Casuarina oligodon

Cultivation Details

This is truly a tropical highland species, being found at elevations up to 2,500 metres or sometimes even higher^[1]. It grows in areas where the mean annual rainfall is in the range 1,900 - 2,600 mm, there is a high relative humidity throughout the year with a weak dry season of up to 2 months and the temperatures vary from 11 - 15°c minimum at night to 24 - 30°c maximum during the day^[1]. Prefers a sunny position^[2]. Mostly found in sandy soils along creeks and rivers in the wild, but also grows well in colluvial soils, humic brown clay soils, alluvial and meadow soils^[1]. Prefers a pH in the range 5.5 - 6.5, tolerating 4.5 - 7.5^[2]. For use as fence posts, a rotation length of 12 - 15 years is sufficient with thinnings at age 6 which could be utilized as fuel wood etc^[1]. According to Johnson (1982), the species consists of two subspecies: subsp. Oligodon and subsp. Abbreviata Subsp. Oligodon has longer leaves, up to 1mm long. It is used locally in the eastern highlands of Papua New Guinea^[3] Subsp. Abbreviata has shorter leaves up to 0.5mm long. It is used to restore soil fertility and control soil erosion in the N Baliem valley of Irian Jaya^[3]. This species has a symbiotic relationship with certain soil micro-organisms, these form nodules on the roots of the plants and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby^[1].