MYP 5 Ecology Booklet Notes

Introduction by Rex

Rex introduces himself as a guide for the Jurassic Park Ecology Booklet.

Welcome to Jurassic Park: Learning Intentions

By the end of this booklet, you will be able to:

• Define key ecological terms.
• Understand how energy flows through an ecosystem.
• Understand the importance of interdependence in food chains and webs.
• Understand important ecological processes such as the carbon cycle, the greenhouse effect, eutrophication, and different forms of pollution.

You are part of a scientific research team sent to Isla Nublar (Jurassic Park) to observe the island's ecology, identify problems, and propose solutions to the board of chairmen.

Key Ecological Terms

When studying ecology, we gather as much information as possible about a particular area to understand what is happening. Key ecological terms to define include:

• Ecology
• Environment
• Habitat
• Populations
• Ecosystem
• Community

Ecosystems and the Biosphere

An ecosystem is self-sustaining, and the entirety of the Earth's surface containing living organisms can be regarded as one vast ecosystem called the biosphere.

• Individuals of the same species are called a population.
• Population & populations of other species are called a community.
• Community & non-living part of the environment is called an ecosystem.

Studying Ecology: Biotic and Abiotic Factors

When studying the ecology of an ecosystem, we gather information about:

• Biotic factors: Predation, reproduction, intra- and interspecies competition, etc.
• Abiotic factors:
  • Surface area/volume of an area
  • Climatic conditions (temperature, rainfall, etc.)
  • Soil conditions (edaphic)
  • Mineral availability
  • pH
  • Oxygen content

Biotic and abiotic factors are interrelated; a change in one affects the other. For example, if the soil pH becomes too acidic, plants won't grow, affecting herbivores and subsequently carnivores.

Terms: Biotic Factors, Abiotic Factors

Feeding Relationships

Food is a source of energy. Green plants are the only things that make food, they are called producers. They use energy from the sun. These plant photosynthesises and makes glucose, which is a form of sugar. Plants get eaten by animals and because of this the sun is the ultimate source of energy for the earth.

It was essential to get the right dinosaurs to live in Jurassic Park so that it would become its own self sufficient ecosystem. All living organisms depend on one another to survive (interdependence). Feeding relationships are studied using food chains. A food chain represents the flow of energy.

Example: Plants -> Brachiosaurus -> Velociraptor -> Tyrannosaurus Rex

The arrows in a food chain represent the flow of energy. Plants produce food via photosynthesis, consumed by the brachiosaurus, eaten by the Velociraptor, which is then eaten by the tyrannosaurus. Energy passes through the food chain from producers to consumers. The stages in a food chain are called trophic levels.

• Plants: Producer (Primary Trophic Level)
• Brachiosaurus: Primary Consumer (Secondary Trophic Level)
• Velociraptor: Secondary Consumer (Tertiary Trophic Level)
• T-Rex: Tertiary Consumer (Quaternary Trophic Level)

Decomposers

When animals and plants die, decomposers (bacteria and microorganisms) break them down, releasing chemical elements that are absorbed by plants and can go through the food chain again.

Food chains show feeding relationships, and arrows represent the flow of energy.

Food Webs

A food web is a collection of food chains within a habitat and is a more realistic representation of feeding relationships. Organisms may be eaten by multiple consumers, and those consumers may feed on multiple species.

Trophic Levels

Trophic levels are the feeding levels in food chains and webs.

Tertiary consumers(T-Rex) are known as top or climax carnivores.

The number of organisms in a food chain is usually limited because energy is lost between each level as organisms respire, move, excrete, and build mass.

Pyramids of Numbers and Biomass

Pyramids of numbers or biomass represent what we see in the field when studying dinosaurs.

The number of organisms that can be supported at each trophic level decreases as you go along a food chain. (Plants feed a smaller number of herbivores, which feed an even smaller number of carnivores.)

A pyramid of numbers is a diagram that represents the number of organisms at each trophic level in an ecosystem at any one time.

Example: 100 Plants -> 10 Triceratops -> 5 Velociraptors -> 1 T-Rex

Unusual pyramid shapes can occur, such as when the producer is very large (e.g., a tree) or when parasites feed on consumers (e.g., lice on a lion).

Pyramids of Biomass

In ecology, a pyramid of biomass is used to determine the dry mass of an organism, which is a better indicator than fresh mass since most organisms contain large quantities of water (e.g., mammals are 67% water).

Biomass decreases up the pyramid as there are fewer organisms at each level.

Energy Loss: Leaky Cups Activity

An activity to demonstrate the loss of energy between organisms in a food chain, represented by passing water (energy) along the chain using cups with holes.

Toxins in the Food Chain (DDT)

Many compounds, such as the insecticide DDT, are toxic because they are not biodegradable (cannot be broken down by the environment).

DDT accumulates in the fatty tissues of animals, so levels build up in primary consumers and then in secondary consumers when they are eaten. Tertiary consumers (T-Rex) can accumulate dangerous levels of DDT, potentially causing death.

In jurassic Park insecticides such as DDT are used to keep the plants that are eaten by the herbivore dinosaurs healthy. It was discovered that dangerously high levels of DDT in our Tyrannosaurus Rex population. A letter to the Board of Chairmen is needed to explain how DDT is travelling through the food chain, accumulating to fatal levels and a solution is needed for the problem.

Fertilizers

A fertilizer is a substance that contains chemical elements needed by plants, such as nitrogen (N), phosphorus (P), and potassium (K).

In a natural plant community, when a plant dies, it decays, and the chemicals are reabsorbed. In a field with crops, plants are harvested, so the chemicals are not returned to the soil, and the soil becomes poor. This can be helped by adding fertilizers to the soil.

There are two kinds of fertilizers: organic and inorganic.

• Organic fertilizers are obtained from animals and plants (e.g., green manure and bone manure) and are natural.
• Inorganic fertilizers are manufactured and are artificial.

Advantages and disadvantages of organic and inorganic fertilizers:

• Organic fertilizers take longer to break down, so nutrients take longer to get into the plant.
• Inorganic fertilizers can be absorbed by the plant immediately.
• Nutrients from organic fertilizers are not as easily washed out of the soil by rain as those from inorganic fertilizers.

Eutrophication

Eutrophication is a process wherein excess fertilizer added to the soil drains into lakes and rivers.

This makes the water richer in nutrients such as nitrogen and phosphorus, causing algae to multiply rapidly, turning the water green (an algae bloom).

When the algae die, they decay, and the bacteria that decompose them multiply so fast that they use up all the oxygen, killing the fish.

Fertilizers can be organic or inorganic and contain nitrogen, phosphorous, and carbon. Fertilizers can be non-bio or biodegradable.

Dino Disaster: Eutrophication in Jurassic Park

Excess amounts of fertilisers used to keep the vegetation in the park healthy have been washed into the water dinosaur pens (Shonisaurus). This has leads to Eutrophication taking place in the pens and unfortunately one of our water dinosaurs has died. A mortuary report to be forwarded to the Board of Chairmen is needed explaining how excess fertilisers cause Eutrophication and possible solutions to this problem to prevent any more dinosaurs being affected.

Water Pollution

Alternative processes of water pollution include:

1. Waste from factories: Water used for cooling may contain poisonous chemicals such as cyanide, mercury, or lead, which can pass along food chains to fish and then to fish-eating animals.
2. Waste from farms (slurry): A mixture of animal droppings and urine that can be sprayed onto fields as a fertilizer and washed into streams and rivers.
3. Oil spills: Spills from tankers and oil rigs poison sea birds and clog their feathers, kill plants and animals along the sea shore, and ruin beaches.

Land Pollution

Forms of land pollution include:

1. Household refuse: Millions of tonnes of waste are produced each year, usually buried in landfill sites or burned, causing environmental problems like breeding grounds for disease and destruction of habitats. This can be reduced by using biodegradable products and recycling.
2. Deforestation: Tropical forests are cleared for timber and land use, destroying important habitats and reducing variation of species. Trees hold soil in position and retain water, so removing trees causes soil to be washed away and clog waterways. This can be reduced by replanting trees and re-ploughing the land to regenerate water levels.

Dino Disaster: Land Pollution at Jurassic Park

Non-biodegradable rubbish from the Jurassic Park shop was blown out of bins and scattered all over the park, posing a health hazard to dinosaurs if consumed.

Air Pollution

1. Smoke: Air pollution from smoke when fossil fuels are burnt can harm both plants and animals.
   • Tiny particles can cause irritation to the respiratory system, leading to bronchitis.
   • Smoke suspended in the air may reduce photosynthesis due to lower light intensity.
   • Soot and ash could coat plant leaves, preventing photosynthesis or blocking stomata.
2. Sulphur dioxide: Released into the air when fossil fuels are burnt, it can cause:
   • Damage to the respiratory system in humans.
   • Reduced growth or death in plants.
3. Acid rain: Sulphur dioxide and nitrogen oxides can combine with water, affecting:
   • Trees, plants
   • Lakes
   • Fish, etc.
4. Carbon dioxide: Increased concentration in the atmosphere traps heat (the "Greenhouse Effect").

A pollutant is a substance that contaminates in a harmful way. There are different forms of pollution.

The Greenhouse Effect

The greenhouse effect is a natural process that heats the Earth up, essential for life. Sunlight hits the Earth's surface and heats it up, then is emitted as infrared radiation. Some of this radiation is trapped by gases (methane and carbon dioxide - known as greenhouse gases), heating up the planet, while some escapes.

However, humans are releasing too much carbon dioxide by burning fossil fuels, causing too much heat to be trapped and the planet to warm up too fast, melting the polar ice caps.

The Carbon Cycle

All living things are made of carbon, which is also part of the ocean, air, and rocks. Carbon is on the move.

In the atmosphere, carbon is attached to oxygen in carbon dioxide ($CO_2$). Plants use carbon dioxide and sunlight to make their own food and grow, becoming part of the plant. Plants that die and are buried may turn into fossil fuels (coal and oil) over millions of years. When humans burn fossil fuels, most of the carbon quickly enters the atmosphere as carbon dioxide.

Carbon dioxide is a greenhouse gas. Humans have burned so much fuel that there is about 30% more carbon dioxide in the air today than there was about 150 years ago, and Earth is becoming a warmer place.

Carbon is released into the atmosphere as carbon dioxide through several processes:

• Respiration: Animals and plants release carbon dioxide.
• Combustion: Fuels containing carbon (wood, oil, coal) are burned, bonding carbon with oxygen to produce carbon dioxide.
• Decay: Decomposer bacteria break down plants and animals, releasing carbon dioxide or converting it into fossil fuels underground.

Carbon dioxide chemical symbol: $CO_2$ (one carbon molecule and two oxygen molecules).

Reducing $CO_2$ in the Atmosphere

Carbon dioxide can be removed from the atmosphere by:

• Being absorbed by the oceans and creating carbonic acid.
• Being absorbed and forming carbonate rocks (calcium carbonate).
• Photosynthesis: Plants use carbon dioxide and water in sunlight to produce glucose (sugar) and oxygen. Planting trees can significantly reduce atmospheric carbon dioxide, which is why deforestation is bad for the environment.