Tags

Type your tag names separated by a space and hit enter

Isotopic and morphologic proxies for reconstructing light environment and leaf function of fossil leaves: a modern calibration in the Daintree Rainforest, Australia.
Am J Bot. 2020 08; 107(8):1165-1176.AJ

Abstract

PREMISE

Within closed-canopy forests, vertical gradients of light and atmospheric CO2 drive variations in leaf carbon isotope ratios, leaf mass per area (LMA), and the micromorphology of leaf epidermal cells. Variations in traits observed in preserved or fossilized leaves could enable inferences of past forest canopy closure and leaf function and thereby habitat of individual taxa. However, as yet no calibration study has examined how isotopic, micro- and macromorphological traits, in combination, reflect position within a modern closed-canopy forest or how these could be applied to the fossil record.

METHODS

Leaves were sampled from throughout the vertical profile of the tropical forest canopy using the 48.5 m crane at the Daintree Rainforest Observatory, Queensland, Australia. Carbon isotope ratios, LMA, petiole metric (i.e., petiole-width2 /leaf area, a proposed proxy for LMA that can be measured from fossil leaves), and leaf micromorphology (i.e., undulation index and cell area) were compared within species across a range of canopy positions, as quantified by leaf area index (LAI).

RESULTS

Individually, cell area, δ13 C, and petiole metric all correlated with both LAI and LMA, but the use of a combined model provided significantly greater predictive power.

CONCLUSIONS

Using the observed relationships with leaf carbon isotope ratio and morphology to estimate the range of LAI in fossil floras can provide a measure of canopy closure in ancient forests. Similarly, estimates of LAI and LMA for individual taxa can provide comparative measures of light environment and growth strategy of fossil taxa from within a flora.

Authors+Show Affiliations

College of Science and Engineering and Centre for Tropical Environmental and Sustainability Science, James Cook University, Cairns, Australia. University of Exeter, CEMPS, Exeter EX4 4QE, Devon, England.Sprigg Geobiology Centre and Department of Earth Sciences, The University of Adelaide, Adelaide, Australia.Department of Ecology and Evolutionary Biology, The University of Adelaide, Adelaide, Australia.College of Science and Engineering and Centre for Tropical Environmental and Sustainability Science, James Cook University, Cairns, Australia.Sprigg Geobiology Centre and Department of Earth Sciences, The University of Adelaide, Adelaide, Australia.

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

32864740

Citation

Cheesman, Alexander W., et al. "Isotopic and Morphologic Proxies for Reconstructing Light Environment and Leaf Function of Fossil Leaves: a Modern Calibration in the Daintree Rainforest, Australia." American Journal of Botany, vol. 107, no. 8, 2020, pp. 1165-1176.
Cheesman AW, Duff H, Hill K, et al. Isotopic and morphologic proxies for reconstructing light environment and leaf function of fossil leaves: a modern calibration in the Daintree Rainforest, Australia. Am J Bot. 2020;107(8):1165-1176.
Cheesman, A. W., Duff, H., Hill, K., Cernusak, L. A., & McInerney, F. A. (2020). Isotopic and morphologic proxies for reconstructing light environment and leaf function of fossil leaves: a modern calibration in the Daintree Rainforest, Australia. American Journal of Botany, 107(8), 1165-1176. https://doi.org/10.1002/ajb2.1523
Cheesman AW, et al. Isotopic and Morphologic Proxies for Reconstructing Light Environment and Leaf Function of Fossil Leaves: a Modern Calibration in the Daintree Rainforest, Australia. Am J Bot. 2020;107(8):1165-1176. PubMed PMID: 32864740.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Isotopic and morphologic proxies for reconstructing light environment and leaf function of fossil leaves: a modern calibration in the Daintree Rainforest, Australia. AU - Cheesman,Alexander W, AU - Duff,Heather, AU - Hill,Kathryn, AU - Cernusak,Lucas A, AU - McInerney,Francesca A, PY - 2019/08/28/received PY - 2020/04/28/accepted PY - 2020/9/1/entrez PY - 2020/8/31/pubmed PY - 2020/10/6/medline KW - cell area KW - forest canopy KW - fossil flora KW - leaf carbon isotope ratio KW - leaf mass per area KW - petiole metric KW - undulation index SP - 1165 EP - 1176 JF - American journal of botany JO - Am J Bot VL - 107 IS - 8 N2 - PREMISE: Within closed-canopy forests, vertical gradients of light and atmospheric CO2 drive variations in leaf carbon isotope ratios, leaf mass per area (LMA), and the micromorphology of leaf epidermal cells. Variations in traits observed in preserved or fossilized leaves could enable inferences of past forest canopy closure and leaf function and thereby habitat of individual taxa. However, as yet no calibration study has examined how isotopic, micro- and macromorphological traits, in combination, reflect position within a modern closed-canopy forest or how these could be applied to the fossil record. METHODS: Leaves were sampled from throughout the vertical profile of the tropical forest canopy using the 48.5 m crane at the Daintree Rainforest Observatory, Queensland, Australia. Carbon isotope ratios, LMA, petiole metric (i.e., petiole-width2 /leaf area, a proposed proxy for LMA that can be measured from fossil leaves), and leaf micromorphology (i.e., undulation index and cell area) were compared within species across a range of canopy positions, as quantified by leaf area index (LAI). RESULTS: Individually, cell area, δ13 C, and petiole metric all correlated with both LAI and LMA, but the use of a combined model provided significantly greater predictive power. CONCLUSIONS: Using the observed relationships with leaf carbon isotope ratio and morphology to estimate the range of LAI in fossil floras can provide a measure of canopy closure in ancient forests. Similarly, estimates of LAI and LMA for individual taxa can provide comparative measures of light environment and growth strategy of fossil taxa from within a flora. SN - 1537-2197 UR - https://www.unboundmedicine.com/medline/citation/32864740/Isotopic_and_morphologic_proxies_for_reconstructing_light_environment_and_leaf_function_of_fossil_leaves:_a_modern_calibration_in_the_Daintree_Rainforest_Australia_ L2 - https://doi.org/10.1002/ajb2.1523 DB - PRIME DP - Unbound Medicine ER -