28122021 Populations and ecosystems WAL about populations ecosystems

28/12/2021 Populations and ecosystems WAL: about populations, ecosystems, communities, habitats & niches. Some Most All • How can a population be distinguished from a community? • What is meant by the terms “ecosystem”, “population”, “community”, “habitat” and “niche”? • What is ecology?

Today we are covering from the specification: Pages 4 – 5 of your textbook

Key words & definitions Key word Ecology Biosphere Biome Ecosystem Community Populations Individual Niche Biotic factors Abiotic factors Interspecific competition Intraspecific competition Definition

ECOLOGY

What is ecology? • The word ecology comes from the Greek for “house” (οἶκος – ‘oikos’) • Why do you think this is appropriate?

The levels on which organisms can be studied Biosphere Biomes Ecosystem Community Populations Individual go to FACTORS

Biosphere • The volume of the earth’s surface where organisms can be found. • It extends from the depths of the ocean (11 km below sea level) to at least the highest plant communities (6. 2 km)

Biome • The biosphere is made up of several types of biome. • These are classified due to their major vegetation types, for example TUNDRA or TROPICAL RAINFOREST.

Ecosystem • An ecosystem is a part of a biome. • Biomes themselves are far too large to study so ecology work tends to be based around a particular ecosystem. • Each ecosystem has a characteristic set of plants, animals and microbes. • The organisms in an ecosystem form a selfsufficient unit in balance with their environment. • The interacting organisms and their physical environment.

Community • This is a group of species that occurs at the same place at the same time. • The word is often used to refer to organisms of a particular kind, such as the plant community on a lawn.

Population • Ecosystems and communities contain populations of species. • A population is made up of all the members of a species living together in the same place at the same time. • An example would be all the ash trees in a wood.

Individual • Finally each population is made up of many individuals. • The genetic and physiological adaptations of an individual organism to its environment is an important aspect of ecology.

Niche

Look carefully at the information about the 2 sea birds on the next slide. . .

The cormorant (Phalacrocorax carbo) Structural niche: Broad cliff ledges and the sea. Feeding niche: A bottom feeder. Eats mainly flatfish, prawns etc. from shallow water in estuaries and harbours. The shag (P. aristotelis) Structural niche: Cliff ledges and the sea. Feeding niche: Dives into the water for fish. What will happen here? How will these species affect each other?

What is a Niche? The niche of a species is its role in the community.

Two species can’t occupy the same niche. . In reality the cormorant is quite different to the shag: • it occupies narrower ledges • it fishes further out to sea • it captures fish and eels from the upper layers of the water This means they are both able to be successful in the same ecosystem.

Competition This happens when 2 or more individuals strive to obtain the same resources when these are in short supply. The more similar the individuals are, the more intense the competition.

Competition can be intraspecific (between the same species) or interspecific (between two or more different species).

If an animal survives for a long time in a particular community it must be able to reproduce there. A large number of biotic and abiotic factors influence how an animal or plant species may interact and change with time.

Biotic factors are any living factors (e. g predators) Abiotic factors are any non-living factors (e. g sunlight). http: //www. youtube. com/watch? v=n. QO 5 x 8 Q 3 e 8 g

Fire Solar radiation Temperature Humidity Wind Day length Atmospheric gases organism Aspect Human activity Soil Competitors Parent material Predators Parasites Wave action Salinity Use a colour key to show BIOTIC and ABIOTIC factors. BOLD arrows show the effect of the factors on the organism. Draw DOTTED arrows to show the effect of factors on one another.

Uninvited Guests • We are going to model an ecosystem. • The “habitat” will be the host of the party. They are the guesser. • “Individuals” within the “community” are going to arrive at the party. • These individuals are going to affected by a change in either a biotic or abiotic factor. • It is up to the host of the party to guess which factor is affecting which individual.

Learning check 1. 2. 3. 4. 5. 6. 7. What is a habitat? What is a niche? What is a population? What is a community? What is an ecosystem? What does an organism’s biotic environment consist of? What is the difference between intraspecific and interspecific competition? 8. Hyenas fighting over an animal carcass are engaging in what type of competition?

Learning check 1. What is a habitat? The place where a species is commonly found. 2. What is a niche? The way a species exploits or makes a living from its environment. This includes where it lives and where, when and on what it feeds. The role of the species within its habitat. 3. What is a population? All the individuals of a particular species living in a particular area. 4. What is a community? All the populations of different species living and interacting together in a particular area.

Learning check 5. What is an ecosystem? A dynamic but more or less stable and self-perpetuating community of organisms interacting with each other and with their non-living surroundings. 6. What does an organism’s biotic environment consist of? All the other organisms that it interacts with, from predators to pathogens. 7. What is the difference between intraspecific and interspecific competition? Intraspecific competition is competition between individuals of the same species. Interspecific competition is competition between individuals of different species. 8. Hyenas fighting over an animal carcass are engaging in what type of competition? Intraspecific competition.

Constructing an ecosystem • Within any ecosystem there are two main processes to consider: – The flow of energy through the ecosystem. – The cycling of elements through the ecosystem. • We are going to construct an ecosystem based on these two main principles.

Lettuce Makes its own food using energy from the sun. Rabbit Eats lettuce and grass. Vole Eats grasshoppers. Slug Eats lettuce. Hedgehog Eats slugs and caterpillars. Sparrowhawk Frog Caterpillar Eats grasshoppers. Eats lettuce. Grass Spider Eats voles and thrushes. Makes its own food using energy from the sun. Aphid Thrush Eats grass. Eats slugs and spiders. Grass snake Fox Eats frogs. Eats hedgehogs, voles and rabbits. Eats aphids. Grasshopper Eats grass.

Constructing an ecosystem • As well as the cards provided, you will also have to add further information to the ecosystem as some elements are missing.

Constructing an ecosystem • Cut out all of the cards and try to arrange them in a logical ecosystem. • Once you’re happy, glue them down. • Draw arrows between organisms to show the flow of energy (and therefore feeding relationships) within the ecosystem. • Around the outside, list any abiotic factors which could affect the individuals in the ecosystem.

An example ecosystem

Summary Each species occupy an ecological niche within their habitat. A group of one species forms a population. Populations of different species form a community; these live in a habitat. A group of habitats then make up an ecosystem.