Human Impacts and Future Ecosystems

In short: Human activities such as habitat loss, invasive species, pollution, overharvesting and climate change are changing ecosystems and driving extinctions. Australia has lost more mammal species than any other continent, and solutions include protected areas, feral animal control, revegetation and cultural burning.

Starting point: what you already know

• Food webs link species, so a change to one can affect many (see Ecosystems, Food Webs and Energy Flow).
• Populations are limited by food, space, predators and disease (see Population Dynamics and Sampling).
• Burning fossil fuels adds $\mathrm{C}{\mathrm{O}}_2$ to the air.

How humans change ecosystems

Australia has the worst rate of mammal extinction of any continent, with more than 30 mammal species lost since 1788. Feral cats and foxes are a major cause.

Looking after future ecosystems

• Protected areas: national parks and marine parks.
• Wildlife corridors: strips of habitat that link patches so animals can move and breed.
• Feral animal control: fencing, baiting and predator-free islands and sanctuaries.
• Revegetation: replanting local native species.
• Captive breeding and reintroduction, as in the story.
• Reducing emissions to slow climate change.

Cultural burning

For tens of thousands of years, Aboriginal people have cared for Country with cultural burning: small, cool, patchy fires lit at the right time and place, following knowledge of plants, animals and seasons.

• Cool fires burn slowly and low, so trees and animals survive.
• They reduce fuel, so later wildfires are less intense.
• The mosaic of burnt and unburnt patches gives animals food and shelter.

After the 2019 to 2020 bushfires, more fire agencies began working with Aboriginal fire practitioners. This knowledge belongs to the communities who hold it, and it is shared on their terms.

Quick summary

• Habitat loss, fragmentation, invasive species, pollution, climate change and overharvesting all damage ecosystems.
• Australia has lost more mammal species than any other continent, largely to cats and foxes.
• Fertiliser run-off causes algal blooms and fish kills (eutrophication).
• Solutions include protected areas, corridors, feral control, revegetation and captive breeding.
• Aboriginal cultural burning uses cool, patchy fires to reduce fuel and care for Country.

Quiz