Download Maintaining Biodiversity (Conservation) PPT CXH

Objectives:
Maintaining Biodiversity
• Conservation of animal and plant species –
economic, ecological, ethical and aesthetic
reasons
• Benefits for agriculture in maintaining
biodiversity of plants and animals
• Consequences of climate change on biodiversity
of plants and animals – changing patterns of
agriculture and spread of disease
• Conservation of endangered species in situ and
ex situ – advantages and disadvantages of the
two approaches
• Role of botanic gardens in the ex situ
conservation of rare plant species or extinct
species in the wild – use of seed banks
• International co-operation in species
conservation – CITES; Rio Convention on
Biodiversity
• Environmental impact assessments – EIA’s (including biodiversity estimates) for local
authority planning decisions
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Maintaining Biodiversity:
important for interdependence and survival of all living organisms
Actions taken at local, national, and global levels – important for:
Economic
• Plants and animals as a source of food and drink – part of food chain
• Clothing & footwear – cotton (plants) & leather (animals)
• Drugs – morphine (analgesic) from poppies
• Fuels – from biomass (ethanol, biogas) – renewable
• Others – wood, paper, dyes, adhesives, oils, rubber, pesticides
Ecological
• Disruption of food chains – e.g. herring, salmon, bear – loss of herring causes loss
of salmon and bear population
• Disruption of nutrient cycles – decomposers (worms, insects, fungi, bacteria)
• Loss of habitats – e.g. hedgerows
• Habitat destruction – e.g. deforestation leads to climate change
Ethical
• Moral issues – not to interfere with nature; right to exist; moral responsibility
to conserve for future generations
• Religious & spiritual – coexistence & harmony with the natural world
Aesthetic
• Attractive environment – leisure, tourism (economic)
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Agricultural Benefits of Biodiversity
• Source of food – for humans and livestock; wider range of food sources in
case of disasters (e.g. potato famine -1845 – 2 varieties of potato – destroyed
by disease – caused famine)
• Source of plants for cross breeding – desired characteristics ) e.g. drought &
disease resistance; faster growth; nutritional characteristics; tolerance to
climate change, increase yield
• Source of natural predators to pests – e.g. frogs, birds, hedgehogs are
predators of pests (e.g. snails)
• Pollinators – insects (bees and butterflies)
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Global Climate Change & Biodiversity
Most species have adapted though evolution to survive in a particular climate due
to genetic diversity and variation. Threats to a species with low genetic diversity
would include – climate change, increase in pollution, new diseases, new pests
Changes in the climate – e.g. temperature, rainfall, wind patterns may cause:
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the migration of species to more suitable areas, or, may cause the
extinction of some.
changes in the patterns by which diseases are spread.
changes in agricultural patterns
Climate change occurs naturally, but recently there is consensus that climate
change is a result of the impact of human activity on the environment – e.g. global
warming due to the increased emissions of greenhouse gases (such as carbon
dioxide, methane, NO, H2O vapour, CFC’s, deforestation)
Climate change leads to:
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Increase/decrease in the temperature of the earth
The melting of polar ice caps and flooding
Emergence and spread of disease
Change in agricultural patterns
Effects on habitats
Global dimming (air pollution – soot)
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Effects on habitats
Uninhabitable area becomes habitable – (and vice versa) – increase or decrease
biodiversity
Increase or decrease in the range of some species – range limit of Sooty Copper
Butterfly has moved 60 miles north in recent decades
Migration – to more suitable areas – change in species distribution – usually
decrease biodiversity in areas the species migrate from, and increase
biodiversity in areas they migrate to
If no suitable habitat is available for a species to migrate to, or the species is a
plant – which cannot migrate, or if the climate change is too fast, the species
may become extinct. This decreases biodiversity – e.g. Corals die if water
temperature changes by just 1 or 2 degrees
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Climate Change and the Spread of Disease
Geographical range of some insects might become greater
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If area becomes warmer and wetter, mosquitoes (vector of malaria) may
spread into the area and spread malaria
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Spread of mosquito increases biodiversity, but the spread of the disease
could reduce biodiversity
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Warmer and wetter conditions encourage spread of fungal disease – could
increase or decrease biodiversity
Climate Change and Agricultural Patterns
Changes in – temperature, rainfall, timings of seasons, frequency of flood and
drought, wind patters – will affect patterns of agriculture and biodiversity
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Previously unsuitable land becomes suitable for agriculture (and vice versa) –
increase or decrease in biodiversity
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Crops suitable for growing in new climate will become established – unsuitable
crops will not grow – increase or decrease in biodiversity
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Extreme weather events (e.g. flood, drought, change in timing of seasons)
may cause crop failure – disrupt food chains – reduce biodiversity
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Disruption of food chains and webs may occur
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Conservation & Endangered Species
Conservation refers to the attempts by humans to maintain biodiversity by
preserving organisms and environments that are at risk as a result of human
activity
Endangered Species – Definition
Species (plant and animal) that are in danger of becoming extinct, unless
steps are taken to prevent it – e.g. the panda, gorilla, and black rhino. The
numbers are at a critical level (i.e. too low) for continued survival of the species.
Extinction – when the last member of a species dies
Some species have become extinct – mammoth, dodo, sabre-toothed tiger
The survival of species can be threatened for a number of reasons – including:
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Climate change
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New predators being introduced
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Destruction of habitats (e.g. by logging; road building) – destroys food
sources and shelter
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Hunting
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Competition for food, shelter, etc.
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Pollutants
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Poaching
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Killed for food
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Killing to prevent damage to farmland and settlements
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Low population
E.g. Whales
Endangered, in danger of extinction. main causes of whale deaths include
Entanglement in fishing nets and drowning
Pollutants in the sea
Colliding with ships during migration
Climate change affecting food sources
Culling and hunting
Money can be made from whales
Live whales– as a tourist attraction
Dead whales– food, oil, making cosmetics (using blubber)
Endangered species can be protected from extinction by
• Education – raising awareness
• Breeding animals in captivity (e.g. zoos) and returning to natural habitat to
create new population
• Protecting (conserving) natural habitats
• Creating artificial ecosystems (e.g. zoos, aquariums) for the species to live in
• Legally protecting endangered species – prevent trapping and captivity
• Prohibiting hunting of legally protected species – permits to hunt issued to
certain people
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Conservation – in situ (“on site”)
In situ Conservation
Involves protecting species in their natural habitat – methods include:
Protected areas – national parks; nature reserves - areas are protected from
developments (industrial, urban) and farming
Control or prevention of species that threaten biodiversity - e.g. grey squirrels (not
native) compete with native red squirrel, causing a decline in red squirrel population.
Protection of habitats - e.g. conserving wetlands, by controlling water
levels; coppicing (trimming trees) to conserve woodlands – allows organisms to live
continuously in their natural habitat
Restoration of damaged areas – e.g. a coastline polluted by an oil spill.
Promoting particular species – by protecting food sources or nesting sites
Legal protection for endangered species – prevent hunting, logging;
countries may not agree
Minimise human impact on the natural environment
Advantages
All required conditions already present; no special provisions required – well adapted
Both species and habitat are conserved; less disruptive; chance of population recovery is
greater
Disadvantages
Difficult to control – poaching, predators, climate change
Species not accepted by other members of the species already present if they have been
reintroduced.
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Conservation parks/nature reserves /SSSI’s
Choosing of reserve or park
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How many species represented; prevailing environmental conditions
Adequacy – is the area large enough to provide for long-term survival
Representativeness - Is there a full range of diversity within each
species and set of environmental conditions
Advantages of designating an area;
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Conservation of plants and animals in their natural environment
Permanent protection of biodiversity and ecosystems
Protects elements of natural and cultural heritage
Facilitates management of designated area – ensuring ecological
integrity
Ecologically sustainable land use and associated economic benefits
Facilitates scientific research
Secure environmental future
Enjoyment of natural environment
Reserve should meet the needs of indigenous people (hunting; religious;
spiritual) – conflict may arise if not considered
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protected animals raiding crops
continued hunting of protected species for food
illegal harvesting of timber and other plant products
tourists feeding protected animals or leaving litter
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Ex situ (“off site”) Conservation
Involves removing part of the population from a threatened habitat, and
placing it in a new location. Used as a last resort
• Relocation of species to safer areas
• Breeding species in captivity and reintroducing them into the wild – carried out
in animal sanctuaries, and zoos.
• Botanic gardens – controlled environments to conserve rare plants and
reintroduce them into the wild.
• Seed (sperm) banks – frozen (or dried) seeds are stored in seed banks for long
periods of time, without losing their fertility. Provides a useful source of seeds
if natural reserves are destroyed – in famine conditions.
Advantages (reverse arguments for in the wild)
• Protect individual animals or plants in a controlled environment – protected
from factors causing endangerment
• Predation and hunting can be monitored and managed easily; monitor health;
treat disease; incubate eggs artificially; hand rear young – reduce mortality;
manipulate breeding (hormones, artificial insemination, artificial selection);
protect from predation, hunters; reduce competition between individuals /
species
• Used to reintroduce species that have migrated to other areas
• Sperm (frozen) from one male – used to fertilise a large number of females;
easy transport; maintains genetic diversity – by importing sperm from another
population
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• Study rare biological organisms at close range
Disadvantages
• Only a small number of individuals can be catered for.
• Difficult and expensive to create and sustain the right environment.
• Less successful than in situ methods – many species do not breed
successfully in captivity.
• Species cannot adapt when introduced to their natural habitat
• Problems of acceptance of introduced member by existing members
Possible solutions
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Choose individuals from different areas – maintains / increases genetic variation (gene
pool)
Choose unrelated individuals - reduces risk of inbreeding between related individuals
Less risk of losing all individuals due to environmental change (e.g. disease)
House in separate centres – less risk of losing all individuals due to natural disasters,
human action
Select higher proportion of females
Preserving of species – long term measures
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Legal protection
Ban cause of endangerment
Protected areas – sanctuaries, reserves – provide breeding sites
Prevent habitat destruction
Monitoring – tagging
Education – to public on importance of the species
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Sperm and egg banks; seed banks
Inbreeding depression is a disadvantage in captive breeding - happens when
closely related individuals – e.g. a brother and a sister, mate.
Offspring are much less likely to survive and reproduce successfully – due to
an increased chance of inheriting harmful recessive alleles from both parents –
an offspring with homozygous recessive alleles may lack vital gene products
and be less likely to survive and reproduce successfully.
Zoos keep detailed records detailing the family trees of all their animals –
allowing them to ensure that individuals that mate are as distantly related as
possible.
Zoos often swap animals with other zoos to promote outbreeding, to maintain
genetic diversity of the captive populations
Success of release of bred species
 Healthy before release
 Adequate food supply
 Protected reserve
 Method to monitor population
 Raise public awareness
 Prepare animals for survival in the wild
 Gradual introduction – e.g. via semi-wild habitat
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Drying and freezing seeds for seed banks
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Inhibits germination
Slows down enzymes and rate of decay - prolongs seed survival
Drying reduces damage by freezing effect
Tested regularly (every 5 years) – to check seed viability/germination
success
Allows new seeds to be produced - stored seeds may need replacing due to
decay/death
Seed banks (and zoos) - maintain endangered species in a protected
environment – giving protection from predators/poachers
Captive breeding programmes are used to reintroduce species into wild;
enable scientific research and education.
Seed banks (and sperm banks) occupy little space and require little
attention
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CITES (Commission on International Trade in Endangered Species)
A number of Governments are signatories to a world-wide programme to protect
endangered species by conservation of biological diversity – addresses illegal
poaching and illegal trade in endangered species. CITES, agreed in 1973. Some
countries do not support conservation programmes. Aims of CITES:
• International cooperation in regulating trade and monitoring international
trade in selected species of plants and animals
• Member countries agree to make it illegal to kill endangered species
• Limiting trade in endangered species through licensing
• Illegal to trade in products made form endangered species
Black rhino - placed on Appendix 1 of CITES. Since then, their number have
stabilised and even increased. Endangered due to poaching ; destruction of
habitat; shot to protect farmland and settlements; killed for meat and horn
Signatory countries agree – illegal to kill/poach rhino
Ban on trade in horns/hide
Increased cooperation between countries
Permits/licences issued to certain people
Education; raising awareness
Monitor habitats and species on a daily basis (wardens)
Legal action (imprisonment, fines, etc)
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Enforcement of international agreements (e.g. CITES) - problems
Not all governments agree with trade policies
Some governments corrupt
Difficult to stop poaching and hunting in the wild
Limited resources or will to police areas effectively
Exported species or products may be exported under false documentation or
smuggled
• Difficult to identify endangered species – e.g. by custom officials
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Environmental Impact Assessment (EIA) and studies of biodiversity
In local planning and development it is important to assess the impact of a
proposed development (e.g. shopping centre, power station) on the environment
and biodiversity – otherwise, there may be destruction of environmentally
sensitive habitats that are rich in biodiversity. Need to conserve species that
are already protected by law. EIA ensures that decision makers consider the
environmental impact of development projects and how projects are to proceed.
• To estimate biodiversity on the project site and evaluate how
the development might affect biodiversity
• To consider impact on wildlife
• To identify possible destruction of environmentally sensitive
habitats that are rich in biodiversity or where there are rare
species
• To legally protect particular species of animals and plants
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If the need to conserve or protect is identified – need to consider whether
development should be stopped or whether other measures could be taken
to protect the species – e.g.
• Providing other suitable (similar) habitats close to the site – e.g.
extension of mudflats on shores for the wading and migrating birds that
used the habitats that were lost to development. Successful in
attracting other bird species as well
• Species of animals and plants may be protected by law
• Translocation of species
• Laws to protect endangered species
• Estimate biodiversity on the development site and evaluating the effect
of the development on biodiversity
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Objection to EIA studies
An EIA study needs to physically investigate the habitat – this may possibly
leading to the destruction of habitats and disturbance of the species in their
habitats
May cause more disruption than the development itself
Damage to environment/ecosystem
Habitats best left alone (left to nature)
Rare species may be discovered – people stealing species for collectors
Need to consider the following in EIA:
Water resources
Drainage
Pollution
Damage & disturbance to habitat
Loss of species and loss of species diversity
Loss of habitat
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Biodiversity and importance of genetic diversity
Genetic diversity makes it possible for a species to evolve
Without genetic diversity plant and animals will not be able to adapt to changes
in the environment
Threats:
• Climate change
• Increase in the levels of pollution
• New disease
• Arrival of new pests
Humans activity affects the genetic diversity of natural habitats.
• Clearing of natural vegetation – reduces size of natural habitat – reduces
population size of the species in that habitat; hunting or killing for
protection; inadvertent introduction of predators and competitors
• Reduces overall gene pool for the species
• Decreases genetic variation and hence the ability of the species to adapt and
evolve
Monoculture and selective breeding reduces variation and genetic diversity of
domesticated animals and plants. Leads to extinction of some varieties within a
species –termed genetic erosion
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