ecological networks

Question 1

How can networks be used in ecological restoration?

Answer 1

• Networks emerge at different levels of organization.
• Links represent ecological interactions.
• Nodes are the units of the system.
• Networks can be used to measure restoration success.

Question 2

What was the early basis of food web research?

Answer 2

• Early network-based food web research was rooted in fishery science.
• Alistair Hardy (1924) contributed to this early work.

Question 3

How can food webs be measured?

Answer 3

• Observations: Counting predation events and number of bites.
• Stomach content analysis: Visual identification or DNA metabarcoding (to determine what an organism has eaten).
• Stable isotope analysis: To study ecological activities through isotope ratios.

Question 4

How does stable isotope analysis work?

Answer 4

• Measures the abundance of C-12 and C-13 isotopes using a mass spectrometer.
• The material is passed through a strong magnet, which splits it by atomic weight.
• The output is the ratio of different isotopes, expressed in delta units (molecules per thousand).
• The ratio of a consumer’s isotopes reflects that of its prey, inferring ecological activities.

Question 5

What is the purpose of the stressor-stressor relationship diagram for coral reefs?

Answer 5

• It shows how different stressors interact on coral reefs.
• The node size reflects how many other stressors are mediated by that node (directly or indirectly).

Question 6

How do people impact food webs and coral reef ecosystems?

Answer 6

• Social-ecological interactions underpin many environmental issues.
• Identifying relationships between people and nature helps understand and influence environmental conditions.