Unit 6.6- Populations and Sustainability Flashcards Preview

A Level (A2) OCR Biology > Unit 6.6- Populations and Sustainability > Flashcards

Flashcards in Unit 6.6- Populations and Sustainability Deck (12)
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1
Q

Carrying capacity definition:

A

The maximum population size that can be maintained over a period in a particular habitat

2
Q

What are the different phases of population growth?

A
  • Lag phase
  • Log phase
  • Stationary phase
3
Q

Features of K-strategists:

A
  • Low reproductive rate
  • Slow development
  • Late reproductive age
  • Long lifespan
  • Large body mass
4
Q

Features of R-strategists:

A
  • High reproductive rate
  • Quick development
  • Young reproductive age
  • Short life span
  • Small body mass
5
Q

Interspecific competition:

A

Competition between individuals of different species

6
Q

Intraspecific competition definition:

A

Competition between individuals of the same species

7
Q

What is coppicing?

A
  • Ancient practice of managing woodland
  • Involves cutting down trees regularly whist leaving a stump to encourage growth
  • Produces thin trunks
8
Q

What is pollarding?

A
  • Like coppicing but the stem is cut higher up

- Herbivores then can’t eat the vegetation

9
Q

Advantages of coppicing:

A

-Replenishes woodstock in 7-20 years which is faster than replanting

10
Q

Disadvantages of coppicing:

A

Thin wood

11
Q

Advantages of rotational coppicing:

A
  • Multiple niches
  • High species richness
  • Secondary succession
  • Soil replenishment
12
Q

Disadvantages of large scale clear felling of trees:

A
  • Destroys habitats on a large scale
  • Reduces soil mineral levels
  • Leaves soil susceptible to erosion