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Flashcards in Population And Sustainability Deck (25):
0

Galapagos (captive breeding)

- 14 giants tortoises left
- 100 offspring released
- only successful if habitat maintained

1

Threats to the Galapagos

- increasing population from tourism as more jobs= more pressure more waste
- over fishing- quotas met lots of opposition
- tourism- stricter measures needed
- exotic species- bring goats/rats eating vegetation/eggs

2

Galapagos conservation projects (project isabela)

- specifically trained hunters to lower goat population
-'judas' goats released with trackers to find the rest
-complete by 2006
- vegetation returned
- endangered insects improved
- tortoises pop improved

3

Endemic species

- found in only one are or country
- ie galapagos islands

4

- increasing forrest efficiency

- matching the tree to the conditions
- the optimum distance between each tree
- control pests and pathogens
- use all the tree ie for fuel
- very best use of land

5

Long rotation time

- leaving sections of the forrest for many years before re-foresting
- time for species variation to build up
- less disturbance from machinery
- although less cost effective

6

Selective cutting

- felling only largest/most expensive trees
- although some disruption minimum + habitat maintained
- good on slopes prevents erosion unlike clear felling
- & maintain nutrients in the soil

7

Clear felling

- removal of all trees from an area at once
- not gd for the ecosystem

8

Sustainable forestry

- can mean removing timber in a way such that it will still be available in years to come
- or maintaining the ecosystem
- ie selective cutting or long rotation time

9

Coppicing

- doesnt destroy woodland
- may improve biodiversity
- cut at the base and new stems available to grow
- small in diameter though
- plus labour intensive and not very cost effective

10

Rotational coppicing

- coppicing different areas each year to allow them to grow
- good for biodiversity
- allows light to woodland floor

11

Coppice with standards

- some trees in each area not cut & allowed to grow full ie standard
- after can be replanted or coppiced

12

Reasons for conservation

- economic - so constant timber supply forever + ie fish levels
- social - tourism + jobs + happiness

13

Conservation

- the active management of habitats in order to maintain/ increase biodiversity
- not necessarily a natural process

14

Biodiversity

- range of habitats & communities & species in an area & the genetic variation that exists within each species

15

Interacting factors

- different factors together tend to control poo size& distribution
- ie barnacles
- not too high temp change to much dependent on high/low tide
- not too low not enough rock space + predation
- not much balanus & chthalmus together as balanus grows faster

16

Interspecific competition

- competition between organisms of different species
- when the niche of 2 organisms overlap
- bigger overlap= bigger competition
- can out compete so do co-exist

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Niche

- the role or position of an organism in an ecosystem
- ie habitat abiotic/biotic factors it affects/affects it

18

Intraspecific competition

- competition between members of the same species
- important in limiting pop size - part of natural selection

19

Competition

- when 2 organisms require a resource that is in short supply

20

Predator-prey relationships

- prey pop increase = increase predator pop as more food
- limits prey pop + more comp for food = predator pop falls
- as predator pop decrease - prey pop increases
- rare as - predator only has 1 prey
- if predator is the main limiting factor for prey
- & food = max limiting factor for predators

21

Carrying capacity

- the upper limit on size of a population that can be sustained
- tends to be caused by a collection of factors

22

Sigmoid growth curve

- the patter of growth shown by many organisms when first introduced to a new enviroment
- ( lag phase then log phase)
- ie pop of a microorganism in a closed system

23

Limiting factor

- anything that stops a population from increasing in size
- ie food availability/predators/parasites/nesting sites

24

Population

- a group of organisms of the same species that live in the same place at the same time & can interbreed