Tropical Australian grasslands are made of many different organisms. Aside from all the animals that roam the parries, the grasslands have a myriad of plant life. One common plant found in an Australian grassland, is called a cycad. Cycads are native to the tropical Australian grassland and have short wooden trunks and stiff evergreen leaves. The cycad is known as a fossil plant because there is evidence that they’ve been around for as long as 200 million years ago. There are around 250 species of cycads in Australia. Acacias are another common plant found in Australian grasslands, acacias are a seed plant that have many uses. Some seeds can be ground into flour and cooked, and some seeds are just eaten raw. These plants are often found in warm climates with spikey yellow flowers. Where those two plants are very common to the tropical Australian grassland, there are other plants that have other interesting features. The lantana flower is a flower that originates from South America, it was brought to Australia as an ornamental garden plant and made its home in the grasslands. It established itself as another plant grown in Australia within 20 years, and is a unique addition to Australia’s plant life. One of the most exclusive plants in the savannah is the red-flowered wattle. This flower is very rare because of its colour. A more common, yet still rare version of this flower is the orange-flowered wattle. These plants are spreading shrubs that can grow 30 centimeters to one metre tall, their leaves are 2-4 centimetres long and have golden or white hairs covering their branches, here is where they differ: the flower. As it says in the name, orange-flowered wattles have golden-orange flowers in a spherical shape, but red-flowered wattles have dark pink to red flowers, the red flowers are less abundant in nature and are beautiful to come across, which is not common.
Not all plants have a positive effect on their habitat. Some plants kill other plants, and are usually not native to their biome, we call these plants invasive species. Knapweed is native to Europe, but has made itself prominent in Australian grasslands. The weed grows quickly and has spread quickly around this biome. Knapweed reduces the carrying capacity of the ground, so other species can’t grow in, it also produces natural chemicals that are toxic to the other plants around them since the Australia native plants aren’t used to it, and the chemicals stunt the growth of other plants. Another invasive plant is called bridal creeper. Bridal creeper originates from eastern and southern Africa, and was introduced to Australia as a foliage plant. The plan backfired, as the reason this species is invasive, is because the large, thick, wide leaf span smothers the natural Australian vegetation. Bridal creeper roots are also very big, taking up space underground, and not leaving room for other plant roots. Both invasive species are killing off the natural native vegetation.
The Australian tropical grassland is a very vast and dry place, this makes many plants susceptible to spontaneous wild fire, so the grassland flora is adapting for its surroundings. These days, plants in the tropical grassland are able to survive long and dry seasons with months of little to no rainfall, as they are good at conserving moisture. Foliage plants have turned almost deciduous to survive this climate, the way they behave similar to deciduous trees, is that they shed their leaves during the dry season. Speaking of the aforementioned spontaneous fire outbreaks, some plants are even evolving to withstand fire! After the fire is extinguished, some plants are still alive and healthy, fire resistance is a trait that all plants are bound to evolve with in order to survive in their biome.
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Symbiosis occurs in almost all aspects of life, this includes the Australian tropical grassland. An example of a symbiotic relationship, is when fungi grows on a plant’s roots, this is a form of mutualism. This situation is mutualism because both parties benefit from the event. The fungi that grow on roots give off phosphorus and nitrogen, which are essential to the plant’s life. In return, the roots give the fungi a place to grow, and carbohydrates to use for energy. This way, both organisms are helping each other survive in the hot and dry grassland. Once again, this is mutualism.
The basalt Greenhood orchid is just one of the many endangered species in the Australian tropical grassland. The basalt greenhood orchid is a dormant plant in the summer, the plant has translucent petals, and oval shaped leaves. There are a few problems the basalt greenhood is facing which are making it seem more and more likely that it will become extinct. One problem is that there is a monumental weed invasion in the grasslands, an example of weeds that are over populating the biome are knapweed, as mentioned earlier. Heavy fertilizers have also been applied to the ground and that means that the basalt greenhood is dying faster than if there wasn’t manmade interference. The last main problem of the basalt greenhood, is that there is over grazing of rabbits and other animals in the fields. The animals aren’t giving the plants enough time to grow back, so the orchid is becoming fewer and fewer. Steps taken towards the preservation of the basalt greenhood orchid are being put in place. Restriction of access to this orchid and minimal disturbance is being enforced, conservers of this plant are hoping to establish the greenhood in other sites to hopefully repopulate the species.
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Sources:
Jacklyn, P. "Plants of the Savannas." Savanna Explorer - Northern Australia. N.p., 24 Nov. 2006. Web. 01 Dec. 2016.
http://www.savanna.org.au/all/plants.html
"The Cycad Pages." The Cycad Pages. N.p., 1 Feb. 2001. Web. 01 Dec. 2016.
http://plantnet.rbgsyd.nsw.gov.au/PlantNet/cycad/cycintro.html
Pace, Matthew. "Hidden Partners: Mycorrhizal Fungi and Plants NYBG Herbarium." The New York Botanical Garden. N.p., 16 Mar. 2006. Web. 1 Dec. 2016.
http://sciweb.nybg.org/science2/hcol/mycorrhizae.asp.html
"Bridal Creeper." Bridal Creeper. N.p., 24 Oct. 2004. Web. 01 Dec. 2016.
http://www.ento.csiro.au/biocontrol/bridal.html
"Lantana Fact Sheet." NSW Government | Office of Environment and Heritage. N.p., 28 Oct. 2011. Web. 1 Dec. 2016.
http://www.environment.nsw.gov.au/pestsweeds/LantanaFactsheet.htm
Threatened Australian Plants. Canberra: Threatened Species and Communities Section, 1997. Threatened Australian Plants. 2 Aug. 2004. Web. 1 Dec. 2016.
https://www.environment.gov.au/system/files/resources/d947f8ec-dd8b-4e7f-bd3b-8246e0702547/files/plants.pdf
"What Do You Know - a Wattle Q & A." Wattle Day Association Inc. N.p., 2 Aug. 2016. Web. 01 Dec. 2016.
http://www.wattleday.asn.au/about-wattles/what-do-you-know-a-few-wattle-facts
Jacklyn, P. "Plants of the Savannas." Savanna Explorer - Northern Australia. N.p., 24 Nov. 2006. Web. 01 Dec. 2016.
http://www.savanna.org.au/all/plants.html
"The Cycad Pages." The Cycad Pages. N.p., 1 Feb. 2001. Web. 01 Dec. 2016.
http://plantnet.rbgsyd.nsw.gov.au/PlantNet/cycad/cycintro.html
Pace, Matthew. "Hidden Partners: Mycorrhizal Fungi and Plants NYBG Herbarium." The New York Botanical Garden. N.p., 16 Mar. 2006. Web. 1 Dec. 2016.
http://sciweb.nybg.org/science2/hcol/mycorrhizae.asp.html
"Bridal Creeper." Bridal Creeper. N.p., 24 Oct. 2004. Web. 01 Dec. 2016.
http://www.ento.csiro.au/biocontrol/bridal.html
"Lantana Fact Sheet." NSW Government | Office of Environment and Heritage. N.p., 28 Oct. 2011. Web. 1 Dec. 2016.
http://www.environment.nsw.gov.au/pestsweeds/LantanaFactsheet.htm
Threatened Australian Plants. Canberra: Threatened Species and Communities Section, 1997. Threatened Australian Plants. 2 Aug. 2004. Web. 1 Dec. 2016.
https://www.environment.gov.au/system/files/resources/d947f8ec-dd8b-4e7f-bd3b-8246e0702547/files/plants.pdf
"What Do You Know - a Wattle Q & A." Wattle Day Association Inc. N.p., 2 Aug. 2016. Web. 01 Dec. 2016.
http://www.wattleday.asn.au/about-wattles/what-do-you-know-a-few-wattle-facts