Lecture 13: Ecosystems

Question 1

What is an ecosystem?

Answer 1

A system of organisms, their physical environment and their interactions.

Question 2

What is a population?

Answer 2

Organisms of the same species that live in the sane habitat.

Question 3

What is a community?

Answer 3

Coexisting populations of different species.

Question 4

What are the fundamental properties of an ecosystem?

Answer 4

• energy flow & productivity
• nutrient cycling
• habitat structure

Question 5

What is the redfield ratio?

Answer 5

The relative number of atoms in living phytoplankton (C:N:P = 106:16:1)

Question 6

What is Liebig’s law of the minimum

Answer 6

Only 1 nutrient limits growth at any one moment

Question 7

Ex: If the water of an estuary contains 27 mol of N per liter & 3 mol of P per liter, will the addition of P increase phytoplankton production in the estuary?

Answer 7

Redfield ratio of N:P = 16:1
Estuary ratio of N:P = 9:1

Therefore nitrogen is the limiting nutrient and adding P will not increase production.