trees and the atmosphere Flashcards
what fraction of earth’s land area is covered by forests?
1/3
Why do plants emit biogenic volatile organic compounds?
theories:
- defend against herbivorous predators
- signal to other plants
- protect against environmental conditions (eg high temp and ozone pollution)
what does bvoc
biogenetic volatile organic compounds
what happens after bvoc are emitted into the air
take part in chemical reactions forming more complicated chemical compounds
what chemicals do bvocs effect
oxidation by ozone, the hydroxyl radical and nitrate radical (O3, OH, NO3)
how to bvocs affect number and size of particles in the air
2 ways: they are large enough to reflect and absorb incoming solar radiation, they can form cloud droplets and alter the brightness of clouds
The emission of BVOCs can also affect concentrations of some gases in the atmosphere like methane (CH4) and ozone (O3) – why is this important for the climate?
Both methane (CH4) and ozone (O3) are greenhouse gases – it is important for us to understand any changes to their concentration as this affects the amount of longwave radiation that gets trapped by the atmosphere.
how does deforestation fires effect the productivity of remaining forests?
Particles produced during deforestation fires can affect the amount of sunlight that reaches the remaining plant canopy. The presence of the fire particles reduces the amount of direct radiation (i.e. entering directly from the Sun) reaching the trees but can increase the amount of diffuse radiation (i.e. sunlight that has bounced off something in the Earth’s atmosphere) – this means that light can reach a greater proportion of leaves on the trees.
how does deforestation fires effect the health of people living nearby
The particles produced from deforestation fires can also affect the health of people living nearby when they are inhaled. Some of these particles are small enough to travel very deep into the lungs and are associated with cardiopulmonary diseases and lung cancer.
