Invasion of the Northern Tablelands of New South Wales by 'Nassella trichotoma' (Nees) Hack. Ex Arechav.: Landholder perceptions and seed ecology

Abstract

'Nassella trichotoma' is widespread in southern New South Wales, but its colonisation of the Northern Tablelands is relatively recent and most infestations are currently scattered and consist of a small number of individual plants. Projections based on climatic suitability have revealed considerable scope for the spread of 'N. trichotoma' in the region. Sheep and cattle farming are of great economic and social importance to the Northern Tablelands, and 'N. trichotoma' can cause heavy productivity losses to farmers. The region also encompasses large areas of public land that are vulnerable to 'N. trichotoma' invasion. Because 'N. trichotoma' can produce enormous quantities of seeds which are effectively spread by wind, animal movement, and human activities, it can rapidly dominate the landscape. Knowledge of seed movements and fates is essential for ecosystem restoration and the control of alien plant species in all biomes. The studies described in this thesis are concerned with addressing gaps in our knowledge of the movement and fate of 'N. trichotoma' seeds.