Drought survival of Australian rainforest seedlings is influenced by species evolutionary history and soil type

Title
Drought survival of Australian rainforest seedlings is influenced by species evolutionary history and soil type
Publication Date
2013
Author(s)
Curran, Timothy J
Clarke, Peter J
Warwick, Nigel W
( author )
OrcID: https://orcid.org/0000-0001-7009-3183
Email: nwarwick@une.edu.au
UNE Id une-id:nwarwick
Type of document
Journal Article
Language
en
Entity Type
Publication
Publisher
CSIRO Publishing
Place of publication
Australia
DOI
10.1071/BT12081
UNE publication id
une:13713
Abstract
Water availability influences regional tree distributions in rainforests, often by affecting survival of seedlings. The occurrence of 'dry rainforest' species in subhumid climates has been attributed to the evolution of drought-resistant species from their mesic rainforest congeners. Many genera are found in both dry and mesic rainforest of Australia but the extent to which this is due to differential drought resistance has not been confirmed experimentally. We compared drought survival within three congeneric pairs of dry and mesic rainforest taxa in a glasshouse dry-down experiment. Soil type could also play a role, with dry rainforests mostly occurring on fine-textured soils such as loams, which have a high available water-holding capacity, compensating for lower rainfall. Hence, we grew plants in loam or sand soil. In all pairs, the dry rainforest taxon was better able to survive drought, providing support for the climate-induced evolution of a dry rainforest flora and further confirming that drought resistance of seedlings can shape tree species distributions at regional scales. Two of three pairs had higher seedling survival on basalt-derived loam soil, suggesting that such soils may aid seedling persistence during drought. Over evolutionary time, this may have resulted in the high fidelity of dry rainforest for these soils.
Link
Citation
Australian Journal of Botany, 61(1), p. 22-28
ISSN
1444-9862
0067-1924
Start page
22
End page
28

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