Ecosystems

Year 11

An ecosystem is the system of links between the living environment and the non-living environment.

Non-living

Producers

Consumers

Decomposers

Sun, water, minerals

Grasses, trees, algae

Rabbits, foxes, owls

Bacteria, certain insects

Nut

rient

s

The largest ecosystems are known as biomes.There are nine major biomes.They are shaped by climate, relief, geology and soils.

Tropical forest Desert

ConiferousForest

DeciduousForest

Plants and animals adapt to fit their ecosystem e.g.: tropical forest

Emergent

Canopy

Undergrowth

Layer Adaptation

Umbrella-shaped, branches near crowns

Branches and leaves highWaxy drip-tip leavesButtress roots

Sparse, hardy plantsWidespread decomposition

Reason

Competition for light

Competition for lightHeavy rain runs offSupport tall trunks

Little lightHot and wet

The three-toed sloth has a lifestyle that is unusual but that suits it perfectly for life in the canopy.

It uses as little energyas possible because it’sdiet of leaves has littlenutrition.

Leaves are hard to digest, so sloths have special large stomachs.

To hide from eagles, it hastiny plants growing in thegrooves of its hair. Theseplants make its hair look greenish.

About once every two weeks,a three-toed sloth makes a very, very slow trip all the waydown to the ground. Here it digs a hole and deposits its droppings in the hole.

Sloths spend most of their time upside-down, hanging from branchesby their three-inch-long claws. They even sleep and have babies in this position.

People affect ecosystems

1. In the UK we have cut down large swathes of temperate deciduous forest to make way for farming and urban areas.

2. The landscape of the New Forest is shaped by farming techniques and ancient laws maintaining good hunting – not a ‘natural’ state.

Deforestation in Brazil

Forestremoval

HYDROELECTRIC POWER- large scale flooding

MINERAL EXTRACTION- valuable commodity- open caste mining cheaper than underground workings

LAND IS CLEARED for cattle farming and growing cattle fodder

POPULATION GROWTHThe government wishes to settle poorpeople, includes road building

LOGGINGOnly certain trees have high valueMany more are cut down for access

Sustainable development - forestry

In the forest:• Cabling (airlift trees out

by helicopter)• Replanting• Zoning (only logging in

certain areas)• Selective logging (most

trees left standing)

Outside the forest:• Create demand

(label products)• Ban sale of non-

sustainable and illegally logged wood

• Conservation / ecotourism

Example: Malaysia exports 30% world’s hardwood under strict controls. Trees have to be of a certain age and height and companies must replant as many as they remove

Case Study

The effects of people on an ecosystem.(i) Name and locate an ecosystem you

have studied.(ii) Describe the structure of the ecosystem.

Refer to plants and animals. Draw diagrams if you wish.

(iii) Explain how and why people are changing (or have changed) the ecosystem structure. [8]

CASE STUDY: Likely to be rain forest areas but could be river ecosystems or savannah/tundra/desert or other forest ecosystems e.g. acid rain in European coniferous forests. Max L3 if do not mention plants and animals.

Levels of response mark scheme. Work upwards from lowest level.Level 1: Choice of case study applied reasonably well. Simple description or explanation. Information is communicated by brief statements. 1/2 marks Level 2: Choice of case study applied well. Gives descriptive points in more detail but little explanation. Communication begins to show structure with occasional use of specialist terms. Sentences show some coherence but occasional errors in spelling, punctuation and grammar. 3/4 marks Level 3: Appropriate choice of case study applied well. Provides a balanced account which gives descriptive detailed points with some explanation. sentences with few errors in spelling, punctuation and grammar. 5/6 marks Level 4: Appropriate choice of case study applied very well. Provides a balanced account, which includes specific detailed description and explanation. Communication is logical, structured and includes specialist terms. Spelling, punctuation and grammar have considerable accuracy. 7/8 marks

Solutions / changes to the ecosystems• Sustainable development – using resources (people and environment) that will allow continued use for future generations without endangering people/environment

• Sustainable logging – Peru – cut strips of forest only 20m wide. Cleared portable saw. Oxen and cart take logs out so minimises damage. Felled area allowed trees to regenerate for up to 40 years

• National Parks – Jau Rainforest Park, Brazil – protects from development so biodiversity (variety of plants and animals not destroyed) and local tribes such as Kayapo are protected.

• Ecotourism – small, scale environmentally friendly money going directly to locals. Yachana Lodge, Ecuador rainforest – fair trade chocolate, improved lodges, school, water filters.