paper 2 full notes

Comprehensive review flashcards for AQA Environmental Science Paper 2, covering the living environment, biological resources, and sustainability.

What is Capture-mark-release-recapture

A sampling method used to estimate the size of a mobile animal population when you can’t count every individual directly.

Uses the Lincoln index

How it works:

1. Capture a sample of animals from the habitat

2. Mark them gently (e.g. tags, paint, without harming them)

3. Release them back into the area to mix freely with the rest of the population

4. After enough time, recapture a second sample

5. Count how many in the second sample are already marked

What is the Lincoln index formula?

N = MxR / S

• N = Estimated total population size

• M = Number marked and released in first sample

• R = Total number captured in second sample

• S = Number of marked individuals recaptured in second sample

(Used for capture mark release recapture)

What are the assumptions for the Lincoln index?

• Marking doesn’t harm the animal or make it more visible to predators

• Marks don’t wear off or fall off

• Marked animals mix fully back into the population

• No births, deaths, immigration or emigration between samples

• Equal chance of being caught for all individuals

Which gases were retained by Earth's gravity to allow early life to develop?

$CO_2$, $CH_4$, and $N_2$.

How did Earth's atmospheric pressure contribute to the development of life?

It kept water in a liquid state.

What factors controlled the temperature range on early Earth relative to insolation?

Incoming solar radiation, albedo, and IR absorption.

Why is Earth's position in the solar system critical for life?

It maintains a suitable distance from the Sun to sustain liquid water temperatures.

What three things create daily and seasonal temperature variations on Earth?

Earth's tilt, rotation, and orbit.

What is the function of the magnetosphere in protecting life?

The molten core generates a magnetic field that deflects harmful solar radiation.

Which organisms were the first to produce oxygen on Earth?

Photosynthetic bacteria, followed by algae and land plants.

How did the ozone layer form?

It formed when $O_2$ reacted with UV radiation in the stratosphere.

What is the biological importance of the ozone layer?

It acts as a UV shield.

How did photoautotrophs change the atmosphere's carbon levels?

They performed carbon sequestration, reducing atmospheric $CO_2$ levels.

What is the role of living organisms in biogeochemical cycles?

They link cycles, preventing waste build-up and resource shortages.

What was a major limitation of early historical condition monitoring methods?

A lack of ancient data and lack of coordination.

What modern method is used to provide long-term data sets for monitoring?

Electronic monitoring data sets.

Which method is used for gas analysis of prehistoric atmospheres?

Ice core gas analysis.

What can ice core isotope analysis tell researchers?

It provides historical environmental data as a proxy method.

Name three platforms used for modern environmental sensors.

Satellites, aircraft, and balloon-mounted sensors.

What are two biological proxy examples used for monitoring historical conditions?

Dendrochronology and pollen analysis.

What are two modern biological monitoring techniques mentioned?

eDNA and acoustic monitoring.

Name five resources derived from wild species as humans benefit from biodiversity.

Timber (structural), fibres, vegetable oils, biofuels, and new food crops.

What is biomimetics?

The practice of copying organisms for engineering purposes like vehicle design, adhesion, ultrasound, and structures.

Why are genetic resources from wild crop relatives valuable?

They hold genes for improving cultivars (found in Vavilov centres/Centres of Diversity).

List four categories of ecosystem services provided by biodiversity.

Atmospheric regulation, biogeochemical cycling, interspecies relationships, and soil formation/erosion control.

What role do detritivores and decomposers play in ecosystem services?

They contribute to soil formation and erosion control.

What are three examples of interspecies relationships contributing to ecosystem services?

Pollination, seed dispersal, and habitat provision.

Which gases are involved in atmospheric regulation via ecosystem services?

$O_2$, $CO_2$, and water vapour.

What are three examples of direct exploitation causing biodiversity loss?

Food, fashion, furniture, traditional medicines, and entertainment.

What is meant by deliberate eradication in the context of biodiversity?

The removal of predators and competitors.

Provide an example of abiotic factor changes related to nutrients caused by humans.

Fertiliser runoff.

Provide an example of abiotic factor changes related to pH caused by humans.

Acid mine drainage.

What is thermal pollution an example of in conservation?

An abiotic factor change caused by human impact.

How do introduced species impact biodiversity?

They cause biotic factor changes and loss of inter-species relationships.

List five causes of habitat destruction.

Deforestation, agricultural expansion, urbanisation, mining, and reservoirs.

What are the two primary roles of the IUCN?

Coordinating global biodiversity data and deploying nature-based solutions.

What is the IUCN Red List?

A classification system for threatened species.

What does the acronym EDGE stand for?

Evolutionarily Distinct & Globally Endangered.

Why are EDGE species high conservation priorities?

They diverged long ago and have high genetic uniqueness.

What is an endemic species?

A species found only in one specific area, usually with small populations.

What is a keystone species?

A species with a disproportionate importance for ecosystem stability.

What is a flagship species?

A charismatic species used to promote conservation efforts.

What is the key UK legislation for species and habitat protection?

Wildlife and Countryside Act (1981).

Define SSSI.

Site of Special Scientific Interest.

Define NNR.

National Nature Reserve.

Define SAC.

Special Area of Conservation.

Define SPA.

Special Protection Area.

What is Natura 2000?

An EU-wide network of protected areas.

What are Ramsar sites designated for?

Wetlands of international importance.

What designations apply to marine protected zones?

MNR, MPA, and MCZ.

Define LNR.

Local Nature Reserve.

What does CITES stand for?

Convention on International Trade in Endangered Species.

What is the difference between CITES Appendix I and Appendix II?

Appendix I bans trade; Appendix II regulates trade.

What does IWC stand for and what is its role?

International Whaling Commission; it regulates whaling.

What is the role of the EU Common Fisheries Policy (CFP)?

It manages European fisheries.

What does ITTO stand for?

International Tropical Timber Organisation.

When is Captive Breeding and Release (CBR) used?

When in-situ conservation is insufficient.

What are the two main selection criteria for captive breeding?

Species facing extinction in the wild and species feasible to breed in captivity.

What techniques are used to increase captive breeding success?

Managing abiotic conditions/group dynamics, artificial insemination, and embryo transfer.

Contrast soft release vs. hard release programmes.

Soft release involves gradual acclimatisation; hard release is immediate introduction to the wild.

Why is post-release monitoring essential for CBR?

To track survival and the success of the reintroduction.

List two examples of habitat creation types.

Wetlands and woodlands.

What is rewilding?

A form of habitat restoration or habitat creation.

Which structural factors affect habitat conservation success?

Area, shape, age structure, ease of colonisation, and biological corridors.

What are the key features of temperate broadleaf woodlands?

Seasonal, moderate climate.

Why are temperate broadleaf woodlands important?

High biodiversity, resources, and climate/soil control.

What are the main threats to temperate broadleaf woodlands?

Deforestation and fragmentation.

What are the key features of tropical rainforests?

Hot, wet climate with high biodiversity and low seasonality.

What roles do tropical rainforests play in global systems?

Carbon sequestration, hydrology, and biodiversity maintenance.

What are the main threats to tropical rainforests?

Fuelwood collection, agriculture, mining, and climate change.

What is a 'Debt for Nature Swap'?

A conservation strategy used to protect ecosystems like tropical rainforests.

What organisms are the primary builders of tropical coral reefs?

Cnidarians.

What environmental conditions do tropical coral reefs require?

Warm, clear, and stable seawater.

List three importance factors of tropical coral reefs.

Fisheries, erosion protection, and tourism.

What are the main threats to tropical coral reefs?

Bleaching, sedimentation, pollution, and fishing.

How do deep-water coral reefs differ from tropical ones?

They are cold, dark, and have slow growth.

What are the main threats to deep-water coral reefs?

Trawling and ocean acidification.

Why are oceanic islands prioritize for conservation?

They often contain isolated endemic species with few natural predators.

What are the main threats to oceanic islands?

Introduced species, habitat change, and sea level rise.

What are the features of mangroves?

Tropical, halophytic trees growing in low $O_2$ conditions.

Why are mangroves important for coastal regions?

They provide coastal protection, fisheries habitat, and timber.

What treaty manages the conservation of Antarctica?

Antarctic Treaty (1959).

Why is Antarctica important globally?

It acts as a water store, carbon sink, and center for research.

What are the main threats to Antarctica?

Climate change, ozone depletion, tourism, and fishing.

Name four population dynamics parameters to monitor in ecological studies.

Size, distribution, survival rate, and age structure.

How is environmental DNA (eDNA) used in monitoring?

It uses DNA databases to identify species presence from environmental samples.

What is a sonogram used for in monitoring?

Acoustic monitoring of species.

List four abiotic factor requirements for species.

Light, water, nutrients, and pH.

List three biotic factor requirements for species.

Food, pollination, and seed dispersal.

Define the term 'Species'.

A group of organisms able to interbreed.

Define 'Taxon'.

Any named group in biological classification.

What is an ecological niche?

An organism's role in its ecosystem, comprising its habitat and function.

Define 'Population'.

Individuals of one species living in a specific area.

Define 'Community'.

All species living in a specific area.

Define 'Ecosystem'.

A community plus its abiotic environment.

What is a Biome?

A large-scale ecosystem type defined by climate.

What is ecological succession?

The process where pioneer species colonise bare ground and modify conditions for subsequent species.

What is a 'Sere'?

A specific stage in ecological succession.

What is a 'Climax community'?

A stable final community suited to the local climate.

What is deflected succession?

When disturbance prevents an ecosystem from reaching a climax community.