Alluvial terraces

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About Alluvial terraces

Before these gardens were developed, Barkers Creek flowed intermittently. At times it was, and remains to this day, often more like a series of interconnected small ponds with linear wetlands edged by areas of damp, fertile soil subject to occasional flooding.

The alluvial terraces alongside it were formed by cyclic erosion and depositing of sediments. They are home to a eucalypt-dominated woodland that provides a canopy for diverse herbs and grasses underneath.

Chief among the eucalypts is the River Red Gum (Eucalyptus camaldulensis) easily identified by its smooth cream bark with grey streaks and flower buds in groups of seven or nine. Other eucalypts found along these terraces include Grey Box (E. microcarpa), Yellow Box (E. melliodora) and Yellow Gum (E. leucoxylon).

Look out, too, for the Buloke (Allocasuarina luehmannii), an ironwood that produces one of the world’s hardest timbers.

Explore the alluvial terraces

Herb Rich Woodland and Creekline Grassy Woodland mosaic

Fire plays a major role in the ecology of the Goldfields area and the Heathy Dry Forest habitat is one which benefits from episodic burns, ideally at intervals of 20 years.

This habitat occupies rocky, poor soils on a variety of hill types from steep slopes to exposed ridge tops and gently undulating hills. Eucalypts dominate creating open canopies up to 20 metres high with Red Stringybark (Eucalyptus macrorhyncha), Red Box (E. polyanthemos), Red Ironbark (E. sideroxylon) and Bundy (E. goniocalyx) dominant.

One of the most notable characteristics of this plant association is the number of shrubs that are native to this habitat with ericoid leaves that have small tough, heather-like foliage. Indeed, a number of these plants are in the Heather family or Ericaceae, a large plant family of c.4250 species in 124 genera. Familiar members of the family include rhododendrons and azaleas, heathers and heaths and cranberry and blueberry.

Amongst ericaceous plants to look out for here is the Native Cranberry (Astroloma humifusum), a prostrate shrub to about 50 cm high and to 1.5 metres across. Its foliage is pine like, narrow and to 1.2cm long and its red tubular flowers, borne from February to June, are followed by berries that become red as they ripen. Described as sickly sweet and apple flavoured, they were favoured by early settlers.

Common Beard Heath (Leucopogon virgatus) is another member of the family, widespread with reduced leaves to 0.5cm wide and forming a sprawling shrub with low upward growth at the end of branches. Daphne Heath (Brachyloma daphnoides) is the third of small heaths in this habitat with leaves to 15 mm long and 3.6 mm wide and most striking when covered by its white tubular flowers from August to December.

Other plants with greatly reduced narrow heathy foliage in this habitat are Honey Pots (Acrotriche serrulata), Pink Bells (Tetratheca ciliata), and to a lesser extent Common Hovea (Hovea heterophylla), a bluish-mauve flowered pea on an erect subshrub to 0.5 metres. This sclerophyllous foliage reduces water loss and assists plants to survive challenging periods of drought.

Examples of Heathy Dry Forest can be found at Muckleford Bushland Reserve and Muckleford Forest.

Low Rises Grassy Woodland

As its name, low rises grassy woodland suggests, this EVC occupies the bottom slopes where the infertile woodlands of the upper slopes meet the surrounding plains. Soils here comprise sedimentary materials and they carry a eucalypt-dominated canopy to 15 metres.

Two eucalypts dominate these woodlands, Grey Box (Eucalyptus microcarpa) and Yellow Gum (E. leucoxylon). Grey Box enjoys a wide distribution from southern Queensland through south-eastern Australia to the Mount Lofty Ranges close to Adelaide. Look for its white flowers from February to June in clusters of seven to eleven and note that it often produces trees with several trunks, rough grey often fibrous bark covering the trunk and the base of larger branches and after this point branches become white.

Yellow Gum also flowers in autumn and winter with colour ranging from white through cream, pink to red. Bark is retained to the base of the tree but upper branches are smooth, coloured from grey to white.

Flowering herbs provide a significant element of the ground layer in this association and from spring through to summer colourful displays of Clustered Everlasting (Chrysocephalum semipapposum), a bright yellow daisy with stems to 40cm, Twining Fringe Lily (Thysanotus patersonii), a plant that weakly climbs through adjacent vegetation to about 0.8 metres, Trailing Speedwell (Veronica plebeia) with stems extending up to a metre and rooting at nodes, producing typical mauve blue speedwell flowers, the short lived Fuzzy New Holland Daisy (Vittadinia cuneata) with typical pale mauve daisy flowers and finally, Shiny Everlasting (Xerochrysum viscosum), a tall growing bright yellow flowered paper daisy notable for its sticky foliage which may trap insects.

Patches of Low Rises Grassy Woodland can be found around Faraday, for example beside the Faraday-Sutton Grange Road.

 

Grassy Dry Forest

Wattles, Acacia spp. are a familiar sight in Australia’s native landscapes, and that is certainly true of the widely distributed Grassy Dry Forest association where they form an under-canopy to the taller growing eucalypts that form an open canopy. Red Stringybark (Eucalyptus macrorhyncha), Red Box (E. polyanthemos), Yellow Box (E. melliodora) and Bundy (E. goniocalyx) may form a canopy to 20 metres.

Wattles most frequently encountered in this association are Hedge Wattle (Acacia paradoxa), so called because with its fiercely prickly stem it was popular as a component of nineteenth century hedges, Gold-dust Wattle (A. acinacea) and Thin Leaf Wattle (A. aculeatissima).

Hedge Wattle may grow to as much as 4 metres forming a small tree canopy and producing masses of its pale creamy yellow flowers through late spring and early summer. Its prickles reduce grazing on the plant by stock but additionally provide protection to small birds, for example Blue Wrens are frequently viewed within its protective foliage.

Gold Dust Wattle has a bushy habit up to 2.5 metres and is densely covered by flowers from July to November and because it is often present in large drifts has significant impact within the woodland shrub layer.

Grasses dominate the ground layer. Supple Spear Grass (Austrostipa mollis) can grow to form dense clumps to 1.2 metres tall. Their seed heads are very fluffy and elegant and take a twisted form covered in hairs but while they are eye-catching, they do cause problems to stock by working their way into skin, eyes of stock and contaminating wool. Grey Tussock Grass (Poa sieberiana) forms a dense tussock with very fine grey green leaves to 500mm and flower spikes that rise to twice this height from spring through summer.

Also grey green are the very tall tussocks of Silvertop Wallaby Grass (Rytidosperma pallidum) which may form a dominant understorey especially in its preferred habitat of shallow stony soils. In flower from November to January, it is worth looking out for its conspicuous orange-red anthers. As conspicuous is the distinctive drooping stalks of spikelets carried by Weeping Grass (Microlaena stipoides) and these contain protein rich, rice-like grains that are now being produced commercially in small quantities.

Grassy Dry Forest can be found within some areas of the Castlemaine Diggings National Heritage Park and, more commonly, west of the Calder Freeway between Harcourt and Ravenswood South

 

Valley Grassy Forest

Higher rainfall, as much as 700-800mm per annum, and more fertile, well-drained soils results in a habitat with indigenous Eucalypts that prefer moist more fertile conditions. Amongst these are tree species that lie at the heart of local honey farming including Yellow Box (Eucalyptus melliodora), Red Box (E. polyanthemos), Candlebark (E. rubida) and Red Stringybark (E. macrorhyncha). Bundy (E. goniocalyx) is another common tree in this association.

Honeys sourced from different eucalypt species vary greatly both in colour and flavour. Yellow Box honey is pale straw in colour, dense and aromatic with a pronounced flavour quite a contrast to the honey produced from Red Box, a very pale honey with a slightly greenish colour. It is dense and aromatic with a hint of oil in its flavour.
Red Stringybark is tawny coloured, firmly textured with a smooth buttery character and strong flavour. Several honey farmers operate in the Castlemaine area; why not seek out some different local honeys to taste?

The shrub layer is a significant component of this association and includes some large growing species including Silver Wattle (Acacia dealbata) that may form a tree to 30 metres.
Short lived, it generally germinates and dominates after fire. However, it is an Australian native plant that has made a significant impact overseas, apart from being a serious weed in many countries, it is an important cut flower especially in southern France where it is called Mimosa.

Drooping Cassinia (Cassinia arcuata) is a member of the daisy family growing to 2 metres. It can become invasive and may form large areas of cover preventing colonisation by other native plant species.
Easily recognised by the curry-like smell of its crushed leaves, it played a significant role on the early goldfields being used by Chinese miners as roofing material for their huts leading to the alternative common name, Chinese Shrub.

Grey Everlasting (Ozothamnus obcordatus) is also a member of the daisy family but more eye catching with bright yellow flowers on an erect 1500mm shrub, the flowers aging to grey. Grey Everlasting may be used as a cut flower.

Valley Grassy Forest can be found in the Castlemaine Diggings National Heritage Park alongside Box-Ironbark Forest on ridges and higher ground.