From the beginning of settlement, sheep were seen as the most important component of the colonial economy. They also proved to be the most influential element in the devastation of the natural environment. From the port towns of Hobart and Launceston their bush runs extended across the landscape, often over grazing the lush native grasslands, created by aboriginal firing practises. This denuded them of their wildflowers and degraded their native grasses. These disturbed native grasslands and woodlands, proved extremely susceptible to invasion by the new introduced flora that resided in the estate gardens, hedges and exotic pastures.
However sheep cannot be blamed solely for this weed invasion. Colonists were directed, once they received their land grants, to clear and cultivate at full speed. The trees and understorey vanished destroying the habitat and sanctuary for the native fauna in the process.
Many settlers were preoccupied with making an English landscape by clearing the forest with reckless abandon. To some extent native trees were replaced by exotic trees, which introduced further opportunities for future "weed trees" such as; "Maple" Acer pseudoplatanus, "Black Locust" Robinia pseudoacacia, "Poplar" Populus sp., "Ash", Fraxinus excelsior, "Willow", Salix sp. and "Hawthorn" Crataegus monogynus, to extend their range. In 1829, Augustus Princep reported in his Journal, that the jungle of thick bush along the road between Hobart and Newtown was now completely cleared of all trees, reflecting the existing situation in proximity to Hobart town.
This clearing was compounded by the fact that the trees were proving to be a valuable resource. They were being used for firewood, timber for building, shingles and shipbuilding, and wattle for tanning leather.
George Hobler wrote in his diary in 1829, that the "Black Wattle", Acacia mearnsii was in huge demand from the English tanning industry for its wattle bark. This in turn was causing massive removal of the wattle tree and damage to the surrounding forest species. Exotic flora was again provided with another window of opportunity to infiltrate in the compromised native communities.