Acacia mearnsii Growth areas and Yield estimation

A native of southeastern Australia, Acacia mearnsii is an evergreen tree growing to 15 m in height. A. mearnsii has proved to be the most drought resistant of the commercial hardwoods grown in South Africa (Herbert, 1993). Acacia mearnsii requires a MAP of 750 mm in colder areas and 850 mm where it is warmer (Smith, 1998). Ideally, mean annual temperature should be in the range 16 - 19 degree Celsius, but with A. mearnsii being sensitive to warm humid conditions, means of January (i.e. mid-summer) temperatures should be > 22 degree Celsius.

Determinations of climatically optimum growth areas of Acacia Mearnsii have been defined in the ICFR's Forestry Toolbox (Kunz, 2004) by mean annual precipitation (MAP) and mean annual temperature (MAT). Acacia meanrsii: Timber yield and bark yield estimates were dune using Smith's (1994) rule-based approach for estimating mean annual increment (MAIs) of A. mearnsii, and considering only his climatic criteria and not soil or management factors. Results show that areas of highest yields of A. mearnsii timber correspond with those of bark, with significant tracts of the northeast of the Eastern Cape displaying considerable potential for future Acacia mearnsii plantations.