Importance of Biodiversity

Biodiversity is the variety of life on Earth and is fundamental to the functioning of all ecosystems. Understanding why biodiversity has value — and what we risk losing when it declines — is a central concern of environmental science.

What Is Biodiversity?

Biodiversity encompasses all living organisms and the ecological systems they form. It is typically considered at three interconnected scales:

• Genetic diversity — variation in DNA within and between populations of the same species
• Species diversity — the variety and abundance of different species in an area
• Ecosystem diversity — the range of habitats, biological communities and ecological processes on Earth

These three levels are interdependent: loss at one level cascades to others.

Why Biodiversity Has Value

Intrinsic Value

Many ethical frameworks hold that species have value independent of human benefit. Biocentrism and ecocentrism recognise the right of all living things to exist.

Instrumental Value

Biodiversity directly supports human survival and well-being through ecosystem services:

Ecological Resilience

Higher biodiversity generally increases an ecosystem’s resilience — its capacity to absorb disturbance and recover. Diverse ecosystems:
- Have redundant species that can fill functional roles if others decline
- Are more resistant to invasive species
- Maintain stable productivity under variable conditions

Biodiversity and Ecosystem Function

Species interact through food webs, nutrient cycles, mutualistic partnerships and competition. Removing even one species can trigger cascading effects:

• Loss of a keystone species (e.g. sea otters controlling sea urchin populations) can restructure entire communities
• Loss of pollinators reduces reproduction in flowering plants, affecting food webs and agricultural productivity
• Decline in decomposers slows nutrient cycling, reducing soil fertility

Biodiversity in Australia and Victoria

Australia is one of 17 megadiverse countries, hosting approximately:
- 10% of the world’s plant species
- Around 800 bird species
- Over 800 reptile species

Victoria’s diverse landscapes — alpine, coastal, arid and temperate — support high levels of endemism (species found nowhere else). Protecting this diversity is the focus of frameworks like the Flora and Fauna Guarantee Act 1988 (Vic).

Declining Biodiversity: The Scale of the Problem

Current extinction rates are estimated to be 100–1000 times higher than background (pre-human) rates, leading scientists to describe the present as a sixth mass extinction. Key drivers include:
- Habitat destruction
- Overexploitation
- Invasive species
- Pollution
- Climate change

KEY TAKEAWAY: Biodiversity has both intrinsic worth and enormous practical value to human society through ecosystem services. Its decline is one of the most serious environmental challenges of our time.