impact of human activity on species diversity

Question 1

how has woodland clearance impacted biodiversity?

Answer 1

reduces species diversity by physically removing source therefore reduces the variety of species

Question 2

how has hedgerow removal impacted biodiversity?

Answer 2

reduces diversity since fewer habitats and reduced food sources. Can also lead to soil erasion

Question 3

how has monoculture impacted biodiversity?

Answer 3

single type of plant so fewer species are supported

Question 4

how has pesticides impacted biodiversity?

Answer 4

lowers diversity by killing pests and by removing a food source for others who depend on them

Question 5

how has herbicides impacted biodiversity?

Answer 5

kills weeds, reduces plant diversity and other organisms that feed on the weeds

Question 6

what is deforestation?

Answer 6

the permanent removal of trees to make room for something else eg agriculture, timber or construction

Question 7

what direct effect would deforestation have on diversity?

Answer 7

directly reduces the number of trees and therefore the variety of trees

Question 8

why is diversity lowered due to deforestation?

Answer 8

because it destroys habitats, some species die or migrate, reducing species diversity

Question 9

explain why climate change is an effect of deforestation

Answer 9

fewer trees means less transpiration, which may lead to a less humid atmosphere since less water evaporates from soil than from leaves

Question 10

explain why reduced soil fertility is an effect of deforestation

Answer 10

removal of trees, particularly deciduous ones, removes the major source of nutrients for the soil. There is likely to be an increase in soil erosion as the bare soil is exposed directly to wind and rain and there are no tree rots to stabilise the soil structure

Question 11

explain why flooding and landslide is an effect of deforestation

Answer 11

usually most of the rain falling on woodland is absorbed either through leaves or roots. If the trees are removed the water accumulates in the soil, increasing instability and resulting in possible landslips. since rainwater is not being absorbed, it can run off into adjacent rivers and lead to flooding

Question 12

explain why destruction of species is an effect of deforestation

Answer 12

if large areas of flooding are lost, species ay be unable to move from one area to another . Populations become isolated and genetic diversity may decrease

Question 13

what info is required to calculate an index of diversity for a particular community?

Answer 13

number of each individual species