APES Chapter 6

What is a keystone species?

A species that has a large effect on its community or ecosystem is called a keystone species, or a key species

What is a trophic level?

A trophic level consists of all those organisms in a food web that are the same number of feeding levels away from the original source of energy

What is a watershed?

A watershed is an area of land that forms the drainage of a stream or river. If a drop of rain falls anywhere to become surface runoff, it can flow out only through the same stream. We are part of the Alder Creek watershed.

What is the difference between an ecosystem and an ecological community?

An ecosystem is an ecological community and its local non living community. An ecosystem is the minimum system that includes and sustains life. An ecological community is a set of interacting species that occur in the same place.

What is succession?

Succession is the process of establishment and development of an ecosystem.

How are boundaries of an ecosystem defined?

The boundaries of an ecosystem are not all uniformly defined. Some are easy to distinguish like the boundary between a lake and its surrounding countryside while others are more difficult to distinguish. Many can use watersheds to determine an ecosystem's boundaries.

What are the three fundamental characteristics of an ecosystem?

The three fundamental characteristics of an ecosystem are Structure, Processes, and Change. Structure is the two major parts of an ecosystem: living and nonliving. Two basic kinds of processes occur in an ecosystem: a cycling of chemical elements and a flow of energy. An ecosystem changes over time and can undergo development through a process called succession.

What are autrotrophs? What are heterotrophs?

Autotrophs make their own food, by obtaining their energy from the sun (Plants are autotrophs). Heterotrophs are organisms requiring organic compounds for its principal source of food but cannot produce these compounds (These are animals such as whales, cats, fish, etc.).

What are community-level interactions?

Community-level interactions are indirect and more complicated interactions within an ecosystem.

What role do decomposers play in ecosystem?

Decomposers feed on wastes and dead organisms of all trophic levels. They can return some nutrients such as nitrogen to the atmosphere.

What are the different ways that ecosystems can be managed?

Ecosystems are managed by managing and conserving life on Earth by considering chemical cycling, energy flow, community-level interactions, and the natural changes that take place within ecosystems (agriculture, deforestation, wildlife preserves).

What is the difference between primary and secondary succession?

Primary succession is a process by which a community arises in a virtually lifeless area with no soil. Secondary succession follows a disturbance that destroys a community without destroying the soil.