The conservation of original vegetation remnants in the Midlands, Tasmania

Abstract

Following 180 yr of agricultural settlement, the Midlands area of Tasmania has been drastically transformed and 83% of the original area of native vegetation has been replaced. By comparing information from 2 recent intensive floristic surveys with historical botanical records, it was determined that 11.8% of the higher plant flora has vanished. With current rates of change and land tenure, it is probable that further extinctions will occur. Grazing increased significantly native species richness on loams and clays; the same relationship was not evident on sandy soils. Management of grassy remnants should include regular burning and/or grazing as a means of intermittently depleting the grass sward. Many herbaceous exotics are habitat specific; their passive spread is not an immediate threat to native vegetation on well-drained land. The long-term viability of native vegetation may, however, necessitate implementation of simple management programs designed to maintain native species diversity and to minimise the spread of the more vigorous woody exotics. -Authors