Environmental influences on the stable carbon isotopic composition of Devonian and Early Carboniferous land plants

• Published in: Palaeogeography, palaeoclimatology, palaeoecology Vol. 531; p. 109100
• Main Authors: Wan, Zhenzhu, Algeo, Thomas J., Gensel, Patricia G., Scheckler, Stephen E., Stein, William E., Cressler, Walter L., Berry, Christopher M., Xu, Honghe, Rowe, Harold D., Sauer, Peter E.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2019
• Subjects: Archaeopteris; Canopy effect; Drepanophycus; Early plants; Sawdonia; Water-use efficiency; Archaeopteris; Drepanophycus; Sawdonia; Early plants; Water-use efficiency; Canopy effect
• ISSN: 0031-0182; 1872-616X
• DOI: 10.1016/j.palaeo.2019.02.025

Systematic analysis of the stable carbon isotopic composition of fossil land plants (δ13Cp) has the potential to offer new insights regarding paleoclimate variation and plant-environment interactions in early terrestrial ecosystems. δ13Cp was measured for 190 fossil plant specimens belonging to 10 genera of Early to Late Devonian age (Archaeopteris, Drepanophycus, Haskinsia, Leclercqia, Pertica, Psilophyton, Rhacophyton, Sawdonia, Tetraxylopteris, and Wattieza) and 2 genera of Early Carboniferous age (Genselia and Rhodeopteridium) collected from sites located mainly in the Appalachian Basin (22–30°S paleolatitude). For the full carbon-isotopic dataset (n = 309), δ13Cp ranges from −20.3‰ to −30.5‰ with a mean of −25.5‰, similar to values for modern C3 land plants. In addition to a secular trend, δ13Cp exhibits both intra- and intergeneric variation. Intrageneric variation is expressed as a small (mean 0.45‰) 13C-enrichment of leaves and spines relative to stems that may reflect differential compound-specific compositions. Intergeneric variation is expressed as a much larger (to ~5‰) spread in the mean δ13Cp values of coeval plant genera that was probably controlled by taxon-specific habitat preferences and local environmental humidity. Among Early Devonian taxa, Sawdonia yielded the most 13C-depleted values (−27.1 ± 1.7‰), reflecting lower water-use efficiency that was probably related to growth in wetter habitats, and Leclercqia, Haskinsia, and Psilophyton yielded the most 13C-enriched values (−23.0 ± 1.6‰, −22.3 ± 1.3‰, and −24.8 ± 1.6‰, respectively), reflecting higher water-use efficiency probably related to growth in drier habitats. •First detailed analysis of δ13C variation among Devonian and Early Carboniferous land plants (309 analyses of 190 specimens)•Analyzed taxa: Archaeopteris, Drepanophycus, Haskinsia, Leclercqia, Pertica, Psilophyton, Rhacophyton, Sawdonia, Wattieza•Sawdonia yields the lowest δ13C values, reflecting low water-use efficiency related to growth in wetter habitats.•Leclercqia, Haskinsia, and Psilophyton yield the highest δ13C values, reflecting high water-use efficiency in drier habitats.•C-isotopic analyses of well-preserved fossil plants can yield insights into habitat preferences in paleofloral communities.