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Air pollution effects on forest ecosystems

colek's version from 2018-11-08 20:29


Question Answer
Are conifers or deciduous trees more susceptible by acid rainConifers
SO2the biggest pollutant; mainly produced by combustion of S containing fuels; Enters plant through stomates and through soil; Plants need it in big ammount, but too big is dangerous
Production of SO2- TrendsDecreases strongly- less S content in oil products; desulfurization; low S-content enregy sources
SO2 sourcesCombustion of oil and charcoal, dressing of S-containing ores; sea salt-Volcanoes
SO2 reactions in the atmosphereSO2+H20→ HSO4- + H+ → SO4- + H+; SO2→SO3 / OHSO2 → sulfate
Why are deciduos tress less vulnerable by air pollution?They change their assimilation Organs and throw away the unwanted stuff
HFAluminium factories release Hydrogen fluorid and it is damaging plants in near area
HF symptomsneedels and leaves start to die from top of the organ
Natural pH of rain5,6, due to catching CO2 and N in the atmosphere
Smog=Smoke + Fog
Wood annualrings reaction to polluted airthey are not bright and are densely concentrated
Ways of reducing damages in Forestryreplacement of conifers by more tolerant species
Ways of reducing damages in Industryreduction of emissions- filters(de-acidification); high chimneys
Why are forest more vulnarable than agricultural plants?Trees are exposed for longer time and have higher surface areas
Emission isthe stuff leaving a chimney
Imission isthe stuff after dispersion; chemical and physical transformation, at the organism it enters
Immisions impactDecreased vitality, leaf injury, decreased growth
Tourism (ski slopes,elevators, mountainbiking) impactDeer damage; Water budget
Sewage sludge (prohibitedin the forests) impactHeavy metals; N-input
Forest grazing impactSoil degradation, soil impaction, tree damage
Forest harvets impactTree damage, nitrate loss by big clearings
Hunting impactdeer damage
Increasing population, recreation area od citiesGeneral pressure on the enviroment
Air pollutants characteristicsSolid, Fluid, Gaseous; change the natural composition; possibly negative impact on organisms
CO2 concentration in the air in 1850275 ppm
CO2 concentration in the air in 2016403 ppm
Tropospgere8-17 km; 85 % of total air mass; Clouds; Weather;
Mixing layer isPart of troposphere 10 m to few km of it; Air pollutants mix with air here and turbulence disperse stuff homogeneously; temperature profile here has big impact on the dispersion
Stable air layering causes= inversions; Air pollutants may be highly concentrated without any changes of emission rates
Deposition of pollutantsDry deposition; Wet deposition; Occult deposition
Dry deposition(dust, aerosols, gases); gas deposition is proportional to the deposition velocity and air concentration; the deposition velocity is a function of particle size, wind speed, temperature and property of the acceptor surface
Wet deposition(rain snow hail)
Occult deposition(Fog or rime) Fog deposition of some components may be quite important; up to 20-50% of total depositon for forests!
Deposition processesSedimentation (rain; snow; coarse; dust); Impaction (particles); Interception (fog; aerosoladsorption); Turbulent diffusion (aerosols); Diffusion (aerosols gases)
NOx sourcescombustion processes at high T- traffic; combustion of biomass; lightening; soils
NOx sinkswet deposition on land / ocean; dry deposition
NOx Trendsproduction was decreased by 30 % from 1990, but but traffic still produces costant ammount
Traffic trends- decreasing ammount ofCO; So2; NMVOC
Traffic trends- increasing ammount ofNOx; CO2; Cd; PAK
Which part of agriculuture emits NH3 and CH4live stock
NH3 trendis stable
N2O trendslight decrease
N2O Sourcetraffic; fertilization
N compounds common info78 % of atmosphere is N; rest in soil and biomass; essential nutrient; fixed by N fixing microorganisms;
NitrificationN compounds oxidized in soil as nitrate
Denitrificationreduction of N compounds and producing N2 and N2O
NO propertiesdoesnt burn; colourless; hardly soluble in water; produced at temp of 1000°C
NO sourcesfrom NH3 with OH*; lightening; denitrification; from laughing gas and O*; combustion; explosives; N- fertilizers
NO2 propertiesbad smelling; toxic; well soluble in water
N2O propertiescolorless; sweet smell; narcotizing; de built in atmosphere; important greenhouse gas
CH4 productiondigestion of plant eating animals and microbial processes
Dust primary particlesdirect emissions into the atmosphere
Dust secondary particlesFormed by chemical reactions in the atmosphere
Dust sourcesSoil erosion (weathering and surface erosion),vulcanos, oceans, fire, pollen, etc.; human industry
CO sourcesmainly small consumers- inefficient combustion
Burning biomass "does not cause" any CO2 – emissions becausesince re-growing raw material is not accounted for. These emissions are “CO2-neutral”, because these CO2 emissions are bound again during re-growth.