River red gum forest River red gum (Eucalyptus camaldulensis) is found on river banks and floodplains where flooding occurs frequently. River red gum seed germination is more successful following flooding, however complete drying is required between floods for the survival of older trees. River red gum forest understorey usually includes grasses, sedges and daisies. |
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The preference curves and other information used by MFAT to assess this species/group in this river zone is presented below. Click on the 'information' buttons  and links for more explanation. |
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Interpretation:
Over what months of the year does adult vegetation prefer to be inundated with floodwater in order to maintain its condition?
More information:
MFAT Technical Manual [PDF 2.9 MB] |
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Evidence:
The ideal timing for inundation of River red gum forests is late winter to spring, reflecting the natural flow regime (the natural flooding would have been progressively later in the season, moving down the river).
Confidence level: A
Sources:
Bren, L. J. (1987). The duration of inundation in a flooding river red gum forest. Aust. For. Res. 17: 191-202.
Bren, L. J. (1988). Flooding characteristics of a riparian red gum forest. Aust. For. Res. 51: 57-62.
Bren, L. J. and Gibbs, P. (1986). Relationships between flood frequency, vegetation and topography in a river red gum forest. Aust. For. Res. 16:357-370.
Bren, L. J., O'Neill, I. C. and Gibbs, P. (1987). Flooding in the Barmah Forest and its relation to flow in the Murray-Edward River system. Aust. For. Res. 17: 127-144.
Chesterfield, E. A. (1986). Changes in the vegetation of the river red gum forest at Barmah, Victoria. Aust. Forestry. 49: 16-27.
Dexter, B. D., Rose, H. J. and Davies, N. (1986). River regulation and associated forest management problems in the River Murray red gum forests. Aust. Forestry. 49: 4-15.
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Interpretation:
For what length of time (in days) does adult vegetation prefer to be inundated for during a flood in order to maintain its condition?
More information:
MFAT Technical Manual [PDF 2.9 MB] |
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Evidence:
In the Barmah Forest the duration of natural floods ranged from one to seven months and occurred primarily in winter - spring (Bren, 1987; Roberts, 2001). In this forest, River red gums have tolerated an estimated 24 months of continuous flooding during two very wet periods in the mid-1950s and mid-1970s (Bren, 1987). However, if flooding duration is too long, soil oxygen is depleted and red gums will be either killed or gradually replaced by other plant communities. Four wet years killed off some low lying forest trees in the Barmah Forest (Chesterfield, 1986).
Confidence level: A
Sources:
Bren, L. J. (1987). The duration of inundation in a flooding river red gum forest. Aust. For. Res. 17: 191-202.
Bren, L. J. (1988). Flooding characteristics of a riparian red gum forest. Aust. For. Res. 51: 57-62.
Bren, L. J. and Gibbs, P. (1986). Relationships between flood frequency, vegetation and topography in a river red gum forest. Aust. For. Res. 16: 357-370.
Bren, L. J., O'Neill, I. C. and Gibbs, P. (1987). Flooding in the Barmah Forest and its relation to flow in the Murray-Edward River system. Aust. For. Res. 17: 127-144.
Chesterfield, E. A. (1986). Changes in the vegetation of the river red gum forest at Barmah, Victoria. Aust. Forestry. 49: 16-27.
Dexter, B. D, Rose, H. J. and Davies, N. (1986). River regulation and associated forest management problems in the River Murray red gum forests. Aust. Forestry. 49: 4-15.
Roberts, J. (2001). Large Plants. In: Rivers as Ecological Systems: the Murray-Darling Basin. Young, W. J. (ed.). pp.187-222. Murray-Darling Basin Commission.
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Interpretation:
What is the preferred length of the dry period (in months) since the last flood?
More information:
MFAT Technical Manual [PDF 2.9 MB] |
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Evidence:
Complete drying between floods is needed to ensure that the soil is aerated (Roberts, 2001). River red gum forest can survive an 18 month drought. Such dry periods occurred in 1904, 1915, 1944 and 1967 (Bren, 1987).
Confidence level: A
Sources:
Bren, L. J. (1987). The duration of inundation in a flooding river red gum forest. Aust. For. Res. 17: 191-202.
Bren, L. J. (1988). Flooding characteristics of a riparian red gum forest. Aust. For. Res. 51: 57-62.
Bren, L. J. and Gibbs, P. (1986). Relationships between flood frequency, vegetation and topography in a river red gum forest. Aust. For. Res. 16: 357-370.
Bren, L. J., O'Neill, I. C. and Gibbs, P. (1987). Flooding in the Barmah Forest and its relation to flow in the Murray-Edward River system. Aust. For. Res. 17: 127-144.
Chesterfield, E. A. (1986). Changes in the vegetation of the river red gum forest at Barmah, Victoria. Aust. Forestry. 49: 16-27.
Dexter, B. D, Rose, H. J. and Davies, N. (1986). River regulation and associated forest management problems in the River Murray red gum forests. Aust. Forestry. 49: 4-15.
Roberts, J. (2001). Large Plants. In: Rivers as Ecological Systems: the Murray-Darling Basin. Young, W. J. (ed.). pp.187-222. Murray-Darling Basin Commission.
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Interpretation:
Is the overall sequence of 'good' and 'bad' years sufficient to maintain the condition of adult vegetation in the long-term?
More information:
MFAT Technical Manual [PDF 2.9 MB] |
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Evidence:
The default parameters for this curve are based on advice from Bill Young (SRP), and agreed to by the REG vegetation discussion group. The parameters may need calibrating for each locality.
Confidence level: C
Sources:
SRP and REG vegetation discussion group, expert knowledge, judgment, and calibration.
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Interpretation:
Thresholds are set for 'good' (e.g. 0.7) and 'bad' (e.g. 0.2) years. A 'memory counter' starts at 0 and keeps a running tally of 'good' and 'bad' years for a flow scenario. The memory counter rewards good years by 'incrementing' the score, and penalises bad years by 'decrementing' the score by a specified amount. For example, an increment of 3 and a decrement of 1 means that 3 'bad' years can be cancelled out by one 'good' year. |
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Evidence:
This setting has been adjusted from the SRP default by REG D.
Confidence level: C
Sources:
Expert knowledge and judgment.
Note: More recent advice suggests that the SRP default setting for 'Good year threshold' and 'Bad year threshold' should be used in place of the settings used by REG D in future versions of MFAT. |
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Interpretation:
What is the preferred average depth of water (in cm) across the floodplain during a flood for the establishment of one year old seedlings?
The 'average depth' of water across a flooded area is different from the actual depth of water than individual plants at a specific location prefer or tolerate. It is calculated based on a volume-area relationship for the floodplain.
More information:
MFAT Technical Manual [PDF 2.9 MB] |
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Evidence:
An average depth of 1 metre across the floodplain ensures adequate watering of red gum seedlings. Larger (or deeper) floods might cause seedlings to be immersed in water for too long a period and result in drowning. Seedlings of 50-60cm tall can survive extended flooding of 4-6 months and complete immersion for a few weeks by shedding leaves (Dexter, 1978). (This curve can be customised for conditions specific to each floodplain).
Confidence level: A
Sources:
Dexter, B. D. (1978). Silviculture of the river red gum forests of the central Murray floodplain. Proc. Roy. Soc. Vic. 90: 175-194.
Heinrich, P. (1990). The eco-physiology of riparian river red gum. Final report, AWRC, October 1990.
Marcar, N. E. (1993). Waterlogging modifies growth water use and ion concentration in seedlings of salt-treated E. camaldulensis, E. tereticornis, E. robusta, and E. globulus. Aust. J. Plant Physiol. 20: 1-13.
Roberts, J. (2001). Large Plants. In: Rivers as Ecological Systems: the Murray-Darling Basin. Young, W. J. (ed.). pp.187-221. Murray-Darling Basin Commission.
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Interpretation:
What is the preferred length of time that the floodplain is inundated for during a flood (in days) for the establishment of one year old seedlings?
More information:
MFAT Technical Manual [PDF 2.9 MB] |
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Evidence:
An average depth of 1 metre across the floodplain ensures adequate watering of red gum seedlings. Larger (or deeper) floods might cause seedlings to be immersed in water for too long a period and result in drowning. Seedlings of 50-60cm tall can survive extended flooding of 4-6 months and complete immersion for a few weeks by shedding leaves (Dexter, 1978). (This curve can be customised for conditions specific to each floodplain).
Confidence level: A
Sources:
Dexter, B. D. (1978). Silviculture of the river red gum forests of the central Murray floodplain. Proc. Roy. Soc. Vic. 90: 175-194.
Heinrich, P. (1990). The eco-physiology of riparian river red gum. Final report, AWRC, October 1990.
Marcar, N. E. (1993). Waterlogging modifies growth water use and ion concentration in seedlings of salt-treated E. camaldulensis, E. tereticornis, E. robusta, and E. globulus. Aust. J. Plant Physiol. 20: 1-13.
Roberts, J. (2001). Large Plants. In: Rivers as Ecological Systems: the Murray-Darling Basin. Young, W. J. (ed.). pp.187-221. Murray-Darling Basin Commission.
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Interpretation:
What is the preferred time of the year (calendar months) for the flow sequence* that is required for seed germination?
*The required flow sequence is a dry period following an inundation event, occurring within a 30 day period.
More information:
MFAT Technical Manual [PDF 2.9 MB] |
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Evidence:
The preferred timing for germination is in late spring, following winter - spring flooding.
Confidence level: A
Sources:
Dexter, B. D. (1978). Silviculture of the river red gum forests of the central Murray floodplain. Proc. of the Royal Society of Victoria. 90: 175-194.
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