Habitat and Lifestyle Unit A: Topic 2

Interdependence Each species relies on many other species in its environment No species can survive by itself Example: Predator-Prey relationship – Predators benefit because they get food – Prey benefit because the old and weak are usually removed allowing the healthy to reproduce – Prey also benefit because the reduction of population allows the resources to last longer.

Symbiosis – “Sym” means together – “Bios” means life A symbiotic relationship is when two organisms live in direct contact with each other There are three main types of symbiosis: commensalism, mutualism, and parasitism Q&feature=fvwrel Q&feature=fvwrel

Symbiotic Relationships Commensalism – One organism benefits and one does not. – No harm is done to the organisms. Example: A bird builds a nest in the tree Example: Barnacles attach to whales Identified by +/n – One benefits (+) while the other remains neutral (n)

Symbiotic Relationships Mutualism – There is a benefit to both organisms Example: A certain tree gives food and shelter to ants and the ants protect the tree from other animals feeding on it by attacking them. Example: Lichens, formed by algae and fungi, live off of each other’s resources. Identified by +/+ – Both benefit (+)

Symbiotic Relationships Parasitism – One organism benefits and the other is harmed – Parasites do not kill their hosts because the host is the food source. Example: A tapeworm attached to the intestine of a human. Example: Parasitic wasp larvae in caterpillar.Parasitic wasp Identified as +/- – One benefits (+) while the other is harmed (-)

What type of relationships are shown here?

Interspecies Competition Two or more species need the same resource and neither benefit. Example: If there are two different species competing for the same food source, there is less for each species. Limits the sizes of the populations of the competing species.

Niche Niche: – The role that an organism plays in its ecosystem. This includes: What it eats What eats it Its habitat, nesting site or range. Its effect on the populations around it Its effect on the environments around it The niche of a population in one area may vary from a population in a different area. Niches can also change throughout the lifetime of the species. For example, the niche of a frog tadpole is different than that of an adult frog.

Types of Niches Type of niche Description Examples of organisms filling this niche Producers  many are photosynthetic organisms, which grow using energy from the Sun  plants  algae Consumers Herbivores  eat producers  may be prey to other animals  cows  deer  snowshoe hare  grasshoppers Omnivores  eat consumers and producers  raccoons  bears Carnivores  eat only other consumers  dragonflies  hawks  lynx Decomposers  break down dead organisms and organic material  release nutrients, which are used by other organisms  certain bacteria  fungi

Broad Niches Broad niches – Organisms that can survive in various conditions and locations have broad niches – Animals in Canada aren’t very diverse, but they can span over large distances and can withstand daily and seasonal changes in temperature. – They must also be able to eat a variety of plants or other animals. – Animals with broad niches are known as generalists

kids/raccoon-kids/ The raccoon is a generalist because it has a natural range that includes most of north and central America, and it is omnivorous, eating berries, insects, eggs, and small animals.

Narrow Niches – Organisms that survive in a very small location that require very consistent conditions. – Organisms have adaptations directed towards competing for one dependable food source, one type of soil, or one level of light. – These organisms are known as specialists. – What could be the danger in narrow niches?

Panda is a specialist species because over 95 percent of its diet consists of bamboo.

Resource Partitioning Division of a resource between species resulting in each niche differing slightly. Example: 5 species of warblers feed on spruce bud worms but they all feed in slightly different areas of the spruce tree.

Planet Earth Seasonal Forest

Review Assignment 1.Explain what is meant by the term biological diversity. 2.In one or two sentences, explain why so many different types of organisms exist on Earth today. 3.Describe how scientists classify organisms. 4.Explain how the classification system helps us to understand how living things are different from or related to each other. 5.Compare and contrast the meanings of population and community.