Extracts from Seeds Section Report No.1
(CSIRO, Division of Forest Research. Canberra 1979. Unpublished)
E. microtheca has been successfully grown in exotic plantations in dry tropical and subtropical regions. It will tolerate heavy textured, calcareous and gypseous soils and has responded well to irrigation in a number of countries where it has been tried, notably Sudan, Pakistan and Iraq.
The species has a wide distribution in its natural habitat in Australia. The latitudinal range is 14–33°S, the altitudinal range varies from just above sea level to 700 m. Conditions are generally continental with very hot summers and mild winters. The mean maximum temperature of the hottest month is in the range 31–41°C while the mean minimum of the coolest month is 4–14°C. Frost incidence varies from 0 to 18 per year. In the northern parts of the distribution range there is a well developed monsoonal rainfall pattern; elsewhere there is a summer maximum, changing to a more even distribution towards the south-east. The long-term rainfall patterns are often overshadowed by the high variability from year to year. The mean annual rainfall ranges from 120 to 1000 mm.
In spite of the wide range of conditions under which E. microtheca grows naturally, it is estimated that more than 90% of the seed of this species exported from Australia has originated from limited areas in northern New South Wales.
During 1978 and 1979 the CSIRO Division of Forest Research, Canberra, carried out seed collections throughout the natural range of the species. 73 seedlots (grouped into 21 “provenance groups”) have been collected for conservation and evaluation purposes. Part of the seed will be made available for international provenance trials to be established under the auspices of FAO, and coordinated by CSIRO.
Governments and institutes interested in participating in the planned international trials should contact the Forest Resources Division of FAO's Forestry Department (Via delle Terme di Caracalla, 00100 Rome, Italy).
