Cool air trapped beneath a layer of warmer air. This stable condition prevents polluted ground-level air from mixing with cleaner air from higher altitudes.

*If this is accompanied by fog, the pollution is known as smog*

Atmospheric inversion acompanied by fog, the word derives from "smoke" and "fog"

Killer smogs are rich in sulphur dioxide and soot and caused the deaths of thousands of urban people in the 1950s, this S0² pollution is reducing smog 

1. switching from coal, a relatively dirty fossil fuel, to "cleaner" fuels such as natural gas, oil or alternative tech: nuclear power, hydroelectricity
2. tall smokestacks to spread emissions over a wider area so ground level exposure was less common/intense (known as dilution solution to pollution)
3. centralizing energy production in large power plants to replace much of the relatively dirty burning of coal in home furnaces and fireplaces, theirby permitting better control of emissions
4. treating waste gases to remove some of their pollutant content, thereby reducing emissions

• replaced reducing smog in many areas, this develops through complex photochemical reactions in which hydrocarbons and nitrogen oxides are transformed into ozone (O3) and other gases.
• Develops under sunny conditions if hydrocarbons and nitrogen are present from automobile emissions, and particularly if an atmospheric inversion reduces dispersion.

Volcanoes emit on average 12 million tonnes of sulphir gas a year (also H2S)

Anthropogenic emissions are about 142 million tonnes a year...

from:

1. fossil fuel combustion (54%) Coal, crude oil, resifual oils, motor fuels (deisel and gas)
2. Manufacturing processes (23%)
3. smelting of metal ores (7%)

1. Flue-gas desulphurization or Scrubbing: Capturing technologies from postcombustion waste
2. Fuel desulphurization or Coal Washing: removal of some of the sulphur content of fuels
3. Particulate control devices: such as electrostatic precipitators, to greatly reduce the emissions of particulates (has little effect on NOx)
4. switiching to low sulphur fuels such as natural gas or no sulphur technologies (nuclear, hydro)
5. Energy conservation: to reduce overall demand for fuel and associated pollutants
6. Taller smokestacks: disperse emissions more widely

Most are from natural sources

H2S from anioxic sediment from shallow marine and inland waters

Dimethyl sulhide ((CH₃)₂S) proiduced by photoplankton and outgassed from the oceanic waters

Anthopogenic is usually H2S from chemical industry, sewage treatment plants and livestock manure

Plants yielding less when exposed to pollutants such as SO2, though with now sign of other acute injury

*Pasture grasses show lower yields at exposures averaging at 0.04 ppm

1. NO: nitric oxide
2. NO2: nitrogen dioxide
3. N20: nitrous oxide
4. NH3: Ammonia

*NO and N02 are often considered together as a complex referred to as N0x

Photochemical pollutants

Developes in the atmpsphere as the result of photochemical reactions in which hydrocarbons and nitrogen oxides are converted into O3

Hydrocarbon or NO_x + Solar energy= O₃

The Ozone Layer is located in the Stratosphere (8-17km) where ozone causes no damage:

1. It protects orgainisms from UV exposure
2. Transports water from ocean to land and
3. regulates surface temperatures

the most damaging of the photochemical air pollutants, cuases Oxidizing smogs which are rich in O₃

• Important to note that this is a secondary pollutant because it is not typically emitted to the atmosphere and are instead synthesized in the atmosphere
• Canada, the US and other countries have deceloped air quality standards to prevent acute damage to vegetation (usually 120 ppb)

Interactions between the atmosphere, ocean, and land

• driven by the sun: radiation penetrates the earth's atmosphere and heats the surface (ocean and land) and the atmosphere
• Differential heating: causes circulation, which translates into ocean currents, wind and weather systems

• Solar radiation penetrates the atmosphere and about 70% is absorbed by the Earth's surface and is absprbed and dissipated in many ways.
• Much of this enegry heats the surface and the atmosphere, most is re-radiated as long wave infrared radiation.
• Atmpspheric moisture and greehouse gases interfere with this process and re-radiate this raditation back to the earth;s surface, thus keeping it warmer than it would be otherwise (at 15 C insteasd of -18C)

In other words, regulates the Earth's energy budget:

1. all energy coming into the system
2. all energy going out
3. any difference that might be internally stored or transformed

• Atmosphere insulates Earth from losing heat to space
• Keeps average surface temperature at 15C instead of -18C
• Important: In the short term this keeps energy in but in the long term this energy is re-radiated into space.

Gases which effeciently absorb infrared radiation and become heated as a consequence... because the various GHGs have such an immense impact on the greenhouse effect, it is reasonable to hypothesize that an increase of these gases will cause an increase in temps.

1. Carbon dioxide (CO₂):  Anthropogenic (combustion of fossil fuels and deforestation), other causes are Respiration/Transpiration, decay.
2. Methane (CH₄): Livestock and decay
3. Ozone (O₃): Photochemical reactions in the atmosphere
4. Nitrous Oxide (N₂O): Chemical reactions in the soil
5. Water Vapour (H₂O): evaporation/transpiration

As the atmospheric concentrations of GHGs have been increasing since 1800, it is hypothesized that the the greenhouse effect will be intesnsified which may cause dramatic climactic and ecological reponses.

• Rates of increase are most important here
• Rates of CO2 and CH4 are increasing the most dramatically while H2O is not 

• Atmosphere retains more heat
• Shift in energy inputs to the global system
• subsequent impacts on tne entire biosphere

1. COmbustion of fossil fuels: a process that results in the carbon content of fuel being oxidized to CO2, which is emitted to the atmosphere
2. Deforestation: an ecological change which mature forest storing large amounts of organic carbon (i.e. carbon sinks) in their biomass are converted into ecosytems that contain much less; the difference isn emitted to the atmosphere as CO2. (38% storage decrease)

1. Livestock waste
2. Rice Paddies
3. Biomass Burning
4. Resevoirs
5. Landfills
6. Fossil Fuel Production
7. Sinks: Reactions with OH- ions and consumption in soils

GWP or Global Warming Potential describes the relative ability of a gas to affect the greenhouse effect (CO2 has a value of 1.0)

• Water Vapor is the most important which causes 36% of the greenhouse effect, followed by CO2 with 20%
• the GWP of CO2 is 1, CH4 is 21, NO2 is 310 however because of the volume of CO2 emitted to the atmosphere it plays a much larger role than these gases

Refers to the long-term change in the weather that a region experiences.

• One of the most important indicators of climate change is the temperature fo the surface atmosphere--i.e. air temperature
• Other indicators may be changes in precipitation, ocean circulation, and extremem events

Difficult to predict with certainty as other factors may onfluence climate change like eruoptions of volcanoes (which cool the earth by blocking UV) or variations in solar output

Computer simulation: predict the potential responses to increased CO2 which produce

1. GCMs: 3-d General Circulation Models: examine how energy and mass circulate in the atmosphere and interact with climate variables (temp, precip)
2. AOGCM: Atmospheric + Ocean Global Circulation Models

Icecores

Tree rings

Temp records

Climate models

Climate modelling suggests that climate change will be more dramatic at higher latitudes...

It is predicte that an increase in temp and decrease in precipitation could lead to difficulties in agriculture and natural ecosystems.

• Particularly in the praries (Alberta) this would lead to more extreme events like forest fires and more pine beetles (which dries out trees and leads to more fires) 
• Drought conditions may desertify arable land and further deplete efforts to irrigate
• Melting of glaciers may alter flow of rivers in Alberta and elsewhere

1. Reduce Energy demand* (political and economic reform to decrease reliance)
2. Replace high carbon fuels with alternatives
3. Carbon Credits: investing in Carbon sinks to mitigate emissions 

• Afforestation: Converting non forested land into forested land
• Reforestation: Replanting a forest in an area where timber was harvested.  

Long Range Transportation of Air Pollution: this denotes the travel of pollutants due to slower oxidizing rates.

Consequently pollutants such as SO2 can travel long distances before they are deposited in aquatic or terrestrial systems or are oxidized into other compounds (i.e sulphate H₂SO₄ acid rain)

1. Sulphur gases: SO2 and H2S
2. Nitrogen Gases: Nitric oxide (NO), Nitrogen dioxide (NO2), nitrous oxide (N20), and ammonia (NH3)
3. Aerosols: Particualtes in the air
4. Ozone: atmospheric or ground level O3

1. Natural: SO2 and H2S are emitted from volcanoes, wildfires, oxygen poor sediment and Ocens** most H2S is naturally emitted
2. Anthopogenic: SO2 (twice the amount of natural emissions) emitted from combustion, smelting and mining sour gas deposits

Nitrogen Pollution (natural and anthropogenic sources)

NO (nitirc Oxide), No2 (nitrous dioxide), N2O (nitrous oxide), NH3 (ammonia) are the most important notrogen containing gases.

Note: NO and NO2 are often consideed together as NOx

1. Natural: wetlands, microbial &bacterial denitrification, lightning, oxidation during fires
2. Anthropogenic: Combustion, Livestock, agriculture

Most Atmospheric Nitrogen becomes nitrate (NO_3^-) which adds to acidic precipitaion

Sulphur dioxide (SO2) and Nirous Oxides (NOx) become sulphuric and nitric acid which falls as wet precipitation or dry dust (acidic deposition) and may injure aquatic or terrestrial productivity.

SO2 can cause acute or hidden injuries to vegetation at much lower levels than animals and humans

• Acid rain has a precipitation less than 5.65 due to reactions of water with sulphur dioxide and nitrogen oxides.
• SO2 ans NOx become sulphuric and nitic acid and either fall as precipitation (wet) or are deposited as dry dust
• Most of this process is due to emissions of these gases from anthropogenic sources (combustion, smelters, livestock rearing, agriculture, industry etc) hence it is a global problem

• Acidifies water bodies thus reducing species' habitat
• Can acidify non-buffered soils and reduce plant productivity
• kills trees
• Increased lung related problems - human health issues

Acid Rain is a broad term that describes the ways that acids form and are transferred from the atmosphere to terrestrial and aquatic surfaces. A more specifc term is "Acid Deposition as there are 2 types:

1. Wet deposition: refers to acidic rain, fog, and snow. As this acidic water flows over and through the ground, it affects a variety of plants and animals.

• The strength of the effects depend on many factors, including how acidic the water is, the chemistry and buffering capacity of the soils involved, and the types of fish, trees, and other living things that rely on the water. 

2. Dry deposition: Atmospheric imputs of chemicals occuring in intervals between rainfall or snow About half of the acidity in the atmosphere falls back to earth through dry deposition.

• The wind blows these acidic particles and gases onto buildings, cars, homes, and trees. Dry deposited gases and particles can also be washed from trees and other surfaces by rainstorms. When that happens, the runoff water adds those acids to the acid rain, making the combination more acidic than the falling rain alone

*Becuase prevailing winds may transfer SO2, NOx, O3 and other particulates long distances (see LRTAP), acid deposition is a global problem, requiring poltical cooperation of many govt's.

Emissions standards are based on a relation of:

1.  Critical loads: how much sulphur the atmosphere can

absorb before it becomes harmful to an ecosytem/lifeforms

and

2.  Target Loads: political limits set in relation to critical loads

However....

As SO2 is a point source pollution (comes from specific and identifiable sources) it is mire successful in actions to reduce it and US and Canada have had agreements since the 80s

NOx is more difficult as it is not a point source pollutant, henece it is in need of stricter emission standards.

1. Promote cloud formation: increases albedo, thus causing cooling
2. Contributes to smog (photchemical reactions), acid rain (binds to SO2 or NOx), and climate change (changes climate zones)
3. Affects human health

UV protection:

• DNA is highly reactive with UV which may lead to skin cancers and melanoma.
• UV can also destroy or weaken membranes in organisms leading to cataracts and blindness and supression of the immune system.
• Also UV can be harmful to photosynthetic organisms and may produce acute or hidden injuries in plants

The Ozone layers thickness varies with latitude and season:

Antarctica

note: Ozone degrades much faster in cold and stagnant air and ozone holes form mostly in the early spring over antarctice and arctic:

Ozone destroying reactions (i.e. with CFCs and NOx) proceed rapidly in cold and stagnant conditions in the stratosphere, hence at polar latitiudes in the early spring these reactions rapidly deplete exisitng O3. Those that occur over antarctica are greater than those over the arctic or Northern Canada.

The thinnning of O3 in the stratosphere is caled ozone holes.

The size of these holes varies from year to year with the largest being in 2000 and covering over 30 million km2.

Though these seasonal holes form over polar regions, when polar air is disperesed by the wind, Ozone may be depleted at lower latitudes.

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Stratospheric O3 is destoryed by various reactions including those with trace gases such as NOx and N2O ans with reactive ions of chlorine, bromine, and flourine.

Because of anthropogenic emissions of these molecules (recultiung increasing concentrations of the above mentioned) O3 is more rapidly depleting.

Halocarbons are especially destructive in this regard

2

1.  

   Increased UV:
1. Stratospheric cooling

By 1996, all developed countries eliminated production of  CFC by banning their  further production

This takes time to be reflected in the atmosphere as CL stays active for many years, however there has was substantial imporvement within 10 years. It is predicted that it wont return until 2050.

Sunlight + nitrogen oxides + VOCs = ozone

*note: Ozone + other pollutants = smog

NOx is produced under any high temperature conversion of fossil fuels...

VOCs, (volatile organic compounds) are widely used as ingredients in household products including; paints, varnishes, wax, fuels, cleaning, disinfecting, cosmetic, degreasing, and hobby products.

Volatile Organic Compounds: may contain oxygen, nitrogen and other light elements in addition to carbon and hydrogen (hydrocarbons).

The simplest hydrocarbon is CH4 (methane)....

US is the source of 30-90% of Ground Level Ozone in Eastern Canada

There are agreements to reduce transboudary air pollution.... though this doesn't totally remidiate the problem it mitigates the levels of Ground level ozone produced.

By Definition, renewable resources are resources that are capable of regenerating after harvesting and can be potentially harvested forever (providing they are managed properly)

Surface water  and groundwater (freshwater) are paramount of these resources and are essential to ecological and economic sustainability. 

• Comprises of Lakes, ponds, Streams, and rivers and can be used for irrigation, drinking, generation of hydroelecricity, industrial services (cooling).
• Surface water is abundant in areas where precipitation is more prevalent than evapotranspiration
• 0.3% of Earth's freshwater!

1. Earth's surface:

3% freshwater-97% saline

1. Freshwater:

30.1% groundwater,

68.7% Ice capes/glaciers,

0.9% atmosphere,

0.3% surface water

1. Fresh Surface Water:

Rivers 2%, Lakes 87%

[image]

Moves 3% of Earth's water

 1. Natural hazards

 2. Drinking water

 3. Irrigation

 4. Recreation

 5. Power production

 6. Industrial use

 7. Ecosystem function

1. The Columbia River: Stretches through BC into the US and its use in Canada is therefore managed by an international treaty
2. Saskatchewan River: Through the North and South Saskatchewan rivers, the saskatchewan river flows through Alberta, Saskathcewan and Manitoba, hence actions in any province to dam or othewise alter the flow or quality is regulated by agreements between each province.

1. Instream: water remains in natural setting... i.e. fishing, transporation

Hydroelectric: 62% of Canada’s total power in 1997

• Cargo transport

• Commercial fishing

• Recreational activities

• Wastewater disposal

• Ecosystem function

2. Withdrawl Uses: Water is removed from natural setting

• Power production

– fossil fuel, nuclear energy generating stations

• Irrigation (largest water consumer)

• Municipal water

• Manufacturing

1. Water quality

60% of freshwater drains North

85% of Canada's population lives in the South with only 40% of the freshwater available  

• East Coast's proximity to the Ocean leads to more runoff because of substantial precipitation
• Prevailing winds (westerlies) move precipitation out of Alberta/Sask border area
• West coast- proximity to Ocen and topography (mountains) leads to more precipitation and runoff near mountain areas.

• AKA: Catchment, drainage basin, river basin 

An area of land from which surface water and groundwater flow into a stream, river or lake.

• Capture area for precipitation inputs, defined by topography

• Extent (km2) delineated by a draineage divide

[image]

Groundwater is not dependent on topography and is instead affected by geology

[image]

[image]

what happens on the land seeps into the groundwater and may affect the quality of that water...

Remember that groundwater is determined by geology and not by topography like surface water...

Pollutants may lower the PH of an aquatic system if the acids being added surpass the acid neutrilizing capacity...

Fish are the most affected as they have skin that absorbs the acids and live in the contaminated water indefinitley, though the disappearance of fish alters the food webs of aquatic birds.

The ability of a surface to mitigate acidification is dependent on the alkalinity (basic) of the surface.

As H+ is added to the water, it is absorbed by acid-=neitralizing reactions until the process exceeeds the water's capacity to neutralize the acid.

Bicarbonate (HC03-) is the buffering sytem in water with ph between 6.0-8.0 as it reacts with H+ to form CO2 and H2O until its alkalinity is exhausted.

The alkalinity of a surface is reliant on geochemistry: the presence of limestone or dolomite in soil or bedrock of a watershed 

Dependent on the Alakalinity of the surface which is in turn largely dependent on geochemistry:

In areas with Carbonbate-rich bedrock or soil (limestone or dolomite) bicarbonate (HCO3-) will neutralize the acids of even largely polluted areas

In areas with hard poorly soluble materials like granite, gneiss, and quartzite, which contain few carbonate materials, there is little in way of neutralization. (common in eastern Canada where there is thin soils overlying hard granitic bedrock)

Headwaters are also vulnerable as they do not usually interact with other water systems or extensively with soils or bedrock.

high elevation mountainous regions (Rocky Mountains, Appalacians) are also vulnerable as granite contibutes very little alkalinity to waters.

Ultimately the damage done by acidification can only be resolved by reducing the emissions of acid forming gases, however this is quite a controversial issue becuase:

• scientists do not know how much the emissions of SO2 and or NOx must be reduced to effectively curtail acidification
• Economic factors: cars vs industry, which should be regulated
•  Needs the cooperation of many governments
• Carbon credits can be bought + sold

Though trees and other vascular plants show little acute injry from acid rain, the acidification of soils leads to decreased growth, however the effects on fresh surface water are more intense:

1. Specific types of pytoplankton disappear as other become dominant in acidic waters, if phosphorus is present, this may result in Eutrification.
2. Aqautic plants are also stimuilated by fertilization more than acidity, however if acidity accompanies fertilization, acidic tolerant plants may flourish.
3. Some zooplankton (mostly crustaceans) respond to an increasing population in phytoplankton and experience growth in population.
4. benthic invertabrates (those living in aquatic soils) are less affected as they live beneath the waters affected by acidity.
5. When waterbodies acidify to a PH of less than about 6.0 they begin to lose their fish species and other sensitive species.

Specifically, it is younger and developing fish that are affected, which is why there are less mature fish in acidic waters: dissolved metal ions such as aluminum become abundant and are toxic to fish.

6. When fish disappear, certain waterfowl are indirectly affected by the loss of thier foodsources, however other birds that eat zooplankton and insects may increase as acidity leads to more of these organisms.

waters that are well supplied with nutrients and, as a result, are highly productive.

There are two types:

1. Cultural Eutrification: water bodies that become eutrophic via anthropogenic nutrient inputs, usually through dumping of sewage, runoff of fertilizer from land, or the use of phosphorus detergents.
2. Naturally Eutrophic: waters that occur in inherently fertile watersheds

Most symptomatic of Eutrification is the Algal bloom: a pronounced increase in primary productivity , expecially of phytoplankton.  

If the water becomes hypertrophic this algal bloom will increase cyanobacteria (blue-green algae) which consume immense amounts of oxygen when they decompose, thus stressing other aquatic organisms.

Sewage treatment is actions taken to reduce inputs of pathogenic microorganisms and oxygen consuming organic materials to receiving waters.

1. Primary sewage Treatment: screening of raw sewage to remove larger materials and sediment.
2. Secondary Sewage Treatment: Biological agents degrade the dissolved orgabic material in the primary effluent
3. Tertiary Treatment: Any contaminants are removed frokm the secondary effluent

Shows the cumulative, detrimental effects of a variety of anthropogenic stressors on the ecological health of a large lake:

1. Eutrification from nutrient loading (industry, agriculture)
2. Habitat damage through siltation from deforestation of the watershed
3. Over-exploitation of a potentially renewable fishery
4. Pollution by oxygen consuming sewage and toxic chemicals
5. Introduction of non-native species (Zebra mussel)

Lake Erie also shows that a highly degraded water system can be partially recovered of the causes of the damage can be mitigated:

1. tertiatry treatment of waste water
2. Political cooperation to reduce phosphorus

Still there is a large amount of untreated or ill-treated waste being added to the Great lakes.

Unclean Drinking water = disease... Sediment carries contaminants

Canadian Guidelines limits substances however is not legally binding

Sediment can be removed by filtration while biological contaminants can be removed by chlorination

Remember:

Walkerton Tragedy: Waterbourne disease (E coli) in South Ontatio town following improperly treated water (manure from livestock) supply leading to seven deaths and millions of dollars in medical expense, water treatment, and legal fees.  

• Seven people died and many others sick from E coli present in their ground water supply from improperly treated livestock waste
• Bacteria was not found during routine quality monitoring, and was not properly dealt with once it was found

Lessons learned, need for:

1. Competent local maintainence and monitoring of public water supplies
2. Oversight of local authorities by provincial and federal governments
3. Sensible regulation and close monitoring of the disposal and environmental impacts of improperly treated livestock sewage in Canada 

Dams are structures ised to contain flowing water, which backs up to form a lake-like impondment. Of the larger dams:

1. 48% were used to aid in irrigation
2. 20% for electricity
3. 15% for water supply
4. 8% flood control
5. 9% for recreation  and other purposes such as navigation

1. Impoundment: accumulation of riverflow and flooding of an extensive area of land so that electricity can be generated all year. Has the greates impact on below dam riverflow becuase it greatly reduces the spring peak flow while increasing the summer, fall and winter flows. *most common in Canada*
2. Run-of-the-River: directly harnesses the flow of a river without creating a large impundment. Utilizes the river flow according to seasonal availability, but has little or no capacity to store the spring peak flow, or to coordinate the electricity woth consumer demand. Cause significantly less environemtal damage
3. Combination system: uses both impoundments and run-of-the-river systems to form a peaking system which releases water during peak consumer periods and accumulates during off times

1. Considered renewable as hydrologic cycle replenishes energy source
2. emissions of greenhouse gases are much smaller than those of other energy sources
3. unlike fossil fuels there is no direct emissions of SO2 or NOx, which cause acid rain
4. Impoundments may control flooding of downstream areas that would be otherwise economically or ecologically damaged by seasonal flooding.
5. Substantial commercial or recreational fisheries may develop in resvoirs.

*Important to remembr that this also cause some significant dmages associated with fossil fuels needed to construct dams, as well as the environmental damages associated with the obstruction of flows, flodding of habitat, altering of biodiversity and lifestyles of local people.

During the 1970s it was discovered that many of the worlds frog populations were declining with many beoming extinct in many areas. This was due to:

1. UV radiation
2. Chemical contamination: Acid Rain, Pestecides, Herbicides and fertilizers
3. Exotic Competitors and predators
4. Disease: Ex. Fungus

This is significant becuase it represents:

1. Loss of biodiversity

2. Environmental Change: Are Humans Far Behind?

4. Potential Medicinal Properties of some lost species

*Significantly, this shows that there are direct links between Species and Habitat* 

the richness of biological variation. It is often consideredc to have three levels:

1. genetic variation within a species or population

2. numbers of species (AKA species richness)

3. the variety and dynamics of ecological communites on large scales such as landscapes and seascapes

• Deals with variation in Genetic Make-up of organisms within a species
• Clones exist, however, that reproduce through asexual reproduction and are genetically the same--trembling aspen, duckweed
• High genetic diversity is generally attractive in terms of greater reproductive success/adaptability, resistance to disease, adaptability to environemtnal conditions

Refers to the number of species in a particular ecological community or in some other defined area, such as park, country or the biosphere.

Greatest in the tropical areas, however disturbance and extinction are rapidly threatening diversity

1.9 million species identified

-35% in the tropics

-59% temperate

-6% in boreal and Polar regions

Tropics has about 80 plant species per 0.5 ha while temperate has 9-12, because the climate of the tropics is suityable for more species.

Refers to the dissapearance of a species sttributed to "natural" causes that they could not adapt to in their environemtents-- increased intensity of disease, predation, or competition with other species.

EX: end of the Cretaceous period 65 million years ago resulted in the loss of dinosaurs and flying reptiles totalling 3/4 of the worlds species at the time

In Canada this refers to indigenous species threatened with imminent extinction or extirpation over all or a significant proportion of their Canadian range

More generally this refers to the idea that a small population or loss of habitat increases the risk of species extinction or extirpation.

Refers to the loss of less or unknown species that have not been discovered or named by taxonomists.

This describes the case of many small invertabrates and plants in poorly explorered tropical areas wherein rapid conversion of ecosystems to agricultural land proceeds quicker than scientific exploration.

an ecological term used to describe species with a local geographic distribution...

These species are particularly in danger of extinction when their habitat is converted into agricultural or urban environemtns or with the introduction of alien competitors or predators and virulent disease.

Hawaiian islands are a good example as 100 endemic plants have become extinct and 500 are threatened or endangered.

1. The dodo: an endemic species of flightless bird living only in Mauritius, the dodo disappeared in 1861, making it the first well documented extinction. Tht dodo was hunted for its meat, eggs and destroyed its habitat for agriculture
2. The great Auk: Though this flightless bird was originally exploited by Aboriginals for its meat, eggs and oils, Europeans overharvested it for its feathers that were used to stuff matresses in th 1700s. It disappeared in 1844.
3. The Passanger Pigeon: 3-5 billion population cneturies ago, it was overharvested as a source of meat, the last one died at the Cincinati zoo in 1914.
4. The Right Whale: slow swimming and rich oild ocntent, plus the fact that it floated when it died, it became extirpated from the Eastern Atlantic off Europe due to over hunting, now is endangered in the western pacific off Japan and Korea

1. The American Ivory Billed Woodpecker: Lived in the Southeastern US where it bred in extensive areas of mature hardwood forest... most of this area was heavily logged or converted to agriculture by the early 1900s, and with the exception of a rare citing in 2005, the American Ivory billed woodpecker has not been seen since the 1960s
2. The Black Footed Ferret: lived on the Praries of North America, but because of habitat loss (short grass and mixed grass prarie) that was convereted to agricultural land, it has become extirpated in Canada and endangered in the US. Also its main food source, the prarie dog is commonly poisoned as pest control... leaving the Ferret with little to eat.
3. The Furbish's Lousewort: herbaseous plant that grows only alosg a 250km stretch of the Saint John river valley (New Brunswick - Maine), though the species was considered extinct, it was rediscovered on a proposed dam spot (which was consequently avoided)

• Pre-exploitation numbered 6o million, migrating in extensive herds over much of the Eastern US and the prairies.
• The bison was overhunted for its hides and meat but also because a) agriculture was disrupted by their mass migrations and b) becuase the herds were essential to Aboriginal cultures, the displacemet of the herds made ot easier to colonize their land 
• by 1889 there were less than 1000 bison left in the US and even less on the Canadian Prairies
• Preserves were established and some bison captured to breed,  soon they numbered over 50,000
• In Canada the wood bison is also threatened by interbreeding with Prairie bison, and has begun to get tuberculosis from bovine populaitions.

Three examples of recoveries, other than the Bison

1. The Sea Otter: lives on the West coast of North America, decimated in the 18th and 19th centuries for its fur, and has recently been recovered because of its reintroductions to previously extiprated areas (Vancouver Island) and now there are 100,000.
2. The Pronghorn Antelope: (Western N.America) overhunted in the 19th century reduced to 20,000, but after strong conservation measures numbers 500,000 and is able to be sport hunted.
3. The Wild Turkey: Widely extirpated from its natural range by hunting and habitat loss, but due to conservation and re-inroduction measures has recovered substantially, for example in Ontario and Quebec.

(landscape level) this is concerned with variety pf different communities occuring wihtin an area, as well as with theier relative abundance, size, shape, connections and spatial distribution.

Within Canada there are many landscapes, seascapes and natural communities that are threatened as they are now only remnants (i.e. they are no longer components of robust, extensive, naturally organizing ecosystems)

1. 0.2% of the original area of tall-grass prairie remains, the rest having been converted to agricultural use.
2. Virtually all of the Carolinian forests of S. Ontario have been destroyed by conversion to agriculture or urban areas.
3. Old Growth forest in coastal BC, with dry Douglas Fir type being depleted to about 7% of it original extent, mostyly due to forestry, and subsequent succession of younger forest.
4. wetlands in S. Canada being degraded by pollution, infiklling and other disturbance
5. natural fish populations, including Great Lakes, salmonoid species in western Canada, and cod and redfish off the Atlantic provinces.

Utilitarian value: AKA instrumental value, humans depend on biodiversity for fishing, forestry, agriculture, tourism, outdoor recreation, and biotechnology (medicine and genetic research)

Ex. Yew Tree->taxol->ovarian cancer

or

Rosy Periwinkle->alkaloids->childhood leukemia

Ecological Processes: nutrient cycling, biological productivity, cleansing of water and air, control of erosion, provision of atmospheric oxygen, removal of carbon dioxide, and other functions that are important to maintaining the stability and integrity of ecosystems.

*Not as economically translatable as utilitarian*

Intrinsic Value: the inherent value of all life, independent of the needs of humans , this concern is philosophical.

Worthwile: Based on charisma (Pandas vs frogs), spirituality of certain places (old growth forests), and undiscovered medicinal plants.

*Though this value is also somewhat subjective, it is informing much political action as many people believe that biodiversity is worthy of protection*

Habitat Alteration (forestry, agriculture, hydro power, transportation infrastructure, industry) which results in changing distribution of species-- monoculture of agricultural crops and forestry plantations, transporation fracures populations

1. Urbanization: clearing land for development (removal of species of plants, alters waterways, destroys migraiton routes) also changes ecological balance by introducing new species (greenbelt trees).
2. Fragmentation: (for any of the purposes mentioned) the separation of habitats leaving remant patches behind
3. Climate Change: Chnges in the ecosystem structure due to changes in climate-- ex. the treeline migration which converts meadows into forested area.
4. Chemical Changes: pollution, nitirifcation, acid rain, Eutrification

1. Mercury: from soils under hydro resevoirs introduces mercury to organisms
2. Lead: lead sinkers emit lead into aquatic systems
3. Perisitent organochlorines: from pesiticides and chemicals

All of these are subject to 

A) bioaccumulation: The occurence of chemicals in much higher concentrations in organisms than in the ambient environment 

B) Food-Web Magnification (food web accumulation, food web concentration): The tendency in a food web for top predators to have the highest residues of certain chemicals, expecially organochlorines.

The illegal harvesting of endangered wildlife due to the high economic value of certain species on the balck market. EX black Rhino and Elephant ivory.

The major issue is that the animals being poached are already endangered, and poltical and legal action has been taken. Countries need to be vigilent in their punishment and investigating of poaching.

1. In Situ: Actions taken to conserve ecosystems in place by maintaining and recovering viable species in their usual habitat.... by protecting or recreating large spaces.
2. Ex Situ: Conserve species in artificial conditions, following decline or desturction of habitat 

1. Protected areas: Parks, ecological reserves, and othr tracts of land or water set aside from intense development to conserve their ecological values. However, many of these allow recreational that contradicts ecological imperatives.
2. National Parks: 3% of Canada is national park, however 70% of olant specied and 80% of vertabrate species is represented. These areas are meant to protect the ecological intergrity of  an area--the qualities most likely to persist in a region.

Problems:

1. Marine ecosystems are not well represented
2. National parks privilege species over ecological habitat, which also must be conserved.
3. Tourism pressures conflict with ecological integrity. 

Therefore: Restoration and Rehabilitation are needed: species recovery must be coincided with ecosystem restoration

Conservation of species in artificial conditions due to loss or lack of suitable natural habitat

Pros: Raises public support, do research

Cons: Expensive, animals lose wild instincts, too many animals to conserve this way, interbreeding leads to lack of biodiversity

Plants: Botanical gardens (Canada has 60), seed banks, Heritage seed program

Animals: zoos, aquarians, aviaries, captive breeding programs