Ecology - Lecture 02 - Distribution

Front 1

What are 2 reasons a species may be absent from a suitable habitat?

Back 1

Historical reasons - Dispersal (i.e. not introduced there yet)

Habitat selection

Front 2

Define:

Dispersal

Back 2

Movement of organisms or propagules(e.g. seeds)

Front 3

Dispersal is both a _____ and a _____ process.

Back 3

ecological

genetic

Front 4

What are the 3 modes of Dispersal that Ecologists recognize?

Back 4

1 - Diffusion dispersal

2 - Jump dispersal (can be human assisted)

3 - Secular dispersal

Front 5

Define and give an example (from lecture):

Diffusion dispersal

Back 5

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

EXA: California Sea Otter

Front 6

Define and give an example (from lecture):

Jump dispersal

Back 6

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

EXA: Zebra mussel (was human assisted)

*Also was the way that islands were colonized

Front 7

Define and give an example (from lecture):

Secular dispersal

Back 7

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

EXA: Antarctic Beech species

Front 8

The colonization of islands likely occurred from what type of dispersal?

Back 8

Jump dispersal

Front 9

Define:

Vagility

Back 9

The ability of an organism to move about freely and migrate

Front 10

What are 2 important variables in dispersal?

Back 10

1 - Barriers

2 - Vagility

Front 11

What is the "Tens Rule"?

Back 11

Of all introductions of organisms to a new habitat, only 10% will survive.

Also, of those 10%, 10% will become pests.

Front 12

What are 2 approaches to studying habitat selection?

Back 12

1 - Proximal approach

2 - Ultimate or Evolutionary approach

Front 13

What are 2 examples of dispersal on the "Local Scale"?

Back 13

1 - Krakatau (dispersal of animals back into the environment after explosion)

2 - Introductions (human induced) and the "Tens Rule"