Conservation Of Biodiversity

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What is Biodiversity?

Biodiversity is the variety of life that exists in a specified area, from global to local scales.
It is important for the resilience of ecosystems; more biodiverse ecosystems are more stable and resistant to change.
Biodiversity is studied at three levels: ecosystem, species, and genetic diversity.

Marine diversity over 600 million years

Ecosystem Diversity

Ecosystem diversity is the range of different ecosystems or habitats within a particular area.
A large number of different habitats means high ecosystem diversity; few habitats means low ecosystem diversity.
Coral reefs are complex with many microhabitats and niches, so they have high ecosystem diversity.
Large sandy deserts have very low ecosystem diversity because conditions are similar throughout.

Species Diversity

Species richness is the number of species within an ecosystem.
Species evenness is the number of individuals of each species within an ecosystem.
High species diversity requires both high species richness and high species evenness.
An ecosystem with many species but few individuals of most species has high richness but low evenness.
An ecosystem with few species but many individuals of each has high evenness but low richness.
Ecosystems with high species diversity are usually more stable and resilient to environmental changes.
For example, pine forests dominated by one or two tree species can collapse if a pathogen wipes out a dominant species.

Genetic Diversity

Genetic diversity is the number of different alleles of genes present in a species or population.
It depends on the proportion of genes with more than one allele and the number of different alleles each gene has.
Genetic differences can exist between populations of the same species due to different selection pressures.
Genetic differences also exist between individuals within a population.
Genetic diversity helps populations adapt to and survive changes in the environment.

Biodiversity Change Over Time

Recent estimates suggest there could be around 8.7 million species on Earth, but only about 1.2 million have been recorded and classified.
The fossil record shows that many past species are now extinct, and there are more species alive today than ever before.
Speciation increases the number of species; when speciation outpaces extinction, global biodiversity increases.
Despite recent extinctions, past periods of speciation mean global biodiversity is still higher than ever.
Classification is subjective; taxonomists may be 'lumpers' (focus on similarities) or 'splitters' (focus on differences).
Incorrect classification affects estimates: lumping too much makes estimates too small, splitting too much makes them too large.

Anthropogenic Extinction

Anthropogenic extinction is extinction caused by human activities.
Scientists believe we are experiencing a mass extinction event, potentially the sixth mass extinction.
North Island giant moa was a large flightless bird hunted to extinction by humans by 1300.
Caribbean monk seals were hunted for oil and meat and declared extinct in 2008.
You need to know three case studies: North Island giant moas, Caribbean monk seals, and a third species of your choice.

Shrinking range of the giraffe

Ecosystem Loss

Human activities damage and destroy ecosystems, e.g. deforestation.
Mixed dipterocarp forests in Southeast Asia are being lost; some areas have lost over 50% of their forests.
Clear-cutting removes all trees, providing timber and clearing land for agriculture such as palm oil plantations.
You need to know two case studies: mixed dipterocarp forests and a second ecosystem loss case study of your choice.

Evidence for Biodiversity Loss

Reliable evidence requires many surveys in a wide range of habitats, repeat data over time, and assessment of both species richness and evenness.
Citizen scientists are members of the public who help gather data, increasing volume but with a trade-off in quality.
IPBES gathers information, recommends policies, and communicates findings on global biodiversity.
IUCN maintains the Red List, which assesses over 150,000 species and lists more than 42,000 as threatened.
IUCN categories include LC (least concern), NT (near threatened), VU (vulnerable), EN (endangered), CR (critically endangered), EW (extinct in the wild), and E (extinct).

Causes of Biodiversity Loss

The growth of the global human population (over 8 billion) is likely the main cause of the biodiversity crisis.
Overexploitation includes overfishing and hunting for ivory, oil, or fur.
Urbanisation causes direct habitat loss and fragmentation by roads.
Deforestation clears land for agriculture, timber, mining, and quarries; agriculture often involves monocultures with low biodiversity.
Pollution includes microplastics and fertiliser runoff into water bodies.
Invasive species such as grey squirrels, cane toads, and rats damage native habitats.
Disease can wipe out species, e.g. chytrid fungus has wiped out 90 amphibian species.

How to Preserve Biodiversity

A mixture of approaches is needed because there is no single solution and conflicts exist between human and natural needs.
In situ conservation includes protected areas, rewilding, and reclamation.
Ex situ conservation includes zoos, botanic gardens, seed banks, and tissue banks.
Protected areas such as national parks and nature reserves restrict human access, regulate industry, and limit hunting.
Rewilding restores ecosystems to be self-sustaining; active rewilding involves human intervention, passive rewilding leaves nature to recover.
Reclamation restores areas damaged by human activities, such as abandoned quarries.

Raising awareness of biodiversity

Ex Situ Conservation Methods

Zoos use captive breeding and artificial insemination to increase numbers and genetic diversity, and are valuable for research.
Botanic gardens use cuttings, seeds, tissue culture, and cloning to establish captive plant populations for reintroduction and research.
Seed banks store dried seeds in cool, temperature-controlled conditions; seeds are periodically grown and replaced to maintain viability.
The Svalbard Global Seed Vault in Norway stores seeds from almost 1 million plant species.
Tissue banks (frozen zoos) store genetic material at very low temperatures; germplasm (sperm, eggs, embryos) can be used for breeding, somatic tissue for DNA research and potential cloning.

Prioritising Species for Conservation

The EDGE programme (Evolutionarily Distinct and Globally Endangered) works with ZSL to prioritise species.
Priority species must be both evolutionarily distinct (few close relatives, unusual traits) and globally endangered (on the IUCN Red List).
Examples of EDGE species include largetooth sawfish, Chinese giant salamander, and purple frog.
EDGE does not make conservation decisions but provides information to stakeholders for debate.
Complex ethical, environmental, political, social, cultural, and economic issues affect conservation priorities.

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Practice questions

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1.Which of the following best defines biodiversity?
Easy
- AThe variety of life that exists in a specified area
- BThe total number of individuals of a single species in an area
- CThe number of different alleles in a population
- DThe total biomass of all organisms in an ecosystem
2.Which of the following is a correct explanation for biodiversity change?
Easy
- ASpecies extinctions occur due to anthropogenic extinction.
- BScientists have changed the way species are classified.
- CClassification can be subjective.
- DThere are more species alive today than have been alive in the past.
3.Which of the following describe(s) anthropogenic extinction? (select all that apply)
Medium
- ANorth Island giant moas were hunted to extinction between 1200-1300.
- BAn asteroid strike resulted in the extinction of most of the dinosaurs around 65 million years ago.
- CCaribbean monk seals were hunted to extinction to provide oil and food.
- DThe extinction of the dinosaurs was caused by human hunting.
- EThe vaquita declined due to bycatch in gillnets.
4.Biodiversity can be studied at three levels: ecosystem, species, and genetic.
Easy
True or false?
5.Which statement(s) about biodiversity is/are correct? I. Biodiversity is a measure of the number of species present. II. Biodiversity can be assessed at the ecosystem level. III. Genetic diversity considers the number of genes that a species has.
Medium
- AI only
- BI and II only
- CII and III only
- DI, II and III
6.Which of the following is an important factor in mixed dipterocarp ecosystem loss in Southeast Asia?
Easy
- AIntroduction of non-native species.
- BEstablishment of nature reserves.
- CClear-cutting of trees to provide agricultural land.
- DChanges in atmospheric oxygen levels.
7.Match each type of biodiversity with its correct description.
Medium
- Ecosystem diversity
- Species diversity
- Genetic diversity
- The number of different alleles of genes present
- The range of different ecosystems or habitats within an area
- The number of species and individuals of each species within an ecosystem
8.Which of the statements about conservation is correct?
Medium
- AThe EDGE programme is concerned with conserving all evolutionarily distinct species.
- BIn-situ conservation is appropriate for all endangered species.
- CEx-situ conservation provides opportunities for important research.
- DOnly body tissue can be stored in tissue banks.

More questions

9.Anthropogenic extinction refers to extinction caused by natural events such as asteroid strikes.
Easy
True or false?
10.A study looked at the effect of regional cold weather on wren populations in the UK. Which of the statements about the results of the study is correct?
Medium
- AThe results cannot be trusted because data collected by citizen scientists may not be valid.
- BThere is a positive correlation between mean winter frost days and mean wren abundance.
- CSevere winter weather has a negative impact on wren populations.
- DAn increase in mean frost days is causing a decline in wren populations over time.
11.Place the following IUCN Red List categories in order from least to most threatened.
Medium
- Least Concern
- Near Threatened
- Vulnerable
- Endangered
- Critically Endangered
12.Which of the following are causes of biodiversity loss? (select all that apply)
Medium
- AOverexploitation of resources
- BUrbanisation
- CIntroduction of invasive species
- DEstablishment of protected areas
- EPollution
13.There are currently around 1.3 million known species, which is estimated to be approximately 15% of the true number of species on Earth. Calculate the estimated true number of species on Earth.
Hard
- A8.7 million
- B1.5 million
- C19.5 million
- D195 million
14.Which of the following are factors that contribute to genetic diversity within a species? (select all that apply)
Medium
- AThe proportion of genes that have more than one allele
- BThe number of different alleles that each gene has
- CThe total number of species present in an ecosystem
- DThe variety of habitats within an area
- EThe number of individuals of each species present
15.An ecosystem contains 1000 species, but 500 of these species are represented by only a few individuals each. Which statement best describes this ecosystem?
Medium
- AIt has high species richness but low species evenness.
- BIt has low species richness but high species evenness.
- CIt has high species richness and high species evenness.
- DIt has low species richness and low species evenness.
16.The IUCN Red List assesses species based on their risk of extinction.
Easy
True or false?
17.Which of the following are in situ conservation methods? (select all that apply)
Medium
- AProtected areas
- BRewilding
- CReclamation
- DZoos
- ESeed banks
18.Match each conservation method with its correct description.
Medium
- Protected area
- Rewilding
- Reclamation
- Zoo
- Seed bank
- A defined geographical space managed and protected for conservation
- Restoration of ecosystems to a point where they can sustain themselves
- Restoration of areas damaged by human activities such as abandoned quarries
- Captive breeding programmes can increase numbers and allow research
- Conserves plant diversity by drying and storing seeds in a temperature-controlled environment
19.Which of the following statements about ex situ conservation are correct? (select all that apply)
Hard
- ACaptive breeding in zoos can increase the number of individuals of a species.
- BArtificial insemination can help maintain genetic diversity between zoos.
- CSeed banks store seeds in warm, humid conditions to increase viability.
- DTissue banks store genetic material at very low temperatures.
- EBotanic gardens use cuttings and seeds from the wild to establish captive populations.
20.A farmer plants crops in September and harvests in June/July instead of the traditional April planting and September harvest. Scientists monitor the number of farmland bird species within a 1 km radius of this farm over 10 years. Which statement best describes the expected result compared with a farm that plants in April?
Medium
- AThe number of bird species will decline because the change in crop timing reduces food availability at critical times.
- BThe number of bird species will increase because crops are present for a longer period.
- CThe number of bird species will remain unchanged because planting time does not affect birds.
- DThe number of bird species will increase because more insects are available in June/July.
21.The IUCN Red List categorises species by their risk of extinction. A species is classified as 'critically endangered' (CR). Which of the following best describes what this classification means for conservation priority?
Hard
- AThe species faces an extremely high risk of extinction in the wild and is a high priority for conservation action.
- BThe species is extinct in the wild but survives in captivity.
- CThe species is at low risk of extinction and does not require conservation action.
- DThe species is only threatened at a local level, not globally.
22.Which of the following are potential conservation strategies that could be used to help the vaquita species? (select all that apply)
Medium
- AEstablishing protected areas in the vaquita's habitat
- BBanning gillnets in the vaquita's habitat
- CCaptive breeding programmes
- DIncreasing fishing in the vaquita's habitat
- EIntroducing invasive species to the vaquita's habitat
23.The EDGE programme prioritises species that are evolutionarily distinct and globally endangered.
Easy
True or false?
24.In an experiment measuring bird species diversity on farmland, which type of biodiversity is being measured?
Medium
- ASpecies diversity
- BGenetic diversity
- CEcosystem diversity
- DFunctional diversity
25.Which of the following changes could be made to improve ecosystem diversity in an agricultural area? (select all that apply)
Hard
- APlanting hedgerows
- BCreating ponds
- CGrowing monocultures
- DLeaving field margins unploughed
- ERemoving all trees
26.A study used data from a citizen science project to investigate the effect of regional cold weather on wren populations. Which statement about the results is correct?
Medium
- ASevere winter weather has a negative impact on wren populations.
- BThere is a positive correlation between mean winter frost days and mean wren abundance.
- CThe results cannot be trusted because citizen scientists may not be valid.
- DAn increase in mean frost days is causing a decline in wren populations over time.
27.Which of the following statements about conservation is correct?
Medium
- AEx-situ conservation provides opportunities for important research.
- BThe EDGE programme is concerned with conserving all evolutionarily distinct species.
- CIn-situ conservation is appropriate for all endangered species.
- DOnly body tissue can be stored in tissue banks.
28.A student surveys two habitats. Habitat A contains 40 species with roughly equal numbers of individuals in each. Habitat B contains 40 species, but 35 of these species are each represented by a single individual. Which statement best compares the species diversity of the two habitats?
Medium
- ABoth habitats have equal species diversity because they have the same species richness
- BHabitat A has higher species diversity because it has higher species evenness
- CHabitat B has higher species diversity because rare species add more diversity
- DSpecies diversity cannot be compared without knowing the genetic diversity of each habitat
29.A citizen science project asks members of the public to record bird sightings over 20 years. Scientists then analyse the data. Which of the following is the main reason this approach is used despite concerns about data quality?
Hard
- ACitizen scientists are more accurate than professional scientists
- BIt allows a much larger volume of data to be collected across a wide range of habitats and over long time periods
- CIt removes the need for expert data analysis
- DIt guarantees that both species richness and evenness are measured correctly
30.A conservation team wants to restore a degraded grassland. They decide to introduce grazing animals rather than simply leaving the area alone. Why is passive rewilding alone unlikely to restore this habitat?
Hard
- APassive rewilding only works on privately owned land
- BWithout grazing, tree species would dominate and the grassland habitat would be lost through succession
- CGrazing animals are needed to increase the rate of speciation
- DGrasslands cannot be restored by any form of rewilding
31.Which of the following are required for evidence of biodiversity loss to be considered trustworthy? (select all that apply)
Medium
- ASurveys carried out across a wide range of habitats
- BRepeat survey data collected over a period of time
- CAssessment of both species richness and species evenness
- DData collected from a single site in a single year
- EData analysed only by the members of the public who collected it
32.A zoo runs a captive breeding programme for an endangered mammal. Which of the following are benefits of using artificial insemination in this programme? (select all that apply)
Hard
- AIt allows gene flow between individuals living in different zoos
- BIt helps to prevent problems arising from low genetic diversity
- CIt guarantees that offspring will survive when released into the wild
- DIt removes the need to study the species' habitat requirements
- EIt can avoid some difficulties associated with captive breeding
33.Seed banks store seeds in cool, dry conditions because this generally increases the length of time for which the seeds remain viable.
Easy
True or false?
34.If taxonomists incorrectly classify two separate species as one, the estimated total number of species on Earth will be too large.
Medium
True or false?
35.Match each term relating to conservation evidence and data collection with its correct description.
Medium
- Citizen scientists
- IPBES
- IUCN Red List
- Data deficient (DD)
- Members of the public who help to gather biodiversity data
- Organisation that gathers information and recommends policies on global biodiversity
- A list of the world's most threatened species, categorised by extinction risk
- A category used when there is not enough data to assign a threat category
36.Place the following steps in the correct order to show how a seed bank maintains a stored collection over time.
Medium
- Seeds are collected from the wild
- Seeds are dried and stored in a temperature-controlled environment
- After a certain period, stored seeds are grown into plants
- Fresh seeds are collected from those plants for storage
37.Which of the following would be an in situ conservation method for this frog species?
Hard
- AEstablishing a protected reserve in its remaining forest habitat
- BBreeding the frogs in a zoo and releasing them later
- CStoring frog sperm cells in a tissue bank
- DGrowing food plants for the frogs in a botanic garden
38.The frog species has few close evolutionary relatives and is unusual in appearance, behaviour and DNA. According to the EDGE programme, what else must be true for it to be prioritised for conservation?
Hard
- AIt must be culturally important to a single nation
- BIt must be globally threatened, not just threatened locally
- CIt must be able to survive in captivity
- DIt must be the only species in its ecosystem
39.A scientist argues that global biodiversity is currently higher than at any time in the past, despite ongoing extinctions. Which of the following best supports this argument?
Challenge
- AExtinction rates have been higher than speciation rates in recent years
- BPeriods of speciation in the past, combined with ongoing speciation, have produced more species than have been lost
- CThe fossil record shows that all past species are still present today
- DClassification of species has become completely objective and accurate
40.Two taxonomists disagree about whether two similar populations of birds are one species or two. One focuses on their similarities, the other on their differences. Which terms best describe these two taxonomists?
Hard
- AThe first is a splitter and the second is a lumper
- BThe first is a lumper and the second is a splitter
- CBoth are lumpers
- DBoth are splitters
41.Complete the sentence about species diversity.
Easy
Species diversity can be measured in two ways: species ____ is the number of species within an ecosystem, and species ____ is the number of individuals of each species within an ecosystem.
42.State the type of extinction that occurred to the Caribbean monk seal.
Easy
43.The number of vaquita declined from 567 individuals in 1997 to 245 individuals in 2008. Calculate the rate of decline in vaquita numbers per year from 1997 to 2008. Give your answer to 2 decimal places.
Medium
44.Complete the sentence about conservation.
Easy
The EDGE programme prioritises species that are both evolutionarily ____ and globally ____.
45.The number of vaquita declined from 30 individuals in 2016 to 19 individuals in 2018. Calculate the rate of decline in vaquita numbers per year from 2016 to 2018.
Medium
46.Complete the sentence about the EDGE programme.
Easy
A species must be both evolutionarily ____ and globally ____ to be prioritised by the EDGE programme.
47.The number of vaquita declined from 567 individuals in 1997 to 19 individuals in 2018. Calculate the rate of decline in vaquita numbers per year over this entire period. Give your answer to 2 decimal places.
Hard
48.Complete the sentence about biodiversity.
Easy
Biodiversity can be studied at three levels: ecosystem, ____, and genetic.
49.There are currently around 1.3 million known species, which is estimated to be approximately 15% of the true number of species on Earth. Calculate the estimated true number of species on Earth. Give your answer in millions to 1 decimal place.
Medium
50.There are currently around 1.3 million known species, which is estimated to be approximately 15% of the true number of species on Earth. Calculate the estimated true number of species on Earth. Give your answer in millions, to 2 significant figures.
Medium
51.The number of vaquita declined from 567 individuals in 1997 to 245 individuals in 2008. Calculate the rate of decline in vaquita numbers per year from 1997 to 2008. Give your answer to 1 decimal place.
Medium
52.The number of vaquita declined from 30 individuals in 2016 to 19 individuals in 2018. Calculate the rate of decline in vaquita numbers per year from 2016 to 2018. Give your answer to 1 decimal place.
Medium
53.Explain the process that species must go through in order to be considered a priority for conservation by the EDGE programme.
Hard
54.Explain two ways taxonomists might choose to classify species that are in conflict with each other.
Hard
55.Explain three specific reasons why the Caribbean monk seal went extinct.
Hard
56.In recent years, farmers have merged grazing fields together by removing hedgerows. Explain why this has resulted in a decline in the biodiversity of farmland birds.
Hard
57.Explain why data collected by citizen scientists may need to be carefully analysed by experts before it is used as evidence of biodiversity loss.
Hard
58.The number of vaquita declined from 567 individuals in 1997 to 245 individuals in 2008. Calculate the rate of decline in vaquita numbers per year from 1997 to 2008. Give your answer to 2 decimal places.
Medium
- A35.13 individuals per year
- B32.2 individuals per year
- C26.34 individuals per year
- D29.27 individuals per year
59.The number of vaquita declined from 30 individuals in 2016 to 19 individuals in 2018. Calculate the rate of decline in vaquita numbers per year from 2016 to 2018.
Medium
- A6.5 individuals per year
- B7.5 individuals per year
- C5.5 individuals per year
- D4.5 individuals per year
60.The number of vaquita declined from 567 individuals in 1997 to 19 individuals in 2018. Calculate the rate of decline in vaquita numbers per year over this entire period. Give your answer to 2 decimal places.
Hard
- A28.7 individuals per year
- B31.3 individuals per year
- C23.5 individuals per year
- D26.1 individuals per year
61.There are currently around 1.3 million known species, which is estimated to be approximately 15% of the true number of species on Earth. Calculate the estimated true number of species on Earth. Give your answer in millions to 1 decimal place.
Medium
- A8.7 million species
- B7.7 million species
- C10.7 million species
- D9.7 million species
62.There are currently around 1.3 million known species, which is estimated to be approximately 15% of the true number of species on Earth. Calculate the estimated true number of species on Earth. Give your answer in millions, to 2 significant figures.
Medium
- A9.7 million species
- B10.7 million species
- C7.7 million species
- D8.7 million species
63.The number of vaquita declined from 567 individuals in 1997 to 245 individuals in 2008. Calculate the rate of decline in vaquita numbers per year from 1997 to 2008. Give your answer to 1 decimal place.
Medium
- A35.1 individuals per year
- B32.2 individuals per year
- C29.3 individuals per year
- D26.4 individuals per year
64.The number of vaquita declined from 30 individuals in 2016 to 19 individuals in 2018. Calculate the rate of decline in vaquita numbers per year from 2016 to 2018. Give your answer to 1 decimal place.
Medium
- A5.5 individuals per year
- B7.5 individuals per year
- C4.5 individuals per year
- D6.5 individuals per year

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