TY - JOUR

T1 - Palynofloral patterns of terrestrial ecosystem change during the end-Triassic event – a review

AU - Lindström, Sofie

N1 - Erratum: https://doi.org/10.1017/S0016756815000904 .

PY - 2015

Y1 - 2015

N2 - A review of the palynofloral succession at the well-documented Triassic–Jurassic boundary sites – Kuhjoch (Austria), St Audrie's Bay (UK), Stenlille (Denmark), Astartekløft (Greenland), Sverdrup Basin (Arctic Canada), Northern Carnarvon Basin (Western Australia), Southeast Queensland (eastern Australia) and New Zealand – show all sites experienced major to moderate re-organization of the terrestrial vegetation during the end-Triassic event. The changes led to subsequent taxonomic losses of between 17% and 73% of the Rhaetian pre-extinction palynoflora. The majority of the typical Rhaetian taxa that disappear are so far not known from in situ occurrences in reproductive structures of macrofossil plant taxa. From an ecological perspective, the most dramatic changes occurred in the Sverdrup Basin, Stenlille, Kuhjoch and Carnarvon Basin, where the pre- and post-extinction palynofloras were fundamentally different in both composition and dominance. These changes correspond to ecological severity Category I of McGhee et al. (2004), while the remaining sites are placed in their Subcategory IIa because there the pre-extinction ecosystems are disrupted, but recover and are not replaced post-extinction. Increased total abundances of spores on both hemispheres during the extinction and recovery intervals may indicate that environmental and/or climatic conditions became less favourable for seed plants. Such conditions may include expected effects of volcanism in the Central Atlantic Magmatic Province, such as acid rain, terrestrial soil and freshwater acidification due to volcanic sulfur dioxide emissions, fluctuating ultraviolet flux due to ozone depletion caused by halogens and halocarbon compounds, and drastic changes in climatic conditions due to greenhouse gas emissions.

AB - A review of the palynofloral succession at the well-documented Triassic–Jurassic boundary sites – Kuhjoch (Austria), St Audrie's Bay (UK), Stenlille (Denmark), Astartekløft (Greenland), Sverdrup Basin (Arctic Canada), Northern Carnarvon Basin (Western Australia), Southeast Queensland (eastern Australia) and New Zealand – show all sites experienced major to moderate re-organization of the terrestrial vegetation during the end-Triassic event. The changes led to subsequent taxonomic losses of between 17% and 73% of the Rhaetian pre-extinction palynoflora. The majority of the typical Rhaetian taxa that disappear are so far not known from in situ occurrences in reproductive structures of macrofossil plant taxa. From an ecological perspective, the most dramatic changes occurred in the Sverdrup Basin, Stenlille, Kuhjoch and Carnarvon Basin, where the pre- and post-extinction palynofloras were fundamentally different in both composition and dominance. These changes correspond to ecological severity Category I of McGhee et al. (2004), while the remaining sites are placed in their Subcategory IIa because there the pre-extinction ecosystems are disrupted, but recover and are not replaced post-extinction. Increased total abundances of spores on both hemispheres during the extinction and recovery intervals may indicate that environmental and/or climatic conditions became less favourable for seed plants. Such conditions may include expected effects of volcanism in the Central Atlantic Magmatic Province, such as acid rain, terrestrial soil and freshwater acidification due to volcanic sulfur dioxide emissions, fluctuating ultraviolet flux due to ozone depletion caused by halogens and halocarbon compounds, and drastic changes in climatic conditions due to greenhouse gas emissions.

UR - https://doi.org/10.1017/S0016756815000904

U2 - 10.1017/S0016756815000552

DO - 10.1017/S0016756815000552

M3 - Journal article

VL - 143

SP - 223

EP - 251

JO - Geological Magazine

JF - Geological Magazine

SN - 0016-7568

IS - 2

ER -