Evidence:
Floods during any season will be beneficial to the Lignum plant community. Floods in spring-early summer will be most suitable as they provide increased soil moisture conditions during the warmer months when growth is most vigorous.

Confidence level: C

Sources:
SRP expert knowledge and judgment.

Evidence:
Lignum swamps on the Chowilla floodplain naturally would have been flooded every 2 to 4 years, lasting 3 to 4 months. River regulation has reduced this to 2-3 months (Sharley and Huggan, 1995; Roberts, 2001).

On the banks of the River Murray in South Australia, Lignum occurs where it floods for 45-115 days per year, usually no more than 60 cm deep (Blanch et al. 1999; Roberts and Marston, 2000).

The REG plant discussion group agreed upon 30-120 days being optimum, after advice from Jane Roberts.

Confidence level: A

Sources:
Blanch, S. J., Ganf, G. G., and Walker, K. F. (1999). Tolerance of riverine plants to flooding and exposure indicated by water regime. Regulated Rivers: Research and Management. 15: 43-62.

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.

Roberts, J. and Marston, F. (2000). Water regime of wetland and floodplain plants in the Murray-Darling Basin - a source book of ecological knowledge. CSIRO Land & Water Technical Report 30/00.

Sharley, T. and Huggan, C. (1995). Chowilla Resources Management Plan. Final Report. Murray-Darling Basin Commission.

Evidence:
In SW NSW Lignum sites flood on average every 3 years (Scott, 1992). In NW NSW they flood every 2-10 years (Goodrick, 1984). On the Chowilla floodplain, Lignum was flooded naturally every 2-4 years, but every 3-10 years under regulated flows (Sharley and Huggan, 1995).

Using this information as a basis, the ideal dry period was taken to be 1.5-3 years and that up to 5 years was tolerated. Also, a minimum dry period of 4 months is required to dry out the soil.

Confidence level: A

Sources:
Goodrick, G. N. (1984). Wetlands of North-Western New South Wales. Occasional Paper Number 6. National Parks and Wildlife Service of NSW.

Scott, J. A. (1992). The natural vegetation of the Balranald-Swan Hill area. Cunninghamia. 2: 597-602.

Sharley, T. and Huggan, C. (1995). Chowilla Resources Management Plan. Final Report. Murray-Darling Basin Commission.

Evidence:
The good/bad year thresholds and the increment and decrement default values for the flood memory 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.

Evidence:
Field experience indicates that the average depth across the floodplain that most suits 1 year old seedlings (or young plants) is around 10-30 cm. Seedlings are at risk of drowning on some parts of the floodplain under greater depths.

Confidence level: C

Sources:
SRP expert knowledge and judgment.

Evidence:
The REG vegetation discussion group selected 10-40 days as the best duration of inundation for Lignum seedlings, based on advice provided to them by Jane Roberts (REG E Coordinator).

Confidence level: C

Sources:
SRP and REG vegetation discussion group, expert knowledge and judgment.

Evidence:
This curve reflects the conditions for seed germination or vegetative reproduction of Lignum. Field experience indicates that the preferred conditions for germination of Lignum is in spring or summer following a flood in late winter or spring.

Confidence level: C

Sources:
SRP expert knowledge and judgment.