Unit 6: Ecosystems—Concepts and Management

A rancher uses a herbicide to kill honey mesquite causing a decrease in the mesquite population and an increase in the number of warm season perennial grasses. This is an example of what Principle of Ecology?

Nature abhors a void and provides plants through the processes of primary and secondary __________ to fill in the openness.

Which of the following describes the definition of management in the text?

Living organisms that interact with one another and with the nonliving environment constitute a(n) __________.

Organisms such as producers (plants) that make their own energy, either by photosynthesis or chemosynthesis, are called __________.

Heterotrophic organisms that eat only producers are called __________.

Organisms that break down organic materials to simpler forms that can be reassimilated as mineral components in plants are called __________.

The energy produced in an ecosystem by photosynthesis, minus the loss of energy by respiration, is called __________. It is usually measured in grams per square meter of land per day.

The number of different species in an ecosystem, and the number of individuals of each species, are measures of __________.

Which of the following is NOT one of the five ecological principles that can “assure that fundamental processes of the Earth’s ecosystems are sustained”?

The US Fish and Wildlife Service defines ecosystem management as __________.