Download Topic 1 1.1.1: Outline the concept and characteristics of a system 1

Topic 1
1.1.1: Outline the concept and characteristics of a system
1.Function and interact in some regular, predictable manner.
2.Can be isolated for the purposes of observation and study.
1.1.2: Apply the systems concept on a range of scales
•Small scale local habitat – Scrub habitat
•Ecosystem – The everglades in South FL
•Biome – Tropical Rainforest
•The entire planet – Gaia hypothesis
-all organisms and inorganic surroundings on earth are closely integrated to form a single self
regulating complex system maintaining conditions for life on the planet
1.1.3: Define the terms open system, closed system, isolated system
Open: exchange both matter and energy with surroundings (ecosystem)
Closed: exchange only energy; not matter (nutrient cycles; biosphere 2)
Isolated: exchange neither energy nor matter ( cosmos)
1.1.4: Describe how the first and second laws of thermodynamics are relevant to environmental systems
•1st Law: Energy can be transferred and transformed but it can never be created nor destroyed
–All energy in living systems comes from the sun
–Into producers through photosynthesis, then consumers up the food web
•2nd Law: With every energy transfer or transformation energy dissipates (heat) so the energy
available to do work decreases
–Always less energy at higher trophic levels
-- energy/matter go from concentrated to dispersed
1.1.5: Explain the nature of equilibria
•A sort of equalization or end point
•Steady state equilibrium -constant changes in all directions maintain a constant state (no net change)
– common to most open systems in nature
•Static equilibrium - No change at all – condition to which most natural systems can be compared but
this does not exist
•Long term changes in equilibrium point do occur (evolution, succession)
•Equilibrium is stable (systems tend to return to the original equilibrium after disturbances)
1.1.6: Define and explain the principles of positive and negative feedback
Positive Feedback
Negative Feedback
•A runaway cycle – often called vicious cycles
•A change in a certain direction provides output that further
increases that change
•Change leads to increasing change – it accelerates deviation
Example: Global warming
1.Temperature increases - Ice caps melt
2.Less Ice cap surface area - Less sunlight is reflected away
from earth (albedo)
3.More light hits dark ocean and heat is trapped
4.Further temperature increase - Further melting of the ice
•One change leads to a result that lessens the original change
•Self regulating method of control leading to the maintenance
of a steady state equilibrium
•Predator Prey is a classic Example
–Snowshoe hare population increases
–More food for Lynx - Lynx population increases
–Increased predation on hares - hare population declines
–Less food for Lynx - Lynx population declines
–Less predation - Increase in hare population
1.1.7: Describe transfer and transformation processes
•Transfers : flow through the system, involving a change in location
•Transformation :lead to interactions in the system, changes of state or forming new end products
-Example: Water processes
Runoff = transfer, Evaporation = transformation
Detritus entering lake = transfer, Decomposition of detritus is transformation
1.1.8: Distinguish between flows (inputs and outputs), and storages (stock) in relation to systems.
-Inputs = things entering the system -> matter, energy, information
-Flows / throughputs = passage of elements within the system at certain rates (transfers and
transformations)
-Stores / storage areas = within a system, where matter, energy, information can accumulate for a
length of time (stocks)
-Outputs = flowing out of the system into sinks in the environment
1.1.9: construct and analyze quantitative models involving flows and storages in a system
(practice)
1.Norwegian Salmon Farm 2.Rice Fish Agriculture 3.Sugar Cane Agriculture 4.Scrub Habitat 5.Sewage
Treatment Plant 6.Amazon Rainforest 7.Slash & Burn Agriculture peasant farm in Costa Rica
1.1.10: Evaluate the Strengths and limitations of models
•Used when we can’t accurately measure the real event
•Models are hard with the environment because there are so many interacting variables – but
nothing else could do better
•Allows us to predict likelihood of events
•They are approximations
•They may yield very different results from each other or actual events
•There are always unanticipated possibilities…
•Discontinuities, Synergistic interactions, Chaotic events
2.1.1: Distinguish between biotic and abiotic (physical) components of an ecosystem
–Abiotic – nonliving components
(water, air, nutrients, soils solar energy (insolation))
–Biotic – living components
(plants, animals, microorganisms)Biota
2.1.2: Define trophic level
The position that an organism occupies in a food chain, or a group of organisms in a community that
occupy the same position in food chains.
2.1.3: Identify and explain trophic levels in food chains and food webs selected from a local environment
•Producers (Autotrophs) – Through photosynthesis convert radiant to chemical energy (energy
transformation)
•Consumers (Heterotrophs) – Must consume other organisms to meet their energy needs
–Herbivores, Carnivores, Omnivores, Scavengers, Detritivores
•Decomposers – Break down organisms into simple organic molecules (recycling materials)
TROPHIC LEVEL
ESTUARY SYSTEM
EVERGLADES HABITAT
Producer
Turtle grass
Phytoplankton
Primary consumer
Grass shrimp
Zooplankton
Secondary consumer
Pin fish
Blue gill
Tertiary consumer
Spotted sea trout
Bass
Quaternary consumer
osprey
Raccoon
th
6 trophic level
alligator
2.1.4: Explain the principles of pyramids of numbers, pyramids of biomass and pyramids of productivity, and
construct pyramids from given data
•Graphic models of quantitative differences between trophic levels
•By second law of thermodynamics energy decreases along food webs
•Pyramids are thus narrower as one ascends
–Pyramids of numbers may be different - large individuals at low trophic levels – large forests
–Pyramids of biomass may skew if larger organisms are at high trophic levels - biomass present at point
in time – open ocean
•Energy is lost between each trophic level, so less remains for the next level
–Respiration, Homeostasis, Movement, Heat
•Mass is also lost at each level
–Waste, shedding, …
2.1.5: Discuss how the pyramid structure effects the functioning of an ecosystem
Limited length of food chains
Vulnerability of top carnivores
Biomagnifications
•Rarely more than 4 or 5 trophic levels
•Not enough energy left after 4-5
transfers to support organisms feeding
high up
•Possible exception marine/aquatic
systems b/c first few levels small and
little structure
•Effected by changes at all lower levels
•Small numbers to begin with
•Effected by pollutants & toxins passed
through system
1.Mostly Heavy metals & Pesticides
•Insoluble in water, soluble in fats,
•Resistant to biological and chemical
degradation, not biodegradable
2.Accumulate in fatty tissues of
organisms
3.Amplify in food chains and webs
4.Sublethal effects in reproductive &
immune systems
5.Long term health effects in humans
include tumors, organ damage, …
2.1.6: Define the terms species, population, community, niche and habitat with reference to local examples
1.Population - a group of individuals of a certain species in a given area at a given time: blue crabs in
the Halifax river
2.Community- interacting groups of populations in an area: the scrub community on campus
3.Species - a group of individuals who can interbreed to produce fertile, viable offspring: FL panthers
4.Niche - The role of an organism in its environment (multidimensional): nocturnal predator of small
mammals in the forest
5.Habitat - Where an organism typically lives: mangrove swamps
2.1.7: Describe and explain population interactions using examples of named species
Intraspecific
Interspecific
parasitism
predation
mutualism
commensalism
competition
competition
•Competition
between
members of the
same species for a
common resource
•Resource: food,
space, mates, etc.
• Territoriality
–Organisms patrol
or mark an area
–Defend it against
others
–Good territories
have
•Abundant food,
good nesting sites,
low predator pop.
–Disadvantage =
Energy, Reduce
gene pool
•2 or more
different species
involved
•Competing for
food, space,
sunlight, water,
space, nesting
sites or other
limited resource
•If resources
abundant, they
can be shared but
in nature they are
always limited
•If fundamental
niches overlap competition
•One of the
species must…
1.Migrate if
possible
2.Shift feeding
habits or behavior
= Evolve
3.Suffer a sharp
population decline
4.Become extinct
•One species
feeds on part of
another organism
(the host) without
killing it
•Specialized form
of predation
•Parasite
Characteristics
1.Usually smaller
than the host
2.Closely
associated with
host
3.Draws
nourishment from
& slowly weakens
host
4.Rarely kills the
host
•Examples =
Tapeworms, ticks,
fleas, fungi
•Members of one
species feed
directly on all or
part of a living
organism of a
different species
•Individuals predator benefits,
prey harmed
•Population - prey
benefits: take out
the weak, greater
resource access,
improved gene
pool
•Predator plays
important
ecological role
•Symbiotic
relationship where
both species
benefit
•Pollination,
Nutrition,
Protection are
main benefits
•Not really
cooperation, both
benefit by
exploiting the
other
Examples
1. Lichens – fungi &
algae living together
- food for one,
structure for the
other
2.Plants and
Rhizobium bacteria one gets sugars the
other gets nitrogen
3.Oxpeckers and
Rhinos - food for
one, less parasites
for the other
4.Protists and
•One species
benefits the other
is neither harmed
nor helped
–Examples
1.Herbs growing in
the shade of trees
2.Birds building
nests in trees
3.Epiphytes = “Air
plants” which
attach themselves
to the trunk or
branches of trees
-they have a solid
base to grow on
and better access
to sunlight & rain
termites - break
down wood for one,
nutrients for the
other
2.2.1: List the significant abiotic (physical) factors of an ecosystem
Terrestrial ecosystems
Aquatic life ecosystem
-Sunlight
• Light penetration
• Temperature
• Water currents
• Precipitation
• Dissolved nutrient concentrations (especially N
• Wind
and P)
• Latitude (distance from equator)
• Suspended solids
• Altitude (distance above sea level)
• Salinity
• Fire frequency
• Soil
2.2.2: Describe and evaluate methods for measuring at least three abiotic factors in an ecosystem
terrestrial
Aquatic (specify marine or fresh)
–Light intensity or insolation ( lux) – light meter;
-- Salinity (ppt) – hydrometer; consider role of
consider effect of vegetation, time of day…
evaporation
–Temperature (C) – themometer; take at different –Dissolved Oxygen (mg/L) – DO meter, Winkler
heights, points, times of day, seasons…
titration; consider living organisms, water
–Soil moisture (centibars) – tensiometer of wet
circulation,
mass dry mass of soil; consider depth of soil
–pH – pH probe or litmus paper; consider rainfall
sample, surrounding vegetation, slope…
input, soil and water buffering capacity
–Turbidity (FTU) – Secchi disk or turbidity meter;
consider water movement,
2.3.1: Construct simple keys and use published keys for the identification of organisms
•http://www.earthlife.net/insects/orders-key.html#key
•Sample key for insect ID
•http://people.virginia.edu/~sos-iwla/Stream-Study/Key/Key1.HTML
•Macroinvertebrate key
2.3.2: Describe and evaluate methods for estimating abundance of organisms
Mark and recapture method
Quadrat method
•Used for fish & wildlife populations
-Used for plants or sessile organisms
•Traps placed within boundaries of study area
1.Mark out a gridline along two edges of an area
•Captured animals are marked with tags, collars,
2.Use a calculator or tables to generate two
bands or spots of dye & then immediately released random numbers to use as coordinates and place a
•After a few days or weeks, enough time for the
quadrat on the ground with its corner at these
marked animals to mix randomly with the others
coordinates
in the population, traps are set again
3.Count how many individuals of your study
•The proportion of marked (recaptured) animals in population are inside the quadrat
the second trapping is assumed equal to the
4.Repeat steps 2 & 3 as many times as possible
proportion of marked animals in the whole
5.Measure the total size of the area occupied by
population
the population in square meters
•Repeat the recapture as many times as possible
6.Calculate the mean number of plants per
to ensure accuracy of results
quadrat. Then calculate the population size with
•Marking method should not affect the survival or the following equation
fitness of the organism
7.N = (Mean # per quadrat) (total area) Area of
N = (# marked in first catch) (Total # in second
each quadrat
catch)/
# of Recaptures in second catch
EVALUATION
EVALUATION
You don’t have to count every
single organism in the habitat
Best in closed
environments
Moving Organisms only
You don’t have to count
every single organism in
the habitat
Quadrats that are randomly
placed may never or rarely
sample your target species
Sessile Organisms only
Size must match the size of organisms sampled
2.3.3: Describe and evaluate methods for estimating the biomass of trophic levels in an ecosystem
•Take quantitative samples – known area or volume
•Measure the whole habitat size
•Dry samples to remove water weight
•Take Dry mass for sample then extrapolate to entire trophic level
•sample biomass / sample area = total biomass / total area
–all individuals at that trophic level are the same
–The sample accurately represents the whole habitat
–But it prevents you from killing the whole trophic level to get your measurement
2.3.4: Define the term diversity
Often considered as a function of two components: the number of different species & the relative
number of individuals of each species
2.3.5: Apply Simpson’s diversity index and outline its significance
D = N (N – 1)
Σ n (n – 1)
•Where D = diversity index
N = total # of organisms of all species
n = # of individuals of particular species
•High values of “D” suggests a stable and ancient site
•A low value of “D” could suggest pollution, recent colonization, or agricultural management
•Index normally used in studies of vegetation but can be applied to comparisons of diversity of any
species
•2.4.1: Define the term Biome
Regions of the earth characterized by specific climates and community types
•Real biomes do not have sharply defined boundaries. Ecotones = Transitional zones
•Biomes not uniform, instead a mosiac of patches
–Vary in microclimate, soil types, disturbances
•2.4.2: Explain the distribution, structure and relative productivity of tropical rainforests, deserts, tundra and
any other biome
tundra
Temperate
deserts
Tropical rainforest
grasslands
•Precipitation < 15 cm /
•Precipitation 25-45 cm •Precipitation < 25 cm /
•Precipitation over 150
Climate
yr – mostly snow &
summer rain Arid
•Bitter cold: -57 – 50 C permafrost
•low insolation gives
short growing season
distribution
•60 – 75 N latitude –
northern North America,
Asia, Greenland
•About 20% of the
earth’s surface
Structure
•Simple – low spongy
mat of vegetation,
/ yr – enough to grow
grass, erratic Semiarid
•fire, drought, animals
prevent tree growth
•May be Tropical,
Temperate
•Moderate insolation
•9% of earth surface Temperate Latitudes –
Major onesNA tall grass
prairie, steppes,
pampas, veldt
•Grasslands overall up
to 40% of earth’s
surface
•Simple – grasses and
herbaceous plants
yr – scattered unevenly
through year Arid
•May be Tropical,
Temperate and Cold
types – always extremes
•High to moderate
insolation
•30% of earth surface between 30 degrees
north and south of the
equator – Major ones
Saraha (Africa), Gobi
(Asia), Mojave (N.
america)
cm / yr – Wet – still rainy
and dry seasons
•Warm humid year round
climate - 80 F
•high insolation gives long
growing season
•Simple – very little
vegetation
•Complex – stratified
layers
•23.5 N to 23.5 S latitude
– Tropic of Capricorn to
Cancer
•About 2% of the earth’s
surface
•Three chunks – S. & C.
America, C. Africa, SE Asia
Relative
productivity
lichens, mosses
•Even trees are less than
knee high
•Low – limited by
temperature and
insolation
•Medium to high – high
turnover of grasses,
rich soils
•Most complex is
temperate desert which
has largest cacti
•Low – limited by water
availability
•High diversity - 50-80% of
terrestrial species
•Highest in terrestrial
system – unlimited by
temperature and
insolation
2.5.1: Explain the role of producers consumers and decomposers in an ecosystem
•Producers (Autotrophs) – Through photosynthesis convert radiant to chemical energy (energy
transformation)
•Consumers (Heterotrophs) – Must consume other organisms to meet their energy needs
–Herbivores, Carnivores, Omnivores, Scavengers, Detritivores
•Decomposers – Break down organisms into simple organic molecules (recycling materials)
2.5.2: Describe photosynthesis and respiration in terms of inputs, outputs and energy transformations.
2.5.3: Describe and explain the transfer and transformation of energy as it flows through an ecosystem
•30% solar energy reflected back into space by atmosphere, clouds, ice
•20% absorbed by clouds & atmosphere
•50% remaining
–Warms troposphere and land
–Evaporates and cycles water
–Generates wind
•< 0.1% captured by producers for photosynthesis
•Energy eventually transformed to heat and trapped by atmosphere “Natural Greenhouse Effect”
•Eventually reradiated into space
2.5.4: Describe and explain the transfer and transformation of materials as they cycle within an ecosystem
2.5.5: Define the terms gross productivity, net productivity, primary productivity, and secondary productivity
1.gross productivity – total biomass produced
2.net productivity – total biomass produced minus amount used by organism
3.primary productivity – productivity at 1st trophic level
4.secondary productivity – productivity at higher trophic level
5.gross primary productivity – rate at which producers use photosynthesis to make more biomass
6.net primary productivity – rate at which energy for use by consumers is stored in new biomass
2.5.6: Define the terms and calculate the values of gross primary productivity (GPP) and net primary
productivity (NPP) from given data.
•Gross Primary Production (GPP) - Amount of light energy converted into chemical energy by
photosynthesis per unit time
–Joules / Meter2 / year
•Net Primary Production (NPP)- GPP – R, or GPP – some energy used for cell respiration in the primary
producers
•Represents the energy storage available for the whole community of consumers
•Standing crop = Total living material at a trophic level
•NPP = GPP – R
2.5.7: Define the terms and calculate the values of gross secondary productivity (GSP) and net secondary
productivity (NSP) from given data.
•Gross Secondary Productivity (GSP) - Total gain by consumers in energy or biomass per unit area per
unit time through absorption (What they eat, digest and absorb)
•Net Secondary Productivity (NSP) - The gain by consumers in energy or biomass per unit time
remaining after allowing for respiratory losses (R)
•GSP = Food eaten – fecal losses
•NSP = change in mass over time
•NSP = GSP – R
2.6.1: Explain the concepts of limiting factors and carrying capacity in the context of population growth
•Capacity for growth = Biotic potential
•Rate at which a population grows with unlimited resources is intrinsic rate of increase (r)
•High (r) - (1)reproduce early in life, (2)short generation time, (3)multiple reproductive events, (4)many
offspring each time
•Environmental resistance = all factors which limit the growth of populations
•Population size depends on interaction between biotic potential and environmental resistance
•Carrying capacity (K) = # of individuals of a given population which can be sustained infinitely in a
given area
•Carrying capacity established by limited resources in the environment
•Only one resource needs to be limiting even if there is an over abundance of everything else
•Ex. Space, food, water, soil nutrients, sunlight, predators, competition, disease
2.6.2: Describe and explain s and J population curves
•Exponential growth - starts slow and proceeds with increasing speed
– J curve results
–Occurs with few or no resource limitations
•Logistic growth - (1) exponential growth, (2) slower growth (3) then plateau at carrying capacity
– S curve results
–Population will fluctuate around carrying capacity
2.6.3: Describe the role of density-dependent and density-independent factors and internal and external
factors, in the regulation of population
•Density Independent Factors: effects regardless of population density
•Mostly regulates r-strategists
–Floods, fires, weather, habitat destruction, pollution
–Weather is most important factor
•Density dependent Factors: effects based on amount of individuals in an area
•Operate as negative feedback mechanisms leading to stability or regulation of population
External Factors
–Competition, predation, parasitism
–Disease – most epidemics spread in cramped conditions
Internal Factors
–Reproductive effects - Density dependent fertility, Breeding territory size
2.6.4: Describe the principles associated with survivorship curves including K and r-strategists
•Two idealized categories for reproductive patterns but really it’s a continuum
•r-selected & K-selected species depending on position on sigmoid population curve
•r-selected species: (opportunists) reproduce early, many young few survive
–Common after disturbance, but poor competitors
•K-selected species: (competitors) reproduce late, few young most survive
–Common in stable areas, strong competitors
•Different life expectancies for different species
•Survivorship curve: shows age structure of population
1.Late loss curve: K-selected species with few young cared for until reproductive age
2.Early loss curve: r-selected species many die early but high survivorship after certain age
3.Constant loss curve: intermediate steady mortality
2.6.5 – Describe the concept and process of succession in a named habitat
•Ecological Succession: the gradual change in species composition of a given area over time
•Species do change spatially within an area at a certain point in time, this is zonation not succession
•2 Types depending on start point
–Primary succession: gradual establishment of biological communities on lifeless ground
–Secondary succession: reestablishment of biotic communities in an area where they already existed
2.6.6 – Explain the changes in energy flow, gross and net productivity, diversity and mineral cycling in
different stages of succession
1.Diversity
•Starts very low in harsh conditions few species tolerate – r selected species types
•Middle succession mix of various species types – most diverse (role of disturbance)
•Climax – k selected species strong competitors dominate
2.Mineral Cycling
•Pioneer, physical breakdown & make organic, Later processing increase – cycles expand
3. Gross productivity changes (total photosynthesis)
•Pioneer = Low density of producers at first
•Middle & climax = high - lots of producers and consumers
4. Net Productivity (G – R = N)
•Pioneer = little respiration so Net is large - system is growing, biomass accumulating
•Middle & climax = respiration increases dramatically - N approaches zero (P:R = 1)
5. Energy flow
•# of trophic levels increases over time
•Energy lost as heat increases with more transfers
2.6.7 – Describe the factors affecting the nature of climax communities
•Characterized by K-selected species
•Determined by
–climate in the area – temperature, weather patterns
–Edaphic factors – saturated wet, mesic, arid
•Climax community structure is in stable equilibrium for each area
•Humans & other factors may maintain an equilibrium below climax
–E.g. current warming trends make climax rainforest communities w/ softer wood, faster growing
species
2.7.1 – Describe and evaluate methods of measuring change in abiotic and biotic components of an
ecosystem along an environmental gradient
•Biota = living organisms
•Change in benthic (bottom) community of rocky intertidal with increased depth
•Gradient in moisture or drying
•Use modified quadrat method
–run transect into deeper water
–At set depths place quadrat and sample organisms
–Do repeated transects along your sample area
–Calculate differences in communities with depth
Abiotic – pick the variable and test samples at different depths
2.7.2: Describe and evaluate methods for measuring change in abiotic and biotic components of an
ecosystem due to a specific human activity
•Measure a comparable area at
•Pre and Post impact assessment Measuring the effects of Eutrophication
•A Method
the same time
1.In the area where the impact
•Compare two ponds of comparable
size, habitat etc that differ in proximity
1.Pick an area with similar habitat
will take place
to a cattle feed lot
characteristics as your impacted
2.Do steps 2•Variables to study = DO, algal density
area
3.Start a reasonable amount of
•Take satellite images before and after
if possible but specifically over time and
2.Pick an index to use
time before the impact and
see changes in turbidity in both ponds
-Biotic: population numbers,
continue afterwards
•Sample fixed volume of water and filter
biodiversity, etc
out algae – calculate density changes
over time
-Abiotic: chemical test, DO, specific
•Sample remaining water for DO use as
pollutant
a means of doing BOD experiment
•In each case T-tests will show you if the
3.Choose an appropriate sampling
ponds are different
method (CMR, quadrat)
•Evaluate
4.Monitor over time and compare
• Other factors like temp can effect DO
•Satellite images can be inaccurate
changes
•Eutrophication is part of natural
aquatic succession
•GOOD - These variables are good
indicators of the amount of
eutrophication that is happening
2.7.3: Describe and evaluate the use of environmental impact assessment (EIAs)
•An EIS typically has four sections:
•An Introduction including a statement of the Purpose and Need of the Proposed Action.
•A description of the Affected Environment.
•A Range of Alternatives to the proposed action. Alternatives are considered the "heart" of the EIS.
•An analysis of the environmental impacts of each of the possible alternatives.
•While not required in the EIS, the following subjects may be included as part of the EIS or as separate
documents based on agency policy.
•Financial Plan for the proposed action identifying the sources of secured funding for the action. For
example, the Federal Highway Administration has started requiring states to include a financial plan
showing that funding has been secured for major highway projects before it will approve an EIS and
issue a Record of Decision.
•An Environmental Mitigation Plan is often requested by the Environmental Protection Agency (EPA) if
substantial environmental impacts are expected from the preferred alternative.
•Additional documentation to comply with state and local environmental policy laws and secure
required federal, state, and local permits before the action can proceed
Steps will include pre, during and post impact assessments
1.Produce a baseline study to see how the environment is in a natural state (done before any
environmental development)
2.Assessment of possible impacts
3.Monitor change during the development
4.Monitor change after the development
3.1.1: Describe the nature and explain the implications of exponential growth in human populations
•Reasons for the Human Population Explosion
•Death rates dropping faster because of
•Causes of disease recognized
•Improvements in nutrition
•Discovery of antibiotics
•Improvements in medicine
•Increase in number of women who actually reach child-bearing age
Implications of Exponential Growth
–Biotic potential exceeds environmental resistance: birth rates exceed death rates
–Outstrip our resource base – nonrenewable gone, renewable maybe used faster than replaced
–Increase strain on the environment – pollution, sanitation needs, biodiversity loss
–Increase food production & land under production
3.1.2: Calculate and explain, from given data, the values of crude birth rate, crude death rate, fertility ,
doubling time and natural increase rate
•3 factors effecting population birth, death, & migration
•Population change = (Birth + Immigration) – (Deaths + Emigration)
•Rates more often used
•Crude Birth rate = # live births / 1000 people in year population
•Crude Death rate = # deaths / 1000 people in year population
-(CBR – CDR)/10 = Rate of increase or decrease in population per 1,000 per year
-70/Rate of Increase = Doubling Time
3.1.3: Analyze age/sex pyramids and diagrams showing demographic transition models
•Analysis by sex, of the proportion of population at each age level
•3 main age categories
–Prereproductive: 0 – 14 years
–Reproductive: 15 – 44 years
–Postreproductive: 45 and up
•Represent a good comparison between countries
•Compare Growth - Rapid, Slow, Zero, Negative
3.1.4: Discuss the use of models in predicting the growth of human populations
•As countries become industrialized first death rate then birth rate will decline
1.Preindustrial Stage - harsh living conditions = little population growth, high B & D
2.Transitional Stage - industrialization starts, better healthcare & food = population growth is rapid,
high B & lower D
3.Industrial Stage - Industry continues = population grows but slowly, B > D by a little
4.Postindustrial Stage - population growth stops, B = D (13% of world) then B < D an may start to
decline (this may be stage 5)
3.2.1: Explain the concept of resources in terms of natural income
•Term coined by ecologically minded economists
•If properly managed renewable & replenishable resources are forms of wealth that can produce
“natural income”
•“natural income” = indefinitely available valuable goods and services (based off of renewable and
replenishable)
–Marketable commodities or goods (timber, grain)
–Ecological / Life-support services (flood & erosion protection from forests)
•Non-renewable resources = forms of economic capital that cannot generate wealth without being
liquidated
3.2.2: Define the terms renewable, replenishable, and non-renewable natural capital
3.2.3: Explain the dynamic nature of the concept of a resource
•Cultural, economic, and technological factors influence a resource’s status over time and space
•Uranium – never valued, but with advent of nuclear technologies now extremely valuable
•Bluefin Tuna – prior to 1970 exclusively sport fish (.05 / lb) - Japanese specialty market develops –now
a single large fish has sold for $180,000
•Solar Power – 1960s space race makes it important - 1970s oil embargo makes it critical - 1990s
competes with dropping oil prices - now peak oil and increasing price make it desirable again
3.2.4: discuss the view that the environment can have its own intrinsic value
•Ecological, Economic, Aesthetic value
•Value assigned based on diverse perspectives
•Industrial Societies emphasize monetary & economic valuations of nature
•Economic value determined by market price of goods or services produced
•Extrinsic Values
•It does have intrinsic value though
•May not provide goods or services identifiable as commodities so they are undervalued
•Ecological processes have no formal value
•Still important though - waste elimination, flood & erosion control, nitrogen fixation, photosynthesis
•Essential for existence but taken for granted
•Value from spiritual, ethical, or philosophical perspective
3.2.5: Explain the concept of sustainability in terms of natural capital and natural income
•Living within the means of nature, on the interest or sustainable income generated by natural capital
•Societies supporting themselves by depleting essential forms of natural capital are unsustainable
•If well being dependent on certain goods or services must harvest with care
•Specifically long term harvest or degradation (pollution) should not exceed rates of capital renewal
3.2.6: discuss the concept of sustainable development
•Term first used in 1987 in Our Common Future
•Development that meets current needs without compromising the ability of future generations to
meet their own needs
•Economist view - stable annual return on investment regardless of environmental impact
•Environmentalist view - stable return without environmental degradation
The Earth Summit (1992) and its aftermath
•Rio de Janeiro Conference on the Environment and Development
•Agenda 21 - focus on sustainable development for the 21st century
•Followed by 2002 world summit on sustainable development in Johannesburg
3.2.7: Calculate and explain sustainable yields from given data and use
•Sustainable Yield = SY
•SY = Rate of increase in natural capital
•Amount to exploit without depleting initial stock or potential for replenishment
•SY for a crop = annual gain in biomass or energy
•These gains from growth or recruitment (production of offspring)
3.3.1: Outline the range of energy resources available to a society
Non-renewable
•Fossil fuels coal, oil, natural gas •Nuclear - fission, fusion
Renewable
•Solar passive, active •Hydroelectric •Geothermal •Wind
•The relative use of different forms depends on the particular area, its needs and its own available
resources
3.3.2: Evaluate the advantages and disadvantages of two contrasting energy sources
3.3.3: Discuss the factors that affect the choice of energy sources adopted by different societies
•Iceland uses geothermal energy because of their location and its low environmental impacts
•China, US, Russia use coal because they have a lot of it available and it’s cheap economically
•US dependence on oil is cultural because of our insistence on cars, suburbs, bigger, more, better
•EU more nuclear power use because of environmental benefits and they have the technology to do it
•LDCs use wood, dung other biofuels that are easily collected
3.4.1: Outline how soil systems integrate aspects of living systems
•Links to lithosphere, atmopshere, and living organisms
•What are they?
•Inputs - organic materials, parent materials, precipitation, infiltration, Energy
•Outputs - leaching, uptake by plants, mass movement
•Transfers - deposition
•Transformations decomposition, weathering & nutrient cycling
•Surface litter = O horizon
–Fresh and partly decomposed organics
•Topsoil layer = A horizon
–Humus mixed with inorganics
–Most life in O & A
•Subsoil = E top, B horizon
–Broken down Inorganics
•Parent material (bedrock) = C horizon
3.4.2: Compare and contrast the structure and properties of sand, clay, and loam soils including their effect
on primary productivity
3.4.3: Outline the processes and consequences of soil degradation
•Lead to degradation by erosion, toxification, salinization, desertification
Overgrazing
Deforestation
Unsustainable Ag
Irrigation
– plants exposed to
intensive grazing over long
periods of time or without
sufficient recovery period
•Reduces Biodiversity
•Causes Desertification and
Erosion
•Increases Erosion by loss of
cover species and loss of
roots that held the soil in
place
•Erosion leads to loss of
organics and drop in
productivity
•In marginal lands this may
lead to desertification as
grassland becomes desert
when productivity
plummets
- Removal of large sections
of forest habitat
•Increases rates of erosion
by increasing runoff and
reducing litter protection on
the surface
•Roads created and
machinery used also
increases erosion
•Roots may hold soil in place
and canopies may disperse
the force of percipitation
•On steep slopes
deforestation can cause
landslides
– Monoculture using high
chemical & fertilizer input
and fossil fuels
•Characteristics of Modern
Agriculture
–High water input
–High pesticide use
–High inorganic fertilizer use
•Traditional agriculture
where soil is tilled at the end
of a growing season
•Idea good in practice – add
nutrients to the soil – but
bare soil exposed to erosion
•Tillage also deteriorates soil
structure
•Can cause increased
erosion, toxification and
salinization
– especially done in arid
areas b/c evaporation leaves
everything but H2O behind
•Often results from
unsustainable agriculture in
areas that are too arid
•Remember that water
includes more than just H2O
–Improper drainage or high
evaporation leads to salt
deposition - crop damage,
reduction of productivity
–Unirrigated or
underirrigated land can lead
to build up of toxic
agricultural waste products
Erosion
Toxification
salinization
desertification
•Erosion = the movement of
soil components especially
surface litter and topsoil,
from one area to another
•Caused by WIND and
WATER
•Plant roots usually anchor
soils in place
•Effects
1.Loss of soil fertility and
water holding capacity
2.Runoff sediment pollutes
water, kills organisms, clogs
ditches, channels, lakes
3.Increased use of fertilizers
4.Increased runoff and
flooding
–Toxification of Soil
–When nonbiodegradable
pesticides and inorganic
fertilizers build up in the soil
they make it toxic
–Kills useful bacteria (N
fixing) fungi, and decreases
productivity
–Can also result from release
of toxic metals like Al+3
when acidity increases (N
based fertilizers mixing with
water forming Nitric Acid)
•Irrigation increases
productivity BUT Irrigation
water contains salts
•Evaporation leaves crust of
salts on surface
•Accumulation of salts =
salinization
–Stunts crop growth
–Lowers crop yields
–Kills plants and ruins land
•Reduced crop yield by 21%
on irrigated land
•Desertification enlargement of deserts
through human activities
•The productive potential of
arid or semiarid land falls by
10% due to
1.Natural climate change prolonged drought
2.Human activities reducing
& degrading soil
Moderate = 10-25%
productivity drop
•Severe = 25-50% drop
•Very severe >50% drop =
sand dunes & gullies
3.4.4: Outline soil conservation measures
•Goal: Reduce soil erosion, restore fertility
•Conventional Tillage Farming is bad plow land in the fall, bare & erodable all winter
•Conservation Tillage Farming disturb the soil as little as possible while planting crops
•Minimum tillage or No till farming
•Using conservation tillage on 80% of farmland would reduce soil erosion by 50%
•Stop ploughing / planting on marginal land
•Fertilizers: compounds that partially restore important soil nutrients lost by erosion, leaching and
harvesting crops
•Condition soils with
–Organic Fertilizers: made of plant and animal materials
–Lime: Increase alkalinity of the soil improves fertility
–Inorganic fertilizers: only add in N, P, K nothing else that good, mature soils require
Terracing
Contour plowing
Alley cropping
Shelter beds/wind belts
–Convert steep slopes into a
series of broad, nearly level
terraces running across the
land contour
–Plowing and planting crops
in rows across the contour of
gently sloping land
–Each row holds soil and
-Crops planted in strips or
alleys between rows of trees
and shrubs which themselves
are harvestable for wood or
Reduce wind effects
1. Less erosion
2. Retain soil moisture
3. Supply products
–Retains water for crops
controls runoff
–Marginal areas, Poor
farmers, little time /
manpower
slows runoff
fruit
-Trees & shrubs provide
1. Shade, reducing
evaporation water loss
2. Retain and slowly release
soil moisture
3. Provide fruit, fuelwood,
clippings for mulch (green
manure)
4. Livestock fodder
4. Habitat for animals
including birds and insects
that eat pests
3.4.5: Evaluate soil management strategies in a named commercial farming system and in a named
subsistence farming system
Florida sugar cane farming (commercial farming)
Tropical slash and burn (subsistence farming)
•Soils of everglades Agricultural area are rich in
•Mainly associated with Tropical Rainforest areas
organics formed from 4,400 years of sawgrass
(Madascar, Malasia, Central America)
decomposition
•Usually small scale subsistence
•Soils are “muck soils” and must be drained for crop
•Practiced in areas with poor soils
growth
•Harvest wood, burn unusable portions
•Even with high organic matter need inputs to keep
•Temporary pulse of nutrients from burning
soil fertile – N, P, K all added on the order of 0-30 lbs •Ash also increases pH of soil
per acre each year depending on specific area
•Burning can drive off pests too
differences
•Land only fertile for a few years
•Soil subsidence happening because of uptake of
•Abandoned when fertility declines
organics
•Forces burning of more land
•Water is seasonally available so may need
suplementation
3.5.1: Outline the issues involved in the imbalance in global food supply
DISTRIBUTION OF FOOD
•Enough food produced in the
world for entire population to
have 2,720 kcal per day
•Many areas no land to grow
food or money to purchase it
•982 million people living in
poverty – actually a decrease
in 20% from 1990’s
•¼ of the world population
consumes ¾ of the food
ECOLOGICAL INFLUENCE
•Developed countries in
temperate areas – plants and
soils conducive to growth of
high yield cereal crops and
livestock
• Soil fertility poor in tropical
areas
•Livestock native to temperate
areas in most cases as well
SOCIOPOLITICAL INFLUECE
•Poverty is a self sustaining
positive feedback process
•Governments in LDCs focus
on exploitation of resources –
Bananas in Costa Rica
•Governments in developed
nations subsidize fossil fuels
•Support use of high yield
green revolution crops
•Research on and use of GMOs
ECONOMIC INFLUENCE
•Fossil fuels & technology
require $$$
•Meat in the diet requires
more $$$
•Luxury foods
3.5.2: Compare and contrast the efficiency of terrestrial and aquatic food production systems
Terrestrial
Aquatic
•Most food at low trophic levels
•Most food harvested at higher trophic levels
•Producers or Herbivores
•Makes total energy storages smaller
•Less energy loss between initial input and level of
•Due to tastes for fish / particularly large predatory
harvest
ones
•Energy conversion in this system is more efficient –
sizes and lack of structural material in low trophic
levels
•Initial amount of sunlight fixed is less efficient
because of reflection and absorption by water
3.5.3: Compare and contrast the inputs of materials and energy (energy efficiency), the system
characteristics, and evaluate the relative environmental impacts of two named food production systems
•There are many food production systems around the world
•They vary depending on the geography, sociopolitical dimensions, culture, needs of the area
•They also vary based on the characteristics of the food being produced
•We will look at a comparison of two of these many systems
•Many areas of the world are dependent on fisheries for food
•Fish is a major component of the human diet
•Some countries almost exclusively based on seafood – Japan
•With wild stocks being increasingly depleted, we are turning to fish farming for various reasons as an
alternative
Rice-Fish Farming - China
•Fish farming in wet rice fields
•In China, Han Dynasty plate (2000 years old) shows fish
swimming from pond to field
•Ecological symbiosis in the system – fish provides fertilizer to
rice, regulates micro-climatic conditions, softens the soil, disturbs
the water, and eats larvae and weeds in the flooded fields; rice
provides shade and food for fish.
•Provides balanced food, reduced costs and labor, less use of
chemicals in the environment
Inputs – All fish food is in the system, small fish left behind as
stock for next year rice requires input of small amounts of urea,
N,P,K and optional lime or manure
System Characteristics – uses native fish, polyculture using
natural principles of ecosystem interaction, sustainable
Socio-cultural - tenant farmers improve income, in china
industrialization threatens its continued use
Environmental Impacts – may use pesticides but generally less
than alternatives, reducing CH4 emissions compared to normal
systems
Outputs – fish and rice, 2 rice crops per year
Norwegian salmon Farms
•Norway and Chile produce 2/3 of the world’s farmed salmon
•60% of world’s salmon is farmed
•High input system of penned fish in ocean areas or on land –
depends on pellet food derived from wild caught fish
•High density high waste systems
Inputs – need pellets for feed made from fishing for smaller fish
in the ocean
System characteristics – monoculture – disease susceptible so
antibiotics used, may selectively breed stocks, human
manipulated
Socio-cultural – farming operations provide local jobs, if effecting
local fisheries that effects jobs as well
Environmental Impacts – 100,000’s escape cultivation & threaten
native fish, farmed fish less effective reproducers than natural
but their offspring are more successful
Outputs – antibiotics, nutrients causing eutrophication
3.5.4: Discuss the links that exist between social systems and food production systems
Modern US
Asia Rice Field System
–Developed, high tech, high fossil fuel input
–Value speed and convenience
–Capitalism based revenue generation
–Removed from food production so don’t see negative results
–We are willing to compromise environmental health for the
benefits now from pesticides, inorganic fertilizers, machine
harvest etc.
•3.6.1: Describe the Earth’s water budget
Fresh water
•97.4% of water is saline
•Remaining 2.6% fresh water
–80% is in ice caps & glaciers
–0.59% inaccessible ground water
•Remaining 20% of fresh water is in lakes, soil water,
water vapor, rivers and biota in order of decreasing
amount stored
•0.014% of the total available for use
•Patchy distribution on earth Canada = 20% of total,
China = 7%
–Tied to asian cultures as a historical practice
–But asian culture is changing more cosmopolitan more
movement to cities
–Could threaten this model system
–It is a form that keeps soil fertility high in areas with high
population density this can be used on the outskirts to maximize
production per area.
•Worldwide 70% of reliable water from surface and
ground for Irrigation
–18% of crop land producing 40% of world food
•Industry uses 20%
•Residential use 10%
•Consumptive water use water not reusable in basin
it came from – evaporation or pollution
•Global Warming may disrupt rainfall patterns and
water supplies
•3.6.2: Describe and evaluate the sustainability of freshwater resource usage
Facts
Sources
•Humans get fresh water from the hydrologic cycle
•We are withdrawing/ degrading water sources with waste at a faster rate than it is being replenished
•Demand is increasing
1.Surface water
-Precipitation that does not infiltrate the ground or return to atmosphere
-Forms wetlands, lakes, rivers & resevoirs
uses
Case
study
Colorado
River
solutions
-1/3 of total runoff = reliable runoff a steady source of water
-Watershed or drainage basin is a region of runoff flowing into a surface water body
2.Groundwater
-Precipitation infiltrates, percolates and fills voids in soil and rock
-Zone of saturation = depth where voids are filled
-Top of zone of saturation is water table
-Above = zone of aeration
-Porous layers where groundwater flows are aquifers
-Recharge zone = area where water returns to aquifer
•Provide drinking water for 1/3 world’s people
•U.S. - 51% drinking water, 43% of irrigation water from aquifers
•Over pumping largely since 1950
•US groundwater is being withdrawn 4X faster than it is being replaced
•Also being degraded with pollutants that leach in from agriculture & other systems
Disadvantages
Water table lowering, Aquifer depletion, Aquifer subsidence (sinkholes), Salt water intrusion, Reduced stream flow
Advantages
Tapping aquifer can be done year round, Not lost by evaporation, Less expensive to develop
•6 states and 2 countries depend on water from this system
•Colorado River compact formed to execute interstate agreements
•Divided into upper and lower basin areas
•Allocated 7.5 MAF each (million acre flow)
•Lower basin almost maxed out, upper less developed and less used
•Water is held behind dams and transported in aqueduct systems
•Large surface area exposed for evaporation
•Current growth in areas like NV will exceed ground and river water in 10 years – where will they borrow from?
•Glen Canyon Dam being decomissioned to limit evaporation
•River is dry by the mexican border now
•Some historical droughts have limited flow to 9.5 MAF in the entire river
1.Desalinization - 2 methods distillation & reverse osmosis
–13,300 desalinization plants worldwide
–Expensive and high energy, produces brine
2.Water conservation
•65% of water used is wasted through evaporation, leaks & losses
•Causes of waste
–Water subsidy policies – low prices discourage conservation
–Water laws – legal rights of water users
–Fragmented watershed management – different distributors
3.Improved Irrigation
•57% irrigation water never reaches target crops – flood irrigation method
–Center pivot low pressure sprinklers, Low energy precision application. Time controlled valves, Soil moisture detectors
water only when necessary, Drip irrigation systems
3.7.1: Explain the difficulties in applying the concept of carrying capacity to local human populations
•Environmental resistance = all factors which limit the growth of populations (limiting factors)
•Population size depends on interaction between biotic potential and environmental resistance
•Carrying capacity (K) = # of individuals of a given population which can be sustained indefinitely in a
given area
•Should be able to estimate this by examining the requirements of a species and the resources
available in the environment
1.Use a wide range of resources
2.If a resource becomes limiting humans readily substitute others
3.Requirements vary according to lifestyle (Differ in time, by populations, by areas)
4.Technology impacts resources used and available
5.Import and export moves resources beyond local boundaries
-Import and export change K for an area but have no impact on its global level
3.7.2: Explain how reuse, recycling, remanufacturing and absolute reductions and material use can affect
human carrying capacity
•Human carrying capacity determined by
–Rate of energy and material consumption
–Extent of human interference in global life support systems – environmental degradation
–Levels of pollution created
•Recycling, Reuse and Remanufacturing
–Reduce these impacts
–BUT can increase carrying capacity as well
•Reduce
–Absolute reductions in energy and material consumed are necessary – do you really need another pair
of ____________, hot water use….
•Reuse
–Replace disposable society with multi use system – refillable bottles, tool banks
•Recycle
–Feedback management type – waste is a raw material to be used – curbside collection, metals are
profitable
3.8.1: Explain the concept of an ecological footprint as a model for assessing the demands that human
populations make on their environment
•Model for quantifying the demands that human populations make on their environment
•The area of land in the same vicinity as the population that would be required to provide for all of the
population’s resources and assimilate all of it’s wastes
•It is the inverse of the carrying capacity
3.8.2: Calculate from appropriate data the ecological footprint of a given population, stating the
approximations and assumptions involved
•Calculations are approximations
•Total area required is the sum of these two per
capita requirements multiplied by total
population
•ignores land and water needed
–for aquatic and atmospheric resources
–for the assimilation of waste other than CO2
–For production of energy or materials needed to
support arable land in an area
–To replace productive land lost by urbanization and so on
3.8.3: Describe and explain the differences between the ecological footprints of two human populations, one
from an LEDC one from an MEDC
LEDC
MEDC
•less economically developed country: a country
•more economically developed country: a highly
with low to moderate industrialization and low to
industrialized country with high average GNP per
moderate average GNP per capita
capita
•Congo DR
•The United States
•Footprint = .7 hectares
•Footprint = 9 hectares
•Almost 100% land for food and fiber growth
•~6/9 is carbon sink
•In general 2x as much diet energy in animal
products
•More grain b/c intensive agriculture
•More fossil fuel use
3.8.4: Discuss how national and international development policies and cultural influences can affect human
population dynamics and growth
Policies targeting death rate
Policies targeting birth rate
- Stimulate rapid growth
–Economic growth itself may lead to decreasing birth
–Agricultural development
rates (Demographic Transition Hypothesis)
–Improving public health and sanitation
–Education about birth control
–Improved service infrastructure
–Family planning service development
•These policies lower mortality without significant
–Increasing women’s education - more economic &
effects on fertility
•Examples = Oxfam, UNICEF
personal freedoms
–Removing parental dependence on children in old
age
3.8.5: Describe and explain the relationship between population, resource consumption and technological
development, and their influence on carrying capacity and material economic growth.
•Carrying capacity may be expanded through continuous technological innovation
•Increase efficiency of energy & material use 2X - double use or population without increasing impact
•But with population growth predictions and necessary economic growth - efficiency will have to
increase 4X to 10X to compensate
•Remember that sometimes technology itself can tax carrying capacity too
•New resources can be imported with transportation technology
•Globally technology is used to intensify food production systems (GMOs, green revolution crops)
•Developing alternative energy technologies
•Technology can reduce populations as well
•Attitudes on resource use must change too because technology is not enough.
4.1.1: Define the terms biodiversity, genetic diversity, species diversity, habitat diversity
1.Biodiversity = the amount of biological or living diversity per unit area. It includes the concepts of
species diversity, genetic diversity and habitat diversity
2.Genetic diversity = the range of genetic material present in a gene pool or population of a species
3.Species diversity = variety among species per unit area. Includes both the number of species present
and their abundance.
4.Habitat diversity = The range of different habitats or number of ecological niches per unit area in an
ecosystem, community or biome. Conservation of habitat diversity usually leads to conservation of
species and genetic diversity
4.1.2: Outline the mechanism of natural selection as a possible driving force for speciation
•Natural Selection = survival of the fittest
•Fitness = a measure of reproductive success
•If all individuals are variable; And populations produce large numbers of offspring without increase in
population size; And resources are limited; And traits are heritable
•Then those individuals who are best adapted to the environment will survive and pass on their genes
•Gradually the gene frequency in the population will represent more of these “fit” individuals
-Environmental Pressures select for some genotypes over others
-Alleles resulting in a beneficial trait will become more common
-Heritable traits that increase survival chances are called adaptations
-There are many niches or habitats and roles available in the environment
-As populations adapt they fill new niches and over time may develop into new species
4.1.3: State that isolation can lead to different species being produced that are unable to interbreed to yield
fertile offspring
the same species are isolated for long periods
–A group may migrate in search of food to an area
with different environmental conditions
–Populations may be separated by a physical barrier
(mountain range, river, road)
–Catastrophic change by volcano eruption or
earthquake
–A few individuals carried away by wind or water to
new area
selection operate independently on the 2
populations to change allele frequencies =
divergence
•If divergence continues long enough genetic
differences may prohibit (1) interbreeding between
populations and/or (2) production of viable, fertile
offspring
•One species has become 2 through divergent
evolution
•For most species this would take millions of years
•Difficult to
4.1.4: Explain how plate activity has influenced evolution and biodiversity
•Speciation processes rely on physical separation of organisms
•Plate tectonics
–can lead to separation of gene pools – mountain ranges form, faults separating land masses
–Can link species and land areas e.g. land bridges
•Plate tectonics generates new habitats
–Island chains over hotspots – Hawaii
–Mountain habitats – Himalayan mountains – also associated effects on surrounding areas
–Hydrothermal vent communities
–Changes climate on land masses – continents drift into new climate zones - e.g. antarctica was once
covered by tropical rainforest now barren polar ice fields
4.1.5: Explain the relationships among ecosystem stability, diversity, succession & habitat
Ecosystem
Complex ecosystems with a variety of nutrient & energy pathways provides stability
stability
•Energy is key to the function of all ecosystems
•Biogeochemical cycles recycle necessary materials through system
•More pathways for energy & matter = more stable
•Insurance against natural or human changes
–Resilience – the ability to bounce back after a disturbance (grassland regrowth days after
a fire)
–Inertia – the ability to remain unchanged in the face of disturbance (Caribbean forests
have palm trees which sway in the wind instead of snapping)
habitat
Habitat diversity influences species & genetic diversity
•More complex areas (more diverse habitats) often have higher species & genetic diversity
•Ex. Tropical rainforest & Coral reef
•In both cases, high degree of structural / spatial complexity
•Promotes coexistence by niche partitioning & diversification
Succession
•Succession – gradual establishment or reestablishment of ecosystems over time
•Pioneer species - Climax species
–Low diversity at first, few species can tolerate harsh conditions (r selected species)
–Most diverse in middle of succession, slower growing species start to fill in
–Medium / high diversity at the end, climax species often strongest competitors (K
selected species)
•Diversity is a function of disturbance - intermediate disturbance hypothesis
Human
•Modify succession by adding disturbance
activities
•Logging, Grazing, Burning – all prevent natural successional processes
•Fragmenting habitats by development
•Isolate populations - more likely to get diseases, succumb to local disturbances
•We simplify ecosystems - tall grass prairie converted to wheat farms - more vulnerable
4.2.1: Identify factors that lead to a loss of diversity
•Natural Processes
–Natural hazards (volcanoes, drought, mudslide)
–Global catastrophies (ice age, meteor impact)
•Human Processes
–Habitat degradation, fragmentation & loss
–Introduction/escape of nonnative species, genetically modified organisms, monoculture
–Pollution
–Hunting, collecting, harvesting. overfishing
4.2.2: Describe the perceived vulnerability of tropical rainforests and their relative value in contributing to
global biodiversity
General info
•2% of the land surface with 50-80% of the terrestrial species
•Characterized by warm constant temperature, high humidity & rainfall
•Vertical stratification provides niche diversification
•Decomposition rates are extremely fast - little litter, thin nutrient poor soil
•Nutrients stored in biomass of organisms
threats
Ecology
Location
politics
•Most of destruction since 1950
•Brazil has ½ remaining world rainforest
•At current rates of deforestation Brazil’s rainforest will be gone in 40-50 years
•Total loss yearly to deforestation is 50,000 to 170,000 km2
•1.5 ACRES LOST PER SECOND worldwide
•Cutting & degradation at even faster rates
•Pollinator relationships – reproduction depends on other organisms
•Poor, thin soils – easily eroded once trees removed, little chance for regrowth
•Regeneration rates estimated around 65-4000 years (low end is to get some species high
end is a fully functioning system)
•Surrounded by rapid population growth of developing countries – pollution, waste, space
•Poor economy benefits from any resources that are harvestable
•Green Politics = a political ideology that places a high importance on environmental goals
and achieving them through grassroots participatory democracy.
4.2.3: Discuss current estimates of numbers of species and past and present rates of species extinction
-About 1.5 - 10 million Species live on Earth
-18000 to 50000 species lost per year
-1 species lost every 20 minutes
-Estimates differ but over 50 species lost per day is probably accurate
Permian
-Permian Period (286-248 million years ago) Formation Of Pangea
- Terrestrial faunal diversification occurred in the
Permian
-90-95% of marine species became extinct in the
Permian (largest extinction in history)
- Causes? = Formation of Pangea reduced
continental shelf area, glaciation, Volcanic
eruptions
Cretaceous
- Numerous evolutionary radiations occurred
during the Cretaceous (144-65 million years ago) 1st appearance of dinosaurs, mammals, birds,
angiosperms
- A major extinction occurred at the end of the
period - 85% of all species died in the EndCretaceous (K-T) extinction (2nd largest in history)
- Causes? = Meteor impact in the Yucatan,
Volcanic eruption - both supported geolocially,
cause climate change, atmospheric changes
4.2.4: Describe and explain the factors that may make species more or less prone to extinction
•Vulnerability of species affected by …
–Numbers – low numbers = automatic risk
–Degree of specialization = generalists adapt better than specialists
–Distribution = widely distributed organisms, may migrate out of harms way & different effects by area
–Reproductive potential – if low = vulnerable
–Reproductive behaviors – how complex, picky, …
–Trophic level – higher are more vulnerable to biomagnification & trophic cascades
4.2.5: Outline the factors used to determine a species’ Red List conservation status
•Organisms are classified for conservation purposes Traditionally into 2 groups
1.Endangered
•So few individuals that it could become extinct over all of its natural range
•Without protection - critically endangered - extinct
2.Threatened
•Still abundant in range but declining numbers
•Ecological warning signs
•Red Data Books
•List the species in the red – the ones most in jeopardy of extinction
•Various factors contribute to identifying species as threatened, of concern, endangered, extinct
•Examples - population size, reduction of population size, numbers of mature individuals, geographic
range and degree of fragmentation, quality of habitat, area of occupancy, probability of extinction
4.2.6: Describe the case histories of three species: one that has become extinct, another that is currently
endangered, and a third whose conservation status has been improved by intervention
African
Endangered
Elephant 1.Ecological pressures – shrinking habitat
2.Socio-political pressures – recovery of elephants in smaller habitats = widespread habitat
destruction, other species now poached for ivory
3.Economic pressures – poaching for ivory
•Ecological Role – keystone species, maintains grassland community by removing trees
•Consequences – loss of ecosystem type
Passenger Extinct September 1, 1914
Pigeon
1.Ecological pressures – clearing virgin forests for agriculture lost food & nests, 1 egg laid per
year
2.Socio-political pressures – Supply meat for growing east coast cities
3.Economic pressures – easy capture in large dense flocks, roosts -markets in the east
•Ecological Role – once most numerous bird on the planet
•Consequences – linked to spread of lyme disease
American Recovered June 4 1987
Crocodile 1.Ecological pressures – shrinking habitat
2.Socio-political pressures – alligator nuisance, sustainable use, tourism
3.Economic pressures – confused with American Crocadile hunted for skins
•Ecological Role – keystone predator, gator holes in everglades, top carnivore
•Consequences – loss of fish & bird populations & change whole everglades ecosystem structure
/ now healthy systems
4.2.7: Describe the case history of a natural area of biological significance that is threatened by human
activities
Facts
•The Amazonian Rainforest covers over a billion acres, encompassing areas in Brazil, Venezuela,
Columbia and the Eastern Andean region of Ecuador and Peru.
•If Amazonia were a country, it would be the ninth largest in the world.
•The Amazon Rainforest has been described as the "Lungs of our Planet" because it provides the
essential environmental world service of continuously recyling carbon dioxide into oxygen.
•More than 20 percent of the world oxygen is produced in the Amazon Rainforest.
•More than half of the world's estimated 10 million species of plants, animals and insects live in
the tropical rainforests. One-fifth of the world's fresh water is in the Amazon Basin.
•One hectare (2.47 acres) may contain over 750 types of trees and 1500 species of higher plants.
Effects
•1/3 of rainforest destruction from shifting cultivation
•Rest cleared for pasture- then planted with African grasses for cattle
•When pasture price exceeds forest prices - incentive for land clearing
•Government subsidized agriculture and colonization
•Improved infrastructure for transport
•In Brazil alone, European colonists have destroyed more than 90 indigenous tribes since the
1900's.
pressures
•Economic – raw materials, exports, cattle, oil & gas
•Socio-political – Pressures of population growth, subsidize tree plantations, colonization
•Ecological – Invasive species, climate change, soil degradation
•4.3.1: State the arguments for preserving species & habitats
A.Ethics = we know what we are doing and its negative effects - is it right to continue this?
B.Aesthetics = the natural world is more beautiful than strip malls and roads - should we keep it
around?
C.Genetic resources = end result of millions of years of evolution – unique gene combinations for
disease resistance, chemical production, etc
D.Commercial = many of the products we rely on result from the biotic component of the planet
- opportunity cost - value of the next best alternative forgone as a result of making a choice
-implies choice of results that are mutually exclusive
E. Life support = plants produce the oxygen we need to survive, soil provides the means for growing
food, organisms/processes cycle and purify the water we need
F. Ecosystem support = the interactions of the world are all connected •4.3.2: Compare the role and activities of governmental & non-governmental organizations in preserving and
restoring ecosystems and biodiversity.
WWF
Greenpeace
•Established in 1961
•“to conserve the natural environment and ecological processes worldwide”.
•WWF’s mission is to stop the degradation of the planet’s natural environment and to build a
future in which humans live in harmony with nature, by:
–conserving the world’s biological diversity
–ensuring that the use of renewable natural resources is sustainable
–promoting the reduction of pollution and wasteful consumption.
•Role – Promoting awareness & conservation of wildlife
•Activities – Directed mostly at wildlife conservation, work with companies like Nike in reducing
CO2 emissions, Aid
•Use of the media – International, internet, newsletters
•Speed of Response – stays current on issues
•Diplomatic constraints – international law & coordination
•Enforceability – Limited, no real governmental power, but broad passive influence
•Greenpeace is a non-profit organization, with a presence in 40 countries across Europe, the
Americas, Asia and the Pacific.
•To maintain its independence, Greenpeace does not accept donations from governments or
UNEP
United
Nations
Envrio
program
Conventions/ Rio
Earth
summit
corporations but relies on contributions from individual supporters and foundation grants.
•As a global organization, Greenpeace focuses on the most crucial worldwide threats to our
planet's biodiversity and environment.
•We campaign to: --Stop climate change , Protect ancient forests, Save the oceans, Stop whaling
--Say no to genetic engineering
•Role - More extreme environmental activist group
•Activities – Greenpeace's history began in 1971. A group of ecologists opposed to the war in
Vietnam contested US nuclear testing in the north Pacific. They decided simply to position
themselves in the middle of the testing zone.
•Use of the media - Embarked on a campaign to save the whales. Using Zodiac inflatables, they
put themselves between the whales and the harpoons, generating images too sensational not to
broadcast and creating new public pressure.
•Speed of Response – rapid, high profile, technological approach
•Diplomatic constraints – Nonviolent but radical group - Greenpeace's scientific and market
research becomes pressure tools.
•Enforceability - Creative nonviolent action mobilizes public opinion against the unsustainable
practices of governments or corporations. The objective is to obtain as much coverage as
possible through the media in order to mobilize public opinion on certain issues.
•Established in 1972
•To provide leadership and encourage partnership in caring for the environment by inspiring,
informing, and enabling nations and peoples to improve their quality of life without
compromising that of future generations.
•Role – negotiate, monitor, implement environmental treaties
•Activities – focus on consumption issues, energy, food, youth programs
•Use of the media – limited, website
•Speed of Response – slower, through government action
•Diplomatic constraints – tied to the UN
•Enforceability – underfunded, undersupported
•The 1992 Rio Earth Summit was attended by 152 world leaders + led to the signing of
conventions on biological diversity +desertification, a framework convention on climate change,
principles for sustainable forestry + Agenda 21.
•Agenda 21 is a programme run by the United Nations (UN) related to sustainable development
and was the planet's first summit to discuss global warming related issues. It is a comprehensive
blueprint of action to be taken globally, nationally and locally by organizations of the UN,
governments, and major groups in every area in which humans directly affect the environment.
•The Millennium Development Goals were agreed by 152 heads of state. These leaders pledged
to moderate globalisation, foster better governance, 1/2 the number of people living in poverty
by 2015, prevent conflict + protect the vulnerable, secure life on earth + strengthen the UN
•In 2002 Johannesburg Summit extended this
•4.3.3: State and explain the criteria used to design reserves
1.Ecosystems are rarely at a stable point – hard to lock them and protect them from change
(nonequilibrium state)
2.Ecosystems which experience frequent, moderate disturbance have the greatest diversity
(intermediate disturbance hypothesis)
3.View most reserves as habitat islands in a sea of developed or fragmented lands
•Island Biogeography
•Diversity on islands is a function of size and distance from mainland (balance extinction vs.
colonization)
•Help determine …
–Areas in greatest danger
–Size of reserve that will be necessary
–How closely must small reserves be spaced to allow immigration
–Size & # of protective corridors connecting parks
–Globular because the core is more buffered from outside effects
–One large – less fragmented and less surface area for human interference (multiple small if you have
many dif. Habitats that you cannot preserve otherwise)
–Heterogeneous - diversity = stability
-corridors help wildlife move for food, migration, etc and also help them respond to global climate
change
–Buffer zones ensure that human impact doesn’t reach the core preserve area
•4.3.4: Evaluate the success of a named protected area.
facts
•South Florida – once 100 km wide knee deep sheet of water moving from Lk. Okeechobee to
FL Bay
•On its way south it created various wetlands with a wide variety of species
•Slight changes in elevation (only inches), water salinity, and soil create entirely different
landscapes, each with its own community of plants and animals.
•Sawgrass is the dominant plant species
•Today 56 endangered & threatened species reside there
•Supplies drinking water directly or through Floridian & Biscayne aquifers for 6-10 million
people
•Since 1948 most of water flow has been diverted by 2,250 km. of canals, pumping stations,
etc.
•In 1960s meandering 103 mile long Kissimmee R. reformed into straight 84 mile canal by army
corps of engineers
•Below Okeechobee intensified agriculture of sugar cane developed
•Now seeing (1) greater inputs of nutrients from fertilizer use (nitrogen & phosphorous)
•(2) Decreased volume of water, moving faster through the system
•(3) Increases in exotic & invasive species
•1947 Everglades National Park established to preserve the lower end of the system
•Contains 20% remaining everglades
•Didn’t work because of all of the influences on the water to the north
•90% of parks wading birds have disappeared
•Other vertebrate populations are down 75-90%
•Now the country’s most endangered national park
•Florida Bay suffering from less fresh water as well as cultural eutrophication
•Threatens reefs & fisheries in the Keys
Successful? 1.Has the protection of the everglades been successful thus far?
2.Does the local community support it? Think about the farmers in the area, the cities of south
east FL, etc.
3.Is there enough funding?
4.Where did the research fail in the past? Where might it fail in the future?
•4.3.5: Discuss & evaluate the strengths and weaknesses of the species based approach to conservation
strengths
weaknesses
CITES
Helped reduce international trade in many
Enforcement is difficult, Consequences are
organisms, organized international awareness, weak, Countries have a choice, value of
protected habitats
organisms may increase
Captive
1.Organisms safe from poachers
1.It is artificial
breeding
2.Ensure good chance of offspring survival
2.Organisms not born in the wild may not be
3.Artificial insemination possible
able to survive reintroduction
4.Cross fostering is possible – raised by parent 3.Few actually returned to wild
of similar species
4.Lack of habitat to return them to
Aesthetic
1.Tourism & recreation – use promotes
1.More interactions with people – more
Value
interest
damage potentially
2.“Sexy megafauna” get public interested in
2.People may overlook the deeper values
conserving whole habitats
3.Personal approach appeals to people
“Save the manatee”
Ecological
1.Shows people the true critical value of
1.May go over the heads of the general public
value
species
2.May be hard to quantify this for some
2.See how it effects us – food web links,
species
nutrient cycling, keystone species
5.1.1: Define the term pollution
The addition to an environment of a substance or an agent (such as heat) by human activity faster
than it can be rendered harmless by the environment and which has an appreciable effect on
organisms within it
5.1.2: Distinguish the terms point source pollution and non-point source pollution and outline the challenges
they present for management
Point Source
Non Point source
challenges
•Discharge pollutants at specific
•Cannot be traced to a single
•Point sources are easier to
locations
point of discharge
manage because effects are
•Factories, sewage treatment
•Acid deposition, surface runoff
localized
plants, mines
•Agricultural forms – sediment,
•Allows emission control
fertilizer, manure
•Allows determination of
•64% total pollutants entering in
responsibility and taking legal
US
action
5.2.3: State the major sources of pollutants
•Combustion of fossil fuels - carbon, sulfur, & nitrogen oxides; particulates; heavy metals
•Domestic and industrial waste -garbage; sewage, materials, toxic waste
•Manufacturing - others above plus chemicals and toxins; packaging; shipping
•Agricultural systems - pesticides; animal and plant wastes; fertilizers; others above
5.2.1: Describe two direct methods of monitoring pollution
In the Water
In the air
•Coliform testing
•Monitoring ozone, sulfur and nitrogen oxides,
•Coliform bacteria from feces – maybe from natural
carbon monoxide, particulates
animals but also input from sewage
•Capture known volume
•Take water samples at desired locations (here taken •Measure amount of target chemical with - Gaseous
along the beach)
sampling probes, spectrometers, etc.
•Plate out a know volume of water on a nutrient
•Set sampling points – monitor over time
medium (some media allow staining of colonies)
•Observe changes taking place
•Incubate overnight then count number of colonies
observed
5.2.2: Define the term biological oxygen demand (BOD) and explain how this indirect method is used to
assess pollution levels in water
•BOD = Biological oxygen demand - A measure of the amount of dissolved oxygen required to break down
organic matter in a given volume of water through aerobic biological activity
•Indirect means of measuring pollution levels in the environment
•Usually measured in context of sewage pollution - more sewage = more decomposable material = higher BOD
•Sewage carried with it disease organisms, detergents & nutrients
•Causes enrichment (excess nutrients we’ll deal with this in eutrophication section) and oxygen demand
•Degraded through decomposition by microorganisms through process of cell respiration into H2O, CO2
•Requires oxygen which is also used by other aquatic organisms
•Oxygen has limited ability to dissolve into water
•With excess organics little oxygen left for organisms
•In extreme situations all fish die
•May lead to dead zone formation
•Sewage and other organic wastes are measured in terms of their BOD
•This is amount of oxygen microorganisms need to decompose wastes
•Usually expressed in mg/L
•When there is a high BOD, the DO is low
•Microorganisms also produce compounds with unpleasant odors
5.2.3: Describe and explain an indirect method of measuring pollution levels using a biotic index
•We can use other aspects of populations and
communities as rough indices too
•Biomonitoring – who’s there
•Abundance – How many of each organism
•Biodiversity calculations work well
•Simpson’s Index in two areas – polluted and
unpolluted
5.3.1: Outline approaches to pollution management with respect to figure 5
•Human pollutants produce long term and far
reaching effects
•Strategies for reducing impacts can be directed at
three different levels in the process
1.Altering the human activity
2.Reducing the quantity of pollutant released at the
point of emission
3.Cleaning up the pollutant and restoring the
ecosystem after pollution occurs
•Of course the earlier action is taken the better –
stopping the emissions altogether would be best
•Remember the need for collaboration in the
management of pollution
–National, state and local policy working in concert
5.3.2: Discuss the human factors that affect the approaches to pollution management
Value
limitations
Human
•Stop pollution before it’s produced
•Requires behavior changes and people resist
activity
•Can generally have multiple good effects that
– conserving home energy reduces
•Individuals sometimes miss big picture
greenhouse gasses, acid deposition,
importance of their actions
photochemical smog, conserves resources
Pollutant
•Same production but with limit on the
•Pollution not gone – still retained in the slurry
into
pollution
material
environment •Removes it at emission source – easy to
•Must be disposed of – landfill
identify necessary location
•Still producing just as much CO2
•Expensive
Long term
•Negative effects can be mitigated
•Impact happens
impact
•Get the value of the process along the
•Behaviors don’t change
way
•It’s hard to get back to the pristine state
•May be cheaper short term than cost of
•If pollution continues to happen then this is
scrubbers
only temporary
5.3.3: Evaluate the costs and benefits to society of the World Health Organization’s ban on the use of the
pesticide DDT
General •DDT - dichlorodiphenyltrichloroethane is one of the most well-known synthetic pesticides
•Use as insecticide starts in 1939 resulting in drops in malaria and typhus & other insect
transmitted diseases
•1962 Rachel Carson writes Silent Spring
•Resulting public outcry about potential linkage to human cancer and food web effects
•1972 banned in US, worldwide in Stockholm convention (2001) under guidance of UNEP
Costs
•WHO in 1955 tried to eradicate malaria worldwide through extensive use of DDT – resistance in
insects started to develop
•Now malaria kills 2.7 million per year and moderate spraying or paint infusion or bed nets dipped
in it might help without negative health effects
•Critics say worldwide ban based on people who have little to lose in comfort of developed
countries banning what could help people in the “poor tropics”
benefits •Recovery of raptors like bald eagles who were effected by thinning eggshells from
biomagnification
•In humans avoid the
–Shown linkages to breast and other cancers
–Acute and chronically toxic – links to diabetes too
–Developmental issues, premature births
5.4.1: Outline the process of eutrophication
•The natural or artificial enhancement of a body of water, particularly with respect to nitrates and
phosphates, that results in depletion of the oxygen content of the water
•It is accelerated by human activities that add detergents, sewage or agricultural fertilizers to bodies
of water
1.Increase in nitrates and phosphates
2.Rapid growth of algae
3.Accumulation of dead organic material
4.High rate of decomposition
5.Decrease in oxygen
5.4.2: Evaluate the main impacts of eutrophication
-positive feedback loop
•Death of Aerobic organisms
•Increased turbidity
•Loss of macrophytes
•Reduction in the length of food chains
•Loss of biodiversity
•Formation of Dead Zones
5.4.3: describe and evaluate pollution management strategies with respect to eutrophication
Alter the •Phosphate free detergents in the home
activity
•Reduced residential use of lawn fertilizers
•Move agriculture away from inorganic broad scale fertilizers to specifically applied organic
fertilizers and manures
•Soil conservation
Stop it at -Sewage treatment modifications
its source -Traditionally remove solids and purify but leave nutrients in effluent
-Advanced (more $$$) but removes nutrients for agricultural application
-Treatment marshes on farms
-Use natural wetland capabilities for farm waste treatment
Clean up •Mud can be pumped out of eutrophic lakes
after
•Plants can be reintroduced to restart natural nutrient cycling
•Once that takes hold reintroduce fish
5.5.1: Outline the types of solid domestic waste
5.5.2: Describe and evaluate pollution management strategies for solid domestic (municipal) wastes
incineration •16% of MSW is combusted in mass burn incinerators
•80% of hazardous waste is burned in commercial incinerators
•The benefits
–Reduced landfill volume, Reduced water pollution,
•Use of incineration has decreased
–High cost, Air pollution & health concerns, Public opinion is poor
Land
•54% MSW disposed of in landfills in US
disposal
•Sanitary landfill
–Waste spread in thin layers; compacted; covered daily with fresh foam or clay
•Lined landfills prevent groundwater contamination
•Pipes vent gasses which build up
•Leachate from older landfills contaminates water bodies & aquifer
•Disadvantages
–Groundwater contamination, CH4 and other gases released, encourages waste production
•Benefits
–No open burning, little odor, low cost, large capacity, easy to construct
Recycling
•Every ton of recycled paper saves 17 trees, 7,000 gallons of water, 4,100 kWh energy and 3
cubic yards of landfill space
•30.1% of US municipal solid waste is now recycled
–45% of paper, 26% of glass, <20% plastic, 55% aluminum cans
–Plastic is hard because there are 46 different kinds
•Some areas promote it by a pay per bag approach to non recycled trash
•Recycling problems – toxic sludge residue, some things can’t be recycled
Composting •Allowing for the complete breakdown of biodegradable materials
•Creates humus – highly valuable fertile material
•Example of upcycling of waste
5.6.1: Outline the overall structure and composition of the atmosphere
•Layered structure – Troposphere, Stratosphere, Mesosphere, Thermosphere
•Troposphere is layer next to earth’s surface – 75-80% of mass of earth’s air
trace amounts of water, argon, carbon dioxide
•Lapse rate – rate at which temperature declines with increasing altitude in the troposphere
5.6.2: Describe the role of ozone in the absorption of UV radiation.
•Ozone is O3 formed from O + O2
•Found in the lower Stratosphere as the ozone layer – good protective qualities
•Found in the Troposphere as a result of human pollution – bad qualities photochemical oxidant
•UV radiation is absorbed in its formation and destruction
•What kind of resource is it? REPLENISHABLE
•When UV strikes O3 it is absorbed and its energy used to break the chemical bond
•O3 + UV - O + O2
•So UV doesn’t make it to the earth’s surface
•Layer in the lower stratosphere
•Keeps 95% of harmful UV radiation away
•Seasonal depletion of ozone layer above Arctic & Antarctic, overall thinning everywhere but tropics
•Depletion is serious long term threat to (1) humans, (2) other animals, (3) sun driven producers
(plants) supporting food webs
5.6.3: Explain the interaction between ozone and halogenated organic gasses.
1.Discovered in 1930
2.Chemically stable, odorless, nonflamable, nontoxic, noncorrosive - dream chemical in the
troposphere
3.Coolants, Propellants, Sterilants, Fumigants
4.1974 discovered to be lowering concentrations of stratospheric ozone
5.Immediate ban called for
•Large quantities being released – use, leaks, production of plastics
•Remain in troposphere – unreactive, insoluble very stable
•11-20 years to rise to stratosphere
•Release high energy Cl atoms when exposed to UV which speed up breakdown of ozone
•Each CFC lasts 65-385 years in stratosphere
•Can break down up to 100,000 molecules of ozone
•THEY ENHANCE THE DESTRUCTION OF OZONE = UPSETTING THE EQUILIBRIUM OF THE OZONE
PRODUCTION SYSTEM
Summary of Reactions
CCl3F + UV Cl + CCl2F Cl + O3 ClO + O2 Cl + O Cl + O2
Repeated many times
5.6.4: State the effects of UV radiation on living tissues and biological productivity.
-On living tissues
DNA mutation - cancer, Immune suppression, Cataracts, Sunburn, Decrease populations sensitive to
UV, Food web effects
-On Biological Productivity
Direct damage to phytoplankton and other photosynthetic organisms, Reduced crop yield, Leads to less
CO2 uptake - increases Global Warming
5.6.5: Describe three methods of reducing the manufacture and release of ozone-depleting substances
•Refrigerants can be recycled
•Alternatives to gas blown plastics can be used
•Alternative propellents – hydroflourocarbons – better but a potent greenhouse gas
•Alternatives to methyl bromide can be used for fumigation and pesticides
•Problems include:
–Existing stockpiles were ok to use after the phase out
–Old CFCs continue to leak out of junked cars and fridges
–Black market trade in CFCs increasing because they are not made but still useful
–China, India, Mexico have increased use and production of CFCs
5.6.6: Describe and evaluate the role of national and international organizations in reducing the emissions of
ozone-depleting substances
National in the us
international
•Government ratified Montreal Protocol agreeing
•Montreal Protocol (1987 – 36 nations) - pledge cuts
stop production of CFC propellents
and awakens awareness
•Taxes levied on CFC production and use
•Copenhagen Protocol (1992 – 177 nations) - agree
•Corporations changing their ways
to complete phase out good model of international
•McDonalds (1987) – stopped use of styrofoam
cooperation
packaging
•UNEP helps forge these agreements as well as
•Caused foam packaging industry to stop use of all
helping LEDCs make the change
CFCs by 1988
•Montreal Multilateral Fund helps in transition
5.7.1: State the source and outline the effect of tropospheric ozone.
•Combustion of Fossil fuels Produces two major pollutants
–Hydrocarbons and nitrogen monoxide
•Nitrogen monoxide reacts with oxygen to form nitrogen dioxide - brownish choking gas = urban haze
•Nitrogen dioxide can absorb sunlight and break –releasing free oxygen
•Free oxygen combines with O2 to make ozone
•Tropospheric ozone is a photochemical oxidant
•Toxic gas and an oxidizing agent
•Damages crops and forests, irritates the eyes, causes breathing difficulties, may increase the
susceptibility to infection
•Highly reactive – attacks fabrics and rubber
5.7.2: Outline the formation of photochemical fog
What is it?
•Any reaction activated by light is a photochemical reaction
•Photochemical Smog = mix of primary & secondary pollutants formed under influence of
sunlight
•100 chemical mixture dominated by photochemical ozone
•Combustion of fossil fuels in cars and industry initiated this process
How made? 1.N2 + O2 -> 2NO = in combustion process
2.2NO + O2->2NO2 = tropospheric process producing choking yellowish gas
- NO2 = brownish haze hanging over cities = smog
3.3NO2 + H2O ->2HNO3 + NO = some nitrogen dioxide forms nitric acid
4.NO2 + UV radiation ->NO + O = UV produces free oxygen atoms
5.O2 + O ->O3 = ozone produced in the troposphere
6.Hydrocarbons + O2 + NO ->PANs = Peroxyacyl nitrates from reaction with hydrocarbons
7.Also includes hydrocarbons, VOCs & aldehydes
Photo
•NO2 & O3 & PANs are photochemical oxidants
Chemical
•Oxidize compounds in atmosphere, damage lungs, damage crops & trees
oxidants
•Hotter temp increase concentrations of photochemical smog – early afternoon peak
•Most common in cities with sunny, warm dry climate with many cars - LA, Denver, Mexico
City, Buenos Aires
•Influenced by:
–Local climate & topography
–Population density
–Concentration of industry
–Fuels used for industry, transportation & heating homes
•Precipitation washes it out of the air and winds disperse it
•When thermal inversions happen it can trap the air in valley areas
–Usually air is warmest near the surface and gets colder with increased altitude
–Occasionally a warmer air mass moves in above a colder air mass near the surface
–Since warm air is less dense it sits on top trapping the colder air & any pollution it contains at
the surface
–The Great Smog in London in 1952 resulted in 1000s of deaths from inversion trapped air
pollution
5.7.3: describe and evaluate pollution management strategies for urban air pollution
•Alter the human activity: Reduction of Fossil Fuel Combustion by
–Reduce demand for electricity
–Reduce Demand for private cars – public transportation, car sharing (zipcar)
–Switch to renewable energy
•Reduce the pollution as it is released
–Catalytic converters on cars – removes toxins from car emissions
•Clean up the environment after the effect
–Vacuum and filter the air
–Blowers to disperse it
5.8.1: Outline the chemistry leading to the formation of acid precipitation
•Coal burning power plants, smelters, cars & industrial plants emit sulfur dioxide & nitrogen oxides into
the atmosphere
•Remain in atmosphere for 2-14 days before descent
•May mix with water in atmosphere - wet deposition as nitric acid and sulfuric acid
•May be converted into particulate compounds as sulfates and nitrates in dry deposition
5.8.2: Describe three possible effects of acid deposition on soil, water & living organisms
5.8.3: Explain why the effect of acid deposition is regional rather than global
•Not a global problem – because it is linked to patterns of air circulation
•Problem in regions downwind from factories & large urban areas
•Remember the pollutants fall out of the air within 2-14 days so can’t circulate around the globe
•Eastern U.S., China
•Ohio river valley industry major pollution source
•E.x. sulfur dioxide produced in industrial plants in Detroit area with automobile industry - forests in Me,
NH, VT experiences effects of acid deposition
•Typical Eastern U.S. precipitation 4.2 – 4.7 compared to natural precipitation pH = 5.6
5.8.4: Describe and evaluate pollution management strategies for acid deposition
Alter
•Best solution because it prevents the pollutants from entering the atmosphere
human
1.Use cleaner energy production technologies
activity
A. Reduce demand for electricity & private cars
B. Switch to alternative energy / renewable energy
•2. Practice energy conservation
•Hard because coal rich countries have an incentive to use it
Reduce
•Install scrubbers on the end of the pipe
pollutants •Pre-clean coal before burning
•Good because it removes the acid causing chemicals
•Bad because it still encourages coal use which releases CO2 for global warming
Clean up
1.Limestone & lime can be used to neutralize soils & water bodies
after
•Expensive, temporary remedy; kills aquatic plants esp. those needing acidic conditions; hard to
know how much to use
•Used in Sweden in early 1980’s
•Cost effectiveness is the question
2.Add Phosphate fertilizer to neutralize acidified lakes
•Further input of inorganic fertilizer to the environment
•Potentially leads to eutrophication and harmful algal blooms
6.1.1: Describe the role of greenhouse gasses in maintaining mean global temperature.
•Balance heat moving in & out of atmosphere
•Keep constant moderate average temperature normal & necessary for life
•Greenhouse gas molecules trap energy as IR radiation and heat lower atmosphere
–Gasses = water, methane & carbon dioxide
–Water relatively constant, CO2 fluctuates
•Really a tropospheric heating effect
•With natural cooling average global temp = 59 ˚F
•Past CO2 levels determined from ice core data – analyzing content of gas bubbles trapped in different
layers of glaciers
• CO2 has varied historically but is peaking presently
•Correlation between CO2 and temperature has been show dating back 460,000 years
6.1.2: Describe how human activities add to greenhouse gasses.
•Since 1750, Industrial Revolution
–Sharp rise in fossil fuel use, landfills - CO2 & CH3
–Deforestation, Clear & burn grasslands - CO2 & N2O
–Rice paddies, inorganic fertilizer use - N2O
–CFCs – entirely human caused
•Mostly cars (700 million) & coal power plants
•Increased greenhouse gas from humans
–Enhance natural Greenhouse effect
–Raise average global temperature of atmosphere near earth’s surface - Global warming
6.1.3: Discuss qualitatively the potential effects of increased mean global temperature
1.Affect water availability, altering precipitation & evaporation patterns
2.Shift areas where crops will grow
3.Change average sea levels – coastal inundation (thermal expansion & melting ice)
4.Alter the structure & location of the world’s biomes
5.Effect human health and the spread of disease
•Natural & Human influenced factors will effect the future of global climate
•Factors may amplify current trends - positive feedback
•Factors may dampen current trends - negative feedback
•These factors could influence how fast and how much temperatures change
•Also effect regional differences
6.1.4: Discuss the feedback mechanisms that would be associated with an increase in mean global
temperature
positive
negative
•Increase Temp
•Increased Temp
•Melt Permafrost
•Increased evaporation in Tropics
•Increased release of methane
•Increased snowfall in poles
•Increase Temp more
•Increase icecap cover
•Melt more Permafrost…
•Increased albedo
•Decreased Temp
6.1.5: describe and evaluate pollution management strategies to address the issue of global warming
Alter
- preventative approach
human
–Switch to alternative fuels, conserve energy, consume less,
activity
Reduce
– preventative but less effective
pollution
–Switch from coal to oil/natural gas, organic agriculture, feed cows garlic
Clean after – reactive and unproven
–Plant trees to suck in CO2, capture it out of the atmosphere and pump it into deep ocean etc.
for sequestration
Local
•Waste less energy
•Rely more on cleaner energy sources
•Choose transportation wisely
•Shifting to organic farming and sustainable agriculture
•Gradually integrate solutions to decrease global warming, air pollution, deforestation &
biodiversity loss
Global
•Phase in output based carbon taxes & input based energy taxes
•Increase government subsidies for energy efficiency & renewable energy technologies
•Fund transfer to renewable fuels
•Place global & national caps on emissions levels
•Sell & trade emissions credits on open market
•Remove CO2 from atmosphere – tree planting
•1997 – Kyoto agreement
implications •MEDCs
•Stand to lose the most economically
•But have the technology to change
•Also some of biggest polluters
•LEDCs
•Rapidly increasing their contribution – China & India
•It’s their turn, why should they curb emissions
•Cheaper energy like coal is used – lack technology for other methods
6.1.6: Outline the arguments surrounding global warming
–There are various and conflicting arguments about global warming because of
–The complexity of the problem – so many variable are having effects
–The uncertainty of computer models – we are trying to see the future with this
–percieved potential harm that will be caused economic cascade caused by doing something about it
–The need to admit we are wrong and doing something bad
•Reduction in the insolation of the earth’s surface –post 9/11 evidence
•Seen in 1960s-1990s
•Caused by increase in anthropogenic particulates like sulfate aerosols
•When aerosol levels started to decline in the 1990’s dimming switched to a brightening trend
•Can create a cooling effect to counter global warming
•Potential Engineering Solution for us
6.1.7: Evaluate contrasting human perceptions of the issue of global warming
•For this be sure that you can describe and defend your own position
•Regardless of where you stand have evidence to back it up
•Make sure you can describe and defend 2 other view points that may conflict with your own
Topic 7
7.1.1 – State what is meant by an environmental value system
•This is a world view or set of paradigms that shapes the way an individual or group perceives and
evaluates environmental issues
•Influenced by cultural, religious, economic and socio-political factors
•Input – education, cultural dogma, religious doctrines, media
•Transfers and Transformations – Processing of information, thinking, discussion, regurgitation
•Outputs – decisions, perspectives, courses of action
7.1.2 – Outline the range of environmental philosophies with reference
7.1.3 – Discuss how these philosophies influence the decision-making process with respect to environmental
issues covered in this course
•Establishing the national park system
•Not signing Kyoto, not having a climate bill in place currently
•Dealing with the oil spill in the gulf right now
•Consider US and international responses
7.1.4 – Outline key historical influences on the development of the modern environmental movement
Bhopal disaster Publication of
Chernobyl
1950’s Minamata
Whaling currently
1984 India
Rachel Carson’s
Meltdown (1986
Japan
Slient Spring
Ukraine)
Union Carbide pesticide
plant released 42 tonnes
of toxic methyl
isocyanate gas - 500,000
exposed, 8,000 dead
within a week, >16,000
dead since
Awakens the world to the
perils of DDT and other
toxins in the environment
•Reactor tests conducted
•Required shutdown of
safety systems
•Cooling system failure
•Leading to meltdown
•Explosion releasing
radioactive cloud
•Permanent evacuation
in 30 km radius
•Eventual deaths 8,000400,000
•Suddenly people
develop acute mercury
poisoning – numbness,
muscle weakness, coma
death
•Minamata disease –
2,300 officially recognized
victims
•Chisso corporation
dumping methyl mercury
into local bay
•Biomagnification of Hg
through food chain into
people
•Historically hunted for
blubber, whale oil
•Now hunted for meat
•International Whaling
commission forms in
1946 – moratorium in
1986
•Now whaling by Inuits &
Norway & Iceland
(legitimate?) & Japan
(Scientific?)
7.1.5 - Compare and contrast environmental value systems of two named societies
•Native Americans
•European pioneers
•Deep respect for the natural world
•Frontier economics
•Thought of themselves as part of it not lords over •Exploitation of seemingly unlimited resources
it
•Becomes Manifest destiny – expansion not only
•Much of their religion was tied to nature so
good but obvious and certain
spiritual connection as well
7.1.6 - Justify your personal viewpoint on environmental issues
See figure 6