Comparison other major crises

In comparison to all other major ecological crises in Earth history, repopulation after the end-Permian crisis proceeded exceptionally slowly. Severe habitat destruction and extinction of the arborescent species resulted in a delayed recovery of woodland. Despite the difference in temporal scale, the patterns of vegetation change from Greenland and Hungary mimic the patterns of recent plant succession. The recovery of woodland strongly resembles the succession towards woodland that occurred after the icecap retreat at the beginning of the Holocene, approximately 11,000 years ago. In both cases, re-establishment of climax forest precedes phases in which herbs and shrubs are important members of the community. The rapid Holocene plant succession was regulated by habitat restoration and migration. The long-term pattern of the end-Permian to Middle Triassic succession was also strongly influenced by evolutionary processes, in contrast to the Holocene. Pleuromeia, Aethophyllum, and the successional dominants, are all immigrants that invaded restoring habitats after originating elsewhere. Habitat restoration, migration and evolutionary processes acted synergistically, setting the stage for ecosystem recovery to precrisis levels of structure and function, within the extremely long period of ~4 to 5 million years.