University Of Tasmania

File(s) under permanent embargo

Fossil evidence for a hyperdiverse sclerophyll flora under a non-Mediterranean-type climate

journal contribution
posted on 2023-05-17, 16:43 authored by Sniderman, JMK, Gregory JordanGregory Jordan, Cowling, RM
The spectacular diversity of sclerophyll plants in the Cape Floristic Region in South Africa and Australia's Southwest Floristic Region has been attributed to either explosive radiation on infertile soils under fire-prone, summer-dry climates or sustained accretion of species under inferred stable climate regimes. However, the very poor fossil record of these regions has made these ideas difficult to test. Here, we reconstruct ecological-scale plant species richness from an exceptionally well-preserved fossil flora. We show that a hyperdiverse sclerophyll flora existed under high-rainfall, summerwet climates in the Early Pleistocene in southeastern Australia. The sclerophyll flora of this region must, therefore, have suffered subsequent extinctions to result in its current relatively low diversity. This regional loss of sclerophyll diversity occurred at the same time as a loss of rainforest diversity and cannot be explained by ecological substitution of species of one ecological type by another type. We show that sclerophyll hyperdiversity has developed in distinctly non-Mediterranean climates, and this diversity is, therefore, more likely a response to long-term climate stability. Climate stability may have both reduced the intensity of extinctions associated with the Pleistocene climate cycles and promoted the accumulation of species richness by encouraging genetic divergence between populations and discouraging plant dispersal.


Australian Research Council


Publication title

Proceedings of the National Academy of Sciences of the United States of America










School of Natural Sciences


National Academy of Sciences

Place of publication

2101 Constitution Ave Nw, Washington, USA, Dc, 20418

Rights statement

Copyright 2013 PNAS

Repository Status

  • Restricted

Socio-economic Objectives

Expanding knowledge in the environmental sciences

Usage metrics

    University Of Tasmania