The Hunter River has its source in the Barrington Tops which is the second hightest range in eastern Australia. The Barrington Plateau is a fragile and special place with many plants reaching either the southern or northern limits of their distribution. Vegetation formations on the plateau include swamp, grassland, subalpine woodland, wet and dry sclerophyl forest, dry subtropical rainforest, warm temperate and cool temperate rainforest. Rainfall is high and the soils are primarily of basalt origin.
Because the Barringtons form an 'island' jutting out of the plains, endemic species exist on the plateau. The introduction of weeds, most notably Scotch Broom, Cytisus scoparius, is a major threat to the fragile environment.
Barrington rainforests are special places
Barrington's sub-alpine peat swamps are fragile environments of major significance
Tall open forest with a grassy and sparce shruby understory exist on the high slopes of Tomalla Plateau, and the Liverpool and Mt Royal Ranges.
Extensive clearing
Plains, foothills and even much of the steep high ground, however, have been heavily cleared of many plant communities, leaving no corridors in which animals can move around as conditions change.
Remnant pockets of mixed open eucalypt forest have been preserved on the north-western fringes of the Valley with the declaration of Goulburn River National Park, but woodland originally covering river and creek valleys has been substantially cleared. The Goulburn is a sandstone region with poor sandy soils.
Glennies Creek Dam at an all time low of 30%
Construction of dams in the Hunter Catchment include Glenbawn, Glennies Creek, Lostock and Chichester, with plans under way for Tillegra Dam on the Williams River. Although meeting community needs of flood mitigation, irrigation and domestic and commercial water supply, the change in hydrology has had a vast and detrimental effect upon the river and land systems.
Natural grasslands were probably of only small extent in the Hunter prior to white settlement, but have now been markedly increased by clearing, and many exotic grasses have either been introduced or have invaded the areas.
Brackish marshes, and periodically damp and permanently waterlogged swamps exist in low lying areas associated with the Hunter River estuary and behind the massive Stockton Sand Dunes. Mangroves line parts of the estuary.
A delicate Nodding Greenhood, Pterostylis nutans, gaining a foothold on an unmaintained roadside verge adjacent to a grazing property. Nature just needs to be given an opportunity.
This is just a brief, simplified overview of land systems in the Hunter Catchment and does not touch on fauna. The remnants of valley floor natural vegetation are few and far between, but together with high country ecosystems and patches of coastal plants, there is a base from which to preserve and restore at least some of the environment to provide habitat for native wildlife and invertebrates.
Similar environmental problems stemming from excessive clearing, over-use, inappropriate planning and poor management, exist Australia wide. Future problems associated with anticipated climate change are looming, painting a grim picture for our plants and animals.
All of the Hunter's environments are still under major threat from continued greed, stupid governmental decisions, mismanagement, ignorance and inaction. We all owe much to the land that sustains us, and would do well to consider how we can assist the environment in our backyard and beyond.
Further reading:
Stockton Dunes to Mt Sugarloaf green corridor
Significance of and threat to peat swamps
Vegetation mapping/conservation of Hunter
Coal mine rehabilitation regulation
