ESS - Topic 3

Biodiversity and Conservation

environmental pressures

environmental pressures

the factors (abiotic or biotic) in an ecosystem which put pressure on an organism's survival and increase competition (whether inter-species or intra-species)

biodiversity

a combination of the species diversity, genetic diversity and habitat diversity of an ecosystem

variation

the differences, either physical or genetic, between individuals of a species

simpson's diversity index

a measure of diversity between similar ecosystems

species diversity

the number of species (richness) and their relative proportions (evenness) in a community

genetic diversity

the range of genetic material present in a gene pool or population of a species

random genetic mutations

the small differences which may occur in an organism as a result of reproduction - these small changes may add up to create variation

hotspots

an area of high biodiversity (which is under threat from human activities)

endemic species

the species which only occur in one specific area

speciation

the gradual change in populations of a species over time - often caused by geographical isolations, resulting in new species

evolution

the process by which a species may adapt to environmental pressures through natural selection of favourable variation - caused by random genetic mutations - over thousands of generations

natural selection

survival of the fittest - only the best suited organisms will be able to compete (due to environmental pressures) and so survive long enough to reproduce - their favourable traits are then passed on to new generations

geographical isolation

the separation of populations of a single species - often leads to speciation if populations cannot interbreed for a very long time

physical barriers

e.g. a mountain, ocean or separation of lakes

land bridges

a connection between land masses - often as a result of lowering sea levels e.g. the Bering Straits

continental drift

the movement of the tectonic plates by around 1cm a year causing the change in shape and location of continents

lithosphere

the Earth's crust - the rocky part of Earth

Gondwana

the land mass made up of Africa, New Zealand, Australia and South America, India, Arabia and Antarctica millions of years ago - separated millions of years ago

background extinction rate

the natural rate of extinction of species - around 1 species per million species per year

extinction

the complete loss of a species from Earth - no more individuals of that species exist

mass extinctions

an extinction rate far greater than background extinction rate

Holocene extinction event

the 6th mass extinction occurring for the last 10,000 years, however, much faster in the last 100 years - generally agreed to be as a result of human activity

weedy species

the species (generally plant or animal) which are able to survive the environments we create e.g. urban rats, domesticated animals

Living Planet Report

a report produced by the Worldwide Fund for Nature (WWF) creates on the state of the world's ecosystems

conservation

the act of preserving nature - attempting to save habitats, species and biodiversity in general

2/3

the proportion of living species which are found in tropical rainforests

current extinction rates

approx. 100 species per million species per year

ecosystem complexity

creates stability and resilience to change in an ecosystem - there are many pathways for energy flow

limiting factors

environmental conditions that limit the growth, abundance, or distribution of an organism or a population of organisms in an ecosystem - when there are few of these, biodiversity is likely to be high (and vice versa)

inertia

the ability of an ecosystem to resist change (maintain equilibrium) when subjected to a disruptive force

natural hazards

naturally occurring events which may have a negative impact on the environment e.g. eruption of Mount St Helens in 1980, the 2004 SEA earthquake and subsequent tsunami

habitat loss

the major cause of loss of biodiversity

habitat fragmentation

when a large area of habitat is broken into many smaller areas, often physically divided by roads, towns, factories, power lines etc - leads to the loss of biodiversity

overexploitation

the overuse of a resource to the point that is has a negative impact on the ecosystem e.g. deforestation

introduction of non-native species

when a species which is not naturally occurring in an ecosystem is introduced and may out-compete the native species - this may lead to a loss of biodiversity e.g. rabbits, cane toads, red foxes, camels in Australia

lungs of the Earth

rainforests - they are called this because they are thought to produce around 40% of the oxygen that animals breath

narrow geographical range

a small area that a species inhabits - makes a species prone to extinction

low genetic diversity

caused by small populations or declining diversity - makes a species prone to extinction as they may not be able to adapt to change

low population density

some species need a large area to hunt - if there are only a few organisms over a large territory this may make them prone to extinction, especially if habitats become fragmented

large body

due to the 10% rule, it is much more difficult for big organisms to find enough food - this makes them prone to extinction e.g. wolves, tigers

low reproductive potential

reproducing slowly and/or infrequently - this makes a species prone to extinction as it may take a long time for a population to recover its numbers

seasonal migration

the movement between different areas at different seasons - this makes a species prone to extinction as they rely on more than one habitat - if one is destroyed, they will not survive

poor dispersers

a species which cannot move easily to new habitats - this makes them prone to extinction - for example plants which rely on a slow dispersal of seeds, flightless birds of New Zealand

specialised feeders

a species which requires a specific food and cannot eat others e.g. giant pandas eat bamboo shoots, koalas eat eucalyptus leaves - this makes them prone to extinction if their food source becomes scarse

minimum viable population size

the lowest number of individuals of a species needed for a population to be able to recover - if a population is lower than this number, they may become extinct

IUCN

The International Union for the Conservation of Nature and Natural resources - often known as the World Conservation Union

made up of government agencies, states, non-governmental organisations (NGOs) and scientists and experts - their goal is to conserve nature and increase sustainability of resource use

IUCN Red List

the conservation status of species based on: population size, degree of specialisation, distribution, reproductive potential, geographic distribution and fragmentation, habitat quality, trophic level and therefore, the probability of extinction

extinct (EX)

IUCN Red List Status - no reasonable doubt that the last of a species has died

extinct in the wild (EW)

IUCN Red List Status - a species is known only to survive in cultivation, captivity or outside of its past range

critically endangered (CR)

IUCN Red List Status - at extreme risk of extinction in the wild

endangered (EN)

IUCN Red List Status - facing a very high risk of extinction in the wild

vulnerable (VU)

IUCN Red List Status - facing a high risk of extinction in the wild

near threatened (NT)

IUCN Red List Status - likely to qualify as vulnerable or endangered in the near future (but does not yet)

least concern (LC)

IUCN Red List Status - widespread and abundant

data deficient (DD)

IUCN Red List Status - when there is insufficient data to determine a species' status

not evaluated (NE)

IUCN Red List Status - when a species has not been evaluated against the criteria

UN

United Nations

UNEP

United Nations Environmental Program

CITES

Convention on International Trade in Endangered Species

UNDP

United Nations Development Program

WWF

Worldwide Fund for Nature

WRI

World Resource Institute