Interpreting vegetation change in tropical arid ecosystems from sediment molecular fossils and their stable isotope compositions: A baseline study from the Pilbara region of northwest Australia

Research output: Contribution to journalJournal articlepeer-review

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Interpreting vegetation change in tropical arid ecosystems from sediment molecular fossils and their stable isotope compositions : A baseline study from the Pilbara region of northwest Australia. / Rouillard, Alexandra; Greenwood, Paul F.; Grice, Kliti; Skrzypek, Grzegorz; Dogramaci, Shawan; Turney, Chris; Grierson, Pauline F.

In: Palaeogeography, Palaeoclimatology, Palaeoecology - An International Journal for the Geo-Sciences, Vol. 459, 01.10.2016, p. 495-507.

Research output: Contribution to journalJournal articlepeer-review

Harvard

Rouillard, A, Greenwood, PF, Grice, K, Skrzypek, G, Dogramaci, S, Turney, C & Grierson, PF 2016, 'Interpreting vegetation change in tropical arid ecosystems from sediment molecular fossils and their stable isotope compositions: A baseline study from the Pilbara region of northwest Australia', Palaeogeography, Palaeoclimatology, Palaeoecology - An International Journal for the Geo-Sciences, vol. 459, pp. 495-507. https://doi.org/10.1016/j.palaeo.2016.07.023

APA

Rouillard, A., Greenwood, P. F., Grice, K., Skrzypek, G., Dogramaci, S., Turney, C., & Grierson, P. F. (2016). Interpreting vegetation change in tropical arid ecosystems from sediment molecular fossils and their stable isotope compositions: A baseline study from the Pilbara region of northwest Australia. Palaeogeography, Palaeoclimatology, Palaeoecology - An International Journal for the Geo-Sciences, 459, 495-507. https://doi.org/10.1016/j.palaeo.2016.07.023

Vancouver

Rouillard A, Greenwood PF, Grice K, Skrzypek G, Dogramaci S, Turney C et al. Interpreting vegetation change in tropical arid ecosystems from sediment molecular fossils and their stable isotope compositions: A baseline study from the Pilbara region of northwest Australia. Palaeogeography, Palaeoclimatology, Palaeoecology - An International Journal for the Geo-Sciences. 2016 Oct 1;459:495-507. https://doi.org/10.1016/j.palaeo.2016.07.023

Author

Rouillard, Alexandra ; Greenwood, Paul F. ; Grice, Kliti ; Skrzypek, Grzegorz ; Dogramaci, Shawan ; Turney, Chris ; Grierson, Pauline F. / Interpreting vegetation change in tropical arid ecosystems from sediment molecular fossils and their stable isotope compositions : A baseline study from the Pilbara region of northwest Australia. In: Palaeogeography, Palaeoclimatology, Palaeoecology - An International Journal for the Geo-Sciences. 2016 ; Vol. 459. pp. 495-507.

Bibtex

@article{f53491e0a12d4b6f900e8ec199254649,
title = "Interpreting vegetation change in tropical arid ecosystems from sediment molecular fossils and their stable isotope compositions: A baseline study from the Pilbara region of northwest Australia",
abstract = "Detection of source diagnostic molecular fossils (biomarkers) within sediments can provide valuable insights into the vegetation and climates of past environments. However, hot and arid regions offer particularly challenging interpretive frameworks for reconstructions because baseline data are scarce, organic matter is generally very low and in the inland tropics in particular, sediments are also often subject to flooding and drought. Here, we investigated whether biomarkers and compound-specific δ13C values could be extracted from a late Holocene sediment record from the Fortescue Marsh (Pilbara, northwest Australia) to allow interpretation of past catchment vegetation and hydroclimate. The low total carbon (TC) content (< 1.4%) was a major challenge for the molecular analyses over the ~ 2000 years old sequence. Nevertheless, they revealed that the dominant hydrocarbon features (e.g., long chain n-alkanes) indicative of terrestrial plants (e.g., C4 grasses; riparian and other C3 plants) encompassed the last ~ 1300 yrs and that low abundance of products from aquatic sources (e.g., n-C17) were detected in the uppermost sediments only when permanently inundated conditions prevailed (recent decades). Similarly, the lower δ13C values (i.e., a difference of − 2.3‰) of long chain n-alkanes in upper sediments reflected a vegetation response to the emergence of wetter conditions through the late Holocene in the region. Based on the diverging dominant source contributions obtained from the molecular distributions and arid based Bayesian mixing model (δ13C of n-C27–33 alkanes) results, less arid conditions may have favoured the input of 13C depleted n-alkanes from the Eucalyptus (C3) dominant riparian vegetation. The deepest sediments (< 700 CE) however, had a TC content of < 0.4%, and no organic compounds were detected, consistent with local and regional records of hyperarid conditions. These results demonstrate that n-alkanes can provide a molecular and stable isotopic fingerprint of important - and perhaps underappreciated - ecological processes in modern tropical arid environments for future paleoclimate investigations.",
keywords = "Biomarkers, CSIA δC, n-Alkanes, Organic matter, Pilbara, Triodia",
author = "Alexandra Rouillard and Greenwood, {Paul F.} and Kliti Grice and Grzegorz Skrzypek and Shawan Dogramaci and Chris Turney and Grierson, {Pauline F.}",
year = "2016",
month = oct,
day = "1",
doi = "10.1016/j.palaeo.2016.07.023",
language = "English",
volume = "459",
pages = "495--507",
journal = "Palaeogeography, Palaeoclimatology, Palaeoecology - An International Journal for the Geo-Sciences",
issn = "0031-0182",
publisher = "Elsevier",

}

RIS

TY - JOUR

T1 - Interpreting vegetation change in tropical arid ecosystems from sediment molecular fossils and their stable isotope compositions

T2 - A baseline study from the Pilbara region of northwest Australia

AU - Rouillard, Alexandra

AU - Greenwood, Paul F.

AU - Grice, Kliti

AU - Skrzypek, Grzegorz

AU - Dogramaci, Shawan

AU - Turney, Chris

AU - Grierson, Pauline F.

PY - 2016/10/1

Y1 - 2016/10/1

N2 - Detection of source diagnostic molecular fossils (biomarkers) within sediments can provide valuable insights into the vegetation and climates of past environments. However, hot and arid regions offer particularly challenging interpretive frameworks for reconstructions because baseline data are scarce, organic matter is generally very low and in the inland tropics in particular, sediments are also often subject to flooding and drought. Here, we investigated whether biomarkers and compound-specific δ13C values could be extracted from a late Holocene sediment record from the Fortescue Marsh (Pilbara, northwest Australia) to allow interpretation of past catchment vegetation and hydroclimate. The low total carbon (TC) content (< 1.4%) was a major challenge for the molecular analyses over the ~ 2000 years old sequence. Nevertheless, they revealed that the dominant hydrocarbon features (e.g., long chain n-alkanes) indicative of terrestrial plants (e.g., C4 grasses; riparian and other C3 plants) encompassed the last ~ 1300 yrs and that low abundance of products from aquatic sources (e.g., n-C17) were detected in the uppermost sediments only when permanently inundated conditions prevailed (recent decades). Similarly, the lower δ13C values (i.e., a difference of − 2.3‰) of long chain n-alkanes in upper sediments reflected a vegetation response to the emergence of wetter conditions through the late Holocene in the region. Based on the diverging dominant source contributions obtained from the molecular distributions and arid based Bayesian mixing model (δ13C of n-C27–33 alkanes) results, less arid conditions may have favoured the input of 13C depleted n-alkanes from the Eucalyptus (C3) dominant riparian vegetation. The deepest sediments (< 700 CE) however, had a TC content of < 0.4%, and no organic compounds were detected, consistent with local and regional records of hyperarid conditions. These results demonstrate that n-alkanes can provide a molecular and stable isotopic fingerprint of important - and perhaps underappreciated - ecological processes in modern tropical arid environments for future paleoclimate investigations.

AB - Detection of source diagnostic molecular fossils (biomarkers) within sediments can provide valuable insights into the vegetation and climates of past environments. However, hot and arid regions offer particularly challenging interpretive frameworks for reconstructions because baseline data are scarce, organic matter is generally very low and in the inland tropics in particular, sediments are also often subject to flooding and drought. Here, we investigated whether biomarkers and compound-specific δ13C values could be extracted from a late Holocene sediment record from the Fortescue Marsh (Pilbara, northwest Australia) to allow interpretation of past catchment vegetation and hydroclimate. The low total carbon (TC) content (< 1.4%) was a major challenge for the molecular analyses over the ~ 2000 years old sequence. Nevertheless, they revealed that the dominant hydrocarbon features (e.g., long chain n-alkanes) indicative of terrestrial plants (e.g., C4 grasses; riparian and other C3 plants) encompassed the last ~ 1300 yrs and that low abundance of products from aquatic sources (e.g., n-C17) were detected in the uppermost sediments only when permanently inundated conditions prevailed (recent decades). Similarly, the lower δ13C values (i.e., a difference of − 2.3‰) of long chain n-alkanes in upper sediments reflected a vegetation response to the emergence of wetter conditions through the late Holocene in the region. Based on the diverging dominant source contributions obtained from the molecular distributions and arid based Bayesian mixing model (δ13C of n-C27–33 alkanes) results, less arid conditions may have favoured the input of 13C depleted n-alkanes from the Eucalyptus (C3) dominant riparian vegetation. The deepest sediments (< 700 CE) however, had a TC content of < 0.4%, and no organic compounds were detected, consistent with local and regional records of hyperarid conditions. These results demonstrate that n-alkanes can provide a molecular and stable isotopic fingerprint of important - and perhaps underappreciated - ecological processes in modern tropical arid environments for future paleoclimate investigations.

KW - Biomarkers

KW - CSIA δC

KW - n-Alkanes

KW - Organic matter

KW - Pilbara

KW - Triodia

UR - http://www.scopus.com/inward/record.url?scp=84979916747&partnerID=8YFLogxK

U2 - 10.1016/j.palaeo.2016.07.023

DO - 10.1016/j.palaeo.2016.07.023

M3 - Journal article

AN - SCOPUS:84979916747

VL - 459

SP - 495

EP - 507

JO - Palaeogeography, Palaeoclimatology, Palaeoecology - An International Journal for the Geo-Sciences

JF - Palaeogeography, Palaeoclimatology, Palaeoecology - An International Journal for the Geo-Sciences

SN - 0031-0182

ER -

ID: 165883662