Ecology - Exam 1 Study Guide Questions

Front 1

1. What is ecology? Environmentalism?
Environmental science?

Be able to identify
examples of each.

Back 1

Ecology - The study of the interactions that determine the abundance and distribution of organisms.

Environmentalism - Advocacy over human impacts on the environment

Environmental science - The broad discipline that studies human impacts on the earth's environment.

Front 2

2. How did the ancient Greeks view the natural world?
What event in the 1850’s changed this view?

Back 2

The Ancient Greeks adhered to the "Balance of Nature" viewpoint which advocates:
- No extinctions

- Individuals act for the "good of the species"

- Species interactions are designed to maintain balance and harmony; to maintain each species.

The "Theory of Natural Selection" that began to gain popularity around the 1850's changed this view.

Front 3

3. At what levels of the biological hierarchy do ecologists work?

Back 3

The first 5 (most complex) of the 12 system hierarchy:

BLECP:

Biosphere
Landscapes
Environment
Communities
Population

Front 4

4. What are the different types of dispersal (and their definitions)?

Back 4

Diffusion, Jump, and Secular dispersal.

Diffusion: The gradual movement across suitable habitat for a period of several generations.

Jump: Movement of long distances over unsuitable habitat. Happens for an organisms lifetime.

Secular: Diffusion over ecological time, e.g. from continental drift.

Front 5

5. What factors could limit the distribution and of an organism?

Back 5

1 - Abiotic (physical) factors

2 - Biotic (living) factors

Front 6

6. What is competition and how does it affect the distribution of organisms?

Back 6

Competition - Negative interaction between two or more species

Depending on the nature of the competition, it can either decrease or hold a population in check.

Front 7

7. What is predation and how does it affect the distribution of organisms?

Back 7

Predation - a relation between animals in which one organism captures and feeds on others.

Depending on the number of predators, it can decrease the amount of its prey species, or hold their population in check.

Front 8

8. What are some of the adaptations displayed by predators and prey as a result of this
interaction?

Back 8

Predator adaptations:
Structural:
- Specialized teeth
- Claws
- Digestive systems
- Poisons

Behavioral:
- Hunting behavior
- Social behavior


Prey adaptations:
Structural:
- Crypsis
- Aposematic coloration and Batesian Mimicry

Behavioral:
- Escape behaviors
- Social behavior

Front 9

9. How do ecologists study competition directly? Indirectly?

Back 9

Ecologists can study competition directly by doing a "removal experiment"

Ecologists can study competition indirectly by inferring competition from distributions of
presumed competitors (checkerboard distributions)

Front 10

10. What are some examples (6) of physical factors that limit the distribution of organisms?

Back 10

1 - Temperature
2 - Moisture

3 - Water chemistry (salinity, pH, etc.)

4 - Nutrient availability - Soils and water

5 - Soil structure

6 - Sunlight

Front 11

11. What are the important variables that determine local climate?

Back 11

1 - Intensity of incoming solar radiation
i.e. where the organism lives in relation to the equator. The farther north/south from the equator, the more dispersed solar radiation becomes.

2 - Distributions of land masses and bodies of water

Front 12

12. How important is light for plants?
How do shade-tolerant and shade-intolerant
plants differ?

Back 12

• Light is important to biological systems:
• Light limits plant distributions.
• Photosynthesis.

Shade tolerant and intolerant plants differ in their distribution based upon the availability (or lack of) light.

Front 13

13. What are the different photosynthetic pathways displayed by plants?

Back 13

C3 - Produced 3 carbon compound.

C4 - Produced 4 carbon compound. More efficient than C3

CAM - Uses both C3 and C4

CAM

Front 14

14. How might global climate change affect species distributions?

Back 14

1. Species may not be able to migrate rapidly
enough to keep pace with warming.

2. Genetic adaptations to local temperature and
rainfall regimes may be lost.

Front 15

15. What is a population?
What are the primary characteristics of populations?

Back 15

Population - A group of organisms of the same species occupying a particular place at a particular time.

Populations increase due to natality and immigration.

Populations decrease due to mortality and emigration.

Front 16

16a. What is absolute density?
By what methods is it determined?

Back 16

1 - Absolute density (e.g. population has 14 individuals / km^2)


Methods to measure Absolute Density:
1 - Total count (count *every* individual in a population)

2 - Sampling methods

Front 17

17. How does fecundity differ from fertility?

Back 17

Fecundity ≡ Potential reproductive output

EXA: Human fecundity = 1 child / 10-11 months


Fertility ≡ Actual reproductive output

EXA: Human fertility = 1 child / 15 years

Front 18

18. (Be able to estimate population density using quadrat data.)

What are the 3 assumptions to quadrat sampling?

Back 18

1 - Numbers in quadrats are counted *exactly*

2 - Area of quadrats must be known *exactly*

3 - Quadrats are representative of whole area (i.e. they were placed in a random manner)

Front 19

19. (Be able to estimate population density using the Peterson method.)

Describe the Peterson Index method of estimating absolute density.

Back 19

1 - Sample of M individuals are removed from a population of size N

2 - Individuals are marked and released back into the population

3 - Sample of n individuals are captured at some point in the future.

4 - Some of those captured (m) will be marked from first sample.

USE:
N = Mn/m

Front 20

20. What are assumptions that are made in mark-recapture studies?

Back 20

1 - Marked and unmarked captured randomly

2 - Marked and unmarked have same mortality (i.e. bunnies are not marked by dipping in yellow paint)

3 - Marks are not lost or overlooked

Front 21

16b. What is relative density?

How is it determined?

Back 21

Relative Density - Area X has more individuals of A than Area
Y.

Methods for determining relative density:
1 - Captures / unit effort

2 - Scats and fecal pellets

3 - Vocalization frequency

4 - Artifacts

Front 22

21. What are the two types of life tables?

What can they tell us about populations?

Back 22

1 - Static Life Table: A record of the age at death of a large # of individuals at one point in time

2 - Cohort Life Table: Follow a cohort from birth until all have died

Front 23

22. What are the three types of survivorship curves?

Know examples of organisms that
display each type of curve.

Back 23

Type I - Most mortality occurs late in life
EXA: Elephants and whales


Type II - Uniform mortality over lifespan
EXA: Lizards and small mammals


Type III - Most mortality early in life
EXA: Sea turtle

Front 24

23. Know how to construct a life table given numbers of individuals by age class and
fertility by age class.

Back 24

yup

Front 25

24. Know how to derive net reproductive rate (Ro), generation time (G), per capita rate
of increase (r), and finite rate of increase (λ) from a life table.

Back 25

yup

Front 26

25. Know how age pyramid diagrams can tell us about population growth rates.

Back 26

Pyramids with a fat base show a large infant/youth population. What they become of age to reproduce, this will cause a large increase in population.

Pyramids where the percentages are relatively the same will not experience high population growth over time.