{"id":{"repo_id":"east-anglia","oai_identifier":"oai:ueaeprints.uea.ac.uk:49706"},"canonical_url":"https://search.dev.ndltd.org/etd/east-anglia/oai:ueaeprints.uea.ac.uk:49706","repository":{"repo_id":"east-anglia","name":"University of East Anglia","base_url":"https://ueaeprints.uea.ac.uk/cgi/oai2"},"display":{"title":"Molecular distributions and hydrogen isotopic compositions of n-alkanes from field studies of tree species: applications for paleoclimate studies","abstract":"The compound-specific δD values and molecular distributions of n-alkanes preserved in sediment archives are used as paleoclimate proxies. This use is based on two assumptions, 1) n-alkane δD values are highly correlated with source water δD values (Sachse 2012), and 2) the δD values of n-alkanes within a single site show little variation (Hou 2007). n-alkane molecular distributions are also used to infer the dominant source of n-alkanes input into sediment archives (Seki 2010). Despite this, paleoclimate reconstructions are being made without full understanding of how the δD values of nalkanes relate to the D isotopic compositions of meteoric waters in the region of synthesis, or how variable n-alkanes δD values could be within a single species. Using an in-depth investigation of Scots pine (Pinus sylvestris), significant variations in n-alkane molecular distributions and δD values were detected. These results suggest height of sample collection within a natural forest exerts a strong control on both n-alkane compositions, and δD values. Furthermore, this investigation indicates evergreen coniferous species synthesize both odd and even-chain-length n-alkanes, with high abundances of mid-chain n-alkanes, previously a diagnostic of aquatic plants. Both of these conclusions could significantly influence paleoclimate interpretations. Moreover, n-alkane δD values from Scots pine and Salix indicate little control of xylem water δD values on n-alkane δD values, suggesting that n-alkanes synthesized during spring are more representative of D-enriched stored assimilates. In addition, this study suggests too favourable conditions for photosynthesis could lead to reduced D-enrichment of leaf water, which is subsequently imprinted on the δD values of n-alkanes. These data suggest that under-estimations of climatic conditions present during the synthesis of n-alkane in sediments could occur if n-alkanes from existing plants are synthesized during periods of climatic stress.","abstract_html":"The compound-specific δD values and molecular distributions of n-alkanes preserved in sediment archives are used as paleoclimate proxies. This use is based on two assumptions, 1) n-alkane δD values are highly correlated with source water δD values (Sachse 2012), and 2) the δD values of n-alkanes within a single site show little variation (Hou 2007). n-alkane molecular distributions are also used to infer the dominant source of n-alkanes input into sediment archives (Seki 2010). Despite this, paleoclimate reconstructions are being made without full understanding of how the δD values of nalkanes relate to the D isotopic compositions of meteoric waters in the region of synthesis, or how variable n-alkanes δD values could be within a single species. Using an in-depth investigation of Scots pine (Pinus sylvestris), significant variations in n-alkane molecular distributions and δD values were detected. These results suggest height of sample collection within a natural forest exerts a strong control on both n-alkane compositions, and δD values. Furthermore, this investigation indicates evergreen coniferous species synthesize both odd and even-chain-length n-alkanes, with high abundances of mid-chain n-alkanes, previously a diagnostic of aquatic plants. Both of these conclusions could significantly influence paleoclimate interpretations. Moreover, n-alkane δD values from Scots pine and Salix indicate little control of xylem water δD values on n-alkane δD values, suggesting that n-alkanes synthesized during spring are more representative of D-enriched stored assimilates. In addition, this study suggests too favourable conditions for photosynthesis could lead to reduced D-enrichment of leaf water, which is subsequently imprinted on the δD values of n-alkanes. These data suggest that under-estimations of climatic conditions present during the synthesis of n-alkane in sediments could occur if n-alkanes from existing plants are synthesized during periods of climatic stress.","abstract_has_math":false,"creators":["Newberry, Sarah"],"institution":"University of East Anglia","degree_name":"phd","degree_level":"doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2013,"date_issued":"2013-09","date_published":"2013-09","updated_at":"2026-07-24T02:12:03Z","subjects":[],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Newberry, Sarah"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2013-09"]},{"key":"dc:date.issued","label":"Date","values":["2013-09"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["School of Environmental Sciences"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of East Anglia"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://ueaeprints.uea.ac.uk/id/eprint/49706/"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["doctoral"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["phd"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://ueaeprints.uea.ac.uk/id/eprint/49706/1/2013NewberrySLPhD.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The compound-specific δD values and molecular distributions of n-alkanes preserved in sediment archives are used as paleoclimate proxies. This use is based on two assumptions, 1) n-alkane δD values are highly correlated with source water δD values (Sachse 2012), and 2) the δD values of n-alkanes within a single site show little variation (Hou 2007). n-alkane molecular distributions are also used to infer the dominant source of n-alkanes input into sediment archives (Seki 2010). Despite this, paleoclimate reconstructions are being made without full understanding of how the δD values of nalkanes relate to the D isotopic compositions of meteoric waters in the region of synthesis, or how variable n-alkanes δD values could be within a single species. Using an in-depth investigation of Scots pine (Pinus sylvestris), significant variations in n-alkane molecular distributions and δD values were detected. These results suggest height of sample collection within a natural forest exerts a strong control on both n-alkane compositions, and δD values. Furthermore, this investigation indicates evergreen coniferous species synthesize both odd and even-chain-length n-alkanes, with high abundances of mid-chain n-alkanes, previously a diagnostic of aquatic plants. Both of these conclusions could significantly influence paleoclimate interpretations. Moreover, n-alkane δD values from Scots pine and Salix indicate little control of xylem water δD values on n-alkane δD values, suggesting that n-alkanes synthesized during spring are more representative of D-enriched stored assimilates. In addition, this study suggests too favourable conditions for photosynthesis could lead to reduced D-enrichment of leaf water, which is subsequently imprinted on the δD values of n-alkanes. These data suggest that under-estimations of climatic conditions present during the synthesis of n-alkane in sediments could occur if n-alkanes from existing plants are synthesized during periods of climatic stress."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Molecular distributions and hydrogen isotopic compositions of n-alkanes from field studies of tree species: applications for paleoclimate studies"]}]}],"canonical_facts":{"dc:creator":["Newberry, Sarah"],"dc:date":["2013-09"],"dc:date.issued":["2013-09"],"dc:description.abstract":["The compound-specific δD values and molecular distributions of n-alkanes preserved in sediment archives are used as paleoclimate proxies. This use is based on two assumptions, 1) n-alkane δD values are highly correlated with source water δD values (Sachse 2012), and 2) the δD values of n-alkanes within a single site show little variation (Hou 2007). n-alkane molecular distributions are also used to infer the dominant source of n-alkanes input into sediment archives (Seki 2010). Despite this, paleoclimate reconstructions are being made without full understanding of how the δD values of nalkanes relate to the D isotopic compositions of meteoric waters in the region of synthesis, or how variable n-alkanes δD values could be within a single species. Using an in-depth investigation of Scots pine (Pinus sylvestris), significant variations in n-alkane molecular distributions and δD values were detected. These results suggest height of sample collection within a natural forest exerts a strong control on both n-alkane compositions, and δD values. Furthermore, this investigation indicates evergreen coniferous species synthesize both odd and even-chain-length n-alkanes, with high abundances of mid-chain n-alkanes, previously a diagnostic of aquatic plants. Both of these conclusions could significantly influence paleoclimate interpretations. Moreover, n-alkane δD values from Scots pine and Salix indicate little control of xylem water δD values on n-alkane δD values, suggesting that n-alkanes synthesized during spring are more representative of D-enriched stored assimilates. In addition, this study suggests too favourable conditions for photosynthesis could lead to reduced D-enrichment of leaf water, which is subsequently imprinted on the δD values of n-alkanes. These data suggest that under-estimations of climatic conditions present during the synthesis of n-alkane in sediments could occur if n-alkanes from existing plants are synthesized during periods of climatic stress."],"dc:format":["application/pdf"],"dc:identifier.uri":["https://ueaeprints.uea.ac.uk/id/eprint/49706/1/2013NewberrySLPhD.pdf"],"dc:language":["en"],"dc:publisher.department":["School of Environmental Sciences"],"dc:publisher.institution":["University of East Anglia"],"dc:relation.isreferencedby":["https://ueaeprints.uea.ac.uk/id/eprint/49706/"],"dc:title":["Molecular distributions and hydrogen isotopic compositions of n-alkanes from field studies of tree species: applications for paleoclimate studies"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["doctoral"],"dc:type.qualificationname":["phd"]},"updated_at":"2026-07-24T02:12:03Z"}