Module 3 Intro

Module 3—Ecosystem Diversity

Lesson Summary

In this lesson you explored the following question:

• How do limiting factors influence the distribution and range of organisms?

Limiting factors can be any biotic or abiotic factor that controls the size of a population. These factors can affect the population size and density. Population sizes can be estimated by taking small samples. It is important that ecologists know the populations of the species in the national parks. Without this knowledge, an ecologist would not be able to measure and maintain the ecological integrity of parks.

In Lesson 6 you will be using the information you have gathered from the last five lessons to prepare for and perform a field study.

Lesson Glossary

exotic species: a species that is not native to an area and has been introduced, in most cases, by humans

interspecific competition: competition for limited resources among members of different species

intraspecific competition: competition between members of the same populations (species) for a limited resource

introduced species: a species that is not native to an area and has been introduced, in most cases, by humans

quadrat: an area of determined size that is marked out for the purpose of sampling a population

transect: a long, relatively narrow rectangular area marked out in a study area for the purpose of sampling a population

Biology 20 © 2008 Alberta Education