Eucalypts of the City of Whittlesea PROTECTING BIODIVERSITY ON PRIVATE LAND SERIES 1 Eucalypts of the City of Whittlesea Eighteen species of eucalypts are indigenous to the City of Whittlesea, occurring across the municipality where they are the dominant trees of the woodland and forest communities. Eucalypts are also commonly found along rural roadsides, river corridors and as isolated paddock trees in largely cleared agricultural areas. Candlebark on roadside, Whittlesea MW EUCALYPTS – DISTINCTLY • The world’s tallest flowering plant AUSTRALIAN Mountain Ash Eucalyptus regnans, is recorded in the damp forests in • There are approximately 700 the far north-east of the municipality. species in Australia, 100 of which • The flowers are pollinated by are indigenous to Victoria. a range of animals including • Mature River Red Gums in an open microbats, mammals, insects as grassy environment are recognised well as being wind pollinated. as one of the most important • Hollows form in the trunks and visual features of Whittlesea’s branches of large eucalypts, local landscape. They are afforded providing valuable habitat for local special protection, being both wildlife. Trees typically need to be culturally and environmentally 80-100 years old before they are significant. large enough to be able to form hollows. 2 RIVER RED GUMS – AN ICONIC SPECIES IN WHITTLESEA The majestic River Red Gum Eucalyptus camaldulensis with their massive trunk, gnarled appearance, heavy twisting branches and broad CoW open canopy are an important River Red Gums in Woodstock natural feature of the Whittlesea landscape. Many large old trees are very large and provide natural habitat estimated to be 200-800 years old for many species including possums, and have significant local heritage and gliders, small marsupials, and environmental values. microbats as well as parrots, lorikeets Mature trees are particularly important and cockatoos to name a few. in providing habitat for local wildlife The City of Whittlesea’s River Red through the formation of hollows in the Gum Protection Policy recognises trunk and branches. When a branch the intrinsic value of these trees in falls off, it creates a wound that allows providing character and identity in the air and water in, which over time urban and rural areas of Whittlesea. begins to rot and may eventually form They are afforded special protection in a hollow. Due to the sheer size of River the Whittlesea Planning Scheme. Red Gums, the hollows formed can be • Hollows can be used by bees with many types of honey being collected from eucalypts, both by Aboriginal communities and apiarists. • Eucalypts provided many uses for Aboriginal communities, with bark used for making canoes and shields and the wood for weapons. • Southern Blue Gum Eucalyptus globulus, which is not indigenous to the Whittlesea area, is the primary source of eucalyptus oil production around the world. Nankeen Kestrel chick using hollow in mature River Red Gum tree JB 3 ABORIGINAL USES OF EUCALYPTS Eucalypts are one of the most versatile and widely used of all plants by Aboriginal Australians. The wood was often used to make weapons, shields and spear throwers as well as musical instruments such as knocking sticks and didgeridoos. The fibrous bark of stringybark trees was used to make coarse string for bags and fishing nets. The oils in some leaves were used to treat colds and chest complaints and the sap was used to DF Typical smooth barked “gum” tree; Mountain Ash EUCALYPT REGENERATION – RESPONSE TO FIRES AND FLOODS GUM TREES AND EUCALYPTS Fire and flood are important features of the Australian landscape and have Eucalyptus is the scientific genus been for thousands of years. For many for this iconic group of Australian Australian plants, including eucalypts, trees, which are commonly referred these events present a unique to as “eucalypts” opportunity for the plants to reproduce. The term “gum tree” is widely used Many species of eucalypt, particularly to refer to eucalypts however, for the thinner barked “gums” can be identification purposes, the term killed by fire of even a moderate “gum” generally refers to the group intensity. However, the passing fire of eucalypts that have smooth will create the perfect environment for bark, which peels in large flakes or the germination of seed in the soil by ribbons. creating a nutrient rich ash bed with All “gums” are eucalypts but not all reduced competition and plenty of light. eucalypts are “gums”. Thicker barked eucalypts can often survive all but the most intense fires and although they may be burnt, often 4 seal burns and mixed with water to treat diarrhoea. Some individual trees are particularly significant to Aboriginal Australians: Scarred Trees: Trees that bear a scar where the bark has been cut, peeled off and shaped over fires and made into canoes or used for shelter. Maternity / Birthing Tree: Very large trees that have been hollowed out at the base could have been used by local Aboriginal Communities for giving birth and also for shelter. Mature River Red Gum scar tree MW Some eucalypts resprout from an underground root mass called a lignotuber in areas where plants have adapted to a frequent fire regime. These are called the mallee eucalypts and are usually short multi-stemmed trees. As their name suggests they are generally found in the Mallee region and not in the City of Whittlesea. Flood events can also provide important cues for some species, particularly River Red Gums, as periods of inundation or sustained JB heavy rains create the necessary soil moisture levels to promote natural Epicormic growth on Eucalypt following Black regeneration. Along flood plains, mass Saturday. germination can often be observed following the recession of winter/ re-sprout from buds under the bark spring flood waters. along branches and the trunk, called epicormic buds. 5 leaves can sometimes be used as a IDENTIFYING key identifying feature when the plant FEATURES OF THE is small and is too young to have any EUCALYPTS buds or fruit and the bark has not Identifying eucalypts can be difficult. fully developed. Juvenile leaves also There is often considerable variation appear on epicormic shoots of mature within individual species, so a trees from the trunk and branches combination of features (leaves, fruits following fire or if the tree is otherwise and bark) may be required to identify damaged. Juvenile leaves tend to your plant. be opposite and sessile (stalkless), whereas adult leaves tend to be Bark stalked and alternate in arrangement. The bark of eucalypts is highly variable and an important identifying Buds and Fruit feature. The bark can range from The number of buds in a cluster can typical thin, smooth gum-type bark vary even within a species so use the which is shed annually in large flakes number as a guide only and combine or ribbons, to the persistent, rough, with other characteristics to identify deeply fissured bark of the ironbarks. your species. Leaves As the bud matures, the top drops off to reveal the flower. Following The leaves of eucalypts go through fertilisation, the bud expands to a marked transformation from the become a woody capsule called juvenile to mature plant. The juvenile Figure 1: Eucalypt leaf shapes Eliptic falcate lanceolate linear oblique ovate round 6 the fruit, which encloses a number The features of the fruit, particularly of seeds. Drying out of the fruit its shape, are extremely useful in (especially after fire) causes the identifying the species. valves to open and release the seed. Figure 2: Eucalypt buds – components and shape-types cap tube pointed cap conical cap club diamond ovoid elongated tube elongated cap Figure 3: Eucalypt fruits – components and shape types valves disk Protruding valves Inserted valves and disk and disk ball barrel barrel cup cone ovoid pear (constricted) 7 Glossary IDENTIFYING THE Refer to Figures 1 – 3 for diagrams EUCALYPTS OF illustrating the components and shapes for WHITTLESEA buds, fruits and leaves. To assist with identification, Alternate: Leaves borne singly at different this booklet groups species levels along a stem (c.f. opposite) together based on similar bark Axil: The angle between the leaf and the characteristics of mature trees in stem the first instance. Once you have determined which bark group Cap: The top of a bud that falls off when most closely matches your tree the flowers open (see Figure 2) in question, read the descriptions Elliptic: Oval shaped, often with pointed and observe the photos for each ends (see Figure 1) characteristic to try and identify Falcate: Curved like the blade of a sickle the species. (see Figure 1) For some species the bark can Fissured: Cracks or splits in the outer be quite variable and it might fit bark of a tree, usually in a vertical into more than one of the groups orientation - in this case you may have to Lanceolate: Lance-shaped, broader work through the different groups toward the base and tapering to a point to try and work out your species. (see Figure 1) Note: Some eucalypts are also Linear: Very narrow in relation to its known to readily hybridise, length, usually with parallel sides (see making identification more Figure 1) difficult. Plants may have Oblique: When the two sides of the leaf features of two species, for base meet at different points on the example the leaf type and shape midrib or petiole (see Figure 1) of one species and the fruits and buds of another. Opposite: Leaves borne at the same level but on opposite sides of the stem Note: Many eucalypts have (c.f. alternate) been planted along street Ovate: Egg-shaped with the broadest part scapes and have been used towards the stalk/stem (see Figure 1) for revegetation. Some older revegetation projects may not Round: Circular (see Figure 1) have used plants local to the Sessile: Lacking a stalk Whittlesea area so there may be Tube: The base of the bud which turns some obscure species that you into the fruit after fertilisation (see come across that do not fit any Figure 2) of the descriptions.