threats to biodiversity

what is biodiversity

The variety of all life forms on Earth—different plants, animals, microorganisms, their genes, and ecosystems.

What are the three levels of biodiversity?

1. Genetic diversity
2. Species diversity
3. Ecosystem diversity

What is species richness?

The number of species present in a given area.

What is species evenness?

The relative abundance of each species in a community.

What is an endemic species?

A species that is found only in one specific geographic area and nowhere else.

Name the five main threats to biodiversity.

1. Habitat loss & fragmentation
2. Overexploitation
3. Invasive species
4. Pollution
5. Climate change

What is habitat fragmentation?

Breaking up of a habitat into smaller, isolated patches.

give two case study examples of over-exploitation

• Ivory trade: $2.5/lb (1969) → $90/lb (1989); elephant populations plummeted

• Fisheries (Western Baltic cod, Gadus morhua)

  • Unsustainable exploitation, low productivity reinforced by climate change

types of habitat disruption

1- habitat destruction

2-fragmentation

3-degration

4-disturbance

give two case study examples for habitat disruption

• Tropical rainforest deforestation

  • Reduces precipitation (Congo: 8–10% reduction by 2100)

  • Tipping points and ecosystem collapse risks

• Neonicotinoid pesticides (Imidacloprid)

  • Systemic, water-soluble, persistent

  • Harm to bees → smaller bumblebee nests; 85% reduction in new queens

How does climate change affect biodiversity?

phenotypic plasticity, evolutionary adaptation, migration & range shifts, species turnover & sorting.

What is an extinction vortex?

A downward spiral where small population size leads to inbreeding and loss of genetic diversity, increasing extinction risk.

What is the IUCN Red List?

A list categorizing species according to their extinction risk.

What is a keystone species?

A species that has a disproportionately large effect on its ecosystem relative to its abundance.

Name a solution to combat habitat loss.

Creating protected areas (e.g., national parks, reserves).

What is the Convention on Biological Diversity (CBD)?

An international treaty aimed at conserving biodiversity, using it sustainably, and sharing its benefits fairly.

How can individuals help protect biodiversity?

By reducing waste, using sustainable products, supporting conservation efforts, and spreading awareness.