Biodiversity under threat

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Biodiversity under threat
Key terms
Biodiversity- UN convention of biological diversity, 1992 earth summit, Rio, `biodiversity means the
variability among living organisms from all sources- terrestrial, marine and aquatic ecosystems and
the ecological complexes of which they are part: this included diversity within species, between
species and of ecosystems.'
There are 3 dimensions to biodiversity
1. Genetic diversity
2. Species diversity ( Includes species richness, endemism and species disparity)
3. Ecosystem diversity.
Species diversity- refers to the variety of plant and animal species present in an ecosystem.
Diversity is needed to enable the ecosystem to carry out its functions, such as carbon cycling, with
maximum efficiency. Species diversity bolsters an ecosystem's resilience to withstand climate
change. Removing species from, the various tropic levels can have a huge impact on energy flows
and nutrient cycling. Species diversity has several aspects, including the total number, abundance
and richness of species as well as disparity. The endemism of species is also relevant.
Genetic diversity- the range of genes found within a particular species. Genetic diversity often
determines the degree of resistance to pests and diseases. In agro-ecosystems, breeding new
varieties of cereals such as rice and wheat has led to genetic erosion and genetic pollution. These
in turn have caused a narrowing of the genetic base and a general weakening of plant resistance to
disease and climate change. This is likely to have a major adverse impact in future global food
Ecosystem diversity- relates to the number of different ecosystems within a given area. This is
partly controlled by physical conditions particularly climate, geology, relief and soils. The ability
of people to modify and eliminate ecosystems is a threat to ecosystem diversity.
Endemism- the amount of unique and rare species present in a particular location.
Species disparity- the range of species
Species richness- the amount of species
Biome- a global ecosystem
Ecosystem- a self-regulating biological community in which the living (biotic) interacts with the
non-living (abiotic) in the environment.
Succession- changes in vegetation which takes place in a community over time.
Primary productivity- the rate at which energy is converted into organic matter. It can be
measured by the amount of biomass produced each year.
Biodiversity hotspot- an area of high biodiversity. Myers ­ hotspots are areas with: high species
richness, high levels of endemism (uniqueness) and at severe threat of human disturbance

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Habitat- an organism's home. Scale varies from small specific location (under a leaf) to a global
Ecofootprint- a measure of biodiversity threat. A measure of human demand on the earth's
ecosystems. It represents the amount of productive land and sea needed to supply humans with the
resources they require.
Terrestrial eco-regions- an area that differs from the surrounding area. This could be due to
variations in climate, geology, and soil and vegetation type.…read more

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Greatest biodiversity is found in tropical rainforest areas which have more than half of the world's
species but only cover 7% of the earth's surface. Brazil has the most biodiversity as it contains the
amazon rainforest.
Biodiversity hotspots
Biodiversity hotspots are areas of high biodiversity. Myers ­ hotspots are areas with: high species
richness, high levels of endemism (uniqueness) and at severe threat of human disturbance
Biodiversity hotspots
Biodiversity hotspots only cover 2.3% of the earth's land surface.…read more

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Biodiversity is valuable for tourism and recreation
The value of ecosystems
Ecosystems provide both goods and services
Goods/ provisioning services- things that have a monetary value
Food- hunting and gathering and farming
Fresh water supply
Wood and fibre
Fuel wood
Regulating services
Atmospheric gases
Flood regulation
Disease regulation
Water purification
Cultural services
Aesthetic value
Spiritual value
Educational value
Recreation and leisure
The guardian- 2012- conserving biodiversity hotspots could bring the world's poor $500 billion a
year if poor people were paid for the services they…read more

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The optimum temperature for most reefs is 26-27°C. However the reefs in
the Persian Gulf have adapted to temperatures of 13°C in the winter and 38°in summer.
Most of the coral reefs around today were formed after melting ice caused sea levels to rise at
the end of the last ice age which flooded continental shelves. This means that most modern coral
reefs are less than 10,000 years old.…read more

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Why are coral reefs important?
Coral reefs are called the `rainforests of the sea' as they have the greatest amount of ocean life
and are the most biodiverse ecosystem on earth with 30 of 34 known animal phyla present. Coral
reefs are some of the most biologically rich ecosystems. Coral reefs only cover 0.17% of the
world's marine environments, about the area of France, but are home to 25% of all known marine
species including fish, molluscs, worms, crustaceans, echinoids and sponge.…read more

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Coral reefs
provide food for 1 billion people in Asia alone. 25% of the entire LEDC fish catch comes from coral
Coral reefs make a major contribution to commercial fishing. Globally 20% of animal protein
consumed by humans comes from marine environments with coral reefs providing 25% of this total
commercial fish catch. .south eastern Asia's coral reef fisheries alone yield 2.4 billion annually. In
the USA NOAA estimates the value of coral reef fishing to be over $100 million.…read more

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A report published in the journal `science' in 2005 said that the reefs in Hawaii were
approximately 60% on their way towards ecological extinction.
Coral reefs are under threat from human actions including; pollution, overfishing, oceanic
acidification, coal mining ,disease, dynamite and cyanide fishing, sedimentation, bleaching caused
by rising ocean temperatures and quarrying for building material.
A study from 2013 has shown that air pollution can stunt the growth of coral reefs.…read more

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According to the World wildlife fund (WWF) more than 80% if the world's shallow reefs are
severely overfished.
Threats to coral reefs are so severe that they now have legal protection and are included in the
global 200 list of environmental- endangered areas. Regions at particular risk are identified as;
the red sea, the Arabian sea, the Persian gulf, the great barrier reef and the southern Caribbean
sea.…read more

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There are also a number of major ports and
shipping lanes within or adjacent to the reef. These activities and their indirect benefits form a
significant and growing population of Queensland's regional economy.
The federal environmental protection and biodiversity protection act of 1999 provides an
overarching mechanism for protecting the world heritage values from inappropriate development.
This requires development proposals to go through rigorous environmental impact assessments often
including public consultation.…read more


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