Contemporary Ecology

Learning intention: To understand the challenges native animals face when their habitat is urbanised and how they may or may not be able to adapt accordingly.

Success Criteria:

• Understand the difference between high density and low density housing and the difficulties associated with each one.

• Identify reasons why some animals can or cannot adapt to urban areas.

• Interpret distribution of animals between two habitats from a graph

Lesson Sequence

1.     Introduction

2.     Video and 'Think, Pair, Share' 

3.     Space and Resources Game

4.     Interpreting data

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Background Information: 

• Conserving biodiversity is becoming an increasingly important issue as rapid urbanization continues to occur worldwide.

• As fragmentation of landscapes occurs, native animals are increasingly exposed to matrix boundaries with varying edge contrasts.

• Edge contrasts are ‘the difference in composition or structure between adjoining ecosystems at both sides of the boundary’, and is a key element in the movement of animals across fragments within the matrix. A ‘hard edge’ will result in a significant reduction in the movement of animals across landscapes than ‘soft edges’. This leads to varying levels of length, depth or penetration of edge effects.

• In the study 'Compact development minimizes the impacts of urban growth on native mammals', the abundance of five out of six species was reduced by up to 6% by compact developments. The diverse developments led to higher summed abundance overall. However, these results differed between species. More dwellings allowed two species to increase by up to ~100%, while three other species showed a decline of up to ~39%. One species abundance was unchanged.

• Two of the ground dwelling mammals and the yellow-bellied glider were predicted to decline more with dispersed urban dwellings as opposed to compact development. The yellow-bellied glider would suffer the greatest impacts with up to 39% decline in abundance as a result of forest loss and urbanization adjacent to forest areas. This species also suffers from negative edge effects that

• The results of this study favour compact developments over dispersed or rural urbanization. Higher density housing has less detrimental impacts on mammals and arboreal marsupials because less overall area is affected by the urbanization. Compact development means that the negative impacts are concentrated to smaller land areas meaning that larger forest areas can be preserved. Plants and animals can be sustained in these large forest areas while housing demand is met within compact urban settlements. These concepts should all be considered in landscape planning and urban growth so that the threat to biodiversity is minimized when building new dwellings.  

• Low density housing developments still provide a suitable living environment for most arboreal animals. They still provide a suitable habitat for most of the species, likely due to the result of only a moderate level of clearing of vegetation that increases the diversity of niches of arboreal marsupials in urban environments.

• High density housing developments experience lower species richness, total abundance and individual species abundance. They do however support the abundances of animals who are urban adapters such as possums. Reduction of vegetation and canopy cover in high density housing developments appears likely to be the main cause of decline. Whereas low density housing developments 

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Introduction (5 mins)

Class discussion and brainstorm on the board.

• Can anyone remember what urbanization means? 

• What is low-density housing?

• What is high-density housing? - Break down these words to make sense of them.

It is recommended that the brainstorm remains on the board for the duration of the lesson.

Video and 'Think, Pair, Share' (15 mins)

How do you think urbanization impacts on native species? Can some species adapt to urban areas? Watch 'Why do some species thrive in cities?'.

Give students 5-8 minutes to think in pairs about: 

1. Why are some species able to survive in cities/suburbs? eg. what traits to they have?

2. What limits other species from surviving in urban areas? 

3. What types of Australian animals might struggle to adapt to urbanization and why? 

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Share some answers with the class and briefly discuss how urban development poses a threat to species that are sensitive to habitat change. 

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Space and Resources Game (30 mins)

This game is best played in an open space or with tables pushed to the sides of the classroom. Read the game instructions and print enough 'marsupial cards' to hand out to each student in the class. Try to ensure that there are equal number of each species. Ask students to arrange the chairs (houses) in either a low or high-density distribution using the images. Then tell them all to find a spot in the room that will satisfy their species' requirements. Any individual who cannot find the space to survive must sit out. 

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Then change the chair arrangement (housing density or scope) and see how that impacts the survival of the the remaining species. 

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As a class, discuss the following questions:  

1. What were the impacts of each different housing arrangement?

2. Which arrangement facilitated the greatest species richness?

3. Which species was most impacted by the urban landscape?

4. Which arrangement had the most detrimental effects on the marsupial species’ abundance? 
    

Interpreting Data (15 mins)

Project the diagram of urban-forest boundaries on the board. Point out the hard and soft edges. Explain how to recognise the boundaries on the graphs that are used in Worksheet 2: Hard and Soft Edges 

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Ask the students to complete the worksheet in pairs. 

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Go through the answers as a class

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Reflection (5 mins)

Write 1-2 sentences: What impact does urban development have on biodiversity?