Tuesday, 27 February 2007

#9 Hunter Valley Ecology

The Hunter Valley's abundant coal deposits and timber were secured and exploited by early 19th centuary governers. Twenty years later, free settlers arrived and established agricultural and pastural activities. The 21st centuary sees agriculture and mining still thriving in the Hunter, but the timber has long gone, sadly, to the extent of environmental vandalism.

Steep hillsides have been excessively cleared

I concede that our forefathers were pioneers intent on the establishment and survival of a viable settlement in a new land. I recognise their fortitude and value in Australia's history. They were resourceful and industrious. But 200 years on, have current governments and constituents learned from history's mistakes?

Australians depend upon agriculture, industry and a stable economy for their livelihood and lifestyle, but is the vast imbalance between economy versus environment necessary?

A diverse range of rock and soil types, together with a wide variation in altitude and rainfall has produced many vegetation formations within the Hunter Valley.

Coal mines and agriculture stretch to the horizoin.

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

Hunter coal production and export

Salinity and the Hunter


Anonymous said...

Top post Gaye, I reckon it's really good to try and get to learn about the history of the region you live in. I love finding out stuff about the history and settlement of the South Coast of NSW. I also like learning a bit about other parts of the country that I have or haven't seen. I'll have to check out the links you've posted.



Evan said...

Is that a photo of Polblue (sorry about spelling)? I went there recently, very cool place. The wombat holes were everywhere.


Gaye from the Hunter said...

Hello Evan,

yes, the snow picture is of Polblue (you had the spelling correct - people often incorrectly put an 'e' between the 'l' and 'b').

There is a walking track surrounding Polblue Swamp just within the tree line. It's a very rewarding walk that I have not done in some years. I would get much more from the walk now than I did several years ago as I am more aware of, and interested in, the nature of things now.

The peat swamps of the Barrington Plateau are the largest on mainland Australia outside the main peat swamps of the Southern Alps, and are of major environmental significance. But they, too, are under threat from proposed ruby mining in the area. It is disturbing and extremely disheartening for the future of our environment that such a selfish and destructive operation can even get governmental consideration.

You would be aware that there is a camping area overlooking Polblue Swamp. I have had some wonderful times camping there. Mist can roll in at any time of day, and nights can be freezing even in summer. Our camps were always in February.


Gaye from the Hunter said...

hi Peter,

Thank you for your comment.

I deliberated much over this blog entry as I considered there wasn't room to do it justice. But a brief account is better than nothing, and I felt it necessary as my nature observations on my blog all come from this area.

Even though I am a long-term Hunter Valley local, I have much to learn.