{"id":{"repo_id":"exeter","oai_identifier":"oai:figshare.com:article/32253108"},"canonical_url":"https://search.dev.ndltd.org/etd/exeter/oai:figshare.com:article/32253108","repository":{"repo_id":"exeter","name":"University of Exeter","base_url":"https://api.figshare.com/v2/oai"},"display":{"title":"The tropical peatland carbon sink: climatic drivers and modelling of peat accumulation at the pan-tropical scale","abstract":"Tropical peatlands are carbon-dense ecosystems and act as a globally important carbon sink. However, uncertainties exist about the climatic and environmental drivers of carbon accumulation and about the future of the carbon sink with climate change. There are also relatively few modelling studies focusing on the tropical peatland carbon sink because of limited available data for parameterisation and validation, and tropical peatland carbon dynamics are notably missing from Earth System Models (ESMs). In this thesis, I examine long-term apparent carbon accumulation rates and their climatic drivers for tropical peatlands and synthesise available empirical data on peatland carbon decomposition to CO2. This thesis also presents a configuration for an Earth System Model land surface scheme which includes a representation of tropical peatland carbon dynamics (Joint UK Land Environment Simulator vn5.8_accumualte_soil, JULES-Peat). Apparent carbon accumulation rates (aCAR) over the last millennium in tropical peatlands range from 1.1 to 152.0 gC m-2 yr-1, and the main climatic control on aCAR differs between lowland and high-elevation (>1000m a.s.l.) sites. For lowland peatlands, the best predictor is the mean monthly precipitation amount of the warmest quarter, while mean annual temperature shows the strongest significant relationship with aCAR for high-elevation peatlands. Carbon decomposition via soil heterotrophic respiration to CO2 (SHR-CO2) shows a sharp decrease under anoxic water-saturated conditions, with a mean ratio of SHR-CO2 under anoxic conditions and SHR-CO2 at the optimum moisture of 0.10 ± 0.08. The median value of Q10 for peat SHR-CO2 is 2.04. Model improvements necessary to simulate peat accumulation in tropical peatlands include setting model spin-up duration to reflect the timing of peat initiation for each site, and improved parameterisation of the litter decomposability and of the carbon decomposition function. Among all the model improvements, the parameterisation of carbon decomposition with moisture has the greatest impact for peat accumulation in the tropics.<p></p>","abstract_html":"Tropical peatlands are carbon-dense ecosystems and act as a globally important carbon sink. However, uncertainties exist about the climatic and environmental drivers of carbon accumulation and about the future of the carbon sink with climate change. There are also relatively few modelling studies focusing on the tropical peatland carbon sink because of limited available data for parameterisation and validation, and tropical peatland carbon dynamics are notably missing from Earth System Models (ESMs). In this thesis, I examine long-term apparent carbon accumulation rates and their climatic drivers for tropical peatlands and synthesise available empirical data on peatland carbon decomposition to CO2. This thesis also presents a configuration for an Earth System Model land surface scheme which includes a representation of tropical peatland carbon dynamics (Joint UK Land Environment Simulator vn5.8_accumualte_soil, JULES-Peat). Apparent carbon accumulation rates (aCAR) over the last millennium in tropical peatlands range from 1.1 to 152.0 gC m-2 yr-1, and the main climatic control on aCAR differs between lowland and high-elevation (&gt;1000m a.s.l.) sites. For lowland peatlands, the best predictor is the mean monthly precipitation amount of the warmest quarter, while mean annual temperature shows the strongest significant relationship with aCAR for high-elevation peatlands. Carbon decomposition via soil heterotrophic respiration to CO2 (SHR-CO2) shows a sharp decrease under anoxic water-saturated conditions, with a mean ratio of SHR-CO2 under anoxic conditions and SHR-CO2 at the optimum moisture of 0.10 ± 0.08. The median value of Q10 for peat SHR-CO2 is 2.04. Model improvements necessary to simulate peat accumulation in tropical peatlands include setting model spin-up duration to reflect the timing of peat initiation for each site, and improved parameterisation of the litter decomposability and of the carbon decomposition function. Among all the model improvements, the parameterisation of carbon decomposition with moisture has the greatest impact for peat accumulation in the tropics.&lt;p&gt;&lt;/p&gt;","abstract_has_math":false,"creators":["Elise Dehaen (21042617)"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2026,"date_issued":"2026-05-18T00:00:00Z","date_published":"2026-05-18T00:00:00Z","updated_at":"2026-07-27T19:33:04Z","subjects":["tropical peatland","Joint UK Land Environment Simulator","peatland carbon sink","hydraulic conductivity","peat carbon accumulation rate","soil heterotrophic respiration"],"languages":[],"rights":["All rights reserved","Open Access after 2027-11-18"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["10779/exe.32253108.v1"],"render_values":[{"text":"10779/exe.32253108.v1","href":null,"code":true}]}]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Elise Dehaen (21042617)"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2026-05-18T00:00:00Z"]},{"key":"dc:relation","label":"Dc Relation","values":["https://figshare.com/articles/thesis/The_tropical_peatland_carbon_sink_climatic_drivers_and_modelling_of_peat_accumulation_at_the_pan-tropical_scale/32253108"]},{"key":"dc:type","label":"Dc Type","values":["Text","Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["tropical peatland","Joint UK Land Environment Simulator","peatland carbon sink","hydraulic conductivity","peat carbon accumulation rate","soil heterotrophic respiration"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["All rights reserved","Open Access after 2027-11-18"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["10779/exe.32253108.v1"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Tropical peatlands are carbon-dense ecosystems and act as a globally important carbon sink. However, uncertainties exist about the climatic and environmental drivers of carbon accumulation and about the future of the carbon sink with climate change. There are also relatively few modelling studies focusing on the tropical peatland carbon sink because of limited available data for parameterisation and validation, and tropical peatland carbon dynamics are notably missing from Earth System Models (ESMs). In this thesis, I examine long-term apparent carbon accumulation rates and their climatic drivers for tropical peatlands and synthesise available empirical data on peatland carbon decomposition to CO2. This thesis also presents a configuration for an Earth System Model land surface scheme which includes a representation of tropical peatland carbon dynamics (Joint UK Land Environment Simulator vn5.8_accumualte_soil, JULES-Peat). Apparent carbon accumulation rates (aCAR) over the last millennium in tropical peatlands range from 1.1 to 152.0 gC m-2 yr-1, and the main climatic control on aCAR differs between lowland and high-elevation (>1000m a.s.l.) sites. For lowland peatlands, the best predictor is the mean monthly precipitation amount of the warmest quarter, while mean annual temperature shows the strongest significant relationship with aCAR for high-elevation peatlands. Carbon decomposition via soil heterotrophic respiration to CO2 (SHR-CO2) shows a sharp decrease under anoxic water-saturated conditions, with a mean ratio of SHR-CO2 under anoxic conditions and SHR-CO2 at the optimum moisture of 0.10 ± 0.08. The median value of Q10 for peat SHR-CO2 is 2.04. Model improvements necessary to simulate peat accumulation in tropical peatlands include setting model spin-up duration to reflect the timing of peat initiation for each site, and improved parameterisation of the litter decomposability and of the carbon decomposition function. Among all the model improvements, the parameterisation of carbon decomposition with moisture has the greatest impact for peat accumulation in the tropics.<p></p>"]},{"key":"dc:title","label":"Title","values":["The tropical peatland carbon sink: climatic drivers and modelling of peat accumulation at the pan-tropical scale"]}]}],"canonical_facts":{"dc:creator":["Elise Dehaen (21042617)"],"dc:date":["2026-05-18T00:00:00Z"],"dc:description":["Tropical peatlands are carbon-dense ecosystems and act as a globally important carbon sink. However, uncertainties exist about the climatic and environmental drivers of carbon accumulation and about the future of the carbon sink with climate change. There are also relatively few modelling studies focusing on the tropical peatland carbon sink because of limited available data for parameterisation and validation, and tropical peatland carbon dynamics are notably missing from Earth System Models (ESMs). In this thesis, I examine long-term apparent carbon accumulation rates and their climatic drivers for tropical peatlands and synthesise available empirical data on peatland carbon decomposition to CO2. This thesis also presents a configuration for an Earth System Model land surface scheme which includes a representation of tropical peatland carbon dynamics (Joint UK Land Environment Simulator vn5.8_accumualte_soil, JULES-Peat). Apparent carbon accumulation rates (aCAR) over the last millennium in tropical peatlands range from 1.1 to 152.0 gC m-2 yr-1, and the main climatic control on aCAR differs between lowland and high-elevation (>1000m a.s.l.) sites. For lowland peatlands, the best predictor is the mean monthly precipitation amount of the warmest quarter, while mean annual temperature shows the strongest significant relationship with aCAR for high-elevation peatlands. Carbon decomposition via soil heterotrophic respiration to CO2 (SHR-CO2) shows a sharp decrease under anoxic water-saturated conditions, with a mean ratio of SHR-CO2 under anoxic conditions and SHR-CO2 at the optimum moisture of 0.10 ± 0.08. The median value of Q10 for peat SHR-CO2 is 2.04. Model improvements necessary to simulate peat accumulation in tropical peatlands include setting model spin-up duration to reflect the timing of peat initiation for each site, and improved parameterisation of the litter decomposability and of the carbon decomposition function. Among all the model improvements, the parameterisation of carbon decomposition with moisture has the greatest impact for peat accumulation in the tropics.<p></p>"],"dc:identifier":["10779/exe.32253108.v1"],"dc:relation":["https://figshare.com/articles/thesis/The_tropical_peatland_carbon_sink_climatic_drivers_and_modelling_of_peat_accumulation_at_the_pan-tropical_scale/32253108"],"dc:rights":["All rights reserved","Open Access after 2027-11-18"],"dc:subject":["tropical peatland","Joint UK Land Environment Simulator","peatland carbon sink","hydraulic conductivity","peat carbon accumulation rate","soil heterotrophic respiration"],"dc:title":["The tropical peatland carbon sink: climatic drivers and modelling of peat accumulation at the pan-tropical scale"],"dc:type":["Text","Thesis"]},"updated_at":"2026-07-27T19:33:04Z"}