The forests come back
Ferns colonise the ruined ground first, then flowering plants return — but not the same ones.
- When
- —
- Duration
- 1 million years
- Known to
- ± 500 thousand years
- Era
- Paleocene, Cenozoic
Immediately above the boundary the pollen record is dominated by fern spores, the signature of a landscape stripped bare and recolonised by whatever grows fastest. Angiosperms return within thousands of years, but the recovered floras are markedly less diverse and differ by region: some parts of the world lose most of their plant species while others barely notice. The reorganisation is lasting. Broad-leaved evergreen rainforest of the modern kind establishes itself in the tropics during this recovery, and the conifer-dominated landscapes of the Mesozoic never come back.