5.1 Habitats and Niches 1. Describe the concept of the niche. 2. Examine how interactions between a species and its environment define the species’ niche

5.1 Habitats and Niches5.1 Habitats and Niches1. Describe the concept of the 1. Describe the concept of the

niche.niche.

2. Examine how interactions 2. Examine how interactions between a species and its between a species and its environment define the environment define the species’ nichespecies’ niche

3. Infer how removal of an 3. Infer how removal of an organism at one trophic level organism at one trophic level can affect another organism in can affect another organism in the ecosystem.the ecosystem.

5.1 Habitats and Niches5.1 Habitats and Niches

• Ecosystems can be large places. The Ecosystems can be large places. The environment in one part of an environment in one part of an ecosystem is different from the ecosystem is different from the environment in another part. For environment in another part. For example, the conditions near a stream example, the conditions near a stream may be very different from those on a may be very different from those on a dry hill above the stream.dry hill above the stream.

• The organisms living in each part of The organisms living in each part of this ecosystem differ from each other. this ecosystem differ from each other.

NichesNiches

• Every organism is adapted to live in its Every organism is adapted to live in its habitat. For example, each organism habitat. For example, each organism has special ways of gathering food, has special ways of gathering food, reproducing, and avoiding predators. reproducing, and avoiding predators. The actions of an organism define its The actions of an organism define its role in the ecosystem.role in the ecosystem.

• The role of an organism in the The role of an organism in the ecosystem in called its ecosystem in called its nicheniche. A niche . A niche is more than an organism’s habitat; it is is more than an organism’s habitat; it is also what the organism does within its also what the organism does within its habitat.habitat.

NichesNiches

• A niche includes both biotic and abiotic A niche includes both biotic and abiotic factors. Some biotic factors that help define a factors. Some biotic factors that help define a niche are food sources and predators. Abiotic niche are food sources and predators. Abiotic factors include temperature, amount of factors include temperature, amount of sunlight and water.sunlight and water.

• All members of a species are adapted to the All members of a species are adapted to the same niche. No two species can share the same niche. No two species can share the same niche in the same habitat or they will same niche in the same habitat or they will compete for resources.compete for resources.

• The extinction of a population due to direct The extinction of a population due to direct competition with another species for a competition with another species for a resource is called resource is called competitive exclusionscompetitive exclusions..

Niche DiversityNiche Diversity

• Niche diversity, the number of different Niche diversity, the number of different niches in an ecosystem, is often niches in an ecosystem, is often determined by abiotic factors in the determined by abiotic factors in the environment. In a marsh, for example, environment. In a marsh, for example, there are many organisms. However, there are many organisms. However, there are few different niches because there are few different niches because the physical environment in a marsh is the physical environment in a marsh is fairly constant. By contrast, in a desert fairly constant. By contrast, in a desert ecosystem, there are few organisms but ecosystem, there are few organisms but many different niches.many different niches.

Niche DiversityNiche Diversity

• A A predatorpredator is an organism that is an organism that actively hunts other organisms. The actively hunts other organisms. The organism that is hunted is the organism that is hunted is the preyprey..

• Predators play an important role in Predators play an important role in increasing niche diversity by increasing niche diversity by decreasing the population size of decreasing the population size of their prey species. their prey species.

PredatorsPredators Predators help maintain diversity in Predators help maintain diversity in

ecosystems in many ways. The Great Barrier ecosystems in many ways. The Great Barrier Reef is one example. A species of sea star called Reef is one example. A species of sea star called the crown of thorns lives and feeds on the corals the crown of thorns lives and feeds on the corals that make up the reef. In the past, the crown of that make up the reef. In the past, the crown of thorns was rare because it was eaten by many thorns was rare because it was eaten by many species of predatory fish, but fishing by people species of predatory fish, but fishing by people has removed many of the sea star’s predators. has removed many of the sea star’s predators. The crown of thorns’ numbers increased, and The crown of thorns’ numbers increased, and they now consume large stretches of the reef they now consume large stretches of the reef every year. The destruction of the reef results every year. The destruction of the reef results in lost habitat to many species, therefore lover in lost habitat to many species, therefore lover diversity in the ecosystem.diversity in the ecosystem.

The Great Barrier ReefThe Great Barrier Reef



The Great Barrier ReefThe Great Barrier Reef• Brain CoralBrain Coral




• Fire CoralFire Coral





Lesson 6 - HomeworkLesson 6 - Homework

1.1. How is a niche different from a habitat?How is a niche different from a habitat?2.2. What might happen to an ecosystem if What might happen to an ecosystem if

all the carnivores were removed? all the carnivores were removed? Explain your answer.Explain your answer.

3.3. Explain how the niche of one species Explain how the niche of one species might influence the niche of another might influence the niche of another species.species.

4.4. List two examples of biotic factors and List two examples of biotic factors and abiotic factors that can limit or increase abiotic factors that can limit or increase the size of a species’ population.the size of a species’ population.

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5.1 Habitats and Niches 1. Describe the concept of the niche. 2. Examine how interactions between a species and its environment define the species’ niche