Part of a revsion guide I made. 

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Geography Revision Guide
Biodiversity Under Threat
What influences it?
Primary Ecological
Size of an area ­ bio increase when the area increases as there is room for more species =
migration encourages
History and age ­ greatest bio found in oldest and least disturbed ecosystems especially the tropics
= few physical constraints/productivity
Isolation ­ remote islands reduces no. species increases/encourages ENDENISMS
Altitude range
­ large range = X section of different climates. Increasing CLIMATE ZONES involved =
Productivity ­ HIGH TEMPERATURES and HUMIDITY LEVELS, rich numbers and light
(PHOTOSYNTHESIS) decreased annual seasons encourage a HIGH level of primary productivity =
abundant energy in Rainforests and Coral Reefs
Factors which limit= COLD and ARIDTY
Habitat achievement ­ HIGH population = encourage development of complex tropics which
ecological RICHES ­ can support HIGH bio levels

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Habitat heterogeneity­ varied physical environment great Bio as it provides a WIDER range of
Succession­ BIODIVERSITY increases as species establish themselves, interact and subtly the
environment. E.g.…read more

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Earths species are found in the Tropical rainforest = only 7% of the Earth's surface
HOTSPOTS = BIODIVERSITY HOTSPOT = areas threatened by humans contain a large number of biodiversity
(Large % = ENDEMICS)
Must have 1500 endemic vascular plants ­ not found anywhere else!
30% or less of its natural vegetation left i.e.…read more

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Oil and gas development
8. Climate change
LOCATION: Pacific approximately 1,000 km from Ecuador
The islands belongs to Ecuador
They are volcanic archipelago (chain of islands)
Belongs to Ecuador's national park systems and a UNESSO World Heritage Site
Fame ­ Charles Darwin `origins of species' evolution theory after he visited
Volcanic Island 13 major, 6 smaller and many islets
5 islands are inhabited by a total population of 21,000 people which increase by approx.…read more

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Intensive Use: 25 zones, maximum of 90 people (4/5 groups of 20 authorised daily)
Extensive Use: 16 zones ­ only approximately 12 people daily = no large groups
Primate Use: Special permit required to visit
Primate Scientific: Only scientific researchers
Special Use: Next to colonised areas may be used for natural resources ­ strictly controlled
BIODIVERSITY THREATS: Energy flows and Nutrient Cycling in the Tropical Rainforest
Tropical Rainforest (TRF) ­ develops I areas which experience a contribution of HIGH rainfall…read more

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Energy Flows = the sun is the driver of most systems on our earth.…read more

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The Nutrient Cycle
NUTRIENT CYCLE = circulation of elements from environment to organism
Nutrient Cycles ­ Nutrients found in the soil and litter the cycled between these stores ­ usually shown in a flow
diagram: size of circles represent amount of nutrient: width of the arrow represents the importance of nutrients.
Nutrients are removed from foliage by RAIN, other nutrients are absorbed by LEAVES aerial roots and epiphytes ­
DECOMPOSITION of LEAVES, FRUITS, FLOWERS, DEAD ANIMALS and FAECES releases minerals into the SOIL.…read more

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IMPORTANT ­ The concentration of nutrients in the through fall different to that in the original rain. Nutrient
inputs and Outputs ­ nutrients dissolved in rainwater = important input.
BIODIVERSITY THREATS:Distribution of threatened areas:
Ecosystems scorecard ­ identifies freshwater ecosystems as the most eco-stressed
Living Planet Index Card ­ identifies that freshwater ecosystems are seriously threatened, as well as
forest, grassland and marine eco-systems
ICUN Red List ­ an annual listing of endangered species that allow from the identification of extinction
hotspots.…read more

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SUGGESTS: there might be some hope for threatened ecosystems if attempts are made to conserve them
As levels of development fluctuate they don't always follow the same patterns. This is a generalised graph to show
the state of ecosystems. When development levels increase there are examples of ecosystems suffering.
Sustainable Yield= the level at which GOODS and SERVICES of an ecosystem can be safely harvested without
harming it.
This is a key concept in relation to sustainable management of an ecosystem and biodiversity.…read more

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Problems with CC = it varies seasonally and is expected to be reduced by climate change.
Sustainable Yield = the safe level at which the goods and services of an ecosystem can be `harvested' without
harming it.
Carrying capacity = the maximum human population that can exist in equilibrium with the available resources
(ecosystems GOODS and SERVICES)
Therefore both measures are key criteria in the sustainable management of ecosystems.…read more


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