Zusammenfassung der Ressource
Geography: The Living World
- Ecosystems
- Ecosystem: unit that
includes all the living parts
(plants and animals) and
the non living (physical)
parts (soil and climate) in
an area.
- Organisms in
ecosystems can be
classed as producers,
consumers or
decomposers
- Producer: an
organism that
uses sunlight
energy to
produce food
- Consumer: an organism that
uses that gets its energy by
eating other organism – it eats
producers or other consumers!
- FOOD CHAIN: shows what eats what!
- FOOD WEB: shows
lots of food chains and
how they overlap
- Decomposer: an organism
that gets its energy by
breaking down dead material.
Bacteria and Fungi for
example!
- When dead material is decomposed,
nutrients are released into the soil. The
nutrients are then taken up from the soil
by plants. The plants may be eaten by
consumers. When the plants or
consumers die, the nutrients are returned
to the soil. The transfer of nutrients is
called the nutrients cycle
- A change in one part of the ecosystem has an impact on other
parts - eg. hot, dry summers or having a hedgerow trimmed
- Global Distributions
- Tropical
Rainforests
- Found near
EQUATOR
- AREAS
- Central America, Amazon, central Africa and south east Asia
- Climate
- hot, wet climate with no definite seasons
- Soil
- isn't very fertile as
heavy rainfall washes
nutrients away, nutrients
at the surface due to
decayed leaf fall, but
this layer is very thin as
decay is fast in the
warm, moist conditions
- Vegetation Structure
- Three tree layers and a shrub layer
- canopy 30m trees
- emergents 40m branches most light
- undercanopy 15 m
- Shrub 10m - little light
- Plant Adaptation
- thick waxy leaves that have pointed tips - run off - adapt to heavy rainfall
- tall trees have buttress roots to support trunks in very shallow soil
- Trees = deciduous - drop leaves in drier periods to reduce water loss
- Hot Deserts
- Found - 15 and 30
degrees north and south of
the equator - less rainfall
- AREAS
- North Africa, the
Middle East, South
West USA, large
parts of Australia
- Climate
- Little rainfall - rain once
every 2 or 3 years. hot
days (45 degrees) cold
nights 5 degrees
- Soil
- shallow with a coarse,
gravelly texture. hardly
any leaf fall so soil isn't
very fertile
- Vegetation
Structure
- Plant growth is sparse due
to lack of rainfall. Plants
that do grow include cacti
and thorn bushes
- Plant Adaptation
- roots are extremely long
to reach deep water
- Cacti have
swollen
stems to
store water
and have
thick waxy
skin to
reduce
water loss
- Cacti have small, spiky leaves
to reduce water loss
- Temperate Deciduous Forests
- Found between 40 and
60 degrees north and
south of the equator - 4
distinct seasons
- AREAS
- Most of Europe,
South east USA,
China and Japan
- Climate
- 4 distinct seasons -
rainfall all year round
- Soil
- The solid is deep
and very fertile
because theres
think layer of leaf
fall
- Vegetation Structure
- three main plant layers
- 30 m - top layer (oak)
- Shrub layer - 20m (hawthorn)
- undergrowth 5m - (brambles)
- Plant Adaptation
- trees are deciduous -
reduces water loss from
leaves in months where
water is harder to get
- Tropical
Rainforest
Deforestation
- Farming
- Mineral Extraction
- Commercial Logging
- Population pressure
- Road Building
- Deforestation
- Environmental
Impacts
- fewer trees =
fewer habitats
- no trees to hold solid together -
heavy rain washes away the soil
(soil erosion)
- soil from
deforestation is
washed into rivers
- without trees = no leaf fall+ no
nutrients supply to the soil = less
fertile
- Trees remove CO2 = more C02 in the atmosphere = adds to Global
Warming
- Social Impacts
- quality of life for
locals improves as
more jobs
- Native tribes
forced out
causing conflict
- Economic Impacts
- Logging, farming and mining create jobs
- Money made from selling timber, mining and commercial farming
- Political Impacts
- Theres pressure
from foreign
governments to
stop deforestation
- Tropical Rainforest: Sustainable Management
- Selective Logging
- Replanting
- Reducing demand for Hardwood
- Educating
- Ecotourism
- Protection - environmental laws