Forestry

120 db

150 db

180 db

240 db

Carbon monoxide

Sulphur dioxide

Ozone

Flourides

Coniferous trees limited to Abies (Fir)

Pinus wallichiana (blue pine) stand singly

In groups over an irregular, sometimes dense, lower storey of broadleaved trees

All of the above

The dividing line between a shrub and a tree is not always well marked

The shrub will have many stems rising from the ground against the single one of a tree

The colour of shrub flowers, its length of blooming and the season of bloom are very important

All of the above

Cajanus and Dalbergia

Cajanus and Aeschynomene

Dalbergia and trigonella

Trigonella and Trifolium

Euphorbia

Acacia

Vallisneria

Aloe

Reaction

Competition

Coaction

Ecesis

Ozone, peroxyacetyl nitrate and Nox

Smoke, peroxyacetyl nitrate and SO2

Hydrocarbons, SO2 and CO2

Hydrocarbons, ozone and SOx

SO2

O2

H2S

CO

Producers

Decomposers

Primary consumers

Secondary consumers