L7 Biodiversity issues

flash cards

Define “Biodiversity, genetic diversity, species diversity, and ecosystem diversity”.

Definitions

Biodiversity:
The variety and variability of life on Earth, including all living organisms, their genes, and the ecosystems they form.

Genetic diversity:
The variation in DNA and genes within a species. It determines a population’s ability to adapt to changes.

Species diversity:
The number of different species (species richness) and their relative abundance in a given area.

Ecosystem diversity:
The variety of different ecosystems (forests, wetlands, coral reefs, grasslands, etc.) found in a region or on Earth.

Define “Extinction”.

Extinction is the complete disappearance of a species from Earth when the last individual of that species dies.

What are the characteristics of kinds of species that are most likely to become

Species most/least likely to become extinct

Most likely to become extinct:

• Species with small population sizes

• Species with specialized niches (need a specific food or habitat)

• Species with large bodies and slow reproduction

• Species that are highly sensitive to environmental changes

• Species with limited geographic ranges

Least likely to become extinct:

• Species with large, stable populations

• Generalists (can eat many foods and live in many habitats)

• Species with high reproductive rates

• Species widely distributed geographically

Describe three factors that influence the genetic diversity of a population.

Three factors that influence genetic diversity

1. Mutation: Creates new genetic variations.

2. Gene flow: Movement of genes between populations (migration).

3. Genetic drift: Random changes in allele frequency, especially in small populations.

List a few biological and ecosystem services values.

Examples of biological and ecosystem service values

• Provisioning services: Food, fresh water, timber, medicine.

• Regulating services: Climate regulation, pollination, water purification, flood control.

• Cultural services: Recreation, tourism, spiritual value.

• Supporting services: Soil formation, nutrient cycling, photosynthesis.

Describe five major human impacts that threaten to reduce biodiversity.

Five major human impacts that threaten biodiversity

1. Habitat loss and fragmentation (deforestation, urbanization).

2. Pollution (air, water, soil contamination).

3. Overexploitation (overfishing, hunting, poaching).

4. Introduction of invasive species that outcompete native species.

5. Climate change altering habitats and survival conditions.

Why is biodiversity in freshwater ecosystems under great threat from human

Freshwater ecosystems (rivers, lakes, wetlands) are highly threatened because of:

• Water pollution (industrial waste, pesticides).

• Overuse of water for agriculture and human consumption.

• Habitat alteration (dams, drainage, channelization).

• Invasive species introduced by humans.

• Climate change affecting water temperature and flow.
  Freshwater systems are small and easily disrupted, making them extra vulnerable.

Efforts to preserve biodiversity involve a variety of approaches. What are they?

Approaches to preserve biodiversity

• Protected areas (national parks, wildlife reserves).

• Species recovery programs (breeding programs, reintroductions).

• Habitat restoration (reforestation, wetland restoration).

• Sustainable resource management (fisheries, forestry).

• Legislation and policies (Endangered Species Acts, conservation laws).

• Community involvement and education.

• International agreements (CITES, Convention on Biological Diversity).