Regeneration of native plants on abandoned Mallee farmland in south-eastern Australia

Abstract

The vegetation is described on 12 sites from which mallee vegetation has been cleared and which have since been left undisturbed for periods from 1 to 39 years. Comparisons are made with three virgin stands. Early regeneration in paddocks is dominated by annual herbs but shrubs, especially Acacia, Dodonaea and Cassia. usually become dominant. Wind-dispersed or soil-stored seed allows species to occur after severe site disturbance. Rabbit grazing effects on native plants appear not to bc catastrophic at present. The only site studied in detail where mallee eucalypt seedlings were seen was a!ong a firebreak recently cleared through virgin mallee. Minimal competition from older eucalypts is an important factor for eucalypt beedllng establishment. No eucalypt seedlings were found more than 10 m from a seed source. Such regeneration is facilitated by seed release following fire or felling. Competition from shrubs and lack of an adequate seed source may well mean that eucalypts will no longer dominate the climax vegetation in many areas. their place being taken by formerly seral species of Acacia and Dodonuea. The findings have features of both the tolerance and inhibition models of succession of Connell and Slatyer.