Dixon, Adele Mary ORCID: https://orcid.org/0000-0003-4297-0892 (2022) Identifying low climate exposure coral reefs for climate-relevant coral reef management. PhD thesis, University of Leeds.
Abstract
Climate change is causing worldwide degradation of coral reef ecosystems. Climate-relevant conservation strategies often identify reef areas with low exposure to thermal stress using remote sensing data and climate model projections. However, the coarse spatial resolution (≥4 km) of climate data and lack of projections for climate stressors other than thermal stress limit the identification of low climate exposure coral reefs.
The overarching aim of this PhD project was to develop and test new tools for identifying low exposure coral reefs to better protect coral reef ecosystems from climate change. This aim was explored through the following three research questions: 1. Can climate models project local and regional scale changes in coral reef climate exposure? 2. How will extreme climate exposure on coral reefs change at local and regional scales in the future? 3. Are local-scale climate projections useful in conservation planning?
Addressing these research questions, this thesis consists of four papers. Firstly, I highlighted the importance of integrating thermal stressors with other environmental threats and ecological characteristics when evaluating reef vulnerability to climate (Paper 1). Second, to address the first and second research questions, I developed a novel 1 km spatial resolution thermal stress dataset for the global coral reef area by increasing the resolution of climate model projections using statistical downscaling (Paper 2). In addition, I tested the suitability of downscaled tropical cyclones for predicting coral reef damage at the scale of coral reef regions (e.g. the Great Barrier Reef) and projected future changes in tropical cyclone-related reef damage (Paper 3). Finally, I determined whether the dataset used alters spatial planning solutions by inputting climate datasets at two resolutions and from two sources to the spatial planning software Marxan (Paper 4).
My PhD’s body of work updates projections of coral reef futures under climate change and advances the use of climate data in conservation planning. In answer to the first two research questions, I found that >90% of coral reefs globally are projected to experience an intolerable frequency of severe thermal stress events with just 1.5°C of global warming relative to pre-industrial levels. Even at the high resolution of 1 km, very few refuges from thermal stress remained. In contrast, I found projections of tropical cyclone-induced coral reef damage in the future are uncertain, with some models projecting increases and others decreases. Additionally, the downscaled models were limited in their ability to represent observed tropical cyclone exposure at the coral reef region scale. In answer to the third research question, I found that both the data source and spatial resolution of climate data altered which coral reefs were prioritised for protection, highlighting both the uncertainty in which data sources conservation planners should use as well as the differences in and potential benefits of using higher resolution data.
Even though there remains uncertainty in observed climate data and model projections of thermal stress, I conclude that they can have value in climate-relevant conservation planning if uncertainty is factored into decision making. To aid conservation planning, I provide a new tool consisting of different thermal stress metrics catering to a variety of climate conservation approaches. My findings also demonstrate where projections are not yet suitable for use in conservation planning. Together, my findings should aid the development of climate-relevant conservation planning for coral reefs.
Metadata
Supervisors: | Beger, Maria and Forster, Piers |
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Related URLs: | |
Keywords: | Climate change; Conservation; Coral reefs |
Awarding institution: | University of Leeds |
Academic Units: | The University of Leeds > Faculty of Biological Sciences (Leeds) > School of Biology (Leeds) |
Identification Number/EthosID: | uk.bl.ethos.878032 |
Depositing User: | Dr Adele Mary Dixon |
Date Deposited: | 22 Mar 2023 15:10 |
Last Modified: | 11 May 2023 09:53 |
Open Archives Initiative ID (OAI ID): | oai:etheses.whiterose.ac.uk:32319 |
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