A4.2_Conservation of biodiversity

A4.2 Conservation of Biodiversity

Guiding Questions

• What factors are causing the sixth mass extinction of species?
• How can conservationists minimize the loss of biodiversity?

A4.2.1 Biodiversity as the variety of life in all its forms, levels and combinations

Biodiversity: the variety of living organisms including plants, animals and microorganisms. There are three levels (D4.2.2):

A4.2.1 Biodiversity as the variety of life in all its forms, levels and combinations

Genetic diversity: Variation that exists in genes of a population (same species) Higher genetic variation increases the probability of alleles in the gene pool that allow an organism to adapt to changing environmental conditions. For example: evolution of DDT resistant mosquitoes

Remember sources of variation? (D2.1)

A4.2.1 Biodiversity as the variety of life in all its forms, levels and combinations

Genetic diversity:

Alleles

Survival

Variation

Mutations

A4.2.1 Biodiversity as the variety of life in all its forms, levels and combinations

Genetic diversity:

Alleles

Survival

Variation

Mutations

A4.2.1 Biodiversity as the variety of life in all its forms, levels and combinations

Genetic diversity:

https://youtu.be/XOxsjdB4-ZQ

A4.2.1 Biodiversity as the variety of life in all its forms, levels and combinations

Species diversity: The variety of species seen in a particular habitat

• Species richness: the number of different species in the area.
• Species evenness: the relative abundance of different species in the given area.

• High: the species abundance is similar across different species
• Low: the numbers of individuals of each species vary

A4.2.1 Biodiversity as the variety of life in all its forms, levels and combinations

Species diversity: The Simpson’s reciprocal index can be used to measure the relative biodiversity of a given community

• It takes into account the species richnes and evenness
• Can be used to compare communities to identify intrinsic qualities
• A higher index is indicative of a greater degree of biodiversity, suggesting:
• a stable site with many different niches
• low competition
• A low index value suggests a site with
• few potential niches where
• only a few species dominate

The index value may change in response to an ecological disturbance (such as human intervention or natural disasters)

A4.2.1 Biodiversity as the variety of life in all its forms, levels and combinations

Species diversity:

Sample A Sample B

1. Which sample shows higher richness? 2. Which sample shows the highest evenness? 3. Which sample shows higher biodiversity according to the Simpson's reciprocal index?

A4.2.1 Biodiversity as the variety of life in all its forms, levels and combinations

Ecosystem diversity:

Different ecosystems within the same area

Example - Rainforest

• the canopy, formed of overlapping branches and leaves of tall trees
• the understory that lies several metres below the canopy
• the forest floor.

Frontiers are not fixed, there are no "limits" between them.

A4.2.2— Comparisons between current number of species on Earth and past levels of biodiversity.

Current vs past biodiversity Strong evidence on past biodiversity comes from fossils However, only a very small percentage of animals that lived on the Earth became fossils. Still, the number of species seen on Earth today is thought to be more varied in number and complexity than at any point in the past.

A4.2.2— Comparisons between current number of species on Earth and past levels of biodiversity.

Known vs hidden biodiversity

• 8.7 million species of plants and animals in existence
• But only 1.2 million species have been identified and categorised.
• This means that 86% of the species still remain to be discovered
• The numbers are higher for procariotes

Kodama jujutsu Japan

Hipposideros kingstonaeThailand and Malasya

Venomius tomhardyi Tasmania

Hyloscirtus tolkieniEcuador

New species discovered in 2023

Sibon irmelindicaprioaePanama and Colombia

Gekko mizoramensis Sout East Asia

https://www.discoverwildlife.com/news/new-species-discovered-this-year

A4.2.2— Comparisons between current number of species on Earth and past levels of biodiversity.

A4.2.2— Comparisons between current number of species on Earth and past levels of biodiversity.

A4.2.3— Causes of anthropogenic species extinction.

We are currently experiencing the sixth mass extinction.

• overexploitation due to overhunting or overharvesting
• habitat loss due to human activity
• introduction of invasive or alien species outcompeting native species
• habitat degradation due to pollution
• climate change.

A4.2.3— Causes of anthropogenic species extinction.

The extinction of the Moas (Dinornis novaezealandiae)

New Zealand bird. Became extinct 600 years ago Evidence (Fossil and DNA) points at anthropogenic extinction: - Large birds offered big meals - Small birds and eggs were easy to collect

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1810089/

A4.2.3— Causes of anthropogenic species extinction.

The extinction of the Caribbean Monk Seal (Neomonachus tropicalis)

• In the 17th century fishermen killed hundreds of seals every night to fuel oil lamps and grease machinery.
• On the 18th and 19th centuries they were hunted for their blubber and other products
• Overfishing in the waters where they lived lead to shortness of food sources like fish and molluscs.
• The last sighting of the animal was in 1952.

A4.2.4— Causes of ecosystem loss.

Habitat transformation: logging, farming...

Climate change

Species explotation

Pollution

A4.2.4— Causes of ecosystem loss.

Loss of mixed dipterocarp forest in Southeast Asia Causes:

• Trees are highly prized for their timber and are extensively felled
• Clearing of the forests for palm oil plantations

Consequences:

• Loss of habitat (orangutans, elephants...)
• Carbon sink loss
• ...

Any CAS ideas?

A4.2.3— Causes of anthropogenic species extinction AND A4.2.4— Causes of ecosystem loss.

Investigate the anthropogenic reasons for the extinction of one species and one ecosystem loss in your area (Europe)

• Work in groups of 4
• Prepare an infographic for each including:
• Species infographic:
• Brief description of the species
• Region were it used to live
• Anthropogenic causes of extinction
• Ecosystem infographic:
• Brief description and region
• Anthropogenic causes
• Consequences

• Upload them to Managabac

Case study

A4.2.5 - Evidence for a biodiversity crisis.

Reliable sources of evidence for a biodiversity crisis include:

• The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) is an intergovernmental body which assesses the state of biodiversity and periodically produces reports.
• Environmental monitoring:
• Population size of a species
• Range of a species
• Diversity of species in an ecosystem
• Richness and evenness in an ecosystem
• Area occupied by an ecosystem
• Extent of degradation of an ecosystem
• e.g. fragmentation of a forest
• Number of threatened species within

a taxonomic group

• Genetic diversity within a species
• The IUCN

A4.2.5 - Evidence for a biodiversity crisis.

Citizens can help monitoring!

A4.2.5 - Evidence for a biodiversity crisis.

Reliable sources of evidence for a biodiversity crisis include:

• The IUCN (International Union for Conservation of Nature) Red List of Threatened Species and the IUCN Red List of Ecosystems seek to assess current status and inform conservation action and policy.

A4.2.6- Causes of the current biodiversity crisis.

The human population grew exponentially from 1 billion to 7 billion in just 200 years. In 2011, the human population was 7 billion and in November 2022, it reached 8 billion

https://www.youtube.com/watch?v=PUwmA3Q0_OE

A4.2.6- Causes of the current biodiversity crisis

Human population growth together with:

• hunting and other forms of over-exploitation;
• urbanization;
• deforestation and clearance of land for agriculture;
• pollution
• global transport
• spread of pests and diseases
• invasive alien species

Any CAS ideas?

A4.2.7— Need for several approaches to conservation of biodiversity.

Conservation of biodiversity is the protection of species and the sustainable use of natural resources. It requires a comprehensive approach and can be different for each species

• Ex situ conservation
• Captive breeding in zoos
• Botanic gardens
• Seeds and tissue banks
• In situ conservation in natural habitats
• National Parks and nature reserves
• Rewilding
• Reclamation of degraded ecosystems

A4.2.7— Need for several approaches to conservation of biodiversity.

1) Ex situ conservation is preservation of plant and animal species outside their natural habitats. Used for critically endangered species when urgent intervention is required

Advantages:

• Control of essential conditions (e.g. climate control, dietary intake, veterinary care, etc.)
• It can improve the chances of successful breeding with artificial methods

Disadvantages:

• Do not prevent the potential destruction of their natural habitats
• Species raised in captivity are less likely to be successfully reintroduced into the wild
• Increases inbreeding by restricting the gene pool and restricts the evolution of the species

Germ plasm: Genetic material present in germ cells is stored in germ and tissue banks

A4.2.7— Need for several approaches to conservation of biodiversity.

https://www.youtube.com/watch?v=2nLKM5Gm68M

A4.2.7— Need for several approaches to conservation of biodiversity.

2) In situ conservation is the preservation of plant and animal species within their natural habitat (in nature reserves, national parks...)Advantages:

• allows the species to continue living in their habitat
• preserves their normal behaviour
• prevents disruptions of the food chains

Management of nature reserves:

• Ecological monitoring of species to ensure viable population levels are maintained
• Interventions may be required to prevent habitat degradation or competition from invasive species
• Legislation may be necessary to ensure adequate funding for policing and education
• Responsible tourism helps to generate funds that contribute to their maintenance and increse public awareness.

A4.2.7— Need for several approaches to conservation of biodiversity.

3) Rewilding: conservation technique by which wildlife and natural processes are allowed to reclaim areas, bringing back biodiversity.The habitat is restored to what it would have been if human disturbance had not happened. Human intervation is needed to reintroduce plant and animal species that have disappeared from the habitat.

1999 2022

https://www.bbc.co.uk/newsround/62344491

A4.2.7— Need for several approaches to conservation of biodiversity.

4) Reclamation of degraded ecosystems: when land and/or water are degraded (erosion of the soil, deforestation, salination...) due to human activities restoration strategies are required.Support from local communities and indigenous people yields higher results as they have a deep knowledge of the land

Reclamation vs rewilding:

• https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2664.13487

• https://onlinelibrary.wiley.com/doi/full/10.1111/brv.13046#:~:text=The%20two%20paradigms%20are%20also,they%20differ%20from%20past%20ecosystems.

https://www.intechopen.com/chapters/45415

A4.2.7— Need for several approaches to conservation of biodiversity.

A4.2.7— Need for several approaches to conservation of biodiversity.

Discuss in situ and ex situ conservation of endangered species. (4 marks)

A4.2.7— Need for several approaches to conservation of biodiversity.

Discuss in situ and ex situ conservation of endangered species. (4 marks)

• both methods ensure continuing survival of species/recover endangered species;
• in situ (conservation) occurs in natural habitat;
• ex situ (conservation) takes place outside original/natural habitat / occurs inartificial/controlled habitat;
• in situ not as disruptive;
• in situ encourages conservation of natural habitat;
• ex situ may be last chance for survival / increase breeding

OR needed if species too rare to be left in the wild;

• one example of either type of conservation;

Max 3 marks if only in situ or ex situ discussed; Or converse for marking points d and e

A4.2.8— Selection of evolutionarily distinct and globally endangered species for conservation prioritization in the EDGE of Existence programme.

The EDGE of existance program:

https://www.youtube.com/watch?v=Le1C3Hx3bdk

A4.2.8— Selection of evolutionarily distinct and globally endangered species for conservation prioritization in the EDGE of Existence programme.

The EDGE of existance program: EDGE = Evolutionarily Distinct and Globally Endangered Created in 2007 as a conservation programme to prioritise conservation of EDGE species The EDGE species:

• are often the only surviving members of their genus or even higher taxa
• are unique in their appearance, behaviour and genetic makeup
• have a unique evolutionary history
• are globally endangered.

Green turtle (Chelonia mydas)

Sumatran rhinoceros (Dicerorhinus sumatrensis)

A4.2.8— Selection of evolutionarily distinct and globally endangered species for conservation prioritization in the EDGE of Existence programme.

The EDGE of existance program: The species are selected according to their:

• Evolutionary Distinctiveness (ED) score: ED scores are higher for species that are evolutionarily more distinct or have fewer closer relatives.
• Globally Endangered (GE) score: based on the IUCN Red List. The more endangered the species, the higher the GE score.

Which species would have the highest ED score on this evolutionary tree? Each branch of the tree represents millions of years of evolution.