unit 8 lesson 1 introduction to ecology copyright © houghton mifflin harcourt publishing company

Unit 8 Lesson 1 Introduction to Ecology

Copyright © Houghton Mifflin Harcourt Publishing Company

The Web of Life


How are living things connected?

• Organisms need energy and matter for life.

• Interactions between organisms allow the exchange of energy and matter.

• Ecology is the study of how organisms interact with one another and with the environment.



• Biodiversity is the variation of living organisms.

• Organisms are connected to all other organisms because each individual organism has a role to play in the flow of energy and matter.

• A biotic factor, such as an organism and how it interacts, is a living part of the environment.




• All organisms rely on the nonliving environment for survival.

• An abiotic factor, or nonliving part, of an environment includes water, nutrients, soil, sunlight, rainfall, and temperature.

• Abiotic factors determine where organisms can survive.



Stay Organized!


What are all the levels of organization in the environment?• The environment can be organized into different

levels that range from a single organism to all of the organisms in an area.

• An individual is the smallest level of organization.


What are all the levels of organization in the environment?• A population is a group of individuals of the same

species that live in the same place.

• A species includes organisms that are closely related and can mate to produce fertile offspring.

• Individuals within a population often compete with each other for food, shelter, and mates.



What are all the levels of organization in the environment?• A community is made up of all the species that

live and interact in an area.

• The species in a community depend on each other for many things, such as shelter and food.

• Just like the members of a population, the organisms in a community compete with each other for resources.



What are all the levels of organization in the environment?• An ecosystem is a community of organisms and

their nonliving environment.

• In an ecosystem, energy and other resources are exchanged between organisms and the environment.



Home Sweet Home


What determines where a population can live?• Organisms that live in the same area play different

roles to get the resources they need to survive.

• Ecologists use the terms habitat and niche to describe where an organism lives and its role in the environment.


What determines where a population can live?• Habitat is the place where an organism usually

lives.

• Abiotic factors such as temperature often determine whether a species can live in a certain place.

• Biotic factors, such as other organisms that live in an area, also determine whether a species can live in a certain place.



What determines where a population can live?• A population’s niche is the role the population

plays in the ecosystem, such as how it gets food and interacts with other populations.

• In general, two populations cannot occupy exactly the same niche.

• Small differences in habitats, roles, and adaptations can allow similar species to live together in the same ecosystem.




Lizard Invasion


• The habitat of South Florida’s green anoles was invaded by a similar lizard, the brown anole.

• The lizards avoid occupying the same habitat by the way they share a tree. Green anoles move to the higher branches, and brown anoles occupy the ground branches.

• Competition exists between the anoles. Brown anoles eat the young of the green anoles.