Identify whether the changes to biodiversity are natural or due to human intervention. A mass extinction occurs after
several volcanic eruptions.
A species of wasp is outcompeted
by several other species and
goes extinct.
A population of grubs decreases
as the population of moles, a
predator of grubs, increases.
A species of wildflower goes
extinct after land is cleared
for agriculture.
Three populations of migratory fish
decline after the construction of
a hydroelectric dam.
The number of offspring produced
by a population of frogs decreases
after pesticides enter their pond.
Natural
Human Intervention

increase soil erosion                                             reduce soil erosion

cattle grazing                                                         hydroseeding

deforestation                                                         contour plowing

                                                                                planting vegetation

plant roots basically hold the top soil

together and stop soil erosion because

in such situation top soil is not removed

during flood but cattle grazing causes

soil erosion because cattle consume the

grasses and herbs and top soil is exposed.

same situation occurs because of

deforestation, the trees and plants are cut

down to expose top soil which causes soil

erosion

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