Natural Ecosystem Processes Natural Ecosystem Processes

• Natural ecosystems are involved in a wide Natural ecosystems are involved in a wide variety of variety of natural processesnatural processes influencing influencing humans and other organisms. humans and other organisms.

• The activities of humans in the The activities of humans in the environment are changing many of these environment are changing many of these natural processes in a natural processes in a harmful fashionharmful fashion. .

Maintenance of atmospheric quality Maintenance of atmospheric quality

• Human activities Human activities (namely (namely UrbanizationUrbanization & & Industrial GrowthIndustrial Growth) ) have increased the have increased the amount of amount of PollutantsPollutants in the atmosphere, in the atmosphere, negatively affecting negatively affecting the environment the environment (acid rain)(acid rain)

Generation of soils Generation of soils

• Agricultural practices have exposed soil to Agricultural practices have exposed soil to the weather resulting in the weather resulting in great loss of topsoilgreat loss of topsoil. .

Control of the water cycle Control of the water cycle

• The cutting of forests and other human The cutting of forests and other human activities have allowed increased activities have allowed increased uncontrolled runoffuncontrolled runoff leading to increased leading to increased erosion and floodingerosion and flooding. .

Removal of WastesRemoval of Wastes

• Untreated Untreated sewage wastessewage wastes and runoff from and runoff from farms and feedlots have led to increased farms and feedlots have led to increased water pollution. water pollution.

Energy FlowEnergy Flow

• Some industries and nuclear plants have Some industries and nuclear plants have added added thermal pollutionthermal pollution to the to the environment. The release of some environment. The release of some gasesgases from the burning of fossil fuels may be from the burning of fossil fuels may be slowly increasing the Earth's temperature. slowly increasing the Earth's temperature. -- (Greenhouse Effect)-- (Greenhouse Effect)

Major Greenhouse GasesMajor Greenhouse Gases

• Carbon Dioxide (COCarbon Dioxide (CO22))

• Methane (CHMethane (CH44))

• Other man-made gasesOther man-made gases

Nutrient RecyclingNutrient Recycling

• The use of packaging material which does The use of packaging material which does not break down, burning of refuse, and the not break down, burning of refuse, and the placing of materials in placing of materials in landfillslandfills prevents prevents the return of some useful materials to the the return of some useful materials to the environment. environment.

• Humans have changed many of these Humans have changed many of these ecosystem processes -- frequently in a ecosystem processes -- frequently in a detrimental way detrimental way

Human Population Growth Human Population Growth

• 1. The total population of humans has risen 1. The total population of humans has risen at a at a rapid raterapid rate, partly because of the removal , partly because of the removal of of natural checksnatural checks on the population, such as on the population, such as diseasedisease. .

• 2. The earth has 2. The earth has finitefinite resources, increasing resources, increasing human population and consumption places human population and consumption places severe stress on natural processes that severe stress on natural processes that renew some resources and renew some resources and depletedeplete those those resources which can not be renewed.resources which can not be renewed.

A lesson on overpopulation …. A lesson on overpopulation …. - - Kaibab National Forest - Arizona - deerKaibab National Forest - Arizona - deer

• 1906 - Stable population of 4,000 deer 1906 - Stable population of 4,000 deer • - Bounty was placed on their predators - Bounty was placed on their predators • (1906-23) deer population swells and (1906-23) deer population swells and

overgrazing begins -- over 6,000 predators overgrazing begins -- over 6,000 predators killed killed

• (1924-25) of the 100,000 deer present -- over (1924-25) of the 100,000 deer present -- over 75% die - chiefly of starvation & malnutrition 75% die - chiefly of starvation & malnutrition

• 1939 - Fewer than 10,000 deer remained 1939 - Fewer than 10,000 deer remained

The moral of the storyThe moral of the story… Destruction … Destruction of natural enemies is not always of natural enemies is not always good for a species -- it can lead to good for a species -- it can lead to its extinction or near extinction. its extinction or near extinction. (Will this also happen to Homo (Will this also happen to Homo sapiens?)sapiens?)

Some specific human influences on Some specific human influences on Ecosystem FactorsEcosystem Factors

• A. Increasing numbers: A. Increasing numbers: • results from an results from an increasedincreased human life span human life span • healthhealth advances largely led to this advances largely led to this

• B. Food: B. Food: shortages and inadequate nutritionshortages and inadequate nutrition lead to starvation and malnutrition lead to starvation and malnutrition

- - population growthpopulation growth is outpacing food is outpacing food production in many world regions production in many world regions

- - starvationstarvation: body lacks sufficient : body lacks sufficient calories for maintenance calories for maintenance

- - malnutritionmalnutrition: diet lacks specific : diet lacks specific substances needed by the body substances needed by the body

• C. Soil: much loss of fertile topsoil due to C. Soil: much loss of fertile topsoil due to erosionerosion and and poor managementpoor management

– the use of biocides has the use of biocides has contaminatedcontaminated the soil the soil (no prior assessment was taken of their (no prior assessment was taken of their environmental impact) environmental impact)

– some causes of topsoil loss include; some causes of topsoil loss include; cutting cutting forestsforests, farming dry grasslands, , farming dry grasslands, damming riversdamming rivers, , draining wetlands, etc. draining wetlands, etc.

– much valuable farmland has been lost due to much valuable farmland has been lost due to increasing increasing urbanizationurbanization & & suburbanizationsuburbanization

• 4. Water: cutting forests has led to 4. Water: cutting forests has led to increased, uncontrolled runoff increased, uncontrolled runoff – water pollution leaves water unfit for use and water pollution leaves water unfit for use and

the living things remaining in it unfit for the living things remaining in it unfit for consumption (typical water pollutants include consumption (typical water pollutants include phosphates, heavy metals, and PCB'sphosphates, heavy metals, and PCB's) )

BiomagnificationBiomagnification

• increase in the increase in the concentrationconcentration of a substance of a substance (poison) in (poison) in living tissueliving tissue as you move up the as you move up the food chain food chain – (ex. tuna and swordfish, water birds and (ex. tuna and swordfish, water birds and

birds of prey from birds of prey from DDTDDT -- thin shelled eggs) -- thin shelled eggs) – This has particularly hurt the peregrine This has particularly hurt the peregrine

falcon & bald eagle. falcon & bald eagle.

• 5. Wildlife: much destruction and damage 5. Wildlife: much destruction and damage has been done to many species (hunting, has been done to many species (hunting, fishing, etc.) fishing, etc.) – ex. passenger pigeon, dodo, great auk, bison, ex. passenger pigeon, dodo, great auk, bison,

Carolina parakeet Carolina parakeet

• ** Other problems include ** Other problems include habitat habitat destructiondestruction, , importationimportation of some organisms of some organisms have caused problems for native organisms. have caused problems for native organisms.

• We have We have alien invasive speciesalien invasive species which have which have caused problems for our area in New York. caused problems for our area in New York. These include the Water Chestnut, Eurasian These include the Water Chestnut, Eurasian Water milfoil, Alewife, Zebra Mussel, and Water milfoil, Alewife, Zebra Mussel, and Purple LoosestrifePurple Loosestrife. .

Remember the Simpson episode where Bart calls Australia to see which way the toilet flushes?

He brings with him a frog and it takes over the country and on the way home, a koala hands on to the Simpson’s helicopter!

• 6. 6. Fossil FuelsFossil Fuels: are becoming rapidly : are becoming rapidly depleted/add to air pollution problems depleted/add to air pollution problems – The search and demand for additional energy The search and demand for additional energy

resources also impact ecosystems in a resources also impact ecosystems in a negative way. negative way.

– Industrialization has brought an increased Industrialization has brought an increased demand for and use of energy. demand for and use of energy.

• 7. Nuclear fuels - environmental dangers 7. Nuclear fuels - environmental dangers exist in reference to exist in reference to obtaining, using, and obtaining, using, and storingstoring the wastes from these fuels the wastes from these fuels

• 8. Air is becoming increasingly polluted 8. Air is becoming increasingly polluted – Acid RainAcid Rain -- sulfur dioxide (also nitrogen -- sulfur dioxide (also nitrogen

oxides) from coal burning sources + rain = oxides) from coal burning sources + rain = ACID RAIN ACID RAIN

Problems from Acid Rain:Problems from Acid Rain:

• Destruction of limestone and marble Destruction of limestone and marble monuments due to increased chemical monuments due to increased chemical weathering weathering

• Acidification of aquatic ecosystems Acidification of aquatic ecosystems destroying the life in them destroying the life in them

• Damage forests and other plants in a Damage forests and other plants in a variety of ways variety of ways

• 9. Living space/available land: is greatly 9. Living space/available land: is greatly decreasingdecreasing as a result of as a result of increasingincreasing population population – creates increasing stress on individual humans creates increasing stress on individual humans – we are also taking up living space and resources we are also taking up living space and resources

needed by other organisms needed by other organisms

• 10. Forests: are becoming increasingly 10. Forests: are becoming increasingly depleted as a result of depleted as a result of timber needstimber needs & the & the need for more need for more agricultural landagricultural land – the direct harvesting of timber has destroyed the direct harvesting of timber has destroyed

many forests many forests – this destruction also impacts land use and this destruction also impacts land use and

atmospheric quality atmospheric quality

• 11. Insects: our chief competitors for food 11. Insects: our chief competitors for food – we have destroyed many we have destroyed many beneficialbeneficial insects insects

and many enemies of harmful insects with and many enemies of harmful insects with insecticides insecticides

• 12. Land use (includes increasing 12. Land use (includes increasing urbanization and the cultivation of marginal urbanization and the cultivation of marginal lands) lands) – this decreases the space and resources this decreases the space and resources

available to other species available to other species

Some Other Factors which influence Some Other Factors which influence environmental qualityenvironmental quality

• 1. Population growth and distribution1. Population growth and distribution• 2. Capacity of technology to solve problems2. Capacity of technology to solve problems• 3. Economic, political, ethical, and cultural 3. Economic, political, ethical, and cultural

viewsviews

Some examples: Some examples: • a.) Wealthy people in the developed world a.) Wealthy people in the developed world

tend to have fewer children.tend to have fewer children.• b.) Some countries like China have laws b.) Some countries like China have laws

concerning the number of children a couple concerning the number of children a couple may have without penalty.may have without penalty.

• c.) In some poor cultures in third world c.) In some poor cultures in third world countries, having many children is seen as a countries, having many children is seen as a means of having economic security in old means of having economic security in old age. age.

• **What are some ways we are attempting to **What are some ways we are attempting to deal with environmental degradation? deal with environmental degradation?

Species PreservationSpecies Preservation

• Some efforts to Some efforts to sustain endangered speciessustain endangered species have included have included habitat protectionhabitat protection (wildlife (wildlife refuges and national parks) and wildlife refuges and national parks) and wildlife management (game laws and fisheries). management (game laws and fisheries).

• Animals which were once endangered but are Animals which were once endangered but are presently successfully reproducing and presently successfully reproducing and increasing their numbers are the increasing their numbers are the bison, gray bison, gray wolves and egrets. wolves and egrets.

• Endangered animals which are currently Endangered animals which are currently responding to conservation efforts and responding to conservation efforts and beginning to make a comeback are the beginning to make a comeback are the whooping crane, bald eagle, and peregrine whooping crane, bald eagle, and peregrine falconfalcon. .

• ** The future of many species remains in ** The future of many species remains in doubt. doubt.

• Human activities that degrade ecosystems Human activities that degrade ecosystems result in a result in a loss of diversityloss of diversity in the living and in the living and nonliving environment. These activities are nonliving environment. These activities are threatening current global stability. threatening current global stability.

Ways to Reduce Air PollutionWays to Reduce Air Pollution

• 1. Use fuels which contain 1. Use fuels which contain less pollutantless pollutant, such , such as low sulfur coal and oil. as low sulfur coal and oil.

• 2. Utilize industrial or energy producing 2. Utilize industrial or energy producing processes which processes which minimizeminimize the creation of the creation of pollutants. pollutants.

• 3. Remove pollutants by using such devices as 3. Remove pollutants by using such devices as afterburnersafterburners or catalytic converters before they or catalytic converters before they enter the air. enter the air.

• 4. Design 4. Design new productsnew products which meet basic needs which meet basic needs without generating pollution. without generating pollution.

• ** There are laws which regulate and guide ** There are laws which regulate and guide the use of natural habitats. the use of natural habitats.

• SEQR (SEQR (New York's State Environmental Quality New York's State Environmental Quality Review Act)Review Act):: A New York State law designed A New York State law designed to provide the opportunity for to provide the opportunity for citizencitizen review and comment of the environmental review and comment of the environmental impact of any proposed impact of any proposed developmentdevelopment that that has been determined to have significant has been determined to have significant impact on the environment. impact on the environment.

Some Methods of Controlling Some Methods of Controlling Harmful InsectsHarmful Insects

• Chemical controls (insecticides) Chemical controls (insecticides) – (many drawbacks) (many drawbacks)

2. Biological controls: 2. Biological controls: • Introduction of Introduction of natural enemiesnatural enemies

• (ex. praying mantis) (ex. praying mantis)

• Use artificial sex hormones to lure insects to Use artificial sex hormones to lure insects to their death (their death (pheromonespheromones) )

– (ex. gyplure -- male gypsy moths) (ex. gyplure -- male gypsy moths)

• SterilizationSterilization and release of male insects and release of male insects – (ex. irradiation of screwworm fly w/cobalt-60) (ex. irradiation of screwworm fly w/cobalt-60) – Note: The screwworm fly only gets to mate once, Note: The screwworm fly only gets to mate once,

so she is out of luck if she mates with a sterile so she is out of luck if she mates with a sterile male!! male!!

• InspectionInspection of all materials before entering the of all materials before entering the country to prevent pest introduction. country to prevent pest introduction.

• DestroyDestroy breeding places of insects breeding places of insects– (may have negative environmental consequences (may have negative environmental consequences

on other species) on other species)

• Rotate cropsRotate crops so that harmful insect species so that harmful insect species can not build in numbers and concentrate on can not build in numbers and concentrate on destroying one crop. destroying one crop.

• Plan the time in Plan the time in plantingplanting certain crops. certain crops. – (ex. plant cotton early so that its flowers mature (ex. plant cotton early so that its flowers mature

before the boll weevil lays eggs in the cotton) before the boll weevil lays eggs in the cotton)

How can individual and societal How can individual and societal choices contribute to improving the choices contribute to improving the

environment? environment?

• 1. Through a greater 1. Through a greater awareness and awareness and applicationapplication of ecological principles, each of ecological principles, each individual can help to assure that there will individual can help to assure that there will be suitable environments for succeeding be suitable environments for succeeding generations on our planet. generations on our planet.

• 2. Individuals in society must decide on 2. Individuals in society must decide on proposals which involve the introduction proposals which involve the introduction of of new technologiesnew technologies. .

• These decisions must assess These decisions must assess environmental risks, costs, benefits, and environmental risks, costs, benefits, and trade-offs. trade-offs.

• Some basic questions for assessing the Some basic questions for assessing the value of these technologies might include:value of these technologies might include:

• a.) What could this technology do to the a.) What could this technology do to the environment? environment?

• b.) What are the odds this technology b.) What are the odds this technology would have this effect? would have this effect?

• c.) How do scientists and engineers know c.) How do scientists and engineers know what this technology will do to the what this technology will do to the environment? environment?