Lecture 1

Question 1

What is the definition of ecology?

Answer 1

Question 2

What is an ecosystem?

Answer 2

Question 3

Define a system in ecological terms.

Answer 3

Question 4

Why is detecting and quantifying interactions important in ecology?

Answer 4

Question 5

What is meant by “quantifying connections” in ecosystems?

Answer 5

Question 6

What is a population in ecological terms?

Answer 6

Question 7

What is a community in an ecological context?

Answer 7

Question 8

How is an ecosystem different from a population or community?

Answer 8

Question 9

What is a habitat?

Answer 9

Question 10

What is primary production?

Answer 10

inorganic carbon (CO2) –> organic carbon

Question 11

How does water temperatrure affect phytoplankton?

Answer 11

Question 12

Explain the oyster effect on water quality.

Answer 12

Question 13

How are levels of organization in ecology “nested”?

Answer 13

Question 14

What is an ecological model?

Answer 14

Question 15

Why can models never perfectly reflect reality?

Answer 15

Question 16

What are the main types of ecological models?

Answer 16

Question 17

What are mathematical models used for in ecology?

Answer 17

• process simulation

Question 18

Why are ecological models special?

Answer 18

Question 19

What is an example of feedback in ecological systems?

Answer 19

Question 20

What are “emerging properties” in ecological systems?

Answer 20

Question 21

Are models a representation of reality?

Answer 21

Question 22

Why is simplicity important in ecological models?

Answer 22

Question 24

How do models deal with causality?

Answer 24

Causality in ecological systems refers to the cause-effect relationships between variables.

• For example, changes in predator abundance can cause changes in prey populations.
• However, ecological systems often display complex interdependencies and feedback loops rather than simple cause-and-effect chains.
• Interdependence: In predator-prey models, for example, the prey population affects the predator’s growth, and vice versa—both populations evolve together, making it difficult to pinpoint a single “cause” for observed changes​
• Emerging Properties: Ecological systems exhibit properties that emerge from the interaction of components rather than individual causative effects.

Question 25

What are the uses of models in ecology?

Answer 25

Question 26

What are external variables or forcings?

Answer 26

Question 27

What are state variables?

Answer 27

Question 28

What are equations in a model?

Answer 28

Question 29

What are universal constants?

Answer 29

Question 30

What are parameters in a model?

Answer 30

Question 31

Explain the Malthus model.

Answer 31

Question 32

Explain the Logistic model.

Answer 32

Question 33

What is the difference between the Malthusian and Logistic models?

Answer 33

Question 34

What is ecological modelling?

Answer 34

Ecological modelling is a tool for simulating interactions among organisms, their environment, and external stressors. It simplifies reality to answer scientific and practical questions.

Question 35

Why is ecological modelling used if it simplifies ecosystems?

Answer 35

Though simplified, it represents critical processes to improve understanding and guide decisions.

Question 36

What are deterministic models?

Answer 36

Models where the same inputs always produce the same outputs, with no randomness involved.

Question 37

What are stochastic models?

Answer 37

Models that incorporate randomness, where repeated simulations with the same inputs can yield different outputs.

Question 38

What are dynamic models?

Answer 38

Models that simulate changes over time, often using differential equations.

Question 39

What is an example of a dynamic model?

Answer 39

Prey-predator interaction models using differential equations to track population dynamics.

Question 40

Define the concept of a system in ecological modelling.

Answer 40

A system is a set of interconnected components functioning as a whole (e.g., a lake).

Question 41

What is the difference between a population and a community?

Answer 41

A population refers to individuals of the same species in an area, while a community encompasses multiple species.

Question 42

What is the difference between a population and a community?

Answer 42

A population refers to individuals of the same species in an area, while a community encompasses multiple species.

Question 43

What are emergent properties?

Answer 43

Characteristics that arise from complex interactions, such as resilience to disturbances and nutrient cycling efficiency.

Question 44

What are forcing functions?

Answer 44

External influences like temperature or fishing effort that impact the system without being explicitly modeled as state variables.

Question 45

Why is constructing an ecological model considered an iterative process?

Answer 45

The process involves cycles of testing, adjusting, and recalibrating the model until it aligns with observations.

Question 46

What is primary production, and how is it regulated?

Answer 46

- Autotrophs, such as algae, convert carbon dioxide into **organic matter** through photosynthesis. - Primary production is regulated by factors such as light, temperature, nutrient availability, and CO₂ concentration. - Positive feedbacks, like nutrient influxes, can boost primary production, - while negative feedbacks, such as nutrient depletion and self-shading, can slow further growth.

Question 47

Model complexity and causality: socio-ecological systems

Answer 47

Question 48

How can we use models?

Answer 48

Question 49

models are not reality

Answer 49