Geography · Year 10 · Environmental Change and Management · Term 1

Ecosystem Resilience and Biodiversity

Explore factors determining an ecosystem's ability to resist or recover from disturbance, focusing on biodiversity.

• ACARA Content Descriptions
• AC9G10K01

About This Topic

Ecosystem resilience measures an ecosystem's capacity to resist disturbances like bushfires or invasive species and recover afterward. Year 10 Geography students focus on biodiversity's role, the variety of species and their interactions that provide backup functions when some are lost. They address key questions: predict how biodiversity loss disrupts stability and services like pollination, explain vulnerabilities such as arid Australian zones to invasives like buffel grass, and assess keystone species like wombats that shape habitats through burrowing.

Australian contexts enrich this unit on Environmental Change and Management. Students analyze eucalypt forests regenerating post-fire via diverse seed banks, contrast with wetlands overrun by feral pigs, and link to AC9G10K01 on biophysical processes and human influences. These cases build prediction and evaluation skills for real management challenges.

Active learning suits this topic well. Students construct food web models, apply simulated disturbances, and compare recovery in high versus low biodiversity setups. Such approaches make invisible interdependencies visible, encourage hypothesis testing, and connect abstract concepts to observable changes.

Key Questions

1. Predict how biodiversity loss affects ecosystem stability and function.
2. Explain why some ecosystems are more vulnerable to invasive species.
3. Assess the role of keystone species in maintaining ecosystem health.

Learning Objectives

• Analyze the relationship between species richness and ecosystem stability in a given Australian biome.
• Evaluate the impact of a specific invasive species on the biodiversity and resilience of a local ecosystem.
• Compare the recovery rates of two different ecosystems following a simulated disturbance, identifying factors contributing to resilience.
• Explain the role of a keystone species in maintaining the structure and function of a temperate forest ecosystem.
• Predict the consequences of biodiversity loss on essential ecosystem services, such as water purification or pollination.

Before You Start

Biomes and Ecosystems

Why: Students need a foundational understanding of different biomes and the components of an ecosystem before exploring resilience and biodiversity.

Food Webs and Energy Flow

Why: Understanding how energy flows through an ecosystem is crucial for comprehending how biodiversity loss can disrupt ecosystem function.

Key Vocabulary

Resilience	The capacity of an ecosystem to withstand disturbances, such as fires or droughts, and to recover its structure and function afterward.
Biodiversity	The variety of life within a particular habitat or ecosystem, encompassing species diversity, genetic diversity, and ecosystem diversity.
Invasive Species	A non-native species that spreads aggressively and outcompetes native organisms, often disrupting ecosystem balance and reducing biodiversity.
Keystone Species	A species that has a disproportionately large effect on its environment relative to its abundance, playing a critical role in maintaining ecosystem structure and function.
Ecosystem Stability	The ability of an ecosystem to resist change and maintain its fundamental structure and processes over time, often linked to its biodiversity.

Watch Out for These Misconceptions

Common Misconception

All species are equally important to resilience.

What to Teach Instead

Functional diversity matters more than species count; some provide unique roles. Role-playing food webs where students remove redundant versus unique species reveals this, prompting discussions on keystone priorities and active prediction of outcomes.

Common Misconception

Ecosystems always fully recover from disturbances.

What to Teach Instead

Recovery depends on remaining biodiversity and disturbance scale; some shifts become permanent. Simulations with iterative disturbances show tipping points, helping students through group analysis refine ideas about thresholds and management needs.

Common Misconception

Biodiversity loss only affects rare species.

What to Teach Instead

Common species drive stability through everyday functions. Collaborative modeling where groups track service losses (e.g., soil stability) after common species removal clarifies this, building shared understanding via peer explanations.

Active Learning Ideas

Food Web Simulation: Disturbance and Recovery

Provide species cards with roles and links; students assemble food webs in pairs. Introduce disturbances by removing cards (e.g., predators), then track cascading effects over 5 rounds by noting surviving species and functions. Regroup to share recovery strategies.

50 min·Pairs

Jigsaw: Keystone Species

Assign small groups to research one Australian keystone species (e.g., sea otters, dingoes). Experts teach home groups impacts of their loss. Groups then predict ecosystem changes and propose restoration.

45 min·Small Groups

Stations Rotation: Biodiversity Scenarios

Set up stations with Australian case studies (Reef, bushland). Groups assess resilience factors, simulate biodiversity loss with manipulatives, record predictions. Rotate twice, consolidate whole class.

40 min·Small Groups

Data Analysis Pairs: Invasive Impacts

Pairs graph real data on invasive species spread (e.g., cane toads) versus native biodiversity metrics. Hypothesize resilience thresholds, present findings to class for debate.

35 min·Pairs

Real-World Connections

• Conservation ecologists working for Parks Victoria use resilience assessments to prioritize management strategies for iconic ecosystems like the Great Otway National Park, focusing on fire recovery and invasive species control.
• Agricultural scientists research the impact of declining pollinator biodiversity on crop yields in Australia's Murray-Darling Basin, linking ecosystem health to food security and economic stability.
• Urban planners in Sydney consider the resilience of green spaces, such as the Royal Botanic Garden, to climate change impacts, evaluating the role of native plant diversity in maintaining ecosystem services for the city.

Assessment Ideas

Exit Ticket

Provide students with a scenario describing a disturbance (e.g., a severe drought) in a hypothetical Australian ecosystem. Ask them to write two sentences predicting how high biodiversity would affect the ecosystem's resilience compared to low biodiversity.

Discussion Prompt

Pose the question: 'Why are arid Australian ecosystems often more vulnerable to invasive species than temperate rainforests?' Facilitate a class discussion, guiding students to consider factors like resource competition, native species adaptations, and reproductive rates.

Quick Check

Present images of three different species, one of which is a known keystone species in an Australian ecosystem (e.g., a wombat). Ask students to identify the keystone species and briefly explain its role in maintaining ecosystem health.

Frequently Asked Questions

How does biodiversity influence ecosystem resilience?

Biodiversity offers redundancy and flexibility: multiple species fill roles like nutrient cycling, so losses do not collapse functions immediately. In Australia, diverse eucalypt understories aid fire recovery, while low-diversity reefs suffer bleaching cascades. Students learn this buffers disturbances, maintaining services like clean water vital for human communities.

What are examples of keystone species in Australian ecosystems?

Keystone species disproportionately shape communities: dingoes control herbivores in deserts, preserving vegetation; sea stars regulate urchin numbers on reefs. Their removal triggers collapses. Year 10 activities like species removal simulations demonstrate these outsized roles, linking to resilience predictions under AC9G10K01.

Why are some Australian ecosystems vulnerable to invasives?

Low native biodiversity or prior disturbances reduce resistance: arid zones lack competitors for buffel grass, accelerating fires. Students assess via case data, connecting to management strategies like targeted removal, fostering skills in evaluating environmental change impacts.

What active learning strategies teach ecosystem resilience?

Use hands-on simulations: build card-based food webs, apply disturbances like species removal or invasives, observe recovery differences by biodiversity level. Group rotations through Australian case stations encourage prediction and data sharing. These methods make dynamics tangible, boost engagement, and develop systems thinking over lectures, aligning with inquiry-based geography.