Projects per year
Geologists and palaeontologists have expressed mixed views about the effects of the end-Permian mass extinction on continental habitats and on terrestrial life. Current work suggests that the effects on land were substantial, with massive erosion following the stripping of vegetation, associated with long-term aridification and short-term bursts of warming and acid rain. Wildfires at the Permo-Triassic boundary contributed to the removal of forests and the prolonged absence of forests from the Earth's surface for up to 10. Myr. These physical crises on land impinged on the oceans, suggesting tight interlocking of terrestrial and marine crises. Levels of extinction on land may well have been as high as in the sea, and this is certainly the case for tetrapods. The mass extinction seems to have been less profound for plants and insects, but it is hard at present to disentangle issues of data quality from reductions in abundance and diversity. Several killing agents have been proposed, and of these tetrapods may have succumbed primarily to acid rain, mass wasting, and aridification. Plants may have been more affected by the sudden effects of heating and wildfires, and the crisis for insects has yet to be explored.
- Mass extinction