UNIT 5. ECOSYSTEMS (NATURAL SCIENCE)

UNIT 5. ECOSYSTEMS

Ecosystems include a physical environment, living things who  live there and the interaction between them. Each ecosystem is unique  although they sometimes have similar characeristics.

WHAT MAKES UP AN ECOSYSTEM?

·        Ecosystem organisation

-          Ecosystem: marine ecosystems are one of the largest because they include many different: coral reefs, open oceans, etc. There are a lot of living things.

-          Habitat: place where an organism lives. For example, marine hábitats are varied.

-          Population: organisms of the same species within an ecosystem. For example, bacteria, algae (big population) or mammals (small number).

-          Community: Different populations which interact with each other.  For example, mammals, fish and invertebrates living together.

DIFFERENT ECOSYSTEMS AND HABITATS

·         Tropical rainforests

They are found at equatorial latitudes (river basins of the Amazon and Congo Rivers and the islands of Indonesia). There are 12 hours of sunshine  and warm wet climate, that encourages biodiversity.

1.       Emergent layer: tres about 50 – 60 metres tall which are adapted to survive in hot temperaturas and strong winds.

2.       Canopy layer: more tan 30 metres tall and many mmamals, birds, insects and reptiles live there.

3.       Understory layer:  trunks, branches, bushes and shrubs Predatoris and snakes live here and some mmmals, reptiles and amphibians too.

4.       Forest floor: Invertebrates, fungi and bacteria . It is dark, with Little light.

·         Tundra

The ecosystems of Tundra are in the areas around the Artic Circle and some parts of the Antarctica. It has low temperatures , permafrost (layer of frozen soil), Little rainfall and short summer seson.  There are few trees, just some mosses, lichens and shrubs. There are some animals like: arctic foxes, arctic hares, reindeer, polar bears.

FOOD CHAINS AND FOOD WEBS

Some organisms make their own food (plants) and others, feed on other organisms. These relationships between different species form food webs and they are made up of many food chains. In a food chain there are three levels:

1.       Producers (autotrophs): are the basis of a food chain and make their food, for example plants and some protists.

2.       Consumers (heterotrophs): feed on other living things. There are three types:

§  Primary consumers: feed on plants. Herbivores are primary consumers, for example, giraffes.

§  Secondary consumers: feed on primary consumers. They can be carnivores and omnivores. A predator is the animal who eats other animal and a prey is the animal who is eaten.

§  Tertiary consumers: feed on secondary consumers. They can be carnivores and omnivores.

3.       Decomposers feed on dead organic matter. Most decomposers are fungi and bacteria.

·         Food webs

Food webs produce energy, it means biomass ( food for the next trophic level). Producers produce most of the biomass, higher levels produce much less biomass. In a healthy food chain there are more plants than herbivores or carnivores. If the food web is damaged, the biomass can decline and the ecosystem can be in danger.

UNIT 5. THE ECONOMY (SOCIAL SCIENCE)

UNIT 5. THE ECONOMY

·         THE PRIMARY SECTOR

Primary sector activities obtain natural products  from nature.

-          Arable farming: cultivation of land to produce crops.  There are dry crops (for example, cereals,) which needs only rainwater, and irrigated crops (for examplem fruit), whihc needs extra water.

-          Livestock farming: farmers buy and sell animals to produce food and other products. There are two types of farming: extensive farming, animals spend a lot of time outdoors, and intensive, in which animals are in farms.

-          Fishing: catching fish and other animals from lakes, rivers, seas and oceans. Deep-sea fishing takes place far away from the coast and coastal fishing, near the coast.

-          Mining: taking natural materials from the Earth´s crust. The underground mining makes tunnels under the Eeather´s surface and the open-cast mining  takes place on the surface.

-          Forestry: exploitation of forests and tree plantations. Deforestation means cutting down forests. The number of forests are decreasing due to human factors.

·         Raw materials

We usually use raw materials to transform them into new products. We can obtain raw materials from underground (sand) or from living things (trees).

·         The primary sector in Spain

In 1900, about 60% of people worked in the primary sector. Nowadays, about 5%. There are crops like olives specially in Andalucía and oranges in Comunidad Valenciana. Pig farming is very important in Extremadura. Spain has got different coasts, for this reason, fishing is quite important too. Mining was more important in the past and the most important forestry product is the cork.

THE SECONDARY SECTOR

Workers in the secondary sector transform raw materials inot manufactured products. It is manufacturing.

-          Energy industries are very important because they produce energy for houses and other industries. We get energy from renewable energy sources like sunlight, wind or water and nn-renewable energy sources as coal, gas.

-          Construction industries: use raw materials to make building and public Works.

-          Consumer goods industries: make clothes, cosmetics etc using products from base industries and capital goods industries.

-          Base industries: transform raw materials into semi-finished products, for example chemical and metal industries.

-          Capital goods industries: use base industry products to manufacture things like machiney and equipment.

·         Manufactured products

Manufactured products can be produced  using craft methods, in which workers use their hands or tools to make their products, or industrial processes in which workers Works in industries and use complex machines to produce large quantities of products.

·         The secondary sector in Spain

This sector is growing, about 30% of active population work in it.  Most industries are in big cities like Madrid, Bilbao or Barcelona. Shoe industries have become more important.

·         The tertiary sector

It is called the service sector too becaus eprovides services to customers.

-          Education: people who work in education help us learn.

-          Healthcare: healthcare workers look after our health.

-          Retail: workers sell us products in shops, supermarkets…

-          Administration: workers organise work in offices.

-          Media and communication: provide us information (newspapers, television, radio, internet).

-          Tourism: gives accommodation and entertainment to tourists.

-          Trade:

o   Domestic trade: buying and selling products within one country.

o   Foreign trade: buying and selling products between different countries. The products we buy are imports and the products we buy are exports.

-          Transport: carry opeople and goods from one place to another. There are three groups:

o   Land transport (road and rail)

o   Air transport

o   Water transport

·         The tertiary sector in Spain

It is the largest sector. About 65% of active people work in it. There are four types of tourism: beach, rural, cultural and adventure.

                In 2013 more tan 60 million tourists came to Spain.

Spain imports machinery, food and textiles and exports chemical products, shoes, fuit and vegetables.

Spain has a big network of motorways, roads, railways, ports and airports.

ECONOMIC SECTORS IN EUROPE

·         Primary sector

In Europe, different types of natural products are produced due to the diveristy of climates. About the 4% of the population of Europe workin this sector.

·         Secondary sector

About 30% of the active population work in this sector

·         Tertiary sector

About 66% work in this sector. Tourims is very importante, specially in France, Spain, Greece and Italy. There are important ports and airoport because Europe has a good road and railway network. Europe imports pretroleum and other raw materials from other continents and exports metal products, cars and chemicals.