Unit 3.1 An introduction to biodiversity

Question 1

What is Biodiversity?

Answer 1

The variety of life found in an area, including animals, plants, fungi, and microorganisms.

Question 2

Importance of Biodiversity

Answer 2

Vital for human needs (food, medicine, ecosystem services) and intrinsic value

Question 3

Values of Biodiversity

Answer 3

Utilitarian: Provides essential resources and ecosystem services.

Intrinsic: Recognizes the inherent worth of biodiversity, independent of human use.

Question 4

Types of Diversity

Answer 4

Species Diversity: Variety of species per unit area, including richness and evenness.

Habitat Diversity: Variety of habitats within a region, contributing to species diversity.

Genetic Diversity: Variation of genes within a species, affecting adaptability and resilience.

Question 5

Measuring Biodiversity

Answer 5

Use of diversity indices, like Simpson’s Diversity Index, to assess and compare community diversity.

Helps identify areas of high biodiversity for conservation efforts.

Question 6

Biodiversity Hotspots

Answer 6

Must have at least 1,500 endemic plant species and 30% or less of original natural vegetation

Question 7

CASE STUDY: Madagascar Hotspot

Answer 7

1. Global Significance: The Madagascar and Indian Ocean Islands Hotspot is one of 36 recognized biodiversity hotspots globally, highlighting its critical importance for conservation.
2. Biodiversity Richness: This hotspot is among the richest areas on Earth in terms of biodiversity, including a high number of endangered species.
3. Geographical Composition: The hotspot includes Madagascar, the Mascarene Islands (Réunion, Mauritius, and Rodrigues), the Comoros, and the Seychelles.
4. Endemic Species: Approximately 15,000 plant species found in this hotspot are endemic, underscoring the region’s unique biological diversity.
5. Threat of Deforestation: Terrestrial ecosystems, particularly in Madagascar, face significant threats from deforestation and forest degradation, with natural forest cover reduced to about 12 percent.
6. Agricultural Practices: Slash-and-burn agriculture, known as tavy in Madagascar, is a major cause of deforestation, soil degradation, and erosion due to shortened fallow cycles and inappropriate land use.
7. Bushmeat Consumption: Hunting and consumption of bushmeat, affecting species like the endangered golden-crowned sifaka, pose significant threats to biodiversity and tourism.
8. Illegal Wildlife Trade: The collection of species for international trade, despite CITES ratification, remains a major threat due to ineffective enforcement and quota violations.
9. Invasive Species: Like many island ecosystems, this hotspot’s biodiversity is particularly vulnerable to invasive species, exacerbating the challenges to native flora and fauna.
10. Climate Change Impact: Coral bleaching due to climate change poses a dire threat to the marine ecosystem, with projections suggesting Indian Ocean corals may disappear within 20 to 50 years due to increasing bleaching events.

Question 8

Threats to Biodiversity

Answer 8

Major Threats: Deforestation, hunting, trafficking of species, invasive species, and climate change.

Question 9

Simpson’s diversity index

Answer 9

DI = (N(N-1) / Sum n (n-1)

N = numberof orgnaisms of all species at a given site
n = number of individuals within each species

Question 10

Discuss the usefulness of providing numerical values of species diversity to understanding the nature of biological communities and the conservation of biodiversity.

Answer 10

Quantification of biodiversity is important to conservation efforts so that areas of high biodiversity may be identified, explored, and appropriate conservation put in place where possible. The ability to assess changes to biodiversity in a given community over time is important in assessing the impact of human activity in the community.