❓ Question regarding the depth of root penetration of native vegetation and eucalyptus mallees, and the implications for soil water movement. The response confirms the findings of the referenced papers, with a clarification about root depth measurement.
AnsweredQoN 3650Legislative Council
QuestionView source ↗
I refer to a booklet which I understand was prepared by Ian Kealley from the Department of Conservation and Land Management (CALM) and Mandy Clews titled ‘Specialty Timbers of the Goldfields’, a journal of hydrology paper dated 1983 titled ‘The Use of Natural Tracers as indicators of soil water movement in a temperate semi-arid region’ and a journal paper dated August 2002 titled ‘Recharge reduction on degraded agricultural soils with agroforestry systems’ -
(1) Is it correct that the 1983 paper referred to above identified that the concentration of environmental tritium in soil water beneath native vegetation is consistent with the hypothesis that some relatively recent water (post 1960) has penetrated to depths of at least 12 metres along channels occupied by living roots?
(2) If no to (1), what specifically is correct?
(3) Is it correct that the August 2002 paper referred to above identified that eucalyptus mallees which were only seven years old had root depths of up to ten metres below ground level?
(4) If no to (3), what specifically is correct?
(5) Is it correct that the August 2002 paper referred to above identified that eucalypt mallee trees can exploit soil water to depths of at least eight to ten metres below ground level within seven years of planting?
(6) If no to (5), what specifically is correct?
(1) Is it correct that the 1983 paper referred to above identified that the concentration of environmental tritium in soil water beneath native vegetation is consistent with the hypothesis that some relatively recent water (post 1960) has penetrated to depths of at least 12 metres along channels occupied by living roots?
(2) If no to (1), what specifically is correct?
(3) Is it correct that the August 2002 paper referred to above identified that eucalyptus mallees which were only seven years old had root depths of up to ten metres below ground level?
(4) If no to (3), what specifically is correct?
(5) Is it correct that the August 2002 paper referred to above identified that eucalypt mallee trees can exploit soil water to depths of at least eight to ten metres below ground level within seven years of planting?
(6) If no to (5), what specifically is correct?
AnswerView source ↗
Answered
22 August 2006
Responded by
Minister for Education and Training representing the Minister for the Environment
Response time
70 days
(2) Not Applicable. (3) Yes, except root depth was not measured directly but inferred from soil water measurement. (4) The conference paper referred to states "Results indicate that trees can exploit soil water to depths of at least 8-10m within 7 years of planting." and "The roots of eucalypt mallee species have been found to rapidly penetrate and dry out sub-soils, to depths of 8-10 m within 7 years." (5) Yes. (6) Not Applicable.
(3) Yes, except root depth was not measured directly but inferred from soil water measurement. (4) The conference paper referred to states "Results indicate that trees can exploit soil water to depths of at least 8-10m within 7 years of planting." and "The roots of eucalypt mallee species have been found to rapidly penetrate and dry out sub-soils, to depths of 8-10 m within 7 years." (5) Yes. (6) Not Applicable.
(4) The conference paper referred to states "Results indicate that trees can exploit soil water to depths of at least 8-10m within 7 years of planting." and "The roots of eucalypt mallee species have been found to rapidly penetrate and dry out sub-soils, to depths of 8-10 m within 7 years." (5) Yes. (6) Not Applicable.
(5) Yes. (6) Not Applicable.
(6) Not Applicable.
(3) Yes, except root depth was not measured directly but inferred from soil water measurement. (4) The conference paper referred to states "Results indicate that trees can exploit soil water to depths of at least 8-10m within 7 years of planting." and "The roots of eucalypt mallee species have been found to rapidly penetrate and dry out sub-soils, to depths of 8-10 m within 7 years." (5) Yes. (6) Not Applicable.
(4) The conference paper referred to states "Results indicate that trees can exploit soil water to depths of at least 8-10m within 7 years of planting." and "The roots of eucalypt mallee species have been found to rapidly penetrate and dry out sub-soils, to depths of 8-10 m within 7 years." (5) Yes. (6) Not Applicable.
(5) Yes. (6) Not Applicable.
(6) Not Applicable.
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