Pollution Flashcards
What is anthropogenic atmospheric N deposition?
Deposits from the atmosphere of man made nitrogen compounds from the biosphere
What is wet and dry deposition?
Wet = in rain Dry = as gas or aerosols
What are the oxidised forms of N deposition?
Wet = nitrate Dry = nitrous oxide
What are the reduced forms of N deposition?
Wet = ammonium Dry = ammonia
What are the anthropogenic sources of atmospheric N?
Fossil fuels, agriculture
What are the factors affecting deposition?
Distance from the source, surface roughness and rainfall
Where are high N deposition rates in the UK?
Upland areas - seeder feeder effect
Areas of major industry and agriculture
Peak district
Scotland
How does nitrogen deposition present an ecological threat?
eutrophication, soil acidification, direct toxicity to plants, susceptibility to secondary stress
eutrophication?
N accumulation allows growth of nitrophilous species, can result in competitive exclusion and reduced biodiversity
What is the evidence for decline in grassland diversity in the UK?
Acidic grasslands are widespread, surveys showed a clear decline in species richness with increasing N deposition , N deposition decreases soil pH
Why are ecosystems important to us?
Food, medicines, raw materials, fodder, ground water
Why is N deposition an increasing global issue?
N deposition estimated to two fold by 2050, is the third greatest threat to global biodiversity. Industrialisation in developing countries is a major issue, because they contain much of global biodiversity
How many world biodiversity hotspots where proposed by conservation international?
35, cover 2.3% of terrestrial surface yet contain 50% of vascular plants and 42% of species
