Ecosystems, Deforestation, and Desertification: Key Concepts and Impacts

What is an ecosystem?

A natural system made up of biotic (living) and abiotic (non-living) components.

What is the role of producers in an ecosystem?

They convert energy from the Sun into biomass.

What is the role of decomposers in an ecosystem?

They break down dead plants and animals, and return nutrients to the soil.

Where do consumers in an ecosystem receive their energy from?

From eating producers or other consumers.

What is a food chain?

It is a sequence showing how energy is transferred from one organism to another

What global-scale ecosystem is found 10°-20° north and south of the equator?

Tropical grassland (savanna).

What type of climate is found in tropical grassland ecosystems?

Hot with wet and dry seasons.

Name a global-scale ecosystem found between 25°-40° north and south of the equator.

Temperate grasslands.

What type of climate is found in temperate grassland ecosystems?

Hot summers and cold winters with a wet and dry season.

Between what latitudes are temperate deciduous forests found?

30°-60° north of the equator.

What is the typical vegetation found in deciduous forests?

Broadleaf trees like oaks that lose their leaves in winter.

At what latitude are coniferous forests found?

50°-60° north of the equator.

At what latitudes are tropical rainforests found?

0°-10° north and south of the equator.

What is the climate like in a tropical rainforest?

Hot and wet all year round.

How do tropical rainforests create their own water cycle?

High levels of evaporation and transpiration return moisture to the atmosphere.

Why do soils in tropical rainforests have few nutrients?

Fast nutrient uptake from vegetation, heavy rainfall leaches

How have spider monkeys adapted to living in a tropical rainforest?

They have prehensile (gripping) tails so they can move through the trees in the canopy.

Name a type of plant that has adapted to living in a tropical rainforest.

Lianas.

What is the underlying reason for deforestation in the Amazon?

Economic development.

What are the main causes of deforestation in the Amazon?

Commercial farming, subsistence farming, logging, road building, mineral extraction, energy development, settlement, population growth.

What percentage of deforestation in the Amazon is because of commercial farming?

70%.

What happens to the local climate when large-scale deforestation takes place?

It becomes drier and hotter.

Why does deforestation contribute to the enhanced greenhouse effect?

the trees can’t remove CO₂ from the atmosphere anymore, CO₂ stored in the trees is released into the atmosphere

What percentage of Brazil's GDP comes from exploiting the Amazon rainforest?

About 50%.

How do activities like commercial farming and logging help Brazil to develop?

Profits can be spent on things like health, education, and infrastructure.

What percentage of the world's plant and animal species are found in tropical rainforests?

About 8%.

Name seven strategies used to sustainably manage tropical rainforests.

Selective logging, replanting, conservation, education, ecotourism, international hardwood agreements, debt reduction.

What is a disadvantage of using replanting as a sustainable management strategy?

It is very difficult to recreate the rainforest as it was before deforestation.

What is a disadvantage of education as a sustainable management strategy?

It relies on goodwill and is not legally enforceable.

What is a disadvantage of ecotourism as a sustainable management strategy?

It is small-scale, so does not have huge economic benefits.

What is an advantage of using debt reduction as a sustainable management strategy?

It makes conserving the rainforest economically beneficial.

Where are hot deserts found?

Between 15° and 35° north and south of the equator, where global atmospheric circulation creates high pressure.

What is the average annual rainfall in a hot desert?

Less than 250 mm per year

Why are hot deserts cold at night?

There is no cloud cover to retain the heat.

What are the characteristics of soils in hot deserts?

Dry with few nutrients.

Do hot deserts have high or low atmospheric air pressure?

High pressure.

How are soils, plants, and animals interdependent in a hot desert?

Plants bind the soils together, animals eat the plants, dead animals and animal waste return nutrients to the soils.

What is the name given to a plant adapted to survive in environments with limited water supply?

Xerophyte.

What is a succulent plant?

A plant that stores water in its stem.

Why do cacti have waxy skins?

reduces water loss through transpiration.

Why do cacti have spines?

They deter animals looking for water.

Why do cacti have wide root systems?

To access water from a wide area.

Why do camels have humps?

store of fat which gives them energy when food is scarce.

Why do camels have long eyelashes and hairy ears?

To prevent sand getting in their eyes and ears.

Why do camels have wide feet?

So they do not sink in the sand.

Name three factors that make development in the Thar Desert difficult.

Extreme temperatures, limited water supply, inaccessibility.

How hot does it get in the Thar Desert?

Daily temperatures can reach 50°C.

What development opportunities are there in the Thar Desert?

Mineral extraction, energy production, farming, tourism.

What minerals are mined in the Thar Desert?

Gypsum, phosphorite, marble.

How is renewable energy generated in the Thar Desert?

solar farms, Jaisalmer (India’s largest windfarm)

How is farming made possible in the Thar Desert?

The Indira Gandhi Canal brings water into the desert.

Name a crop grown in commercial agriculture in the Thar Desert.

Wheat, cotton, maize.

What is the name of a national park in the Thar Desert?

Desert National Park.

What is desertification?

Soil degradation making (semi)-arid land infertile

Name five reasons for desertification.

Population growth, over-cultivation, overgrazing, removal of firewood, soil erosion.

What are 'stone lines'?

A management strategy for desertification: stones are laid along contour lines to prevent water washing soil away.

How can drought-resistant trees help reduce the risk of desertification?

binds soils together , provides shade

How can solar ovens reduce the risk of desertification?

They stop people cutting down trees for cooking.