Scattered native trees and soil patterns in grazing land on the Northern Tablelands of New South Wales, Australia

Author(s)
Wilson, Brian
Growns, Ivor
Lemon, John
Publication Date
2007
Abstract
Over large areas of south-eastern Australia, the original cover of native woodland has been extensively cleared or modified, and what remains is often characterised by scattered trees beneath which the ground-storey vegetation is largely grazed or otherwise managed. This study investigated the influence of scattered Blakely's red gum ('Eucalyptus blakelyi') trees on both near-surface and deeper soil layers in temperate grazed pastures on the Northern Tablelands of New South Wales, Australia. A significant canopy effect was observed with elevated soil pH, carbon, and nutrient status inside the tree canopy indicating soil enrichment in a zone around the tree. This effect, however, was largely restricted to the surface (0-0.20 m) soil layers. Chloride concentrations were elevated near to trees but only in the deeper soil layers, suggesting that a modified water use and deep drainage mechanism occurred near the trees. Close to the tree, however, a significant acidification was observed between 0.40-0.60 m depth in the soil, without any obvious depletion in other soil element concentrations. It is concluded that this acidification provides strong evidence in support of a 'biological pumping' mechanism that has been proposed elsewhere. Key questions remain as to the management implications of these results, whether the subsurface acidification that was observed is common among native Australian trees, if it might be persistent through time, and if this might be a soil issue that requires management.
Citation
Australian Journal of Soil Research, 45(3), p. 199-205
ISSN
0004-9573
1446-568X
1838-6768
1838-675X
Link
Publisher
CSIRO Publishing
Title
Scattered native trees and soil patterns in grazing land on the Northern Tablelands of New South Wales, Australia
Type of document
Journal Article
Entity Type
Publication

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