The delayed resurgence of equatorial forests after the Permian–Triassic ecologic crisis

Abstract

In conjunction with the Permian-Triassic ecologic crisis Ϸ250 million years ago, massive dieback of coniferous vegetation resulted in a degradation of terrestrial ecosystems in Europe. A 4-to 5-million-year period of lycopsid dominance followed, and renewed proliferation of conifers did not occur before the transition between Early and Middle Triassic. We document this delayed re-establishment of equatorial forests on the basis of palynological data. The reconstructed pattern of vegetational change suggests that habitat restoration, migration, and evolutionary processes acted synergistically, setting the stage for successional replacement of lycopsid dominants by conifers within a period of Ϸ0.5 million years.

A New Genus of Rhynchonellid Brachiopod from the Lower Triassic of South China and Implications for Timing the Recovery of Brachiopoda After the End‐Permian Mass Extinction

“…This conclusion is in contrast to the opinion of Hallam (1991), who, on the basis of reefbuilding organisms, estimated that the biotic recovery after the end-Permian extinction might have taken some 5 myr following a prolonged survival stage through the earliest Triassic. Our conclusion also contrasts sharply with those of Erwin and Pan (1996), Foote (1996) and Looy et al (1999) based on gastropod and crinoid faunas and terrestrial coniferous vegetation respectively, and is also in disagreement with Erwin (1998), who suggested that the Early Triassic biotic recovery took place some 3±9 million years after the end-Permian extinction. It is thus clear that signi®cant discrepancies exist among the estimations about the timing of recovery in the Triassic, and that these discrepancies may well re¯ect the fact that the timing of recovery was different for different marine taxonomic groups and in different ecosystems or biogeographical regions.…”

Lessons from the past: Biotic recoveries from mass extinctions

“…If the results of (12) are valid, they suggest the recovery involves positive feedback, and the active creation of ecospace (12,13), similar to that recently proposed on the basis of a recent analysis of the delayed recovery of forests in the Early Triassic after the end-Permian mass extinction (15). This pattern of positive feedback is a likely feature of biotic recoveries, irrespective of the validity of ref.…”

“…The weedy lycopsid Isoetes diversified rapidly and dominated many Early Triassic assemblages (49). Looy et al (15) documented a long period of dominantly opportunistic lycopsid pollen into the Spathian stage, when a rapid diversification occurs in Europe. The recovery of this equitorial conifer assemblage corresponds to the recovery of higher latitude peat forests, ending the ''coal gap'' (50, 51).…”

An exceptional role for flowering plant physiology in the expansion of tropical rainforests and biodiversity

“…Along with the various other climate effects that have been hypothesized for the End-Cretaceous bolide impact (O'Keefe & Ahrens 1989;Gupta et al 2001), the destruction of forest canopies in its immediate aftermath may be expected to have resulted in substantially less precipitation until the vegetation recovered, as well as a temperature increase owing to the loss of transpirational cooling-an effect that is seasonally as large as 58C in the Amazon basin today (figures 1, 3 and 4). Alternatively, the degradation of non-angiosperm vegetation during earlier events, such as the End-Permian (Looy et al 1999) or Triassic/ Jurassic extinctions (McElwain et al 2009), would have had a much smaller feedback with climate. Thus, angiosperm evolution should be a consideration in future studies of mass extinctions and other environmental perturbations like the Palaeocene/Eocene Thermal Maximum (Wing et al 2005) because the same angiosperm-initiated climate modifications that contribute to the high diversity of angiosperm ecosystems may also make those ecosystems prone to more exaggerated responses to environmentally destructive events.…”