Succession

Question 1

Pioneer species

Answer 1

The first species to take the opportunity to grow to the change in environments which then drives to create a new environment

Question 2

Properties of pioneer species

Answer 2

1. Grows in the sun
2. Often fixes nitrogen
3. Good at dispersing
4. Small seeds
5. Poor competitors as they put energy in growth and reproduction

Question 3

Climax species

Answer 3

The species that stabilises in the new environment

Question 4

Properties of climax species

Answer 4

1. Be more shade tolerant
2. Slower growth
3. Better competitors
4. Longer lived

Question 5

Types of succesions

Answer 5

Primary - sand dunes, bare rocks, nothing to begin with, bare area, no soil
Secondary - habitat occupied by a species, modified, e.g. forest gaps

Question 6

Models of succession

Answer 6

1. Facilitation - Species that arrive early and facilitates a better environment for later species
2. Inhibition - Early species inhibit later species when conditions become too tough
3. Tolerance - Neither negative or positive interactions between early and late species. Process that takes place without interactions

Question 7

Resilience in ecology

Answer 7

How long before a community returns to an “equilibrium” after disturbance? Are there equilibria?

Question 8

Roles of disturbance in structure

Answer 8

Acts as a driver of species richness and community composition (succession).

Question 9

Intermediate disturbance hypothesis

Answer 9

Certain amount of disturbance is beneficial as it stops species from becoming really dominant. When low disturbance occur, competitive organisms will push the origin species to extinction

Question 10

Habitat fragmentation

Answer 10

Happens when parts of a habitat are destroyed, leaving behind smaller unconnected areas

Question 11

Biomass collapse

Answer 11

Caused by habitat fragmentation where the loss of biomass increases over the years due to the microclimatic factors affected on edges

Question 12

Irreversible shifts

Answer 12

Ecological meltdown of trophic cascades due to the loss of large animals. Predators are essential to balance the trophic cascades as they help regulate the preys (that are mainly herbivores). More herbivore density means increasing forest loss

Question 13

HIPPO stands for

Answer 13

Habitat Destruction, Invasive species, Pollution, human over Population, Over harvesting

Question 14

Evil Quartet is

Answer 14

Alien species
Over hunting
Habitat loss
Co-extinction