Topic 15

Question 1

Ecological Community

Answer 1

Multiple species living together in the same place at the same time and interact

Question 2

Fundamental Niche

Answer 2

The limits of all things (abiotic)
needed for survival, growth
and reproduction

Question 3

Realized Niche

Answer 3

Fundamental niche limited by
the presence of other species
(biotic factors)

Question 4

Commensalism (+/0)

Answer 4

One species is unaffected the other receives positive interaction
- often when one gives a habitat to the other

Question 5

Ammensalism (-/0)

Answer 5

One species has no effect the other has a negative.
- trampling is an example

Question 6

Competiton

Answer 6

-/-

Question 7

Mutualism

Answer 7

+/+
Symbiosis

Question 8

Parasitism

Answer 8

-/-
Symbiosis

Question 9

Competitive Exclusion

Answer 9

• No two species can occupy the same niche indefinitely
• Complete competitors cannot coexist
• The superior competitor will outcompete the lesser competitor
• More likely true in stable environments

Question 10

Niche Partitioning

Answer 10

Species finding different ways to live in the same enviroment
- Differences in niches among similar species
- Can promote co-existence between species

Question 11

How a -/- relationship continues

Answer 11

Competitive exclusion
Niche Partitioning

Question 12

Trophic structure

Answer 12

feeding relationships within an ecological community

Question 13

Food Chain

Answer 13

Transfer of food energy
up the trophic levels

Question 14

Limits on Food Chain Length

Answer 14

1. Energetic Hypothesis
   * Not all energy is passed on to higher trophic levels, only 10% of energy is
   available for next trophic level
2. Dynamic Stability Hypothesis
   * Long food chains are too unstable
3. Carnivore Size

Question 15

Bottom Up

Answer 15

Driven by changes in herbivore
abundance

Question 16

Top-down

Answer 16

Predators control community
structure

Question 17

Dominant Species

Answer 17

• Tend to be large and/or high abundance
• May provide habitat or food for other species
• Often good competitors for light, nutrients, space etc.

Question 18

Keystone Species

Answer 18

• Found in relatively low abundance and low
  biomass
• Have disproportionately large effect on
  community structure despite low abundance

Question 19

Ecosystem Engineers

Answer 19

• Dramatically alter their physical environment