The Living World

Ecosystem

A community of plants and animals living together in a habitat and their abiotic factors

The food chain is the direct transfer of energy between organisms in an ecosystem

Interdependence means that if one factor changes it will affect the other organisms within an ecosystem

The Nutrient cycle demonstrates how minerals are stored, moved and recycled within an ecosystem

Epping Forest

Its the remains of a larger forest that colonised England at the end of the last ice age

Bogs + Ponds in the forest have their unique species, 20 kinds of dragonfly

For 1000 years, it has been run by royals as hunting ground and for timber but is now for recreation

A layer of shrub layer at 5 meters, overlying a field layer of grasses and brambles

177 species of moss + lichen

9 amphibious + reptiles

38 bird species

700 species of fungi

Biomass is large due to height of trees, soil store is large as there is plenty of humus

High flow rate reflect rigorous cycle of growth

The forest loses a lot of nutrients via leaching, during episodes of heavy rainfall

Tropical Rainforests

Large Scale Ecosystems

Desert

Tropical Savannah

Arctic and Alpine Tundra

Grassland

Temperate Boreal forest

Tropical Rainforest

Temperate Deciduous Forest

Chaparral

Spring, summer, autumn, winter, in the autumn the leaves change colours and in winter the trees lose leaves

Also known as Taiga the evergreen forest is cold woodland - largest biome at 17% of land area

1/5 of land, little precipitation, short growing season and poor nutrients, below freezing at night all year

Very hot and very dry - very little grows and found 30 degrees N and S of equator

Dry and hot area composed of grassland and scattered shrubs and trees found between a tropical rainforest and a desert

Large biome of rolling terrains and grasses, flowers and herbs, few trees as precipitation is unpredictable that drought and fires keep trees down

Very hot and wet biome on or around the equator - most biodiversity on Earth

Found in small areas - flat plains, rocky hills and mountain slopes - very hot and dry - winter is 10 degrees but 40 degrees in summer

Structure

Shrub layer <5m
Under or lower tree canopy 5 - 15m
canopy 15-30m
Emergents or top canopy 30-60m

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Sources of nutrients

Leaves falling, plants dying, animals excreting and dying, nutrients leach into soil
Some nutrients are leached away by heavy rainfall

Deforestation

The lower level of development the more deforestation happens - need the money

The process by which natural forests are cleared through logging or burning, either to make use of the wood or to replace the area with alternative activities

1361000 hectares lost in 2019 in brazill

Economic Impcats

Environmental impacts

Amazon rainforest Case Study

Largest forest on Earth - 6 million km^2
covers 40% of South America
1000 species of birds
60000 species of plants
10 million species of insects
20% of species on Earth
20 million people live there
17% of forest has been lost

Deforestation, selective logging, mineral extraction, commercial farming, infrastructure development, subsistence farming, logging, soil erosion

Deforestation is caused by demand and money made from farming - the government encourages it for the economy and to feed the growing population

IBAMA - against logging

The goverment builds roads and the logging companies move in, only taking cedar and mahogany - the cattle ranches burn the rest away - soya bean farmers arrive

Destroys + displeases indigenous tribes that have lived for centuries off the land

Effects of Deforestation - Destruction of ancestral lands, Violence, loss of medicinal plants, water pollution, jobs, loss of biodiversity - 137 species lost per day, CO2 released, enhances greenhouse effect, decline in soil fertility, warmer and drier bad for agriculture so make less ,money, loss of medicinal plants, loss of tourism

Key points in 9 marker
selective logging - only cutting down right ones, allows trees of same type to grow back - teach their children - its also fells other trees when logging - illegal logging has to be stopped by IBAMA which is hard as how big Amazon is
Educating - raises awareness and causes more protests by WHO - pressure on logging companies - passed down generation - WHO relies on donations
Reducing Debt - in LIC's such as $28.5 million in Indonesia - binds them into stopping logging - but they might not use the money to stop