Ecology is the study of the relationships amongst organisms (living things) and the

connections between organisms and their physical environment.

EcosystemAn ecosystem is a community of living and non-living things that work together. Ecosystems have no particular size. An ecosystem can be as large as a desert or a lake or as small as a tree or a puddle. If you have an aquarium, that is an artificial ecosystem. The water, water temperature, plants, animals, air, light and soil all work together. 

Major biomes

Urban ArcticForest Reef

Jungle Rainforest Temperate Evergreen

Coastline BeachesAlpine (high on mountains) DesertsPasture WetlandsPlainlands

Environment

The environmental factors which affect a species can be divided into abiotic(physical) and biotic factors.

Major biomes

Urban ArcticForest Reef

Jungle Rainforest Temperate Evergreen

Coastline BeachesAlpine (high on mountains) DesertsPasture WetlandsPlainlands

List the abiotic and biotic factors. (Ref Pg4)

Abiotic factors Biotic factors

UrbanOrganisms: domestic cats, dogs/ human/ rats/ pigeons/ sparrows

Structures Temperature Wind speed

Predation : cats on rats Competition for food:

rats

Arctic Temperature Wind speed Salinity Precipitation: snow Amount of oxygen

dissolved in water

Predation: polar bears on fish

Competition for food Competition for space

Forest, Alpine Air pressure Humidity Amount of nutrient (in

soil) Light intensity

Predation Competition for food

and resources Competition for space

Reef

Deserts

Pasture

Wetlands

What are the features of the environment?

Aquatic environment:

Terrestrial environment:

Abiotic factors of Aquatic environment

The amounts of dissolved gases in the water Water temperature Light Currents or waves

Question: Oxygen and Carbon Dioxide

1.Which organism requires carbon dioxide? Why?

2.Which organism requires oxygen? Why?

3.How do aquatic organisms obtain oxygen and carbon dioxide?

Amount of gas dissolved in the water decreases with a rise in temperature. Therefore, small bodies of water such as ponds or rock pools which tend to heat up quickly have lower amounts of dissolved gases.

Answer:

1.Which organism requires carbon dioxide? Why?Coral reef: they carry out photosynthesis

2.Which organism requires oxygen? Why?Fishes: To produce energy from foods

3.How do aquatic organisms obtain oxygen and carbon dioxide?Both gases are soluble in water. Gases dissolve in the water where the air touches it at the surface. Oxygen is produced by aquatic plants and algae during photosynthesis. Carbon dioxide is produced during respiration by all organisms.

Question: Light

Why is the availability of light very important organisms in aquatic environment?

The amount of light decreases with the depth.

Plants and algae use light in photosynthesis to make oxygen and their food.

Currents and Waves:

Why are currents and waves important for organisms?Waves and turbulent water help to increase the amount of dissolved gases in the water. When the waves crash over rocks water traps bubbles of air thus allowing more oxygen to dissolve in water. Water falls and rapids churn up of water and allow more of the gases in the air to dissolve in the water.

Abiotic factors of Terrestrial environment

The living environment is all the living things that interact with an organism – its food, predators, competitors and disease organisms. The non-living or physical environment includes temperature, light, humidity and nutrients. These factors are extremely important for the survival of organisms.

Research Task: Make notes on following.

1. Choose a biome (particular ecosystem). Eg. Pupuke Lake

2. Describe the features of the environment.3. Describe the physical factors of the

environment found in the environment.4. What animals are found there?5. What plants are found there?6. Describe biotic factors of the environment.

Adaptation : Features of the species that allow organisms to survive in their habitat.

Features for survival: How it

Gets its nutrition Protect itself from predators, from the

weather etc. Find its mates – attract, display, call

etc.

3 types of adaptation:

There are three types of adaptation.

Using Pathfinder p5, make notes on the three types of adaptations.

Adaptation: Seagulls

Structural, physiological or behavioural? They have wings for flight to find food. They have inflatable air bags on chest to cushion impact

during dive. They have wings to escape from predators. They have webbed feet to aid swimming. They are carnivores feeding on crabs or fish. They nest in large colonies. They attack predators. They lay 2-3 eggs. They will scavenge.

Research Task: Make notes on following.

Why do plants and animals live in the places they do?

Find out about behavioural, physiological, structural adaptation of animals in your chosen ecosystem.

Features of the animal. How the feature help the animal to

survive.

Adaptation

1. Structural adaptation: The shape of their body (part)2. Behavioural adaptation: What they do3. Physiological adaptation: How their body works

An animal was found in a very fast-flowing stream. From the list below, choose the structural adaptations it might have.

A streamlined body Long, thin legs A flattened body shape Large head and eyes Short, muscular legs Large gills to absorb the small amount of dissolved oxygen Hooks on the ends of its legs A round, ball-like body shape A smooth, shiny body

Niche = habitat + feeding role + adaptationThe environment where specie lives(habitat), what the species feeds on(feeding role), and the features of a specie has that allows it to survive(adaptation).

Specie is 1 type of organism.

Every species has its own niche.

Law: No 2 species can have the same niche at the same time.

Feeding roleProducers make their own food but absorb nutrients from the soil.

Consumers eat food. Nutrient and glucose are obtained from the organisms they eat.

1) Herbivore – eat plants2) Carnivore – eat animals3) Omnivore – eat both plants and animals

Scavenger: eat dead animals or plants Parasite: gets food from an animal / plant it

lives in. Browser: eat leaves Grazer: eat grass Predator: hunt + eat animals

4) Decomposer: Breakdown dead organisms. Left over minerals are returned to the soil. Eg. Bacteria, fungi

Copy the table. Write down the statement that best describes what job each of the following groups of living things do.

Job What job do they do in a community ?

Producer

Herbivore

Carnivore

Omnivore

Scavenger

Parasite

Decomposer

Food Chain

A food chain is the series of organisms showing feeding relationships. A food chain almost always begins with a green plant (producer) which is eaten by an animal (consumer). The arrow means ‘is eaten by’, and shows the flow of matter and energy along the food chain. There are no decomposers in a food chain.

The trophic level is the position of an organism in a food chain.

Eg. Rosebush → Greenfly → Ladybird →Sparrow. The rosebush is the producer, the greenfly is the primary consumer, the ladybird is a secondary consumer and the sparrow is the tertiary consumer.

Example of a Food ChainGrass(Producer) Grasshopper(1st order Consumer)

Kookaburra(2nd order Consumer)

Why do we start food chain with a producer?

Plants and algae contain chlorophyll and are able to absorb sunlight as an energy source to make food. So the energy you obtained from your breakfast foods came originally from the sun’s energy which the corn, wheat and oat plants absorbed.

Nectar (From plants) honey (from bees) human

Grass milk (from cows) human

Animals are consumers because they do not make their own food and have to rely on other organisms for food.

Food chains involve less than 6 organisms in a food chain. Why are they short?

Food chains are short because the transfer of energy from one trophic level to the next is very inefficient. About 10% of the energy is passed to the next trophic level, about 90% of the energy being used for respiration to supply energy to stay alive.

There are never usually more than five steps, because a lot of energy is lost at each step, and after three steps most of the available energy has been expended.

This also explains why the organisms at the top of food chains (eg hawks) are very small in number compared with those lower down (eg buttercup plants). After 2 steps there is simply not enough available energy to support more than a few top predators.

1. Use the information in parts (a) to (f) to write out six food chains.a Grasshoppers eat daisies; lizards eat grasshoppers;

hawks eat lizards.Daisies grasshopper lizards hawks

b Rats eat worms; stoats eat rats; worms eat dead leaves.

(Dead) leaves worms rats stoats

c Hedgehogs eat slugs; slugs eat lettuce; foxes eat hedgehogs.

Lettuce slugs hedgehogs foxes

d Cod (fish) eat eels; shrimps eat simple plants called plankton; eels eat shrimps.

Plankton shrimps eels codse Falcons eat sparrows; ladybirds eat aphids; sparrows

eat ladybirds; aphids feed on the juice in the leaves and stems of a rose bush.

Rose bush aphids ladybirds sparrow falcon

f Perch (fish) eat sticklebacks; water fleas eat simple plants called green algae; pike (fish) eat perch; sticklebacks eat water fleas.

Algae water fleas sticklebacks perch pike

2 Look at your six food chains again.a List all the producers.b List all the herbivores.c List all the carnivores.

Food webs

Feeding relationships among the organisms in a pond: Plants and algae snails Plants and algae water bugs frogs Plants and algae tadpole fish Plants water bugs fish

To show more complete picture of the feeding relationships in the pond, these food chains can be combined to give a food web.

Food webs show the feeding habits of all the organisms living together in a particular place.Eg. you can see from the food web that fish eat tadpoles as well as water bugs, but frogs eat water bugs only.

Food web can be very complex. Animals usually eat many different foods. This means lots of arrows on the food web.

Producer

Consume

Herbivore

carnivore

CONSTRUCT A FOOD WEB

COMPETITION BETWEEN SPECIESIn a community the number of animals of a species (its population) is usually limited by the food available.

If the prey population increases, more food is available for its predators and their population may also ________.

If the predator population increases, more food is needed and the population of prey will ___________.

The population size may be affected by: The total amount of food or nutrients

available Competition for food or nutrients Competition for light (plants) Water Predation or grazing Disease.

Plants often compete with each other for space, and for water and nutrients from the soil.

Animals often compete with each other for space, food and water. Animals which kill and eat other animals are called predators. The animals they eat are called prey.

Population size

If any one species is disturbed, then all species will undergo changes in its population.

If small fish numbers go down then snail and cockle numbers will go up. Big fish and seabird numbers will go down.

A small fish may eat certain types of snails, but he may also be eaten by a duck. So the small fish is both predator and prey in this food web.

Use Pg 9 Science Yr10

Complete the table.Term Definition and exampleMutualismCommensalismParasitesdecomposer

Pg12

Food chains are short because the transfer of energy from one trophic level to the next is very inefficient. About 10% of the energy is passed to the next trophic level, about 90% of the energy being used for respiration to supply energy to stay alive.

When organisms die, decomposers release the energy stored in the dead tissue by respiration. Eventually that energy escapes into the physical environment as heat. Energy enters a community in the form of light but it leaves as heat, which is not a useful form of energy.

The one-way flow of energy through a community can be shown on an energy flow diagram.

When living things die..

Animals which eat the flesh and organs of dead animals are called scavengers. They are classed as consumers in a food web.Eg. maggots, hawks, ants.

DecomposerThe disappearance of dead organisms is also due to microscopic organisms, mainly bacteria and fungi. These organisms cause decay. Decomposers are not classed as consumers. Bacteria and fungi have no mouth parts. In their cells, they make enzymes which can break down large molecules of food.

Major elements that organisms need include _________, _________, _________ and _________. These elements are found in environmental reservoirs. Carbon, oxygen, hydrogen and nitrogen atoms are combined into _________ molecules by producers. When _________ break down dead bodies they release elements back into the soil or air. Major elements that organisms need include carbon, oxygen, hydrogen and nitrogen. These elements are found in environmental reservoirs.

Carbon, oxygen, hydrogen and nitrogen atoms are combined into food molecules by producers. When decomposers break down dead bodies they release elements back into the soil or air.

*Terrestrial = on the land

Major elements are found in environmental reservoirs, for example for terrestrial organisms the carbon reservoir is CO2 gas in the air.

The Carbon cycleThe element carbon is one of the main materials in sugars, proteins and fats. It is also found in waste products like carbon dioxide and urea.Proteins and fats make up the tissues of all living things. Animal obtain the raw materials to make these substances by eating other organisms.Plant and algae can make these substances from carbon dioxide and water by the process of photosynthesis. Decomposers breakdown the larger molecules in dead organisms into smaller ones and finally to carbon dioxide. All these processes fit together to form a cycle in which the carbon is used over and over again.

Question:The mud at the bottom of oceans and seas contains an abundance of bacteria.

(a) Why are so many bacterial found here?(b) Why is this an important part of the marine

food web?

To do:1.Pg13 Copy the oxygen cycle diagram.2. Year10 Science Pg14, 15 Q1 – Q9