ESS CT1 Flashcards
(64 cards)
1
Q
Biodiversity
A
A broad concept that refers to the variety of life on Earth. It includes the three different diversities; species, habitat, and genetic.
2
Q
Species diversity
A
- The variety of species per unit area; including both the number of species and their relative proportions in communities.
- The higher the species diversity in a community, the greater the complexity.
3
Q
Richness
A
The number of species in an area.
4
Q
Eveness
A
The relative abundance of each species.
5
Q
Habitat diversity
A
The range of different habitats in an ecosystem or biome.
6
Q
Genetic diversity
A
The range of genetic material present in a population of a species.
7
Q
Gene pool
A
- All the different types of genes found within every individual of a species. - A large gene pool leads to high genetic diversity.`
8
Q
Conservation of biodiversity
A
- Focuses on protecting habitats and ecosystems from human-made threats like deforestation and pollution.
- Protecting habitats helps conserve species and genes.
9
Q
Quantification of biodiversity
A
- Using tools like diversity indices (e.g., Simpson’s index) to measure and assess the variety of life in an area.
- It helps understand the impact of disturbances and guides conservation efforts in areas with high biodiversity.
10
Q
Simpson’s index
A
N(N-1) divided by n(n-1) n is no. of individuals
11
Q
Species
A
A group of organisms sharing common characteristics that can interbreed and produce fertile offspring.
12
Q
Habitat
A
The environment in which a species normally lives.
13
Q
Endemic species
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Species that are native to and found only within a limited area
14
Q
Evolution
A
The gradual change in the genetic composition of a species over many successive generations leads to species different from the ancestor.
15
Q
Biological variation
A
- The difference between cells, organisms, or groups of a species.
- It’s caused by genetic differences or the environment’s effect on genetic expression.
16
Q
Natural selection
A
- Individuals with certain traits survive and reproduce more than others because of those traits.
- This happens through evolution, often called survival of the fittest.
17
Q
Speciation
A
Formation of new species when populations of species become isolated and evolve differently.
18
Q
Isolation of populations
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When populations become separated from each other so that genes cannot be exchanged
19
Q
The role of isolation in forming new species
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Natural selection happens and then speciation will occur.
20
Q
Geographical isolation
A
A physical barrier, such as mountains, that causes populations to be separated.
21
Q
Tectonic plates
A
Sections of the Earth’s crust that move due to convection currents. These can create geographical isolation.
22
Q
Plate tectonics
A
The movement and reforming of tectonic plates.
23
Q
Natural causes of species loss
A
- Volcanoes.
- Drought.
- Ice ages.
- Meteor impacts.
- Tectonic movements.
24
Q
Habitat destruction
A
Destroying native habitats and replace them with for example farm lands.
25
Introducing invasive species
If new species are introduced to a new area and compete with the native species, it can lead to the native species going extinct.
26
Why overharvest and hunt?
Animals are hunted for food, medicines, and souvenirs.
Plants can be overharvested due to a huge demand for a crop.
27
Threats to tropical biomes
Tropical biomes are some of the most globally biodiverse areas on Earth. They are threatened by deforestation because it destroys habitats, messes with the canopy layer and the soil, etc.
28
Oil palms and habitat destruction
- Over 90% of the world's palm oil exports come from Malaysia and Indonesia.
- The global demand for palm oil is rising because it’s used in food and bio-diesel.
- This leads to deforestation, as many trees are being cut down, disrupting the environment.
29
Conflict for LEDCs with export and sustainability
- Tropical biomes are mainly in LEDCs, which rely on the forest industry for their economy.
- Unlike MEDCs, LEDCs can't just stop and choose something else.
- LEDCs want to become MEDCs, and economic growth through industries like palm oil is key to that.
30
The Red List
A list of worldwide threatened species maintained by the International Union for Conservation of Nature (IUCN).
31
Purposes of the Red List
- To identify species requiring some level of conservation
- To identify species for which there is concern about their conservation status
- To catalogue plants and animals facing a high risk of global extinction
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Conservation status
Records on how endangered a species are.
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Factors to determine a species' Red List conservation status
Small populations = Less genetic diversity → Higher extinction risk
Top predators = Most vulnerable in food chains
Specialized species = Rely on specific needs → Risky if lost
Fragmented habitat = Harder to maintain populations ( X survive & reproduce)
34
Fragmentation
The process or state of breaking or being broken into small or separate parts.
35
Arguments for preserving biodiversity (AEEES)
Aesthetic = Beautiful to look at
Ecological = Vital for ecosystems and rare species
Economic = Provide income and future genetic resources
Ethical = We must protect nature for future generations
Social = Home to indigenous people and cultural value
36
NGOs
Non-profits = Provide services & humanitarian aid
Focus = Protect & restore ecosystems and biodiversity
Tactics = Use media, activism & research to be heard
Impact = Influence laws but need independence
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IGOs
Global agreements = Unite governments for environmental protection
Approach = Conservative & conventional, not controversial
Research = Fund their studies
Power = Can enforce laws, unlike NGOs
38
In situ conservation
Conservation methods within the natural habitat.
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Ex situ conservation
Preservation of species outside their natural habitats. E.g. botanic gardens and zoos,
40
Area size
Usually, larger is more advantageous because it can host more species.
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Edge effects
Edge Effect = Abiotic changes at protected area borders → Attracts exotic species → Increases competition → Lowers biodiversity.
42
Areas shape
Best shape = Circle (lowest edge effects) → But actual shape depends on available resources & land, so parks are often irregular.
43
Corridors
Pros:
Allow gene flow (immigration & emigration)
Enable seasonal movements
Reduce animal-car collisions
Reduce road areas
Cons:
Species may breed outside reserves, lowering numbers
Exotic pests/diseases can spread between reserves
Poachers can move between reserves
Narrow corridors increase edge effects
44
Buffer zones
Buffer zones = Areas around conservation areas (managed or undisturbed)
Purpose = Minimize outside disturbances (e.g. people and diseases)
Importance = Essential for successful protected areas.
45
Designing protected areas (General)
Large reserves = Better than small (more habitats, bigger populations, less edge effect)
One large > Several small (bigger populations, less edge effect)
Close reserves > Isolated (easier animal dispersal and recolonization)
Clumped reserves > Spread out (better dispersal and recolonization)
Corridors > No corridors (easier animal migration)
Round shape > Other shapes (less edge effect, less poaching)
46
Choosing in situ vs ex-situ conservation
Animal size = Smaller animals are easier to keep in zoos
Threats = Species threatened by habitat loss/diseases need ex-situ conservation
Zoo suitability = Depends on staff expertise & space
Local support = In situ works better with local help, ex-situ if there are political issues
Ex situ = Often used for tourism and revenue, sometimes for species that don’t need it
47
Zoo requirements
No thirst, hunger, or malnutrition.
No thermal or physical discomfort.
No pain, injuries, or diseases.
Enough space for natural behaviours and social interaction.
No fear or distress, with proper treatment to avoid mental suffering
48
Breeding program considerations
Aim to conserve and restore species in the wild.
Genetics should ensure healthy offspring.
Birth control may be needed if there’s no space for more animals.
Keepers might need to intervene if females reject their young.
Updated knowledge of reproduction and genetics is essential.
49
Pros and cons of zoos
Pros:
Educates the public on conservation.
Helps people empathize with wildlife.
Can boost population sizes and genetic diversity of endangered species.
Well-managed zoos with proper space and diet are beneficial.
Cons:
Animals may struggle to re-adapt to the wild and could become prey.
Some species have difficulty breeding in captivity.
Zoo habitats differ from natural ones, especially for species with complex environments
Ethical concerns about caging animals, leading some to boycott zoos.
50
Flagship species
Large, charismatic species are used to promote biodiversity conservation.
They are often cute or beautiful to attract human empathy.
This approach is effective for fundraising.
However, it causes favouritism towards certain species.
A downside is that while species may be preserved in zoos, their natural habitats continue to be destroyed.
51
Keystone species
A keystone species is one that other species in an ecosystem depend on. If it were removed, the ecosystem would drastically change.
Keystone species are crucial to preserve, but identifying them is difficult due to complex ecosystems. It's better to conserve entire ecosystems than focus on individual species.
52
Mixed approach of in situ and ex-situ
The best solution for conservation: Combine different methods.
Example: Giant panda conservation.
Pandas were put in zoos to help preserve them and raise money.
Breeding in zoos was hard, so they also set up nature reserves to protect them in the wild.
53
Crude birth rate (CBR)
The total number of births per 1,000 people in a year.
Formula:
Birth Rate = (Total births divided by total population) × 1000
54
Crude death rate (CDR)
The total number of deaths per 1,000 people in a year.
To compare death rates, use age-specific rates like the infant mortality rate (IMR).
Death rates are usually higher in LEDCs than in MEDCs
Other factors include social class, occupation, and place of residence.
55
Total fertility rate (TFR)
The average number of children a woman will have in her lifetime.
LEDCs tend to have higher TFRs than MEDCs.
Education plays a big role in TFR.
Government laws and programs (e.g., birth control, awareness) also affect TFR.
As GNP increases, TFR tends to decrease.
56
Doubling time (DT)
- The time it takes for a human population to double in size, assuming the natural growth rate remains constant.
- Calculated by taking 70 years divided by NIR.
57
Natural increase rate (NIR)
The percentage by which a population grows in a year.
- Calculated by subtracting CDR from CBR and dividing the whole thing by 10. Expresses as a %.
58
Age/sex pyramids
Population pyramids represent the population based on age, sex, and ethnicity.
They show birth and death rates, baby booms, and immigration and emigration crises.
59
The demographic transition model (DTM)
shows the change in population structure from LEDCs to MEDCs.
It suggests that death rates fall before birth rates, leading to population growth.
60
Strengths and weaknesses of DTM
Strengths:
Helps predict population changes over time.
Shows a clear pattern of development from LEDCs to MEDCs.
Useful for planning resources and policies.
Weaknesses:
Based on data from only a few countries, so not universally applicable.
Doesn’t consider factors like migration or environmental influences.
Assumes all countries will follow the same pattern, which may not be true.
61
Population dynamics
Economic Development: As economies grow, birth rates fall (better education and jobs).
Women’s Emancipation: More education and career options for women lead to fewer children.
Healthcare: Better healthcare lowers death rates and increases life expectancy.
Income Levels: Higher income leads to fewer children.
62
National population policies
Official government actions to control the population in some way. There are pro-natalist policies and anti-natalist ones.
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Pro-natalist policies
Government policies are in favour of increasing the birth rate.
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Anti-natalist policies
Government policies attempting to limit the birth rate.
