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

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

ECOLOGY

What is ecology? The word ecology comes from the Greek for “house”. Why do you think this is appropriate?

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

The volume of the earth’s surface where organisms can be found. It extends from the depths of the ocean (11km below sea level) to at least the highest plant communities (6.2km) Biosphere

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.

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 self-sufficient unit in balance with their environment. Ecosystem

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. Community

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. Population

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. Individual

Niche

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

The cormorant (Phalacrocorax carbo) Feeding niche: a bottom feeder. Eats mainly flatfish, prawns etc from shallow water in estuaries and harbours. Structural niche: Broad cliff ledges and the sea. 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 Competition can in intraspecific (between the same species) or interspecific (between two or more different species).

The distribution patterns of 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.

The distribution patterns of species Biotic factors are any living factors (e.g predators) Abiotic factors are any non-living factors (e.g sunlight).

organism temp Solar radiation Fire humidity Wind Day length Atmospheric gases organism Aspect Human activity Soil competitors Parent material Predators Salinity Wave action parasites 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.

Learning check 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? Hyenas fighting over an animal carcass are engaging in what type of competition?

Learning check What is a habitat? The place where a species is commonly found. 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. What is a population? All the individuals of a particular species living in a particular area. What is a community? All the populations of different species living and interacting together in a particular area.

Learning check 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. What does an organism’s biotic environment consist of? All the other organisms that it interacts with, from predators to pathogens. 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. 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 Hedgehog Caterpillar Frog Grass Spider Rabbit Sparrowhawk   Lettuce Makes its own food using energy from the sun. Hedgehog Eats slugs and caterpillars. Caterpillar Eats lettuce. Frog Eats grasshoppers. Grass Makes its own food using energy from the sun. Spider Eats aphids. Rabbit Eats lettuce and grass. Sparrowhawk Eats voles and thrushes. Aphid Eats grass. Thrush Eats slugs and spiders. Vole Eats grasshoppers. Slug Eats lettuce. Grass snake Eats frogs. Grasshopper Eats grass. Fox Eats hedgehogs, voles and rabbits.

Constructing an ecosystem As well as the cards provided, you will also have to draw/add your own elements to the ecosystem as some are missing.

Constructing an ecosystem Cut out all of the cards and try to arrange them in a logical ecosystem. Once your 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

And finally... Ecology Bingo Draw a 2 x 3 grid and fill it with 6 of the key words from today’s lesson... Ecology Niche Biosphere Biotic factors Biome Abiotic factors Ecosystem Interspecific competition Community Populations Individual Energy flow

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.