Nutrient cycles - Contamination L4

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Nutrient cycles - ContaminationL4

• English in Natural Science
• ???????

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Ecosystem processes
Metabolism
Primary production Photosynthesis
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Carbon cycle
CO2 Atmosphere CO2

Terrestrial biota CH2O
Aquatic Biota CH2O
Water CO3-2
CH2O soil Rocks
CO3CaMg
Sediments CO3CaMg
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Nitrogen cycle
N2 N2O, NH3 Atmosphere N2O

Terrestrial biota
Water
Aquatic biota
microorganisms NOx Soil NH4
Ocean sediments
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Phosphorous cycle
Atmosphere

Terrestrial biota
Water
Aquatic biota
Soil - rocks
Ocean sediments
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Sulphur cycle
SH2 Atmosphere SO2
SH2
Terrestrial biota
SO4-2 Water
Aquatic biota
SO4-2 Soil - rocks
Ocean sediments
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Primary productivity

• Photosynthesis
• Aquatic (algae) 92.4 x 1012 kg/yr 255 t/km2
  yr
• Terrestrial (plants) 132.1 x 1012 kg/yr 899
  t/km2 yr

C3 most plants Monocotyledons crop
plants wheat, rye-grass
alfalfa, beans trees Fagaceae, Pinus
C4 tropics and arid zones tropical
grasses Dicotyledons crop plants
corn, sugar cane
sorghum, millet
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Primary productivity (x109 tons C)
Biome Net PP
Polar desert / alpine tundra 0.4
Wet tundra 0.6
Boreal woodland 1.1
Boreal forest 2.9
Temperate coniferous forest 1.1
Temperate mixed forest 3.3
Temperate deciduous forest / broadleaf evergreen 2.2
Temperate woodland 2.2
Mediterranean shrubland 0.5
Short grassland 1.0
Arid shrubland 1.8
Desert 0.6
Tall grassland 1.2
Tropical savannah 5.3
Dry tropical forest 2.9
Tropical deciduous forest 3.8
Tropical evergreen forest (jungle) 18.0
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Natural resources

• Renewable
• Biological
• Forestry
• Agriculture
• Crops
• Grazing animals
• Fisheries
• Non-renewable
• Metals
• Inorganic materials
• Fossil fuels (crude oil, coal)

Non-recyclable
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Biological resources
Ecosystem x 1012 kg/ yr total productivity Human use
Forest 48.7 36.9
Woodland 35.0 26.5
Grassland 17.1 12.9
Cultivated 15.0 11.4
Shrubland 7.7 5.8
Desert 3.1 2.3
Wetland 3.0 2.3
Tundra 2.1 1.6
Other 0.4 0.3
TERRESTRIAL 132.1 58.8 Earth 39 - 50
Freshwater 0.8 0.9
Oceans 91.6 99.1 8
AQUATIC 92.4 41.2 Earth
TOTAL EARTH 224.5 100
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Human use of natural resources
Freshwater usage gt50
Nitrogen input (soil, water) gt50
Land transformation 45
CO2 input (atmosphere) gt20
Biodiversity loss 20
Fisheries 8
(Vitousek et al., 1997)
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A) Land transformation

• Objective
• Urban expansion ? population 6 billion
• Agriculture
• How?
• Deforestation
• Tropical forest - Amazon, India, South-East Asia
• Temperate forest - USA, Europe, China
• Coastal mangroves (50)
• Annual rate 1
• Exponential increase in the last 50 years

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Tropical deforestation

• Cleared land unsuitable for agriculture
• Rainfall ? loss of soil
• topsoil lost ? decrease productivity
• Big losses of biodiversity

Deforestation (Km2/yr) Rate 1980-1990 () Area remaining in 1990 (Km2)
Brazil 36,710 0.90 4,093,000
Venezuela 5,990 1.31 457,000
Bolivia 5,320 1.16 459,000
Colombia 3,670 0.68 541,000
Peru 2,710 0.40 674,000
Ecuador 2,380 1.98 120,000
Decrease absorption of atmospheric CO2
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B1) Exploitation - fisheries

• Fishing industry
• 8 global productivity
• 35 continental shelf
• 3 discarded (non-target species dolphin, etc)
• 22 overexploited (cod, sardine)
• 44 limit of exploitation (tuna)
• Colateral damage
• Dredging ocean floor
• Algal blooms
• Fish kills
• Shellfish poisoning

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B2) Exploitation - forestry

• Resources
• Timber, lumber
• Paper
• Rubber
• Fruits (nuts)
• Medicines
• Sustainability
• Plantations
• Adequate management
• Selective cutting
• NO clearcutting

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C) Impacts of climate change

• Increased productivity (biomass)
• 3.2 billion tons/yr CO2 ? C3 plants more biomass
• Warmer atmosphere ? C4 plants advantage
• Decreased yield in wheat, barley crops
• Physiological threshold
• Pollination failure ? fewer insects

X
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D) Global biogeochemistry

• Water
• Humans use over 50 surface water
• 70 used in agriculture (35 global)
• 6 evaporation losses
• 24 consumption - electricity
• 2/3 of river flows regulated (dams, weirs)
• Underground water NOT renewable - Saudi Arabia
  (3/4)
• Ecosystem disturbances
• Little water reaches the ocean Colorado, Nile,
  Ganges
• Estuary, coastal ecosystems ? fisheries losses
• Inland seas dry up Chad (Africa), Aral (Asia)
• Biodiversity losses (fish, plants)
• Increase of dust, diseases
• Useless soil - salination

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other impacts on aquatic ecosystems

• Dams
• erosion downstream
• local climate (temperature, rainfall)
• Change of chemistry
• Danube river ? silica in Black Sea
• Water pollution ? reduced water quality
• Agrochemicals (fertilizers, pesticide residues)
• Industry chemical, mining, pharmaceutical,
  paper, plastics
• Urban waste

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Global biogeochemistry - Nitrogen

• N Fixation (x
  109 kg year)
• Terrestrial ecosystems 90-130
• Aquatic ecosystems 100
• Human input
• Fertilizers
  140
• Biofertilizers (legumes) 40
• Fossil fuel combustion 20
• Consequences
• Increase in NO2 (greenhouse gas) and reactive N
  (NH4, NOx) in atmosphere
• Acid rain (NO3-) ? damage to crops and forests
• Water pollution eutrophication ? algal blooms

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• Sulphur
• Fossil fuel combustion
• Acid rain (SO4-) ? damage forest, crops, health
• Phosphorous
• Fertilizers
• Water pollution eutrophication ? algal blooms
• Fuel combustion
• smog (ozone) ? crop damage, health
• Heavy metal mobilization - mining, industry
• Lead (Pb)
• Cadmium (Cd)
• Mercury (Hg)
• Nickel (Ni)
• Chromium (Cr)
• Copper (Cu)

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Effect of air pollutants on Picea
forests (Schulze 1989)
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Chemicals in the environment

• All chemicals are toxicit is only the dose
  which makes a thing a poison Paracelsus
  (1493-1541)
• Toxic substance negative effects at very low
  doses e.g. below ppm (mg/kg body weight)
• Chemical industry in developed countries
  produces
• 100 m tons/yr
• 70,000 different compounds
• 1,000 new every year

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Chemical pollutants
Source Main causes Pollutants
Natural Volcanic eruptions Blue-green algal blooms Planktonic bloom SH2 Natural toxins
Urban Sewage Solid waste treatment Household heating fossil fuels NH3, P not toxic Dioxins CO2, polycyclic aromatic hydrocarbons (PAH)
Industry Chemical pharmaceutical waste Mining waste/spills Electrical insulators Anilines, phenols, plasticisers Cyanides, heavy metals (Pb, Hg, Cu) Polychlorinated biphenyls (PCB)
Transport Combustion gases Oil (petroleum) spills CO, CO2, SO2 Aromatic hydrocarbons (AH, etc)
Agriculture Fertilizers Pesticides N2O, NO3-, PO4-2 not toxic As, organic toxins
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Environmental pollution
Garbage bin
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Long-range transport

• Global distillation effect
• Very volatile compounds condense with latitude
• Example ocean waters (40-60 m deep)
• HCH hexachlorocyclohexane
• CHBs chlorobornanes (toxaphene)
• HEPX heptachlor exo-epoxide
• TC, CC trans-, cis-chlordane
• Endo-I and II endosulfan
• TN trans-, cis-nonachlor

(Jantunen and Bidleman, 1998)
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Bioamplification

• Multiplication effect through the ecosystems
  food web
• Due to cumulative nature of some chemicals
• Persistent, resistant to degradation
• Heavy metals, Organochlorines (PCBs, DDT, etc),
  Dioxins

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Aquatic bioindicators

• Mollusks mussels, clams, oysters
• Ecology filter water and particles
• Sedentary, easy to collect, long life
• Tolerant to neurotoxic insecticides
• Accumulation of OC and OP residues
• Crustaceans
• Waterflea Daphnia magna
• Bioassay for ChE inhibiting insecticides (OP,
  Carb)
• Shrimp Thamnocephalus spp.
• Bioassay for micotoxins and CYN
• Birds dipper (Cinclus spp.)
• Ecology pristine streams in mountains
• feed on aquatic larvae
• Indirect indicators of pollution - food
  disappearance

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Solutions to pollution

• Industry
• Reduce outputs filter traps
• recycle or destroy waste (remediation)

• Agrochemicals
• Reduce inputs fertilizers pesticides
• New methods of pest control
• Bioremediation of residues

• Waste
• Reduce input less consumption
• Improve disposal
• Incinerators (burning) and compost technology

• Energy - fossil fuels are NOT sustainable
• clean energy sources - solar, wind, geothermal

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References

• Lange et al. (eds). 1983. Ecosystem processes
  mineral cycling, productivity and man's influence
  / ????? call 471.5E
• Freedman, W. 1989. Environmental ecology the
  impacts of pollution and other stresses on
  ecosystem structure and function / ??-????? call
  466
• Vitousek et al. 1997. Human domination of Earths
  ecosystems. Science 277 494-499