the living world

Ecosystem

A natural system made of plants, animals, and their physical surrounding environment

Biotic components

Living components of an ecosystem Smallsuch as plants and animals

Abiotic components

Non living components of an ecosystem like rocks and soil

Small scale ecosystem

Also called habitat

E.g. garden, fish tank, tree

Global scale ecosystem

Also called a biome

E.g. tropical rainforest, desert, tundra

Food chain

The sequence of who eats what in an ecosystem to obtain nutrients and energy

Food web

A number of food chains joined together in one habitat. It shows how an organism doesnt eat just one thing

Autotroph

Organisms that use photosynthesis to provide energy for themselves

Also known as producers

Heterotroph

Organisms that consume other organisms for energy

Also known as consumers

Trophic level

The position of an organism it occupies in the food chain

Lost energy in ecosystems

At each trophic level energy is lost

Only 10% of energy on average is passed onto the next trophic level

Organisms respire, move, excrete matter

Each process loses energy

What does an ecosystem depend on?

1. Flow of energy between consumers and detritivores

2. Recycling of matter via the nutrient cycle

Detritivores

Eat and break down detritus (small bits of dead organisms) for decomposers to feed on

Decomposer

Eat microscopic dead or decaying organisms

Break these down into simple molecules using chemicals and then absorb the nutrients

Gersmehl diagram

Epping forest - type of ecosystem

Deciduous forest

Interdependent:

Every organism rely on every other to survive

Epping forest - Climate

July average: 19 degrees

January average: 6 degrees

Usually quite rainy in summer and winter

Epping forest - nutrient cycle

Trees are deciduous so lose leaves in autumn

Decompsers and detritivores work on leaves

Nutrients in leaves are converted to humus in the soil

This supports plant growth, in which fruits are fed on by consumers

Epping forest - gersmehl diagram

Circles:

Large Biomass

Medium Soil

Low Litter

Arrows:

From B to L: Low leaves falling

To L: Minerals from rainfall

From L: Low runoff

From L to S: High decomposing

From S: High leaching

To S: Medium weathered rock

From S to B: Medium uptake by plants of nutrients

Epping forest: management

Dead wood left to rot to promote fungi, which is a decomposer in the nutrient cycle

Grassy areas left uncut to promote butterflies

Biking areas clearly marked to prevent damage

How can changes in an ecosystem occur

Naturally or human

Global or local

Ecological impacts in the absence of wolves in yellowstone

Elk pop began to rise

This caused conditions in the park to decline:

Deciduous, woody species such as aspen and cottonwood began to decline due to overgrazing

Coyote pop increased which led to reduction of pronghorn pop

Ecological impacts after the reintroduction of wolves in yellowstone

Elk pop declined

This led previously overgrazed fauna to flourish

Elk behavior changed: less favourable habitat, browse wider so other flora species could survive

Beaver colonies increased 1 to 9 as elk browsed less on their food

Dams from beavers led to more moose, otter, birds, fish, amphibians

Rivers meander less due to less erosion as stronger tress regenerated due to less focused grazing by elk

Tropical rainforests

High temp

Heavy rainfall

These conditions creates ideal environment for plants to grow

These plants support animals

More than half of animal and plant species in the world come from TRF

Hot deserts

Around 30 degrees N/S

High pressure subtropical belts result in sinking air and no precipitation

No clouds so no sunlight blocked during day so high day temps

Low night temps as no clouds trap heat

Plants and animal need to be highly adapted to survive e.g. cacti

Where can you find tropical rainforests?

Tropical rainforests are located in the tropics, near the equator.

How much rain do they get?

Most rainforests get at least 75 inches of rain with many getting well over 100 inches in areas.

What's the temperature there? Would you like this climate?

Because they are close to the equator, the temperature stays between 25 and 28 degrees C for most of the year.

Which continent should you travel to find a rainforest?

To Africa, to South-east Asia or to South America.

How many percent of the animals on Earth live here?

50%. Scientists say that around half of the planet's animal and plant species live in the world's rainforests.

In which layer would you searh for monkeys?

In the canopy layer.

In which layer would you searh for snakes?

In the undercanopy layer.

Why are rainforests so important for humans?

Because they act as the Earth's lungs by producing around 40% of the world's oxygen. The rainforests also provide a number of important drugs to help sick people and cure diseases.

Is the territory of the rainforests growing or getting smaller?

It is getting smaller. Unfortunately, human development is killing off much of the world's rainforest. Around 40% of the world's rainforests have already been lost.

Biodiversity

The variety of life in the world or a particular habitat.

Deforestation

The chopping down and removal of trees to clear an area of forest, usually because of business needs

Logging

The business of cutting down trees and transporting the logs to sawmills.

Loss of biodiversity

An environmental impact of deforestation

Medicines as a result of deforestation

could be lost due to deforestation including Reserpine, a drug which can be used to treat people with high blood pressure.

Indigenous Tribes as a result of deforestation

Lose their homelands when developments take place

Soil erosion

Happens as trees no longer protect the soil through interception

Flooding

can increase as there is less interception

Improving transportation

means easier access to raw materials like minerals and timber.

Economic benefits of deforestation

are selling hardwoods like mahogony and allowing farming

Nutrient cycle as a result of deforestation

is damaged during deforestation as there is no loger litter to decompose

Mineral Deposits in trf deforestation

including bauxite, iron ore, manganese, gold, silver and diamonds can be exploited and sold

Undergrowth layer

The rainforest layer where trees grow up to 5 metres. Much of the sunlight is blocked by the canopy only 1-2% of sunlight

Understorey layer

below the canopy layer; usually shrubs and smaller trees - 17m and only 2-5% of sunlight where plants rarely grow above 10m in height

canopy layer of tropical rainforests

This layer of a rainforest contains the majority of the largest trees, typically 30-45 m tall. The densest areas of biodiversity are found here, a more or less continuous cover of foliage formed by adjacent treetops. It is home to 50 percent of all plant species, suggesting that perhaps half of all life on Earth could be found there. Epiphytic plants attach to trunks and branches, and obtain water and minerals from rain and debris that collects on the supporting plants. The fauna is similar to that found in the emergent layer, but more diverse. A quarter of all insect species are believed to exist in this layer and 90% of all trf organisms are found here - 29m in height

emergent layer of tropical rainforests

This layer of a tropical rainforest contains a small number of very large trees , which grow above the general canopy, reaching heights of 45-55 m. They need to be able to withstand the hot temperatures and strong winds that occur above the canopy in some areas. trees can grow 25 to 45m in height and many leaves have flexible bases to face towards the sun and pointed tipped leaves for rain to drip off

Uses of TRF - chocolate

cacao tree native to amazon rainforest

Uses of TRF - rivers

can be used as a Hydroelectric energy source

Uses of TRF - rice

2nd most produced food crop in the world which originates from trf regions across the globe

estimated amount of forest lost every year

size of england

fraction of medicines with ingredients derived from trf species

¼

total damage cost of forest loss for global economy

12 trillion dollars

deforestation activities causing forest to be cleared

Road building, settlement of population growth and commercial farming

sustainable management

management that meets the needs of the present population without endangering the ability of future generations to meet their own needs

selective logging

The cutting out of trees which are mature or inferior, to encourage the growth of the remaining trees in a forest or wood.

conservation and education of trf

rainforest can be preserved conservation areas

ecotourism of trf

introduce people to the natural world

income benefits the gov for protecting trf

income for indigenous

Debt reduction

Countries are relieved of some of their debt in return for protecting their rainforests.

Where is Malaysia?

Southeast Asia, it consists of peninsular Malaysia and the island of Borneo

How much of Malaysia is covered and by what?

67% of Malaysia is covered in tropical rainforests.

What are the causes of deforestation in Malaysia (7) ?

Logging

Road Building

Energy Development - Dam building

Mineral extraction

Urbanisation from population pressure

Subsistence farming

Commercial farming - palm oil

Why did logging occur in Malaysia?

In 1980s, Malaysia was largest exporter of tropical wood so clear felling was taking place on a wide scale

What is clear felling?

Absolute clearance of all trees from an area leaving bare soil and destroying habitats

What dam has been built?

The Bakun Dam in Sarawak which cleared 700km^2 of forest

Why has mining caused deforestation?

Due to open-cast mining which requires large amounts of trees, soils and bedrock to be cleared.

What is palm oil?

- Type of vegetable oil which gives food smooth texture

- Used in 50% of supermarket products - e.g. ice cream

Why is Malaysia linked with palm oil?

Malaysia is the largest exporter in this growing industry and has around 90% of the world's oil palm trees.

Benefits of palm oil farming?

It directly provides employment for 1 million people in Malaysia.

It contributes to 10% of Malaysia's total exports.

Costs of palm oil farming?

Intentional forest fires to destroy huge areas of forest and contributes to greenhouse gas emissions

Between 70,000 to 200,000 children are estimated to work on plantations.

What were the impacts of deforestation for Malaysia (3)?

Soil Erosion

Loss of Biodiversity

Contribution to climate change

What were the impacts of deforestation for Malaysia (4)?

Loss of Biodiversity

What were the impacts of deforestation for Malaysia (4)?

Contribution to climate change

What were the impacts of deforestation for Malaysia (4)?

Economic Development

What is soil erosion?

The removal of soil which acts as an important part of ecosystems present.

How does it contribute to climate change?

Deforestation reduces the amount of carbon trees store which increases CO2 emissions.

Trees give off moisture from transpiration - so lack of trees causes drier climate

Economic benefits of deforestation (2)?

An increase in number of jobs because land will be used for commercial/industrial processes.

Improved infrastructure opens up areas for development and tourism.

Economic losses of deforestation (3)?

Fires can destroy forests as well as cause harmful pollution.

Number of tourists may decrease

Rising temperatures may ruin some crops from growing such as tea, fruits and flowers.

Desertification

where semi-arid areas/drylands is gradually turned into desert.

Where does desertification usually happen?

On the edges of an existing desert

When it rains, what may happen that leads to the degradation of soil(desertification)?

Instead of the water being absorbed by the soil, it runs off the surface(surface runoff).

What is the degradation of soil a result of?

Decreased fertility and structure.

What is a result of soil degradation?(desertification)

Harder to grow crops/natural vegetation

Why would the soil be exposed to hot sun and rain in desertification?

There are no plants/natural vegetation to intercept those factors.

The heat bakes the soil to the point where it _______.

cracks

Physical Reasons for desertification

soil erosion-soil exposed to wind and rain

Physical Reasons for desertification

natural occurrences-droughts for example

Human Reasons for desertification

Overcultivation-the need to produce more food, this exhausts the soil

Anthropogenic climate change-slight climate changes can lead to a big impact, as to increase global temperatures would set the stage for hot desert climate

Overgrazing-the pressure on semi-fragile areas could lead to desertification as too many animals exceed vegetation limits

Social effects of desertification

20 million people in Sahel region of Africa faced hunger in 2014(source:UN)

Loss of species affects medicinal availability

Population pressure stopped traditional nomadic farming - soil drained intensively of nutrients, thus infertile/poor soil and regular crop failure

Economic effects of desertification

UN required 2 billion in food aid due to desertification

Environmental effects of desertification

Loss of vegetation, thus damage to animal habitats

Less tree cover and more grasses which protects the soil less

Plant adaptations to TRF(buttress roots)

buttress roots-large roots growing above the grounnd from the stem of their trunk-this is to provide them with stability so they do not fall over

Plant adaptations to TRF(lianas)

lianas-wind themselves around rainforest trees and climb high - this is to reach available sunlight

Plant adaptations to TRF(drip tip)

drip tips-the pointed end of a leaf - directs water away from the middle of the leaf

Plant adaptations to TRF(waxy leaves)

waxy leaves-waxy waterproof coating on leaf surface - helps water run off easier to preevent them from being weighed down