2.6 - Biodiversity
What biodiversity is
Biodiversity refers to the variety of different species living in a particular area or across the entire planet. This variety includes all types of living things, from plants and animals to microorganisms, and it exists at different levels such as within ecosystems, habitats, or globally.
Key aspects of biodiversity
- Species variety - This measures the number of different species in an area, where more species mean higher biodiversity.
- Balance in populations - Biodiversity also considers how evenly distributed these species are, with healthy systems having a good mix rather than one dominant type.
- Genetic differences - Within species, variations in traits contribute to overall diversity, helping populations adapt to changes.
High biodiversity creates a rich web of life where different species interact and depend on each other.
The links between biodiversity and ecosystem services
Ecosystem services are the benefits that humans and other organisms get from healthy ecosystems. Biodiversity plays a key role in providing these services because a variety of species work together to keep natural processes running smoothly. Without enough species variety, these services can weaken or fail.
Specific ecosystem services supported by biodiversity
- Water purification:
- Diverse plant and microbial species filter pollutants from water as it flows through wetlands, rivers, and soils, making it cleaner for drinking and other uses.
- This occurs because different species break down harmful substances at various stages of the process.
- Nutrient recycling:
- A mix of decomposers, such as bacteria and fungi, along with plants and animals, break down dead material and waste.
- They return essential nutrients like nitrogen and phosphorus to the soil.
- This recycling supports new growth and prevents nutrient buildup or loss.
- Soil stabilization:
- Varied plant species with different root systems hold soil in place, preventing erosion from wind or water.
- This stability maintains fertile land for farming and protects against landslides or flooding.
These services show how species variety directly contributes to the practical benefits ecosystems provide.
How biodiversity supports ecosystem health
Ecosystem health describes how well an ecosystem functions, stays balanced, and recovers from disturbances like storms or pollution. Biodiversity supports this health by creating resilience and stability, as a greater variety of species helps the system handle changes without collapsing.
Ways biodiversity contributes to ecosystem health
- Resilience to changes - With many species, if one is affected by disease or environmental shifts, others can step in to maintain key functions, helping the ecosystem bounce back.
- Balanced interactions - Diverse species create a network of relationships, such as predator-prey balances or pollination, which prevent any one species from overgrowing and disrupting the system.
- Long-term stability - High biodiversity leads to more consistent nutrient cycles and resource availability, reducing the risk of ecosystem breakdown over time.
As a result, ecosystems with greater species variety are generally healthier and better able to support life.