Current Threats Flashcards
What is the largest conservation conference
ICCB
How many species have been described
1.8 million
Why is it some times hard to protect species
If we don’t know they are there
How many mammals have we lost since 1600
87 species
How many birds have we lost since 1600
131 species
How many amphibians have we lost since 1600
5
How many reptiles have we lost since 1600
22 species
How many fish have we lost since 1600
92 species
How many dicots have we lost since 1600
83
How many plants have we lost since 1600
90
How many animals have we lost since 1600
726 species
Percentage of annual species loss
0.27%-0.63%
What did MEA 2005 stay
Over the past 50 years humans have changed ecosystems more rapidly and extensively than in any comparable period of time in human history.
Has resulted in substantial and largely irreversible loss in the diversity of life on Earth.
What did the Millennium Ecosystem Assessment say
Current extinction rates estimated to be 100 times greater than background geological rates and predicted to increase strongly during this century.
10-30% of mammal, bird and amphibian species are threatened with extinction.
What is the ipbes
Intergovernmental science policy platform on biodiversity and ecosystem services
What are the foci of value for ipbes
Nature.
Nature’s contribution to people.
Good quality of life.
What are the types of value in ipbes
Intrinsic (animal welfare)
Anthropocentric - instrumental and relational. (Food and energy and physical, mental health.)
What are the main drivers of biodiversity loss
Direct/ proximate
Indirect/ underlying
What are direct drivers of biodiversity loss
Habitat loss and fragmentation. Over-exploitation. Invasive species. Pollution. Climate change.
What are indirect drivers of biodiversity loss
Economic factors. Cultural factors. Policy/institutional factors. Demographic factors. Underlying drivers. Synergistic effects.
What are proximate causes of tropical deforestation
Infrastructure extension
Agricultural expansion
Wood extraction
What are underlying causes of deforestation
Demographic factors. Economic factors. Technological factors. Policy and institutional factors. Cultural factors.
What is habitat loss and fragmentation
Loss of total area of habitat.
How does fragmentation cause biodiversity loss
Decreased patch size.
Increase patch isolation - can cause road kill.
Increased edge effects -there’s more edge, sunny and windy abiotic factors impact and implicate which species live there.
Why do small and isolated fragments have fewer species
Late fragments contain high variety of habitats.
Large fragments have common and rare species.
Large fractions have large populations so less go extinct.
Isolated fragments are less likely to be colonised if a species is lost.
Why does large populations means animals are less likely to go extinct
Large area has large abundance.
Large genetic integrity.
More for predators.
Example of fragmentation
Forest mammals in SW USA.
Tropic forest in Madagascar - 10% remains.
Causes of fragmentation in Madagascar
Timber extraction.
Forest conversion to pasture for grazing.
Mining now.
Consequences of fragmentation in Madagascar
Mass extinctions of fauna since human arrival.
Important not to conflate with an understanding that extinction is normal.
From 1950-2000 what percentage of species has been driven to extinction through deforestation
9.1%
What percentage of Madagascar’s fauna is endemic
75% of 200,000 species
How many species in Madagascar are critically endangered according to IUCN data
37
How many species in Madagascar are endangered
88
How many species in Madagascar are vulnerable
137
Example of biodiversity loss in Britain
Semi-natural habitats have reduced dramatically during the last 50 years e.g lowland hay meadows and active raised bogs
Cause of semi-natural habitats in Britain decreasing
Agriculture intensification.
Removal of hedgerows to create fields.
Ploughing closer to the edge of the field edge.
Drainage to increase productive areas.
How does Ploughing closer to the edge of the field edge create biodiversity loss
Using machines we can get right to the edge, to get them there we use harvest tech and flatten a field which losses niches
What has declined in the semi natural habitats
Butterflies, birds and plants over the past 40 years.
What happens when we change habitats
Specialised species move out but generalists thrive like blackberries
Why do we need to protect fragmented ecosystems
Because they might hold the last individuals of certain species. Important for people to have access to nature, if we give up on the small patches we are giving up on species that are confined to the environments e.g chameleon species in Madagascar.
Causes of over exploitation
Pets Ornamental plants Medicine Cultural artefacts Recreation Food
What is over exploitation
Human Harvest of a species at a faster rate than it reproduces - hits a threshold the population can’t sustain
Example of pets
Seahorses
Example of ornamental plant
Orchid
Example of medicine
Rhinoceros horn
Example of cultural artefact
Skins and ivory
Historical cases of over exploitation
Woolly mammoth - 8000 years ago.
Dodo - 1674
Great Auk - 1854
How are ornamental orchids over exploited
Modern extinctions
Local extrications
Growing demand as species become more rare and desirable
Example of a rare orchid
paphiopedilum canhi. 1 population with less than 10 mature individuals. Endemic to limestone karats
Consequences of over exploitation of orchids
Changes to population structure - removes an entire area usually when harvest
Consequences of over exploiting fisheries
Changes in community structure.
Tropic cascades - as you remove species it has downstream impacts.
Changes in population structure and relationships with others.
What are the numbers provided by the FAO (2010) about fishers
3% underexploited 12% moderate 53% fully exploited 28% over exploited 3% depleted 1% recovering
What is an invasive species
Any exotic species that out competes, displaces or eradicates any native species
What is an exotic species
Any species living outside it’s native geographic distribution- doesn’t have to be invasive.
What is the native range
The geographic range a species will occupy without human interference.
How do invasive species move
Accidentally introduced by people.
Deliberately introduced by people.
Expansion naturally because human changes to the environment.
Example of invasive species being accidentally introduced
Norway and black rats which stowayed on ships.
Plant seeds in packing materials e.g European plants to Australia.
Pathogens e.g rabies.
Examples of deliberate invasive species
Pest control e.g cave toad in Australia.
Recreation e.g feet squirrel in Uk.
Food e.g crayfish in Europe.
Example of naturally expansion of invasive species
Construction of canals meant parasitic sea lamprey into Great Lakes
Why do species become invasive
High dispersal ability.
High reproductive potential.
Broad ecological niches.
Lack of enemies in area of invasion- lack bio control.
Example of invasive animal species in Uk
Endangered white headed duck frin Spain and Africa and Asia hybridised with native species - ruddy duck
Examples of invasive plant species in Uk
Rhododendron from Asia, Russia etc - distribution of ecosystems structure and function. Nectar is toxic to European honey bee (synergised threat)
Example of invasive animal species in Australia
Cane toads From America are highly poisonous. Extinctions of native species theough competition and predation - snakes, lizards and crocodiles all decline. Tried to expose wild animals to small doses of venom to create an eversion. Expensive.
What is pollution
The introduction of contaminants to the environment that disturb physical and biological systems.
What are the two types of pollution
Toxic and non toxic
What is toxic
Normally lethal, affecting organism functions and may be persistent and may bioaccumulate
What is non toxic
Disturb behaviour and can be lethal
Example of toxic air pollution
In Newcastle. High concentrations of S02 in the air produced by factories eliminated lichen species
What causes toxic water pollution
Many sources of pollutants: regularly discharged by factories and sewage treatment plans.
Sediments, fertilisers and pesticides from agricultural practices.
Catastrophic surges are a result of accidents.
Example of toxic water pollution forgeign
Fuhe River in China. Ammonia pollution killed fish
Toxic water pollution in Europe
In the Rhine.
High levels of pollution in large river led to the loss of most of its freshwater invertebrate fauna.
Example of toxic DDT pesticide pollution
British raptors declined following spread in agriculture use of DDT, which causes thinner eggs shells so can’t reproduce as well
How do DDT pesticide cause threats to non target species
Bioaccumulation so Toxin accumulated in living organism and passes to their predators. Toxin becomes more concentrated in higher trophic levels. It’s long lasting and easily spread
Example of non toxic micro-bead pollution
Directly consumed by many species
Example of Non toxic light pollution
Affects behaviour of nocturnal animals like turtles. They use the moon light signals to navigate but tourists and hotels disorientate them so don’t know where to dig or get to sea. Now use red light and hotels limit.
Example of noise pollution
M6 creates noise but re nesting boxes gets affected. Measuring cortisone in birds - their stress levels and communication behaviour
How much has global average surface temperature increased by
0.6*C during the last century
What is responsible for the increase in temperature
Emission of greenhouse gases form human activities
What is species thermal tolerance
The range of temperature species tolerate. Their thermal optimum is the peak of species functioning best. Too high or too low they can’t function.
What are the responses to climate change
Changes in phenology - life cycle events.
Changes in distribution - geographic and altitudinal distributions limited by temp.
Examples of changes in phenology
Insects fly early.
Reproductive events will happen early.
Birds will migrate early.
Examples of change in distribution
Expansions pole-wards and uphill.
Contractions at warm limits and downhill.
Example of phenological changes in British plants
Study of 385 species first blooming has advanced by 4.5 days
What is the problem with advanced blooming
Ecological problems - where are the pollinators. Some plants only survive a few days so if pollinators haven’t arrived then reproduction is much lower.
Example of changes in bird migration times
Study of 10 migratory birds species show they are arriving 12 days early compared with 50 years ago.
Example of changes in animal distribution
Species shifting ranges northworards as a result of climate warming across many species in Britain. Linked to changes in thermal optimance.
What are the species less likely to adapt or respond to climate change
Polar and high elevation species.
Tropical mountain species.
Species with low mobility.
Why are polar and high elevation species less likely to adapt
Already at their maximum thermal tolerance. Nowhere to go
Why are tropical mountain species less likely to adapt
Narrow thermal tolerance that can be easily disrupted
Why are low mobility species less likely to adapt
Not able to shift their distribution
Example of tropical species being unable to adapt
Neoteopical amphibians.
67% of anuran (frogs) species endemic to the American tropics have disappeared over 20 years.
83% of extinctions occurred after warm years bc of limited water.
What is the predicted increase of temp by the end of the century
2.5-4.1*C
What is the predicted amount of animals and plants that would go extinct by 2050
15-37% of a sample of 1,103
In a climate scenario of 0.8-1.7*C increase what percent of the species are committed to extinction
18%
In a climate scenario of 1.8-2*C increase what percent of the species are committed to extinction
24%
In a climate scenario of over 2*C increase what percent of the species are committed to extinction
35%
Example of underlying demographic factor driving biodiversity loss
Migration
Population density and distribution
Example of underlying economic factor driving biodiversity loss
Market growth and commercialisation.
Urbanisation and industrialisation.
Example of underlying technological factor driving biodiversity loss
Agro-technical change.
Agricultural production factors.
Example of underlying policy factor driving biodiversity loss
Formal policies.
Policy climate.
Property rights.
Example of underlying cultural factor driving biodiversity loss
Public attitudes values and beliefs.
Individual and household behaviour.
Example of underlying factors causing regime shift
Social drivers in the North Atlantic fisheries.
Key changes in distal drivers contributing to refine shifts in the North Atlantic continental shelf.
Price of cod goes up as there’s less of it.
Scales that drivers affect biodiversity
Spatial scales and temporal scales
How do drivers affect biodiversity at spatial scales
Climate change is a spatial scale of a large region.
Political change is a scale of a nation or a municipal district.
What are temporal scales
Sociocultural change typically occurs slowly. Economic forces are more rapid.
What is synergistic effects
The impact of 2+ factors together is greater than the sum of individual effects
How does habitat loss and climate change have a synergistic effect
Deforestation increases co2 emissions, leads to warmer and drier climate and then forest fires leading to more forest lost. Cumulative effect - more powerful than if they were on their owns
example of underlying drivers and synergistic effects
Global road development plans - increase access to remote areas, facilitated harvest, new opportunities for landscape change, demand increase, more money, new resources for investment, habitat loss again due to road development. Roads increase agricultural potential.
Example of synergistic drivers in the Uk
Most butterflies have a southern range (warming is meant to benefits) but they are habitat specialists. Lost flowery meadows and the species adapted to life here. Habitats may warm but are also lost.
Average temperature increase in the Uk
1.5*C
Example of habitat specialist butterflies
Duke of Burgundy
Example of habitat generalist butterfly
Comma
Why are habitat generalists good
Because climate improves and habitat available so the species can respond to climate change and spread
