Water relations of woody plants on contrasting soils during drought: does edaphic compensation account for dry rainforest distribution?

Title
Water relations of woody plants on contrasting soils during drought: does edaphic compensation account for dry rainforest distribution?
Publication Date
2009
Author(s)
Curran, Timothy John
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/BT09128
UNE publication id
une:5048
Abstract
The occurrence of dry rainforest in climates considered drier than the recognised limit for rainforest has been explained by the edaphic compensation hypothesis, which proposed that finer-textured soils facilitate the occurrence of rainforest at climatic extremes.We Tested this by examining the effect of soil type on the water relations and plant traits of four dry rainforest species, during a severe drought and subsequent non-drought periods. We predicted plants growing in sandy soils would exhibit higher levels of water stress (lower predawn water potential and stomatal conductance) and possess morphological and physiological traits that more typically reflect drought resistance (late leaf fall in deciduous species, low specific leaf area, vertical leaf angles and stomata that close at low water potential) than those growing in loam soils. During drought, levels of water stress were similar across soil types, while post-drought plants on sandy soils were less stressed. Soil type did not cause shifts in drought tolerance traits, suggesting there has been no ecotypic differentiation of dry rainforest species across soil types for these traits. Hence, we found no support for the edaphic compensation hypothesis in adult plants; future studies should consider other life-cycle stages, such as seedlings.
Link
Citation
Australian Journal of Botany, 57(8), p. 629-639
ISSN
1444-9862
0067-1924
Start page
629
End page
639

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