Introduction to Ecology

Question 1

what is ecology

Answer 1

relationship of an organism to its environment

External relations of plants and animals to each other and to past and present conditions of their existence

Question 2

More modern definition of ecology

Answer 2

scientific study of interactions that determine distribution and abundance of organisms

Question 3

Interactions may be between

Answer 3

organism and abiotic environment
Organism and biotic environment
Organisms of same or different species

Question 4

algal bloom

Answer 4

growth of algal population out of control- produce toxins and start killing fish

Question 5

Most important elements for any organism

Answer 5

Phosphorous
Carbon
Nitrogen

Question 6

Which element is the cause of algal blooms

Answer 6

phosphorous

Question 7

Ecology essential for

Answer 7

• monitoring long term changes in environment eg GW
• Assessing and understanding impact of humans on their environment
• Underpinning conservation eg preserving biodiverisity

Question 8

4 levels ecology can be studied at

Answer 8

organism, population, community and ecosystem

Question 9

organism level

Answer 9

how individuals are affected by the environment
1 species/population
Related to evolution

Question 10

Population level

Answer 10

What explains presence of particular species and abundance

Question 11

Community level

Answer 11

How they emerge, structure of communities and pathways followed by energy

Question 12

ecosystem level

Answer 12

looks at combination of communities of organisms and physical and climatic properties

Question 13

Population ecology

Answer 13

growth of populations and variation in size

Question 14

population

Answer 14

group of organisms of the same species that occupy particular space
Rely on same resources, influenced by similar environmental factors, similar gene pool and can potentially interbreed

Question 15

Population structure

Answer 15

encompasses density and spacing of individuals within suitable habitat and proportion of individuals of each sex and age class

Question 16

Spatial structure

Answer 16

part of pop structure that encompasses density and spacing of individuals

Question 17

3 ways to describe a population

Answer 17

size area and density

Question 18

Area

Answer 18

use GIS- maps species
Larger area for population- can handle variety of environ factors
Smaller- more specialised, maybe endemic
Having this data is helpful for identify how healthy populations are
Some populations have clear boundaries, others don’t

Question 19

Size

Answer 19

Number of individuals of all ages alive at a particular time in a particular population
Varies over time
Need multiple measurements
Use sampling and marking to determine pop size because not easy to count individuals eg if move around
Mostly working with estimates

Question 20

How to measure size

Answer 20

collect x individuals say x=100
mark them
resample y individuals, say y=100
Proportion of these individuals will be marked

N= (originally marked x resampled)/ recaptured

Question 21

Size assumptions

Answer 21

Marked and unmarked equally likely to live/die, and are equally distributed through the pop
Marks stay on
Sampling is the same ie not a lot of births and deaths
Not a lot of migration

Question 22

Density

Answer 22

Combo of size and area

Helps estimate pop size in v large areas

Question 23

density=

Answer 23

pop size/area

Question 24

relationship between body size and density

Answer 24

usually strong negative correlation

Larger body sizes better fitness, so fewer individuals

Question 25

Dispersion

Answer 25

pattern of spacing among individuals

Question 26

Types of dispersion

Answer 26

Clump (fishes). uniform (penguin), Random (seed dispersal)

Question 27

dispersal limitation

Answer 27

absence of a pop from a habitat because of barriers to dispersal

Question 28

more suitable conditions for a species=

Answer 28

higher density

Question 29

areas with narrowest range of conditions tend to support

Answer 29

highest pop densities