Unit 3.6 - Human Impact On The Environment Flashcards
Define species extinction
The death of the last individual of a species capable of reproduction
Explain the reasons that species become endangered
- natural selection
- habitat destruction
deforestation - pollution
- hunting/collection
- competition
Define endangered
A species at risk of becoming extinct throughout all or a significant portion of its range
Define conservation
The sensible management of the biosphere and enhancement of biodiversity locally.
The protection, preservation, management and restoration of natural habitats and their ecological communities to enhance biodiversity
List methods by which species may be conserved
- protecting habitats
SSSIs
-CITES - gene + sperm banks
- seed banks
- species reintroduction
- ecotourism
what is a monoculture
the growth of large numbers of genetically identical crops in an area
why are monocultures bad
they cause reduced biodiversity and reduced soil fertility
why do monocultures increase the need for chemical fertilisers
roots grow to the same length ∴ extract minerals from the same length
why do monocultures increase the need for pesticides
plants of the same species grown so close together are all susceptible to the same pests + disease which spread rapidly
why is overgrazing bad
causes soil compaction, reduces air spaces + inhibits nitrogen fixing ∴ reduces soil fertility
what farming schemes reverse the decline in biodiversity + soil fertility
- organic farming
reduces need for chemical
fertilisers - set-aside schemes
land is set aside for conservation - legislation
provide nesting sites allowing
wildlife to move safely
define deforestation
the loss of trees due to human activity in an area.
what are 6 consequences of deforistation
- soil erosion
- lowland flooding
- desertification
- habitat loss
- decrease in biodiversity
- climate change
name 3 forest management techniques
- coppicing
- selective cutting
- long rotation time
what are 2 methods used in overfishing
- drift netting
- trawling
