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