VCE Environmental Science

Learning Intention: Students will understand the purpose of a variety of tools used to measure biodiversity, including Simpson’s and the Shannon-Weiner Indices. They will identify the knowledge required to undertake a population viability analysis and the consequences of low genetic diversity in a population.

Success Criteria: Students will be able to explain how scientific data is applied to the assessment of environmental risk in ensuring biodiversity.

Species richness and Species diversity: Species richness is the number of different species in a specific location. Species diversity includes the number of species and their relative abundance. To determine these measures of biodiversity the scientist must identify the different species (using field guides, museum specimens and/or dichotomous keys) and then count the total number of individuals (a census) or, more commonly, estimate the numbers using a sampling technique. Sampling techniques include transects, quadrat studies, surveys, questionnaires, pelt records, aerial photographs, mark-and-recapture techniques and other methods. Biodiversity: Richness, Evenness and Importance.(YouTube video)

Levels of endemism: An organism is endemic (native or indigenous) to a region when it exists in one location and no-where else, such as platypus or the  Wollemi pine in Australia. Endemic species are more likely to develop in geographically isolated locations, where barriers to reproduction reduce opportunities for genetic exchange and speciation occurs over time. The smaller and more isolated a population, the more prone to extinction it will be. The Lord Howe stick insect is a classic example – it was thought to be extinct by 1930, but a population of just 24 individuals was rediscovered in 2001, at a small islet called “Ball’s Pyramid”.

Simpson’s Index: Simpson’s Diversity Index (D) is a measure of ecological diversity. In ecology it is often used to quantify the biodiversity of a habitat. It takes into account the number of species present, as well as the abundance of each species. This index is based upon the probability that two specimens belong to the same species. It ranges from 0  (low diversity) to 0.9999 (high diversity). Simpson’s Diversity Index(YouTube video)

Population Viability Analysis: Population Viability Analysis is a technique that assists with risk management in conservation biology. It is a tool that enables users to examine how management decisions can affect population numbers and the rate of extinction. PVA has been used with the Eastern Barred Bandicoot and Leadbeater’s Possum. It is used because it links planning, research and data collection, assessment of vulnerability and the ranking of management options. A PVA includes:

The Grampians National Park is a popular destination for bushwalking, art and photography, rich in geology, flora and fauna. If you would like to join us at the Grampians YHA for a two night study camp, please complete your details below:

“Extinction – Just how bad is it and why should we care?” is an interesting article, written by Deakin University Ecology Lecturer, Euan Ritchie. He makes the point that 99% of species that have ever existed are now extinct, and at this time (the Anthropocene) species are becoming extinct at between 1,000 and 10,000 times the ‘usual’ or background levels. We will be looking at two local species that have been severely impacted by human activities in Victoria.

The Orange Bellied Parrot (Neophema chrysogaster) and the Eastern Barred Bandicoot (Perameles gunnii) are both threatened species that existed in much larger numbers prior to European colonization in Victoria. The OBP is now classified as “critically endangered”, as less than 50 individuals have been recorded in their native habitat. The EBB is in an even worse position, listed as “extinct in the wild”, with only three captive populations surviving in the state, although a sub-species still exists in the wild in Tasmania, where there are no foxes.

The Orange Bellied Parrot (OBP) is a small, migratory parrot (a bit larger than a budgerigar) that is very similar in appearance and behaviour to several other parrots of the same genus (the blue-winged parrot, the elegant parrot and the rock parrot). It is distinguished from these other birds by it’s brighter colour, orange belly in the males and a distinctive call. In summer it occupies coastal woodlands in the SW of Tasmania (in and around Melaleuca), where it nests in tree hollows in eucalypts and feeds on the button grass plains. The female OBP lays 4-5 eggs in October to January. In late March/April this courageous little bird flies across Bass Strait, island hopping, to the southern coast of the mainland, including SA, SW and Gippsland. This is where the OBP spends the colder winter months, feeding on samphire of the salt marsh flats and sheltering in the woolly tea tree scrub.

The Eastern Barred Bandicoot (EBB) is a grey/brown marsupial of about 800grams and 40cm in length (including it’s tail) – a little smaller than a rabbit. It has a long nose and ears, with several off-white stripes across it’s rump. It leaves funnel shaped burrows when it is digging for it’s food, including worms, invertebrates, fungi and grasses. In a good season the female can produce up to five litters a year, with three offspring in each litter. The young are born at just 12 days, about the size of a small jelly bean, and climb into the backwards facing pouch, where they spend the next 6 to 8 weeks. They then spend another two weeks in the nest before leaving for a solitary life. The Eastern Barred Bandicoot used to be widespread across western Victoria, as far as the SA border, occupying native grasslands and grassy woodlands.

The main threats to both the OBP and EBB are habitat destruction (land clearing due to agriculture and development) and introduced species (foxes and feral cats are predators of both species). In addition, both species have reached very low numbers (about 40 EBB were discovered at the Hamilton tip before they became extinct in the wild, and there are only 36 wild OBP known to exist at the 2011/12 survey). Such small numbers in a population increase the chances of inbreeding and result in low genetic diversity, which makes these species less able to adapt to changes in their environment and more vulnerable to extinction.

As well as habitat destruction, introduced species and low genetic diversity, the OBP is vulnerable to a disease (Psittacine Circoviral Disease) and stochastic events – random disasters, such as storms during migration, bush fires in their breeding habitat etc.

Both species have been listed on the Victorian List of Threatened Vertebrates and have a co-ordinated management plan that includes the following strategies:

• Captive Breeding Program (to maintain a viable population in captivity to allow re-introductions into suitable protected habitats)
• Habitat Protection and enhancement (Protecting remnant habitats and revegetation with appropriate flora)
• Introduced species control (feral cat and fox baiting/shooting, as well as fences to exclude these predators from the habitats)
• Monitoring and Research programs (collecting quantitative and qualitative data to increase the reproductive and reintroduction success of these species)
• Education programs (increase public awareness about the plight of these species and how they can be protected)

Your task this week is to produce a written report, multimedia presentation or presentation to the class about either the OBP or the EBB, using the task sheet that has been emailed to you. A draft copy is due this Friday (10th May). There are three parts to the task (1) the characteristics of the species and it’s habitat (2) the threats to this species and (3) how these threats are managed and if these strategies have been effective. Make sure you use at least five reliable and up to date references and list the ones used in a Bibliography or References section.

Orange Bellied Parrot Resources:
Wikipedia – Orange Bellied Parrot
Parks and Wildlife Service Tasmania – orange bellied parrot
Birdlife Australia – Orange bellied Parrot
Australian government department of the Environment and Heritage – Saving the Orange Bellied parrot
Zoos Victoria – Orange Bellied Parrot
National Recovery Plan for the Orange Bellied Parrot
Flora and Fauna Guarantee Action Plan - Orange Bellied Parrot
YouTube video – Saving the Orange Bellied Parrot
Act Wild for the Orange Bellied Parrot from Zoos Victoria (video)

Eastern Barred Bandicoot Resources:
Parks and Wildlife Service Tasmania – Eastern Barred Bandicoot
Zoos Victoria – Eastern Barred Bandicoot
ABC Vodcast – Saving the Eastern Barred Bandicoot
Melbourne Museum – Eastern Barred Bandicoot
Australian Government department of Sustainability, Environment, Water, Population and Heritage - Eastern Barred Bandicoot
Flora and Fauna Guarantee – Eastern Barred Bandicoot
Act Wild for the Eastern Barred Bandicoot from Zoos Victoria

 

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It is essential that you understand the following key terms and how each of these factors impact on biodiversity:

• extinction
• symbiotic relationships and symbionts (close relationships between particular species)
• parasitism, parasites and hosts (eg. mistletoe – the host is negatively affected)
• commensal relationships (eg, epiphytes – host neither benefits nor is harmed)
• mutualistic relationship (eg. grouper and wrasse; nemo and anenome fish – both organisms benefit)
• alleles (different forms of a particular gene or position on a chromosome)
• genotype (genetic makeup of an individual) and phenotype (physical characteristics expressed by those genes)
• genetic drift (random change in a population due to mutations; not affected by natural selection)
• inbreeding (when closely related individuals produce offspring; often results in harmful alleles being expressed)
• genetic swamping (when the genotypes from a larger population overtake the genotypes of a smaller population; usually when a number of individuals are introduced to a previously isolated population).
• demographic variation which includes numbers of individuals of each gender in each age group, resulting from births and immigration; deaths and emigration and changes in sex ratio.

The “population pyramid” above shows an example of the age and gender demographics of West Africa compared to Western Europe. This variation may be due to falling birth rates and better medical care in Western Europe, whereas the West African graph would be the more ‘natural’ distribution, with gradual decrease in populations over time due to mortality. If you can imagine an animal population in which there has been significant ‘stochastic’ events, such as floods, drought, bushfires or storms that have prevented breeding, or wiped out individuals within a particular age range, there will be irregularities or gaps in the graph, that deviate from the smooth curve.

Let’s use an example of the mass fish kills that have occurred from time to time in the Surry River, near Narrawong. In 1995, 1997, 2005 and 2006, thousands of fish were killed due to low oxygen levels in the water. (“Low flow means Surry opening no go” ) This means that it will take many decades for the river to recover in terms of the population distribution of fish on the river, as breeding age fish of several generations have been affected.

Image source – “New tool for river mouth openings to have worldwide application.”

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Learning Intention: Students will understand the six major threats to biodiversity and the impact they have on our environment.

Success Criteria: Students will be able to identify, discuss and give examples of each of these threats.

This week I would like you to finish reading Chapter 6 and complete the chapter review questions. If you have completed this work, go on to Chapter 7 and the next set of chapter review questions. Attend the Blackboard Collaborate session on Tuesday evening at 7.30pm so we can discuss your answers and go through the next section of work. See if you can categorise this list (EPBC List of Key Threatening Processes) of threatening processes into the six headings below. (Root-rot fungus or Phytopthera cinnamomi is an introduced disease but chytrid fungus is not. Perhaps climate change or pollution has made our amphibians more vulnerable to this disease?).

If you missed this week’s Blackboard Collaborate session, here is the link to 3B.2 Threats to Biodiversity.

Climate Change

• Ocean acidification troubles from the Encyclopedia of Earth
• Tough times for toads and frogs – effects of climate change on amphibians.

Habitat Destruction

• Fragmentation -from the Biodiversity Information System of Europe.
• Habitat loss – causes and consequences from The Habitable Planet

Introduced species

• Feral animals in Australia – Federal Dept.of Sustainability, Environment, Water, Populations and Communities
• Effects of rabbits on Macquarie Island and their eradication - ABC podcast
• Effect of introduced turtles on native species in US and Australia
• Invasion by exotic species  – from The Habitable Planet

Pollution

• State of the Environment report (2011) – effects of pollution on biodiversity
• Biodiversity information system for Europe

Poaching

• Tanzania’s elephants in peril
• Elephant ivory poaching (map of Africa)
• See Turtles – Illegal poaching of turtles for meat, eggs and shells.
• Borneo Orangutang Survival - Orangutangs are killed for bush meat, body parts are sold as souvenirs or ‘traditional’ medicine and babies may be sold as pets.
• African Rhino poaching crisis – from WWF

Overharvesting

• World Wildlife Fund – Bycatch
• Overexploitation – from the Biodiversity Information System of Europe.
• Overfishing - from the Encyclopedia of earth

 

Diversity in the biosphere
This area of study examines the concept of biodiversity and its role in sustaining ecological integrity and the survival of populations. Students investigate processes that threaten biodiversity and examine scientific principles applied in managing biodiversity.
Outcome 2
On completion of this unit the student should be able to describe the characteristics of biodiversity, evaluate strategies to reduce the effects of threatening processes on biodiversity, and apply this knowledge to one selected threatened animal.

During term 2 we are working on concepts related to biodiversity, so it will be helpful if you have some prior understandings of the three different levels of biodiversity (genetic, species and ecosystem) and why each level is important. The following resources are excellent references for your research in this Area of Study:

• ABC Photo gallery about biodiversity
• Biodiversity from the Australian Museum
• Biodiversity from the CSIRO
• The Encyclopedia of Earth – Biodiversity
• Conservation of Australia’s Biodiversity
• Victoria’s Biodiversity from the Department of Sustainability and Environment.
• ARKive – information, photos and videos of 15,000 endangered species
• The Habitable Planet – Biodiversity Decline – an online textbook with 12 chapters about biodiversity and it’s decline.
• The IUCN red list of threatened species – searchable data base of threatened species worldwide.

Your tasks during week 1 of term 2 will be to read the information in this web page:
Conservation of biodiversity and then write definitions of genetic, species and ecosystem diversity and give two examples of each. You will also draw up a table with three columns:

1. Biological products (eg wood for furniture and homes, fruit and vegetables for food, medicines such as penicillin),
2. Ecosystem services (tree roots filtering water and preventing erosion, bees, bats and birds pollinating crops) and
3. Social benefits (Companion animals for the elderly, natural landscapes for recreation etc).

List as many different examples as you can think of under each heading.

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In 1992 the United Nations Framework Convention on Climate Change convened and began to consider what countries could do to limit average global temperature increases and how to reduce and manage the impacts of climate change. Since then, all levels of government and various non-government and private organisations have begun to formulate responses to increases in greenhouse gas levels in the atmosphere and the resultant increases in global average temperatures.

International:

• Kyoto Protocol (International agreement created by the UNFCCC in 1997 and ratified by the Australian government in December 2007)
• Copenhagen Accord;
• Cancan (2010);
• Durban (2011);
• Doha (2012)
• International pledges on climate change action

Federal:

Clean Energy Future

State:

Victorian Climate Change Adaption Plan (March, 2013)

Local:

Cities for Climate Change Protection (Moyne Shire)

Individual:

• What are the individual actions you can take to reduce your carbon footprint?
• How can you use energy more efficiently and reduce the amount of fossil fuels burnt on your behalf?

 

Images from NASA showing maximum and minimum sea ice coverage.

The Intergovernmental Panel on Climate Change (IPCC) is the leading international body for the assessment of climate change. It is a scientific body under the auspices of the United Nations, who review and assess the work of thousands of volunteer scientists from across the world. During 2013 this body is working on the Fifth Assessment Report, which will be comprised of the work of over 800 authors.

Chapter 5 in your text, “Issues of Sustainability” describes some of the impacts of climate change in Victoria, Australia and across the world. These impacts include:

• Rises in global average air and ocean temperatures, resulting in widespread melting of ice and snow and rising global average sea levels.
• Increased severe weather events (floods, storms, drought and bushfires)
• Changes in water availability
• Increased risk of extinctions
• Increased ocean acidification and coral bleaching
• Changes in food productivity
• Changed distribution of disease vectors and increase in morbidity and mortality.

You can find more information about the impacts of climate change using the following resources:

Impacts of climate change in Victoria from the Australian government Climate Change website.

Interactive world map showing some of the impacts of global warming.

Ocean acidification – an ABC Catalyst video about the serious consequences of increased carbon dioxide emissions.

An ABC Science article about ocean acidification.

Video clip about the decline of antarctic glaciers - from the ABC Education video library.

Global warming and human health – A NOVA webpage about the impacts of climate change on the health of humans.

Impacts of global warming on biodiversity – A NOVA webpage about the decline of biodiversity due to climate change.