U11: Community

Species in a Particular Area

• A species is a group of the same organisms that are able to reproduce naturally produce fertile offspring. A mule is not a species because it is an offspring from a male donkey and a female horse. Organisms of a particular species, living in a given geographic area are called a population. A community is a collection of populations of different species, interacting with one another.

• List three populations in the Londonderry community ________________________________________

Horse, Donkey & Mule One of these is not like the others!

Populations make up a Community

• No individual organism lives completely on its own. It may live with other individuals of the same species to form a population.

Populations make up a Community

• If you counted all the daisies in a field they would make up the daisy population of that field. You might also find populations of spiders, earthworms, or field mice. A change in the size of one population often causes a change in the size of another population.

• Populations can be counted in many different ways such as ear tags, leg bands, radio transmitters, and physical counts. Populations are not spread out evenly for example the human population is clumped larger in cities. A clumped population can be useful as they can help one another find food or shelter Elephant seal

• Many species of animals live in groups for protection. Some groups are called herds, flocks, or packs. Plants living in clumps can help each other too, for example trees clumped together protect each other from strong winds.

List a population that lives in a group for protection from predators ______________ (not one in this presentation) Starlings

The levels of organization

species make up a population and populations make up a community. How are the other levels organized? An interacting system that consists of groups of organisms (biotic) and their abiotic environment is an ecosystem. List an ecosystem in NH ________________________

Ecosystems make up biomes. Southern NH is in the deciduous forest biome, Arizona is in the desert biome, and Alaska is in the tundra biome. NH Biome- a large geographical area with a similar climate.

Biomes make up Earth’s biosphere. Biosphere – all the biomes with all the living things on Earth

• List the levels of organization from smallest to largest. (biome, biosphere, community, ecosystem, population, species) _____________--> _____________--> _____________-->_____________--> _____________--> ____________

Levels of Organization Individual = species

Every Organism Has a Job

• • Every organism has a role or job in a community. All of an organism’s activities or jobs within its ecosystem are called a niche. All organisms in a community are related to each other through their niches.

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Niche

What is your niche at your home? Here are some questions to consider when you interact with your environment. What do you eat? What jobs do you do? When do you wake or go to sleep? The answers to these questions describe your own specific niche.

• What is your niche? _____________________________________ • If your parents left town for 2 weeks how would your niche change while they were away?

__________________________________________

Producer Niche

• Producers: The niche of green plants is to produce food from sunlight, water and carbon dioxide during photosynthesis.

Consumer Niche

• Consumers: The niche of the mouse is to consume the plants and to be food energy or prey for predators. A bee’s niche is to pollinate flowers when they collect nectar to make honey.

Decomposer Niche

• Decomposers: The niche of the earthworm is to help decompose the organic matter in the soil into nutrients. The earthworm brings these nutrients to different locations and moves increasing water and air flow so that plants roots can get water and nutrients.

• The populations of daisies, mice, bees, spiders and earthworms in the field make up a community. A community is a collection of populations of different species, interacting with one another. • The different populations in a community depend on each other. How can this be true?

Depend on Each Other

• The daisies in the field can provide shelter for the spiders. The mice can eat the seeds of the daisy. The earthworm feeds on the decaying matter in the soil.

• How do mice and earthworms help the daisies?

• All organisms in a community are related to each other through their niches. List two examples of niches in a community. 1. 2.

Niches Change with Competition

• Why don’t populations increase forever? Any condition that keeps the size of a population from increasing is a limiting factor. Lack of light, space, water, oxygen, nutrients or food are all examples of limiting factors.

Friends of Nairobi National Park, Kenya -

6x a yr

Niches Change with Competition

• Some organisms may not get enough of these materials. The lack of needed materials causes population growth to slow down by decreasing the number of births and increasing the number of deaths. Moving in (immigrate) or out (emigrate) of an area also increases or decreases the population of an animal. Competition prevents organisms from occupying all of their niche.

Niches Change with Competition

• The struggle among organisms to get their needs for life is called competition. As a population increases in size the competition for the same resources (food, sunlight, etc) increases.

Every Organism Has a Home

The address or home of an organism is their habitat. The worm and the spider may use a hollow log and the surrounding area as its habitat while our skin is the habitat for millions of bacteria that live there.

• What is your habitat? _____________________________________

Habitat

• The habitat for some species of bacteria is on the outside as well as in the inside of our bodies (skin, eyes, nose, stomach, intestines, mouth…) • • The bacteria cells in or on our body outnumber human cells 10 to 1, because they are much smaller than human cells, they account for only about 1 to 2 % of our body mass though they do make up about half of our body’s waste! How many cells does a human have? 100 trillion?

Bacteria on YOU!

Vocabulary

Light (exposure to light can change climate & growth of plants) Heat (will determine the weather/climate of an ecosystem) Mechanical Support (any features (i.e waterfalls, valleys, hills) which can either facilitate or inhibit a species survival Organic Matter (this will determine soil nutrition and therefore plant growth) Nutrients (Oxygen, Nitrogen, Carbon, Phosphorous etc.) are essential stability of an ecosystem Water/ Air (Water and Air quality will play a drastic role in the survivable of a species; streams, rainfall etc.) Predation (Predators will limit the growth of the population as well as human pouching) Competition (Competition within the species and with other species for food, water, mates will limit further growth) Geographical Space (If the species can only survive within a given ecosystem, the size of that ecosystem will prevent further population increases)

Questions

• 1. The barnacle species Chthamalus can survive in shallow and deep water. The barnacle species Balanus can live only in deep water. When Chthamalus and Balanus live in the same habitat how would the niche of Chthamalus change due to competition?

_______________________________________ _______________________________________

• 2. What would happen to Chthamalus if Balanus moved away from this habitat?

_______________________________________ _______________________________________ • 3. What is the limiting factor for the barnacles in this habitat? _________________

4. How can limiting factors cause a population to change? __________________________________________ __________________________________________ 5. Explain why it is easier to count plant populations rather than animal populations in a community? __________________________________________ __________________________________________

6. List abiotic and biotic factors in a forest ecosystem. ____________________________________________ ____________________________________________

Ecosystem - An interacting system that consists of groups of organisms (biotic) and their abiotic environment.