But this isn't the case everywhere across the range of native grasslands in southern Australia. In the more xeric areas (300-400 mm rainfall), native grasslands are still a feature of the landscape, e.g. the Riverine Plains grasslands of northern Victoria. In part, they survive because agricultural use has been of lower intensity, i.e. sheep grazing has been rather conservative and cropping largely unsuccessful. Additionally, perennial exotic grasses are absent (it's too dry) meaning that the integrity (if not composition) of the native grasslands remains largely intact.
For many years, however, the extent of xeric grasslands in southern Australia was overlooked. The conservation imperative first focused on the mesic C4 grasslands on volcanic soils near Melbourne. Xeric grasslands protection was so poor that by the early 1990s, none of the ecosystem was under conservation management.
Thankfully, this has changed - reservation has increased the area of xeric native grasslands in the National Reserve System from zero hectares in 1995 to an estate now in excess of 10 000 ha. This is a remarkable achievement. This increase has been driven, to a large extent, by government land purchase coupled with private conservation agreements. I, for one, have much greater hope that grasslands in these areas can now be conserved in a meaningful way. The challenge now will be to manage them for their biodiversity and ecosystem processes in the face of a changing climate. Understanding the factors that affect the resilience of these systems to change is a pressing research need.
I recently undertook a tour of some of the new conservation reserves protecting grasslands in northern Victoria and I thought I'd share some of these sites with you. While it's mid-winter here (and not the best time to see the diversity and colour of grasslands), I was impressed by the scale of grassland protection being achieved.
|In some areas, it is obvious that overgrazing in the past has|
led to dramatic soil loss. Large, bare scalds result and there is almost
no recolonization by native species from the surrounding grassland.