Natural Grassy Vegetation and Native Forbs in Temperate Australia: Structure, Dynamics and Life-Histories

Abstract

This paper describes aspects of the structure, floristics and dynamics of natural grassy vegetation in temperate Australia. The community structure of this vegetation type can be conceptualised using a matrix-interstitium model which may be useful in studies of the dynamics of forb populations and the role of disturbances in grassland management. Disturbance alters the balance between the matrix and interstitial components and is important for herbaceous communities as an agent in changes to, and losses of, native species. Life history characteristics conferring tolerance of disturbance upon native forbs are discussed, and the ruderal nature of the exotic component is suggested as a characteristic leading to the replacement of native forbs by exotic species, where substantial exogenous disturbance occurs. Despite the demonstrated importance of exogenous disturbances in influencing native species diversity and exotic invasions, there is still a poor understanding of the specific and interactive effects of various disturbances and the roles of particular plant traits in determining forb survival. Further research, utilising comparative or functional group approaches, is required to explain responses of natural grassy communities and native forbs. Such studies would provide opportunities for developing ecological theory and improving the management of natural grassy communities and their native forbs.