Issuu on Google+

[

Coastal Plant Biomes of Northern

New South Wales

A look at the diversity of the Australian

]

Landscape


[

Coastal Plant Biomes of Northern

New South Wales K yl e LA

]

Rader 490

Spring

2010

A look at the diversity of the Australian

Landscape


[

]

Table of Contents

3

Plant Biomes Introduction Coastal Sand Dunes Coastal Heath Subtropical Rainforest

4-5 6-9 10-11 12-13

Plant Profiles Introduction Banksia Aemula Banksia integrifolia Pandanus tectorius Melaleuca quinquenerva Melaleuca quinquenerva Archontophoenix cunninghamiana Acronychia imperforata

14-15 16-17 18-19 20-21 22-23 24-25 26-27 28-29

Invasive Plants Introduction Asparagus aethiopicus Ipomoea cairica Senna pendula Lantana camara Chrysanthemoides monilifera

30-31 32 33 34 35 36


[

Plant Biomes

]


5 Plant

B i o m e s: a survey of the diverse

plant biomes in coastal areas of New South Wales

The coastal area of northern New South Wales features a wide range of plant biomes. From pioneering sand dune populations to majestic old rainforest, the area consists of a vast array of environments. The following pages feature three of the most prominent biomes in the region.

[

Survival of Australian plant communities is dependent on maintaining balance and harmony

]


[

Plant Biomes

]

Coastal Sand Dunes


7 What are coastal sand dunes? Coastal sand dunes are the first line of defense against the ocean’s fury. They prevent sand erosion and provide a buffer for inland plant ecosystems. Dunal vegetation consists of the plant material that covers the dune system along the coast. This vegetation grows in distinct bands. This is because certain plants adapt to the changing environmental conditions that arise at various distances from sea.

Photo: Erika Tishner

Coastal vegetation is always changing states. Pioneer species first begin to colonize the bare sand dunes or foredunes. This consists of salt tolerant grasses, groundcovers, and creepers such as Spinifex sericeus (spinifex), Ipomea pes-caprae (goatsfoot), Hibbertia scandens (guinea flower), and Carpobrotus spp (pig face). Farther inland, plants such as Casuarina equisetifolia (coastal sheoaks) form a band that is noticeably taller than the foredune vegetation. Behind this band is the Banksia communities, mangroves, and salt marshes. Particularly in northern New South Wales, the primary vegetation consists of the Banksia integrifolia (coastal banksias), Pandanus tectorius (screw palm), and Cupaniopsis anacardioides (tuckeroo). Originally, New South Wales was almost entirely covered in rainforest. Pockets of littoral rainforest still exist along the coastline. If left undisturbed, the dunal vegetation will eventually transform into rainforest. However, human activity has altered this landscape and will most likely have a major role its transformation.


[

Plant Biomes

]

Coastal Sand Dunes Coastal Sand Dunes: A Fragile System Sand dunes are a very fragile system. Sand is poor in nutrients, and the plants are subject to extreme/harsh environments. The dunes are constantly battered by salt spray, wind, waves, and recently human activity. Natural forces such as rogue waves, harsh storms, high tides, and cyclones can alter the dune ecosystem. From these forces, the dunes will recover. However, human activity has a more detrimental effect on this system. Clearing of vegetation and introduction of invasive plants threaten this fragile environment.

healthy Banksia Community Above features a healthy dune community featuring coastal banksias. A variety of native groundcovers, grasses, and perennials cover the dune. Notice the fullness of the leaves of the banksia canopy. The banksias and native groundcovers grow in harmony of one another in this delicate cycle.

Unhealthy Banksia Community Above shows an unhealthy banksia community. Take notice of the bare canopy of the coastal banksias. This allows invasive grasses and vines to take over. These grasses in turn overuse the nutrients in the sand and choke out the banksias, which at this particular location, are dying. Once one part of the harmonious cycle is interrupted, the whole system is thrown out of balance.


9 Coastal Sand Dunes: Environmental Threats Natural forces can also negatively affect the coastal sand dunes. As shown in the picture to the left, banksias have a shallow root system that makes them susceptible to being blown over by strong winds. Once a banskia

falls, an opening is made for invasive plants to take ground. Patches of invasive plants surrounding a fallen banskia are common along the northern coast of New South Wales. Furthermore, the primary dunes have eroded away. The foredunes are supposed to be free of vegetation which allows the dune to move forward and back as needed. However, the foredune is nonexistent on most beaches of northern NSW. What is left is a steep bank on which the waves wash against during high tides. This is seen in the photo above. This erosion is caused by human influence on the landscape, and will take time and an extensive amount of work to repair.


[

Plant Biomes

]

Coastal Heath


11 What is a coastal heath? A coastal heath is an environment made up of mostly shrubs and groundcovers growing in nutrient-poor soils. Coastal heathlands are found coastal lowland areas ranging from Queensland to Tasmania. Vegetation ranges in height from 30 cm to 2 m. Plant spacing ranges from dense (70-100% cover) to mid-dense (30-70%). Grasses are rare, but some such as the Poaceae family can be

present. Many plant families are co-dominant in the heathland. These include Epacridaceae (tree heath), Fabaceae (wattles), Myrtaceae (tea trees), and Proteaceae (banksias). Much like the prairies of the Midwest of the United States, fire plays a major role in this ecosystem. Plants regenerate either from deep root systems or from seeds. Due to the poor soil quality, coastal heaths are usually free of weeds. Also, due to the easy clearing of coastal heathlands, much of this landscape was once cleared for sand mining. Today’s threat is clearing for housing development. With none to very few trees present, it is very easy to develop the coastal heathland. Also, the terrain on which these are usually found is normally flat. This combination few trees to cut and flat ground in conjunction with the nutrient poor soil creates an ideal landscape for development. However, this biome is home to many species of birds. It is important to protect the coastal heaths as they are a critical factor in the coastal environment.


[

]

Plant Biomes S u b t r o p i c a l R a i n f o r e s t


13 What is a subtropical rainforest? Most of New South Wales was once covered in dense rainforest. Much of the coastal areas featured subtropical and littoral categories of rainforests. A Sub-tropical rainforest is generally located in areas from sea level to around 900 meters in elevation. Rainfall

is more than 1300 mm annually. The soil consists of fertile eutrophic parent rocks such as basalt and rich shales. The littoral rainforests is very similar to the subtropical rainforest but only occurs within about 2 kilometers of the sea. It consists of plants that can withstand the salt sprays and strong coastal conditions of the eastern coast. The littoral rainforest grows in nutrient filled sand, and also in slates and basalt soil of the subtropical rainforest. Subtropical rainforests consist of a multi layered canopy of10-60 tree species. Prominent species include the ficus (fig), Argyrodendron (booyongs), and the Syzygium (lilly pillie) families. Some easily identifiable specimens include the Ficus watkinsiana (strangler fig) and the Archontophoenix cunninghamiana (bangalow palm). The understory features climbing vines, ferns, and large leafed herbs. Some communities of littoral rainforest also feature strands of conifers. These strands include species such as Araucaria cunninghamii (hoop pine) and Podocarpus elatus (plum pine).


[

Plant Profile

]

Family Scientific Name Common Name Height Habit Location

Characteristics


15 Plant

P r o f i l e: An indepth look at key

plants in coastal areas of New South Wales

The coastal biomes of New South Wales feature unique and diverse plant specimens. Due to the harsh coastal conditions and poor soils, these plants have developed unique features to adapt to these conditions. The following pages showcase a selection of notable plants of the various coastal biomes of northern New South Wales.

[

Australian plants each possess a ruggedness and adaptability reminiscent of the unforgiving country

]


[

Plant Profile

]

Rutaceae Family Scientific Name Acronychia imperforata Common Name Beach Acronychia Height 15 m Habit Shrub or small tree Location Seacoast, coastal dunes

Characteristics The beach acronychia is salt-tolerant and drought hardy tree. It is also referred to as a logan apple or Fraser Island apple. The name Acronychia comes from the greek words across (end/edge) and onyx (claw). This refers to the unique leaf shape. The beach acronychia is a pioneer species and can also be used for dune stabilization. It can also be found in littoral rainforests.


17

Photo: Flickr/ Stephanie Haslam

Leaves of the beach acronychia are opposite, elliptic in shape, and leather like in feel. They are 3-12.5 cm long and 1.6-5.5 cm wide. A unique feature of the tree is the tip of the leaf, which is indented. The veins on the leaves are prominent.

The branchlets of the beach acronychia feature pale lenticels. The bark is grey with creamy spots, similar to the grey birch. The beach acronychia is a single stemmed tree, and can be upright in habit, or can be spreading.

Flowers bloom from summer to autumn, and are cream or yellow in color. The fruit is an orange berry 7-12 mm in diameter. The fruits occur in winter or early spring. They are edible, though sour, and can be made into a jam.


[

Plant Profile

]

Arecaceae Family Scientific Name Archontophoenix cunninghamiana Common Name Bangalow Palm Height 25 m Habit Palm Location Sub-tropical, Littoral, and lowland Rainforest

Characteristics Archontophoenix cunninghamiana is a tall palm that dots the rainforests of New South Wales. Archontophoenix derives from archontos (a chieftain) and phoenix (date). Cunninghamiana comes from the Australian explorer and plant collector Alan Cunningham. It is a notable tree of the subtropical rainforests, growing in strands underneath the towering hardwood trees. It also has many uses by the aboriginal population in the area.


19

Photo: Flickr/ Tommy G.

The leaves of the bangalow palm consist of large fronds. These drop rather regularly, and it is common to see a large frond fall walking through the rainforest. The indigenous Australians have many uses for the leaves of the bangalow palm. Containers are made from old leaf sheathes. Also, the curved leaf base is used to collect grubs. The growing bud of new leaves can be eaten either raw or cooked.

The trunk of the Archontophoe Cunninghamania is straight and slender. The bark forms rings that can be seen in the photo above. This light blue-grey continues up the point at which the flowers and fruit are born. From this point the trunk becomes smooth and green, terminating in the growing bud at the top. Cutting or damaging the growing bud will kill the palm.

The flowers of the Archontophoenix cunninghamania are light blue to pink in color. They are monoecious, meaning the flowers are either male or female with both kinds occurring on the same plant. The fruit is a drupe. It is red in color, round, and is 10-15 mm in diameter. The fruits can be seen in the image above.


[

Plant Profile

]

Proteaceae

Family

Scientific Name Banksia aemula Common Name Wallum Banksia Height Up to 3 m Habit Shrub Location Coastal heath Areas

Characteristics There are 78 species of banksia, all of which occur in Australia. Most are native to the south western part of the continent, but a few exist along the New South Wales coastline. Banskia comes from Joseph Banks, a botanist on the voyage that discovered the east coast of Australia. Banksias occur in most environments, from the tropics to the desert areas. The wallum banskia occurs in NSW in the coastal heath environment. It is a dense shrub that grows in sandy soils.


21

The flowers of the Banksia aemula are particularly showy. The inflorescences are a green-yellow color. They reach lengths of 20 cm and are 8 cm in width. The wallum banksia flowers in autumn (March to June). The leaves of the wallum are 3-22 cm long by 2 cm wide. The margins are serrate.

Old cones feature persistent flowers which turn to a brown or grey color. This can be seen in the image above. The image on the previous page shows the various stages of the wallum banksia’s cones. This variation in color is an interesting characteristic of the banksia aemula.

Wallum banksias in coastal populations normally stay small. The specimens of the coastal heath pictured above are around .5-1 m tall. The thick trunks are brown grey in color, gnarled, and warty looking. The trunk is also features an orange tinge.


[

Plant Profile

]

Proteaceae

Family

Scientific Name Banksia integrifolia Common Name Coast Banksia Height Up to 10 15 m Habit Small Tree Tree Location Coastal sand dune dunes Areas of NSW

Characteristics Banksia integrifolia is the best known of the eastern banksias. It is primarily found along the sandy dunes of the eastern coastline. The coast banksia is the iconic plant of the coastal sand dunes. However, it can occur farther inland, but is usually limited to a small shrublike form. Due to its habitat, the banksia usually takes on a bent, twisted, or gnarly form. This is in response to the harsh coastal conditions that it must tolerate. The coast banksia is a soft wood that is sometimes used in woodwork. It is also used as a honey tree.


23

The flower of the Banskia integrifolia is a pale yellow in color. The flowers are very small in size. Hundreds of them form around an inflorescence that is around 6-12 cm in length by 5 cm in diameter. This inflorescence is cylindrical in shape and is one of the key identifying features of the banksia.

After the flowers have fallen, a woody cone is left where the inflorescence once stood. This cone contains the seeds of the banksia in small follicles. Two seeds are within each follicle. The seeds have a papery wing which allows them to be spread by the wind. Most banksias require fire to open the follicles in order for the seeds to be distributed. However, some seed cones do open on their own without the aid of fire.

The leaves of the coast banksia are 7-14 cm long by 1 cm across. They are obovate in shape, have a rounded tip, and taper to a short base. The undersides of the leaves are white, which creates a nice effect when blown in the wind.


[

Plant Profile

]

Myrtaceae Family Scientific Name Melaleuca quinquenerva Common Name Broad-leaved Paperbark Height 25 m Habit small to medium Tree Location Along waterways and swamps

Characteristics Melaleuca quinquenervia is a medium tree that grows along water edges in New South Wales. The name Melaleuca comes from the Greek words melas (black) and leukos (white), which refer to the marks on the trunks due to fire. The name quinquenervia comes from the Latin quinque (five) and nervus (nerve) which refer to the leaf vein pattern. The tree is similar to the river birch in its tolerance of water and peeling bark. It is mainly seen growing in pure stands, and is also dry tolerant.


25

The paperbark can reach heights of 25 m with a spread of 5-10 m. Leaves are alternate, a dull green, and are 5-10 cm long by about 2.5 cm wide. They are ovate to obovate, with entire margins. The leaves of the paperbark are also leather in feeling. The leaves stay hard after dying, and create a dense mat under the tree.

The bark is the most distinguishing feature of the paperbark. As the picture above shows, it has a light and airy look to it. It grows in a multi-layered papery habit. It then peels off in sheets, much like the Betula nigra. Since the bark can be torn off in large sheets, it is sometimes used locally as a natural lining for hanging baskets.

Flowers of the paperbark occur from September to March, which is spring to early autumn in Australia. They are cream or white in color, and are arranged in cylindrical brushes 4-8 cm long and 2-3 cm wide. They emerge from the end of each branchlets. After the flowers subside, small, woody seed pods are left which release tiny seeds annually.


[

Plant Profile

]

Epacridaceae Family Scientific Name Monotoca elliptica Common Name Tree Broom-heath Height 4m Habit Shrub or small tree Location Sand dunes and headlands

Characteristics The Monotoca elliptica is a small tree or bushy shrub that grows in the sand dunes and headlands of the New South Wales area. It is usually around 4 meters tall, but can occasionally reach a height of 10 m. The tree broom-heath is a long lived tree, living longer than a hundred years. It is a slow growing tree, and its germination is slow and difficult. The Monotoca resprouts after a fire through epicormic shoots, meaning new growth comes from dormant buds on existing branches.


27

The leaves of the Monotoca elliptica are elliptic, around 10-25 mm in length, and 3-7 mm wide. They are oblong to oblanceolate with entire margins. The undersides of the leaves are glaucous.

The fruit is a drupe that is ovoid in shape and 3-4 mm long. It is orange or red in color. A few can be seen in the image above. The fruit of the tree broom-heath appears from August to November. The fruit is eaten by several species of bird, which provide the main method for seed dispersal. It is also a food source for a species of butterfly larva.

The flowers of the tree broom-heath are white to cream in color. Blooming occurs from July to October, peaking in August. The flowers are very small, being only about 2 mm wide. 4-16 are grouped together in either terminal or auxiliary racemes at branch tips.


[

Plant Profile

]

Pandanaceae Family Scientific Name Pandanus tectorius Common Name Screw Palm Height 5-6 m Habit Branching Tree Location Exposed coastal headlands/ beaches

Characteristics Pandanus is a genus of over 600 species. While found worldwide, only around 30 occur in Australia. They are primarily found in Tropical and subtropical areas. Pandanus are dioecious shrubs or trees, meaning each individual plant are either male or female. They also have aerial roots present, usually taking the form of prop roots. Pandanus tectorius is a small tree that is hardy in tropical, sub-tropical, and warm temperate areas. It is also coastal tolerant. In NSW it is found among the coastal sand dunes.


29

The fruit resembles a large pineapple, and is found only on the female plants. When it is ripe the color is divided into yellow, red, or orange segments. The fruit is edible, and is a major form of food for Micronesia. The fruit and seeds are roasted and then eaten.

The Pandanus has aerial roots, which take the form of prop roots. These roots emerge from the trunk of the tree and extend into the sandy soil. This allows the Pandanus to support itself in the sandy soils where it is commonly found. This allows the tree to withstand the heavy wind that is common along the coast during cyclones. The prop roots also give the screw palm its distinct look.

Leaves are linear and are around 3 feet in length by 4 inches in width. The leaves emerge in a screw-like pattern from the branches. This is how the Pandanus gets its common name. Small spines run along the edges and midrib of the leaves. The dead leaves sheath off at the base and form a dense mat under the tree.


[

Invasive Plants

]

Family Scientific Name Common Name

Native to


31

Family

Invasive

Scientific Name

P l a n t s: A look at key weeds

threatening the biomes of NewCommon South Name Wales

Invasive plants are a major threat the coastal biomes of New South Wales. Whether Native tooriginally brought in with good intentions, or just used as a garden specimen, these plants have now overtaken native areas. These plants are aggressive, quickly spreading and choking out native flora. Extensive work has been done to remediate this problem, with local volunteers leading the effort. The following pages highlight a few of the most serious weeds affecting the coastal biomes of New South Wales.

[

Invasive plants are threatening the existence of native plants who must utilize every resource in order to survive

]


[

Invasive Plants

]

Asparagaceae

Family

Scientific Name Asparagus aethiopicus Common Name Asparagus (ground)

Native to South Africa Asparagus is a herbaceous perennial that is considered a noxious weed in New South Wales. It is very hardy due to its tuberous water sacs that allow it to store water for dry periods. It forms dense mats of these roots and chokes out native ground covers. Its leaves are actually short stems that can be up to 2.5 cm long. The flowers are small, bell shaped, and white or pale pink. Asparagus is spread by birds and humans.


Family

33

Asteraceae Scientific Name Chrysanthemoides monilifera Common Name Bitou Bush

Native to South America Bitou bush is a weed of national significance that was originally used for sand stabilization in NSW. Bitou is a sprawling shrub that reaches 2 meters high. It has yellow flowers that consist of 13 petals. Fruits are egg-shapped and are around 5-8 mm in size. They are green and fleshy, with a black covering. Bitou is spread primarily by animals.


[

]

Invasive Plants C o n v o l v u l a c e a e

Family

Scientific Name Ipomoea cairica Common Name Coastal Morning Glory

Native to Tropical Africa and Asia Coastal morning glory is a major threat to the dunal vegetation of NSW. Another noxious weed, it climbs over its victims and can reach lengths of 5 meters. Morning glory is a climbing or trailing vine which puts down roots whenever in contact with the soil. The leaves are 9 cm long with 5-7 lobes. The flowers of the morning glory are purple or pink, and are around 8 cm across. They are solitary, or in groups of 2-3. Morning glory is spread by humans, wind, or water.


Family

Verbenaceae

35

Scientific Name Lantana camara Common Name Lantana

Native to Tropical South America Lantana camara is considered a noxious weed in the New South Wales area. Used in residential gardens, much like in the United States, the weed is spread from birds, animals, water, and human activity. It is a thicket forming shrub that can reach 4 meters high. Lantana features wooded, four sided stems. The leaves are course, feature prominent veins, have serrated margins, and are strongly scented. The flowers are a combination of white, cream, and pink.


[

]

Invasive Plants C a e s a l p i n i a c e a e F a m i l y Scientific Name Senna pendula Common Name Winter Senna

Native to South America Winter senna is a noxious weed that is found along the coast of New South Wales. Senna is a shrub that can reach 3 m tall. The leaves are compound, with the leaflets rounded. The flowers are a showy yellow, as can be seen in the pictures. The fruit is a legume up to 8 cm long. The plant is spread by birds, insects, and humans. This plant is commonly used in gardens around the NSW area.


[

FSources amily

]

37 Image Sources Scientific Name All images are that of the Commonunless Name otherwise author noted Information Sources Australian Native Plants Society. ANPSA, Apr 2010. Web. 12 Apr 2010. <http://asgap.org.au/>. Environment, Climate Change, and Water. DECC, 12 Feb 2008. Web. 20 Apr 2010. <http://www.environment.nsw.gov.au/>. Holliday, Ivan. A Field Guide to Australian Trees. 3rd ed. Sydney, Australia: Reed New Holland, 2009. Print.

Specht, Ray L., and Alison Specht. Australian Plant Communities Dynamics of Structure, Growth and Biodiversity. Melbourne, Victoris: Oxford University Press, 2002. Print.

Native to

Williams, J.B. Trees and Shrubs in Rainforest of New South Wales and Southern Queensland. Armidale: University of New England Printery, 1984. Print.

[

Coastal Plant Biomes of Northern

]

New South Wales


Plant Biomes of New South Wales