A Study of the Fate of Seedlings Growing on Sandy Red Earths in the Charleville District, Queensland

Abstract

A field study was1 conducted at two sites in south-western Queensland into the fate of over 2100 seedlings which emerged in response to rain falling between October 1969 and April 1972 from sandy red earths that originally supported mulga (Acacia aneura) scrubs. The four most numerous taxa were the grasses Aristida and Digitaria, a group of herbaceous Malvaceae and the shrub Eremophila gilesii. Of the emerging seedlings more than 50% died within 14 days and only 7 % flowered. Over 60% of those plants which flowered took longer than 4 months to reach this stage. Wilting was common, 31 % of plants which flowered having wilted previously, although only 4% of these wilted before 30 days of age.

Of the seedlings which exhibited secondary growth, e.g, tillering in grasses, only 49 % eventually flowered. Only 33% of tillered grasses flowered, the perennials in general tillering and flowering later than the annual grasses. Insects, particularly grasshoppers, were a continual problem, over 28 % of seedlings which survived 30 days being damaged by them.