Human Impact C1 Flashcards
Define biodiversity:
The number of species and individuals of each species in a given place at a given time
Define endangered
A species that is at risk of extinction
Define extinct
A species that has no living members
List four reasons animals may become endangered
Natural selection, habitat destruction such as deforestation and loss of hedgerows; pollution such as PCBs and oil; hunting and collecting; competing domestic or invasive animals.
List four ways we could conserve species
Habitat protection by nature reserves and SSSI; international cooperation restricting trade (eg CITES); breeding programmes by zoos and botanic gardens; sperm banks and seed stores and reintroduction, education, ecotourism.
List four ways we have made agriculture more intensive in the last 70 years
Hedgerow removal, fertiliser, pesticide, herbicide and fungicide use
Why do fish die during eutrophication?
Aerobic bacteria decompose dead plants and algae, using up O2 in the water
Give the three ways deforestation increases atmospheric CO2
Less photosynthesis, cut trees either decay or are burned
Describe coppicing
A tree trunk is cut, leaving a ?stool? a few cm high. Shoots can still emerge from the stool, and can be cut on rotation to provide timer of different widths
Give three ways to reduce overfishing
Larger mesh size , quotas, exclusion zones (best three answers)
Define planetary boundary
A threshold value for a global process affected by human activity. If crossed could lead to unpredictable/irreversible change
What is the status of the biodiversity planetary boundary?
Crossed
What is the status of the climate change planetary boundary?
Crossed
What is the status of the nitrate and phosphate planetary boundary?
Crossed
What is the status of the land use planetary boundary?
Crossed