Human impacts and threats to woodlands

Question 1

agriculture

Answer 1

destroyed a lot of ancient woodland and remaining fragments often became too small to support viable populations of plants and animals. field drainage, nutrient enrichment from nitrate fertiliser and agricultural sprays change species composition along woodland edges

Question 2

settlement/industry/infrastructure/quarrying

Answer 2

new roads and the widening of existing ones, airport and quarry expansion and the construction of industrial estates, housing etc have resulted in direct loss of woodland habitats. even where trees have been spared, adjacent to new developments have altered local hydrology and sometimes cause air pollution

Question 3

recreation

Answer 3

e.g. New Forest; horse-riding, off-road parking and trampling damages soils and vegetation. high traffic volumes on roads cause noise pollution and disturb wildlife especially ponies. dogs chase wild animals and disturb ground nesting birds whilst picnicking increases fire risk

Question 4

pollution

Answer 4

prior to clean air acts (1950) smog reduced light levels in urban areas which encourage deciduous trees to shed their leaves prematurely. acid rain damaged, decline in ph makes soil toxic.plant nutrients e.g. calcium are leached by acidic water and micro-organisms are less active

Question 5

invasive species

Answer 5

sycamores have spread through woodlands displacing native trees
-e.g. grey squirrels competer with reds

Question 6

diseases

Answer 6

dutch elm disease altered the structure and composition of woodland, as the trees dies, canopies were opened up to species e.g. alder filled the gaps. sudden oak death has spread from america

Question 7

conifer plantations

Answer 7

up until 1980’s, conifers were often planted within deciduous woodlands. the trees acidified the soil, altered species composition and their dense spreading branches prevented light reaching the floor, eliminating shrub and herb layers