Lecture3: Ecosystem Components, Processes & Function

Question 1

Broadly there are two types of ecosystems which are?

Answer 1

1. Terrestial ecosystem
2. Aquatic ecosystem

Question 2

From the two broad categories of ecosystems, individual ecosystem types are based on?

Answer 2

1. Organisms present
2. type of environmental habitat

Question 3

Which two types of components make up the biosphere and its ecosystems

Answer 3

1. Abiotic components: non-living components
2. Biotic components: living components

Question 4

What are some examples of abiotic components? (four)

Answer 4

1. Water
2. Air
3. nutrients
4. solar energy

Question 5

What are some examples of biotic components? (three)

Answer 5

1. Plants
2. Animals
3. Microbes

Question 6

Life in an ecosystem is often about competition for limited resources, true or false?

Answer 6

True

Question 7

What resources do organisms compete for? Give three.

Answer 7

1. organic material / food
2. sunlight (especially plants)
3. water
   anything that helps them grow and have energy

Question 8

Other than limited resources what else affects a community’s dynamics?

Answer 8

1. Latitude
2. topography
3. temperature
4. rainfall
5. available species
   basically a community’s environment and composition.

Question 9

Each organism in an ecosystem has its own range of tolerance to variations in its physical and chemical environment. (true or false)

Answer 9

True

Question 10

Describe the law of tolerance

Answer 10

levels of one or more chemical or physical factor determine existence, abundance and distribution of an organism in an ecosystem depending on its range of tolerance of said factors.

Question 11

Describe a tolerance graph in relation to organisms. ( its quite simple)

Answer 11

there is the zone of intolerance
then zone of physiological stress
then optimum range.
(keeping in mind before intolerance there are upper or lower limits)

Question 12

Before going into limiting factor principle, distinguish between law and principle in relation to this topic.

Answer 12

Maybe a possible “informal” distinction is: a law is usually expressed by a “theorem” of the theory, while a principle is a sort of axiom: the starting points of the theory. Thus the principle builds the law determining existence and abundance of an organism.

Question 13

What is the limiting factor principle?

Answer 13

Too much or too little of any abiotic factor can limit or prevent growth of a population even if other factors are at/near optimum.

Question 14

What are the two main limiting factors on terrestrial ecosystems?

Answer 14

1. Precipitation. (think deserts)
2. Soil nutrients

Question 15

Conversely, what are five limiting factors in aquatic ecosystems

Answer 15

1. Dissolved Oxygen
2. Temperature
3. pH
4. Salinity
5. Sunlight
6. Available nutrients