grossiord et al., 2020; Marchin et al., 2022). Despite its significance, the independent effect of heat on plant health is understudied, largely due to the difficulty in isolating heat stress from drought stress in natural conditions. With climate change, carbon dioxide (CO2) levels are expected to rise significantly, potentially reaching 550 ppm by 2050 (compared to 420 ppm today). While elevated CO2 can contribute to warming through greenhouse effects, it also stimulates photosynthesis (Gardner et al., 2022), enhancing the forests’ role in carbon sequestration. However, tree species adapted to drier habitats (xeric) may exhibit greater resistance to heat and drought but may be less efficient at carbon uptake than species from more temperate (mesic) environments. Mangrove ecosystems are vital habitats for wildlife and provide essential ecosystem services for coastal communities, such as wave mitigation. However, rising CO2, increased temperatures, and increased salinity due to sea-level rise are facilitating the expansion of mangroves in saltmarsh communities and can lead to widespread mangrove mortality (Gauthey et al., 2022). There is a critical gap in our understanding of how mangrove ecosystems respond to climate change. Therefore, this study would explore the effects of elevated CO2 and temperatures on the water and carbon dynamics of mangrove species. This project is part of the BIFoR Global theme.

Project Highlights:

The project will examine how increasing temperature and elevated atmospheric CO2 affect gas exchange, at the leaf level. This study aims to quantify the water-use efficiency of mangroves under future climate conditions to improve model predictions for forest ecosystems. Experiments will be performed both in (1) natural conditions within a newly restored mangrove habitat in Dubai, and (2) in controlled conditions at the Wolfson glasshouses. The PhD student will develop skills in plant ecophysiology and remote sensing, utilising UAVS equipped with hyperspectral and thermal cameras, with opportunities to network internationally and participate to outreach activities. For further information on this project and details of how to apply to it please visit https://centa.ac.uk/studentship/2025-b34-mangroves-in-a-changing-climate-impacts-of-elevated-carbon-dioxide-and-rising-temperatures-on-mangroves-carbon-and-water-dynamics/ Further information on how to apply for a CENTA studentship can be found on the CENTA website: https://centa.ac.uk/

Funding notes:

The CENTA DTP is currently awaiting confirmation of funding under the BBSRC-NERC Doctoral Landscape Award (DLA) scheme, which is the new name for Doctoral Training Partnerships (DTPs). This funding will support cohorts starting from 2025 onwards. We anticipate receiving further information by late October or early November 2024. Funding for this PhD opportunity is therefore subject to this confirmation. For further information please visit https://centa.ac.uk/. UKRI allows international students to be eligible for studentships but only for a maximum of 30% of the cohort. Please be aware that CENTA funding does not cover any additional costs relating to moving to and residing in the UK. All international applicants must ensure they can fulfil the University of Birmingham’s international student entry requirements, which includes English language requirements. For further information please visit https://www.birmingham.ac.uk/postgraduate/pgt/requirements-pgt/international/index.aspx.