17/18: Causes of Biodiversity Loss Flashcards
Trees hold the soil with their roots. Bacteria decompose waste. Wetlands absorb water. All these are examples of__________
all these are examples of ecosystem services (things that the ecosystem does for us)
What are causes of biodiversity loss?
- habitat loss/ habitat fragmentation/ habitat degradation
- overharvesting/ overhunting/ overfishing
- invasive species
- pollution
- climate change
What is habitat loss/ habitat fragmentation/ habitat degradation?
taking away places in which the other species live
What is fragmentation?
POPULATIONS IN PATCHES THAT AREN’T IN CONTACT WITH EACH OTHER
What is an example of habitat loss?
spotted owl lives on 200-year-old trees in the Pacific Northwest
- because of logging, the number of trees has been going down, negatively affecting them
What is an example of overharvesting/overhunting/overfishing?
elephants hunted for ivory
What is poaching?
illegal hunting or fishing
What are examples of invasive species (biological pollution)?
Ex: rabbits in Australia
- 1901- built fence that prevented rabbits from moving to the west of the fence
Ex: Dutch Elm Disease
- caused by a fungus, spread by a beetle
Why are species introduced to a new area?
- food
- aesthetic value
- as a form of pest control
- by accident
What are examples of pollutants?
- DDT (insecticide)
- plastics
- lead
What is bioaccumulation?
buildup of pollutants in an animal
- ex: DDT, mercury
How do pollutants accumulate?
they accumulate in fat tissue and they are not properly eliminated
- higher concentration as time goes on
What is biomagnification?
process by which contaminant concentrations increase in the tissue of species at higher levels of the food chain
Where are pollutants highest in biomagnification?
pollutants highest at the top of the food chain
What does ppm stand for?
parts per million
