Intro & population growth

Question 1

What is ecology?

Answer 1

Study of interactions that determine the distribution & abundance of organisms

Question 2

What might interactions be between?

Answer 2

Orgs & abiotic environment
e.g. temp, humidity

Orgs & biotic environment e.g. orgs of same/diff species

Question 3

Why are Lime swallow tails (Papillio demoleous) an ecological problem?

Where are they originally from?

Where did they spread to?

Answer 3

When they’re caterpillars they destroy citrus plants v fast

SE Asia

Hispaniola (2004)
Portugal (2012)

Question 4

What things should be taken into account to be prepared when Lime swallow tails reach the US &/or Brazil?

Answer 4

> Physical range they can survive (temp, humidity, alt etc.)

> Ability to evolve new strategies

> Predators & parasites that could control them?

> What do they eat?

Question 5

What is needed to predict species response to enviro changes?

Answer 5

Strong conceptual knowledge
Mathematical modelling
Good hypothesis
Good empirical skills

Question 6

What were the 2 hypotheses on the cause of algal blooms?

Why are algal blooms bad?

Answer 6

Lab: phosphates
Industry: Carbon

Produce toxins –> kill fish

Question 7

What did Schindler do in 1974 to test his hypothesis?

Answer 7

Used whole lakes
Added N + C to 1 lake
Added N + C + P to the other

Results showed P must be added for algal blooms to occur

Question 8

What 4 things is ecology essential for?

Answer 8

> monitoring long-term changes in environment e.g. global warming

> assessing impact of human on environment

> underpinning conservation e.g. preserving habitats & species

> revealing how to use resources in sustainable ways

Question 9

What are the 4 levels ecology can be studied at?

Answer 9

Organism
Population
Community
Ecosystem

Question 10

Which ecology level is affected by evolution & natural selection?

Answer 10

Organism

Question 11

What is population ecology?

Give 2 examples

Answer 11

The growth of populations & their variation in size

Bees - what is causing population decrease & how can we increase it?

Crop pests - why are they successful & how can we reduce pop size?

Question 12

What is a population?

Answer 12

Group of orgs of same species occupying an area at a particular time

Rely on same resources
Influenced by similar enviro factors
Can potentially interbreed (gene pool)

Question 13

Which 3 things are used to describe a population?

Answer 13

Size
Area
Density

Question 14

What can be used to calculate population area?

What can population area indicate?

Answer 14

GIS

Specialisation or lack of (endemism)

Question 15

What is population size?

How must they be measured?

Answer 15

No. of individuals of all ages living at a particular time in a particular population

Over time w/ multiple measurements due to fluctuations

Question 16

How can population sizes be estimated?

Answer 16

Sampling

e.g. mark, release recapture
or quadrats
or tracking cameras
or faeces/feathers

Question 17

What is the equation for estimating population size when using mark, release, recapture?

What is this also known as?

Answer 17

N = (originally marked x resampled) / recaptured

Lincoln-Peterson index

Question 18

What are the 4 assumptions of the Lincoln-Peterson method?

Answer 18

1. marked & unmarked indiv are equally likely to live or die & are randomly distributed in population
2. marks stay on
3. not a lot of births or deaths between mark & recapture
4. no significant emigration or immigration

Question 19

How do you calculate population density?

Answer 19

Density = pop size/area

Question 20

What is the relationship between body size & population density?

Answer 20

As body mass increases, density decreases

Question 21

What are the 3 types of dispersion?

Answer 21

Clumped e.g. herds for safety

Uniform e.g nesting territories & penguins to reduce aggression

Random e.g. trees in forest