Rapid internal plant-soil feedbacks lead to alternative stable states in temperate Australian grassy woodlands

Temperate lowland grasslands and grassy woodlands were once dominant across extensive areas of south-eastern Australia. This chapter proposes ecological models to describe the dynamics of native perennial and exotic annual-dominated understorey states in the most mesic of Australia's temperate grasslands and grassy woodlands (550'1000 mm average annual rainfall) ' those where the ground-layer was naturally dominated by the perennial tussock grass Themeda australis (R. Br.) Stapf (syn. T. triandra Forrsk., hereafter Themeda), sometimes mixed with Poa sieberiana Spreng. (hereafter Poa). We begin by summarizing knowledge to date on processes associated with understorey degradation and restoration in Themeda'dominated grasslands and grassy woodlands, then place this knowledge in the context of models of ecosystem dynamics.