Section B - The Living World

Define: Ecosystem

A natural system of biotic and abiotic components interacting in and with their living, physical environment.

Define: Biotic + Give examples

Living things like plants, bacteria, fungi.

Define: Abiotic + Give examples

Non - living things like air, water, soils.

What is the role of the producers?

• To provide all of the energy for the entire food chain.

• Absorb energy from the sun to produce their own food via photosynthesis.

• Form the base/beginning of the food chain or web.

How do the producers provide their own energy?

Photosynthesis

Define: Consumer

An organism that eats other plants/animals to gain energy.

What is the role of the consumers?

Eat other organisms to gain energy.

Define: Decomposer

An organism that breaks down dead plants/animals to return nutrients to the soil.

Define: Food Chain

Single, direct flow of energy between organisms that rely on each others for food.

Define: Food Web

Complex network of multiple interconnected food chains.

What is the difference between a food chain and food web?

Food chain is the single flow of energy between organisms that rely on each others for food with straight, direct lines from producer to each consumer whereas a food web is made up of multiple, interconnected food chains.

What do the arrows show in a food chain/web?

Flow of energy.

Define: Interdependent

All biotic and abiotic components in an ecosystem relying on one another for survival.

Define: Biodiversity

A variety of living organisms in an area.

Define: Leaching

Process where water dissolves and removes nutrients from the soil by rainfall.

Describe deciduous trees during summer and winter.

Summer - Trees have broad leaves to maximise photosynthesis.

Autumn - Lose leaves to conserve energy and moisture.

What is our case study for a small scale ecosystem?

Epping Forest, Essex

Where in England is Epping Forest located?

South East England - to the North East of London in Essex.

Does Epping Forest have high or low biodiversity?

High biodiversity

How many species of birds are found in Epping Forest?

38

How many species of fungi are found in Epping Forest?

700

What biome is Epping Forest a part of?

Deciduous Woodland

Which nutrient store is the largest in Epping Forest?

Biomass

Name a producer in Epping Forest.

Deciduous trees + Shrubs.

Name a primary consumer in Epping Forest.

Insects + Beetles + Worms + Caterpillars.

Name a secondary consumer in Epping Forest.

Mouse + Badger.

Name a tertiary/top predator in Epping Forest.

Sparrow hawk + Owl.

Name a decomposer in Epping Forest.

Fungi

Which physical factors can distrupt ecosystem balance?

• Climate change - rising sea levels.

• Extreme weather events - flooding, wildfires or drought.

• Introduction of new, invasive species.

• Disease.

Which human factors can distrupt ecosystem balance?

• Hunting.

• Deforestation.

• Urbanisation.

• Fertilisers, herbicides and pesticides.

How are humans interdependent with the ecosystems like Epping Forest?

• When humans walk through the forest, seeds attach to their clothing so as they walk, these seeds spread and are dispersed elsewhere, increasing plant growth.

• People pick berries/fruits to disperse seeds.

• Deforestation encourages new growth for timber.

Define: Biomass

Total weight of all organisms in a given area.

Name the trophic levels from top to bottom.

Tertiary Consumer, Secondary Consumer, Primary Consumer, Producer.

Name the trophic levels from bottom to top.

Producer, Primary Consumer, Secondary Consumer, Tertiary Consumer.

Does biomass decrease or increase as we increase trophic levels?

Decreases

Does biomass decrease or increase as we decrease trophic levels?

Increases

How do you calculate percentage decrease?

(Old - New / Old) x 100

Why is biomass lost at each trophic level?

• Parts of plants are not eaten by animals e.g. caterpillars do not eat the roots/bark of tress so plant biomass is left.

• Carnivores do not eat all of their prey e.g. a sparrow hawk doesn’t eat the bones of a small bird.

• Energy is lost at each trophic level e.g. hunters use kinetic energy when chasing their prey + some herbivores search for lots of plants to eat so energy is constantly used up in respiration so don’t gain biomass.

Give the three components of the nutrient cycle

Biomass, Litter, Soil

Which 3 ways are nutrients removed from the nutrient cycle?

• Leaching.

• Deforestation.

• Loss through wind or rain eroding the soil.

Which 2 ways are nutrients added to the nutrient cycle?

• Gain from precipitation.

• Gain form weathered rock breaking down.

How does biomass gain nutrients?

Uptake of nutrients from the soil.

How does litter gain nutrients?

• Leaves fall and animals die from the biomass.

• Input from precipitation.

How does soil gain nutrients?

• Litter decomposes.

• Gained from weathered rock breaking down.

How does litter lose nutrients?

Loss through wind/rain eroding soil.

Define: Biome

A large scale global ecosystem.

Which biome is found along the Equator?

Tropical Rainforest.

Which continents are Tropical Rainforests typically located in?

South America, Asia and Africa.

Give some characteristics of a Tropical Rainforest biome.

• 2000mm annual rainfall.

• High temperatures.

• High levels of biodiversity.

Which biome is found at 40-45°?

Mediterranean

Which continents contain the Mediterranean biome?

Southern Europe + Northern Africa.

Give some characteristics of the Mediterranean biome.

• Hot, dry summers and wet, mild winters.

• Temperatures around 20-25°C.

• 800mm average rainfall.

• Vegetation like citrus trees, olives, oaks, lavender and rosemary.

Which biome is found at 50° North of Equator?

Deciduous Forest.

Which continents are Deciduous Forests typically located in?

Europe + North America.

Give some characteristics of a Deciduous Forest biome.

• Warm, dry summers + Wet, mild winters.

• 4 distinct seasons.

• Trees shed leaves in winter to retain energy and moisture.

• High biodiversity.

Which biome is found at 20-30° North and South of Equator, near the Equator?

Hot Deserts.

Give some characteristics of a Hot Desert biome.

• High diurnal temperature range; daytime up to 50°C and night below 0°C due to lack of clouds.

• Less than 250mm of annual rainfall.

• Low biodiversity.

• Arid conditions (hot, dry).

Which biome is found at 60° North and South of Equator?

Polar/Tundra

Which countries and continents are Polar/Tundra biomes typically located in?

Northern Canada, Arctic and Antarctica.

Give some characteristics of a Polar/Tundra biome.

• Cold, extreme temperatures.

• Less than 250mm of annual precipitation.

• Low biodiversity.

• Very fragile and easily damaged by humans.

Which biome is found at 50-60° North of Equator?

Coniferous Forest.

Give some characteristics of a Coniferous Forest biome.

• Cold, dark winters + Quite warm summers.

• Trees are evergreen so stay green all year round.

Which biome is found at 30-40° North and South of Equator?

Temperature grassland.

Which continents are Temperature Grasslands typically located in?

North America, South America & South Africa.

Which biome is found at 15-30° North and South of Equator?

Temperature grassland savanna.

Which continents are Temperature Grasslands Savanna typically located in?

South America, Africa & Australia.

Are tropical rainforests found at low or high latitudes?

Low latitudes.

What is the average temperature for the Tropical Rainforests?

26°

What is the average annual rainfall for the Tropical Rainforests?

2000mm

How many layers does the Tropical Rainforest have?

5 layers.

Name the 5 layers of the Tropical Rainforest from highest to lowest

• Emergent layer

• Canopy layer

• Under canopy layer

• Shrub layer

• Forest/ground layer

Explain the location of Tropical Rainforests.

Located along the Equator as sun rays are concentrated at the Equator because they have a shorter distance to travel, making suns insolation strong. This creates a low pressure system.

Leads to high temperatures of around 27°C, annual rainfall of 2000mm and humid conditions as warm air rises, cools and condenses for clouds to form and rain to fall.

Do tropical rainforest form in a low or high pressure environment?

Low pressure.

Describe the soil in the Tropical Rainforest

Poor, thin and infertile.

Where are most nutrients stored in the Tropical Rainforests and Why?

Biomass

1. Nutrients are concentrated in the topsoil and therefore the roots quickly uptake nutrients from the soil.

2. Heavy rainfall means many nutrients are washed away/leached before they reach the rest of the soil.

Does the Tropical Rainforest have high or low biodiversity?

Very high.

Which biome has the highest level of biodiversity in the world?

Tropical rainforest.

Why is the Tropical Rainforest able to have such a high biodiversity?

1. Humans have little interaction so organisms + vegetation can thrive in peace.

2. Humid, hot, wet climate with high temperatures + heavy rainfall allows for ideal conditions for wildlife to thrive in.

3. Since nutrients are rapidly recycled and therefore uptake is very quick, more vegetation can grow faster and survive. If more producers thrive, then consumers thrive too, leading to higher biodiversity.

4. Large range of habitats - 5 layers reaching 45m means birds can live in canopy, mammals can live in trees (sloth/monkey), other mammals live on the forest floor (rabbits/frogs).

How do traditional tribes live in harmony with the rainforest?

They only hunt what they need to.

How do humans disturb the ecosystem balance in the Tropical Rainforests?

• Deforestation for materials like paper/medicines/wood or minerals exploit the rainforest for commercial gain.

• Hunting + poaching. This can lead to endangered or extinct animals, reducing biodiversity.

What are some consequences of loss of biodiversity?

• Indigenous tribes have to abandon their lifestyles and move to cities. This can lead to loss of valuable knowledge.

• Extinct or endangered animals.

• Medical plants lost.

• Impacts food webs and causes ecosystem imbalance.

How much sunlight can reach the forest/ground floor of the Tropical Rainforest and why?

2% of sunlight as the canopy layer blocks out most sunlight.

Define: Adaptation

Plants and animals developing new behaviours or characteristics to survive and reproduce.

What must plants and animals adapt to in the Tropical Rainforest?

• 2% of sunlight reaches the forest floor - competition for sunlight.

• Infertile, poor, dry soil - competition for nutrients.

• Annual rainfall of 2000mm.

Which plants adapt to the Tropical Rainforest?

Liana’s, Drip Tip’s, Epiphytes, Tree Trunks & Buttress Roots.

Which plants have to adapt to the Hot Desert?

Spider Monkey, Toucan & Fox.

What do Liana’s have to adapt to in the Tropical Rainforest?

2% of sunlight reaches the forest floor.

How do Liana’s adapt to the Tropical Rainforest?

K - 2% of sunlight reaches the forest floor.

E - Liana’s have long, winding vines that wrap around trees.

J - Very efficient as they can support themselves to reach sunlight higher up.

What do Drip Tip’s have to adapt to in the Tropical Rainforest?

Average annual rainfall of 2000mm.

How do Drip Tip’s adapt to the Tropical Rainforest?

K - Average annual rainfall of 2000mm.

E - Drip Tip’s have pointed tips to ensure the leaves don’t break off due to heavy rainfall.

J - Therefore, water can quickly and smoothly run off the leaf, not breaking it.

What do Tree Trunks have to adapt to in the Tropical Rainforest?

• 2% of sunlight reaches the forest floor.

• Annual rainfall of 2000mm.

How do Tree Trunks adapt to the Tropical Rainforest?

K - 2% of sunlight reaches the forest floor.

E/J - Tall + Thin tree trunks that can reach up through the canopy layer for a sufficient amount of sunlight.

K - Annual rainfall of 2000mm.

E/J - Water can run down the branchless trees to the soil layer, intercepting the rain and reducing the risk of flooding.

What do Epiphytes have to adapt to in the Tropical Rainforest?

Dry, thin, poor, infertile soil.

How do Epiphytes adapt to the Tropical Rainforest?

K - Dry, thin, poor, infertile soil.

E - Epiphytes live up high in the canopy layer, gaining nutrients from the air and water, rather than the soil.

J - Therefore, plants can still get enough nutrients to thrive and grow, despite the infertile soil.

What do Buttress Roots have to adapt to in the Tropical Rainforest?

Dry, thin, poor, infertile soil.

How do Buttress Roots adapt to the Tropical Rainforest?

K - Dry, thin, poor, infertile soil.

E - Buttress roots spread out and can be seen across the first floor/surface so the tree can absorb as many nutrients as possible from the fertile topsoil/humus layer.

J - Therefore, the tree gets lots of nutrients, allowing it to grow and reach sunlight for photosynthesis to then support an entire food web if it’s a producer.

What do Spider Monkey’s have to adapt to in the Tropical Rainforest?

The Tropical Rainforest has 5 layers, reaching up to 45m in height.

How do Spider Monkey’s adapt to the Tropical Rainforest?

K - The Tropical Rainforest has 5 layers, reaching up to 45m in height.

E - Spider Monkey’s have long, strong limbs.

J - Therefore, the monkeys are able to reach food that grows up in the canopy layer that other animals can’t reach + can easily swing between trees, increasing survival rate.

What do Touncan’s have to adapt to in the Tropical Rainforest?

High biodiversity meaning lots of competition for food.

How do Toucan’s adapt to the Tropical Rainforest?

K - High biodiversity meaning lots of competition for food.

E - Toucans have a long, hard beak.

J - Therefore, they can reach across trees for their food + reach food that other animals can’t access, increasing chance of survival.