IB ESS Unit 3 Revision

Biodiversity

broad concept of encompassing total diversity which includes genetic diversity, species diversity and habitat diversity.

Genetic diversity

Range of genetic material present in the population of a species

Species Diversity

number of organisms within each different species

Habitat diversity

range of different habitats within a biome

Habitat Diversity Advantages

higher rate of resilience,

higher genetic diversity,

more nutrients in the soil for other plants to use

Habitat Diversity Disadvantages

- Can be the result of fragmentation

- Some don't have a lot of plants

How do we measure biodiversity?

- Measuring pollution, eutrophication, colonization, patterns in biodiversity

- Quadrat sampling

- Simpson's Diversity Index

Hotspots

region with a high level of biodiversity that is under threat from Human Activities.

Endemic Species

species that are only found in one geographic location

Aspects of a hotspot

- 70% of the habitat has been lost already

- Over 1,500 species of plants that are endemic

- Tend of large densities of human habitation nearby

- Cover 2.3% of the land surface

Examples of Hotspots

Caribbean Islands, Cerrado

Evolution

gradual change in the genetic characteristics of populations over many generations achieved largely through the mechanism of natural selection

Genotype

genetic makeup of an organism

Phenotype

physical characteristics of an organism

Natural Selection

those who are more adapted to the environment through genetic variation have an advantage and flourish and reproduce.

Survival of the Fittest

Those who are fit to suit an environment, survive and reproduce

Adaptation

Change in genetic structure or behavior in order for a species to survive in their environment

Speciation

formation of a new species

physical barriers

physical separation of a species not allowing them to reproduce. This can include mountains or a river.

Causes isolation -> speciation

Land bridges

Lowered sea levels cause 2 geographic locations to conjoin.

- New species from the two recently conjoined areas can invade the new area. Some species may be able to interbreed with the newfound species,

Continental drift

- movement of continental plates over the earth's surface over time.

- Continents can move into new climate zones, forcing species to adapt to survive.

Plate activity

- Plate tectonics move around on the earth's surface, and if they meet they can diverge, converge, or slide past each other.

- New species can invade each other's areas and interbreed with each other to create new species.

Similarities between groups of animals

Could have to do with the fact that the continents might have been connected and those species originated in those connected places.

How old is the Earth?

4.6 billion years

Background extinction rate

Natural extinction rate of all species

How many mass extinctions have there been?

5 mass extinctions, were in the 6th now

what is the current background extinction rate?

One species per million species per year

what is the current mass extinction called?

Holocene extinction

Why has extinction rate risen?

- climate change

- hunting

- Destroying environments with industries

- Created pollution in the environment

What can cause a mass extinction?

Volcanic Eruption

Meteor

Climate Change

weedy species

Species that do well in the environment we create (ex: dogs)

How many species on Earth today?

- 7 million species are thought to be on earth today

- Only 1.4-1.8 million have been described and named

Factors that maintain biodiversity

System Complexity

Succession

Limiting Factors

Inertia

System Complexity

The more resilient the species, the easier it is to recover from the loss of a species. Species have many other options to fill that gap of food source through higher biodiversity.

Succession

Species diversity increases with time until a climax community (Max. species an environment can sustain) has been reached and then the species composition is stable and biodiversity is plentiful.

Limiting factors

Raw materials are limited, such as water is a desert. If many abiotic factors are present, then the ecosystem will react well to a change and maintain biodiversity.

Inertia

The property to resist change if a disruptive force becomes present. Higher inertia means higher rate of survival if there is a disruptive force.

Factors that lead to a loss of biodiversity

Natural hazards

Loss of habitat

Fragmentation of habitat

Pollution

What are natural hazards?

Volcanoes, earthquakes, hurricanes

Vulnerability in rainforests

- Many niches

- Low density human population

- 50% off all species

- Rainforest have lost 8% of land

What makes a species prone to extinction?

- Narrow geographical range

- Island organisms

- Small population

Island organisms

- Small population

- Endemic species

- Dodo bird

Small population

- Small genetic diversity

- Snow leopard tiger

IUCN Red List

- Determines the conservation status of a species

- States the world's most threatened species

Who is Involved in the IUCN Red List?

- 83 States

- 110 Government Agencies

- 800 + NGOs

- 10,000 scientists

- 110 IGOs

- 181 countries

IUCN Red List Mission

Influence societies globally to conserve the natural world and sustain natural resources.

Factors that affect a species conservation status:

- Population size

- Degree of specialization

- Distribution

- Reproductive potential and behavior

- Geographic Range

- Degree of Fragmentation

- Quality of habitat

- Trophic Level

- Probability of extinction

Change a species conservation status might be due to:

- Conservation efforts

- Population Growth

- Land set aside for that species

- Predator dying out

Minimum viable population size

Minimum size needed for a population to survive in the wild

Conservation Biology

Sustainable and management of natural resources

Preservation Biology

Attempts to exclude human activity in areas where humans have not invaded

CITES

Reduces trade in endangered species

Prioritizes

Captive breeding and zoos

Keep species protected in enclosed spaces

Botanical gardens

Keeps plants stored

Flagship species

single large or instantly recognizable species

Keystone Species

Crucial to environments

Designing protected areas

- Surrounding land use for the conservation area

- Distance from Urban areas

- Good agricultural land

- What shape?

- Small or large reserveses

edge effect

Change in populations/environment between two habitats

Ecotone

- Where two habitats meet and there is a near change in boundary

- Where the edge effect occurs

SLOSS

single large or several small reserves