4. Evergreen Woodlands

Woodlands and Open-woodlands have their canopies clearly separated, with a crown cover < 40% and are variable in height. In the Hunter Valley they form a major part of the vegetation cover. They are highly variable in their structure, and may have sub-canopies and/or shrub layers, or lack these and possess only a grassy ground cover. In the river and creek valleys the original woodland has been substantially cleared.

Distribution: Woodlands occur across most of the Hunter Valley, westwards from the east of Maitland and Cessnock, and as small areas of Sub-alpine Woodland on the Barrington Tops plateau. They merge with the open-forests and rainforests on the higher areas on the southern watershed and the mountainous areas and escarpments of the Barrington Tops, Mt. Royal and Liverpool Ranges and the Wattagan mountains.

Structure: the Woodland communities vary in height from 7 - 30 m, and vary in crown cover from mid-dense at the boundary of the open-forests to very sparse where a thin scattering of trees occurs in grassland with isolatd trees. In the Woodland - Shrubland sub-formation a shrub understory occurs, however, in the other sub-formations this is mostly lacking and is replaced by a grassy ground cover.

Climatic and edaphic factors: Woodlands occur in response to one or more of the environmental factors of poor soils, lower rainfall, exposure and/or extremes of temperature.

The following sub-formations occur:

4A. Eucalyptus Tall Woodland

Extending from the north of the Lower Hunter River and into the southern end of the Mt. Royal Ranges, in gullies to the west of the Barrington Tops plateau, and in sheltered patches on the Liverpool Range, this sub-formation occurs on undulating to mountainous Carboniferous shales and clays; with an altitude varying from 30 - 300 m, and a rainfall of 750 - 1000 mm. The trees range in height from 20 - 30 m tall, shrubs are few, but a grassy ground cover is present. Canopy species include E. propinqua, E. sp.aff. punctata, E. piperita, E. eugenioides, E. teretecornis, E. amplifolia, E. moluceana, broad leafed ironbarks and Corymbia maculata. Scattered Angophora floribunda and Allocasuarina torulosa may be present and Waterhousea floribunda may occur along the streams. Ground covers includes Imperata cylindrica and species of Poa and Paspalum with sedges and bracken fern in the moister areas, grading into Themeda australis and Sporobolus and Dichanthium grasses where drier. Nearer the coast a heath understory tends to be formed. Closed forest of rainforest species may be found in sheltered areas and intrude into the Tall Woodlands as a mesic understory.

Eucalyptus tall woodland north of Raymond Terrace

4B. Eucalyptus Woodland - Shrubland.

This sub-formation occurs on the Triassic sandstone country surrounding the Goulburn River. It merges with the Open Woodland - Grassland on the Merriwa Plateau in the north, and with the Woodland in the east where the sandstones give way to the Permain strata of the valley floor. It is confined to skeletal sandy soils on flat ridge tops and steep gully sides, at an elevation of 200 to 1000 m. The rainfall varies from about 550 to 750 mm. With a canopy of ironbarks and gums about 10 m tall, Callitris endlicheri may occur as scattered individuals or as dense stands within this sub-formation. A sparce to dense sclerophyllous shrub layer 1 - 2 m tall and a patchy ground cover of grasses and herbs is present. In areas of thin soils or of water logging in wet periods the woodland gives way to patches of heath. The ironbarks E. crebra and E. fibrosa, together with the stringybark E. sparsifolia and the gums E. dawsoni and E. punctata are dominant. Other canopy species include E. prominula, E. saligna, E. tereticornis and less commonly E. nubila, E. sideroxylon, E. caleyi, E. rossi and the mallee E.dwyeri. Corymbia eximia occurs in the south-east and is replaced by C. trachyphloia westwards. Angophora floribunda occurs at lower levels in the valleys. Shrubs are numerous and varied, while the ground cover is sparse.

Woodland-shrubland with ironbark dominated woodland-shrubland in the Pokolbin - Broke area. On more protected sites a dense understory often occurs. Further west in the Goulburn valley, with decreasing rainfall the tree hight decreases and acacias may be common, as here in Dingo Ck.

Pokolbin - Broke

Dingo Ck

This sub-formation also includes a number of different communites, e.g. Acacia doratoxylon on a dry ridge top, with little or no understory, and stands of mallee (E. castrensis) in woodland-shrubland near Broke.

Acacia doratoxylon

Mallee

4C. Eucalyptus Woodland

This Woodland occurs in the central valley, north-west from near Maitland and along the floodplains and terraces of the major rivers and streams. On flat to mostly undulating and low hilly country, the substrate includes Permain clays and shales, granites, Tertiary basalts and Quaternary sands and alluvium. The altitude varies from about 30 m to 900 m, and the rainfall from about 1000 mm near the coast to about 550 in the west. The trees range in height up to about 10 m tall, and there may be occasional scattered shrubs or low heath (mostly in the far western part) and a grassy ground cover is usually present. In the eastern parts the dominant trees are: E. moluccana, E. tereticornis, E. paniculata, E. fibrosa and C. maculata. Near the centre of the sub-formation E. tereticornis and C. maculata are replaced by E. blakelyi, E. dawsonii and E. punctata, particularly where it joins the Woodland - Shrubland. E. moluccana and E. crebra often form an exclusive alliance. Further inland, E. moluccana grades into E. albans and E. microcarpa, and E. crebra is joined by E. fibrosa, E. nubila and E. caleyi (near Murrumbo). E. melliodora becomes increasingly frequent from about the centre of the range. In the east the ground cover is composed of Sporobulus indicus var. capensis, Paspalum dilatatum, Themeda australis, Aristida species and Cynodon dactylon. Dichanthium sericeum occurs throughout the sub-formation except on sandy soils and dry areas where it is rare, whereas Aristida species are common across the whole range. Notodanthonia linkii is most common in the western half of the range where Austrostipa setacea also occurs.The greater part of this woodland has been thinned or cleared, with remnants of the former woodland existing only in scattered pockets.

Gum-Ironbark-Box Woodland with a grassy ground cover in the central valley

On the sands by the Wollombi Brook near Warkworth an unusual community, characterised by Banksia integrifolia and Melaleuca species exists. Communities of mixed non-Eucalyptus species (related to the rainforests species near the coast) frequently occur on scree slopes and non-eucalypt vine thicket shrubs may form small communities.

Wollombi Brook

Scree Slope

4D. Eucalyptus Open-Woodland

Extending from the slopes and ridges of the Liverpool and Mt Royal Ranges towards the southern edge of the Merriwa Plateau and into the Upper Hunter Valley, this Open-woodland occurs on undulating to mountainous landforms of Devonian limestones and shales and Carboniferous shales and clays, Tertiary basalts and Quaternary alluvium. The altitude ranges from 100 m. to 1200 m. and the rainfall from 550 to1000 mm. It is an open-woodland of Eucalyptus and Angophora trees about 10 m tall, mostly with a ground cover of grasses with patches of shrub understory. In the sheltered areas on the Liverpool and Mt. Royal Ranges patches of non-sclerophyll closed-forest occur. Angophora floribunda, E. melliodora, E. laevopinea (confined mostly to the higher and cooler aspects), E. moluccana and E. blakelyi (at lower altitudes and lower rainfall) are the main tree species. In the upper reaches of the valley, E. moluccana grades into E. albens. Shrubs of genera Rubus, Acacia, Bursaria, Cassinia, Rapanea and Exocarpus amongst others occur mostly at the higher altitudes. Species of Poa, Pteridium and Trifolium and Themeda australis form a ground cover and are most common in the cooler parts of the sub-formation, while species of Dichanthium, Aristida, Eragrostis and Chloris and some Austrostipa setacea are common in the drier parts.

In the protected parts on the Liverpool Ra. the woodland merges with close-forest "brush"

In more exposed parts on the Liverpool Ra. the woodland is more open

E. albens open-woodland in the far west of the Valley on the Dividing Ra.

In the Upper Hunter near Timor stands of Xanthorrhoea glauca occur on the limey soils associated with the Timor Devonian limestones. On remnant basalt caps in the Goulburn valley open-woodland is also found, such as on Mt Dangar and above the Goulburn R.

Mt Dangar

Goulburn R.

4E. Eucalyptus Open-woodland and Grassland.

This Open-woodland - Grassland occurs on the undulating lowlands of the rivers and creeks of the Merriwa plateau, and in patches on the undulating country bordering the flood plain along the Upper Hunter River, and on the Wybong and Sandy Creeks and Dartbrook floodplains. The substrates are of Carboniferous and Permian clays and shales, Tertiary basalts and Quaternary alluvium. The altitude varies from 200 - 500 m and the rainfall is about 550 mm. This sub-formation is more sparse than the above Open-woodland and has scattered trees up to 10 m tall with a grassy ground cover. Shrubs are generally absent. On undulating country E. albens tends to occur, while E. blakelyi and E. melliodora along with Angophora floribunda tend to occupy the low lying areas and Brachychiton populneus is scattered throughout the formation. Ironbarks are absent. Grass cover is predominantly species of Austrostipa, Dichanthium, Chloris and Notodanthonia linkii and Aristida ramosa.

Open-woodland - grassland in the river valleys on the Merriwa plateau

4F. Sub-alpine Woodland.

The Sub-alpine Woodland occurs above the Cool Temperate Closed-forest and Eucalyptus Tall Woodland on the higher and exposed hills of the Barrington Tops - Tubbrabucca plateau, at an altitude of 1350 to above 1500 m. Here the substrate is Tertiary basalt and the rainfall is from 750 - 1500 mm. The dominant tree is E. pauciflora, about 15 m tall, with E. dalrympleana and E. stellulata as associates. The canopy cover is mostly sparse but in places the canopies may touch. A shrub understory is sometimes present, and where this occurs, Acacia dealbata subsp. subalpina is the common shrub species along with species of Tasmannia and Dicksonia antarctica. Mostly a tussock grassy ground cover of Poa labillardierii is present. In sheltered areas, stunted Nothofagus moorei and Elaeocarpus holopetalus closed-forest may occur.

Sub-alpine woodland of Snow Gums with a grassy ground cover and mixed understory on the Barrington plateau