Sustaining biodiversity and ecosystem

8/18/2019 Sustaining biodiversity and ecosystem

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BG/CH 0493Environmental Sustainability:

Chapter 9Sustaining Biodiversity: SavingSpecies & Ecosystem Services

“The natural world is everywhere disappearingbefore our eyes – cut to pieces mowed down,

plowed under, gobbled up, replaced by humanartifacts” – Edward O. Wilson


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Honeybee

Fig. 9-1, p. 190


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• Bees play a key role in pollination – Collect pollen & nectar for feeding their young (pollen) & adults

(honey); pollen is transferred within/among plants to produceseeds & fruit (many vegetables, fruits, tree nuts – almonds)

• Globally, about 1/3 of food supply comes from insect-pollinated plants

• Currently, agriculture depends heavily on a singlespecies of bee (European honeybee – 80%) – Violation of biodiversity – Suffering from Colony Collapse Disorder

• Each year (from 2006), 30-50% of colonies in Europe & U.S.• Human activities cause habitat loss, climate change, extinction• Causes : mites, pathogens (virus, fungi), stress, poor nutrition

Core Case Study : Where Have Allthe Honeybees Gone?


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• Species becoming extinct 100 -1,000 times faster thanbefore modern humans arrived on the earth – By the end of this century, the extinction rate is expected to be

10,000 times higher than that background rate

• Extinctions Are Natural but Sometimes Increase Sharply – Biological extinction – no longer found anywhere on Earth

(irreversible), none alive – Trophic cascade – Decline/extinction of connected species – Mass Extinction – Many species (50 – 95%) extinct in short

period of time restored after Millions of years

9-1 Role of Humans in Loss ofSpecies & Ecosystem Services


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• Background extinction rate – 1 extinct species / year / 1 million species (~10M species)• Extinction rates have risen recently

– Current extinction rate at least 100 × higher than typicalbackground rate - 0.0001% (may rise to 10,000 × by century end)

• Rate of extinction & threats to ecosystem services likelyto rise sharply – Harmful human impacts – 6 th major extinction? (1 century)

• Biodiversity hotspots – Extinction rates projected to be much higher than average (31 %

temperate, 61% tropics – living planet index);• Biologically diverse environments eliminated/fragmented

– Ecosystem extinction can lead to speciation crisis (biodiverseenvironments), loss of air/water purification, natural pest control,pollination

– reduce emergence of new species – Norman Meyers, Speciation crisis essay

Human Activities Hasten Extinctions& Threaten Ecosystem Services


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• Endangered species – So few members that the species could soon become extinct

• Threatened species (vulnerable species) – Still enough members to survive, but numbers declining – May soon be endangered – E. O. Wilson: “first animal species to go are the big, the slow, the

tasty and those with valuable parts such as tusks & skins”

Endangered/Threatened Species:Ecological Smoke Alarms I


7/51Fig. 9-3, p. 194

41%Amphibians

30%

Mammals 25%

Birds 13%

Conifers

Endangered natural capital: Comparison of the percentages of various types of known speciesthat are threatened with extinction hastened by human activities as of 2012 (Concept 9-1).Quest ion: Why do you think so many of the world’s amphibians are threatened with extinction?(See Chapter 4 Core Case Study, p. 78.)


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• Regionally extinct – In areas a species is normally found

• Functionally extinct – To the point at which species can no longer play a functional role

in the ecosystem – Species numbers drop to certain extent, other species

interaction greatly diminished; important ecosystem servicesmight be lost

– Case study : American alligator creating gator nests for certainbirds

Endangered/Threatened Species:Ecological Smoke Alarms II


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Stepped Art

Fixed migratorypatterns

Blue whale, whoopingcrane, sea turtle

Feeds at hightrophic level

Bengal tiger, bald

eagle, grizzly bear

Narrow distribution Elephant seal,desert pupfish

Commerciallyvaluable

Snow leopard, tiger,elephant, rhinoceros, rareplants and birds

Low reproductiverate

Blue whale, giantpanda, rhinoceros

Characteristic Examples

Rare African violet, some

orchids

Large territories California condor,

grizzly bear, Floridapanther

Specializedniche

Blue whale, giantpanda, Everglades kite

Fig. 9-4, p. 194


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9-2 Why Care about the RisingRate of Extinction?

Endangered orangutans depend on arapidly disappearing tropical forest habitat

50-60K in the wild; cleared tropical forests for palm oil plantations; 1-2Kdisappearing per year


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1. Species provide vital ecosystem & economic services – Help keep us alive: honeybees, plants for food – Support economies: food crops, fuelwood, lumber, paper – Bio-prospectors: animals & plants for medicinal plants (62% of

cancer drugs) – Ecotourism: Male lion - $515,000 from tourism (Kenya), but

$1,000 if killed for skin

2. 5-10 million years to regain species biodiversity – Descendants unable to depend on life-sustaining biodiversity &

vital ecosystem services that support well-being & economies3. Right to exist (stewardship view – protect Earth’s species)

– Which to protect? Animals, plants?; Appeal factor? (Elephants,whales, tigers, but not plants and insects? Fear factor –

mosquitoes, cockroaches, snakes, sharks etc

Species are a Vital Part ofEarth’s Natural Capital


12/51Fig. 9-6, p. 196

Pacific yewTaxus brevifol ia ,PacificNorthwest

Ovariancancer

RosyperiwinkleCathran thus roseus ,Madagascar

Hodgkin'sdisease,lymphocyticleukemia

RauvolfiaRauvolf ia sepen t ina ,

Southeast Asia Anxiety, highblood pressure

Neem treeAzadirachta ind ica , IndiaTreatment ofmany diseases,insecticide,spermicides

FoxgloveDigi ta l ispurpurea ,Europe Digitalis forheart failure

CinchonaCinchonaledogeriana ,South AmericaQuinine for

malariatreatment

These plant species are examples of nature’s pharmacy. Once the activeingredients in the plants have been identified, scientists can usually producethem synthetically. The active ingredients in nine of the ten leading prescriptiondrugs originally came from wild organisms.


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• Greatest threats to species are (in order): – Loss or degradation of its Habitat – Harmful invasive species – Human population growth – Pollution – Climate change – Overexploitation (HIPPCO)

9-3 How are we ThreateningSpecies & Ecosystem Services I


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How are we Threatening Species& Ecosystem Services II

• Habitat fragmentation – Divided by roads, crops, urban development – Decrease tree cover, block animal migration, isolated animal

communities – more vulnerable to predators, competitors,

disease & catastrophic events (storms, fires)

• National parks, nature reserves as habitat islands – Surrounded by logging & mining operations, coal power plants,

industrial activities, human settlements – Freshwater lakes also vulnerable to invasive species & human

pollution


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Stepped ArtFig. 9-8, p. 198

Natural capitaldegradation: Thesemaps reveal thereductions in theranges of four

wildlife species,mostly as the resultof severe habitatloss andfragmentation andillegal hunting for

some of theirvaluable body parts.Question: Wouldyou supportexpanding theseranges even thoughthis would reducethe land availablefor human habitationand farming?Explain.

IndianTiger

Range 100 years agoRange today

BlackRhino

Range in 1700Range today

AfricanElephant

Probable range 1600Range today

Asian or IndianElephant

Former rangeRange today


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• Many species introductions are beneficial – Corn, wheat, rice & other crops; cattle, poultry, & livestock

provide >98% USA food; 85% of world’s trees nonnative – Introduced for pest control, European bees for honey (USA)

• Nonnative species may have no natural: – Predators, competitors, parasites, pathogens

• Nonnative species can crowd out native species – Invasive species, disrupt ecosystem services, cause human

health problems, lead to economic losses – cause populationdeclines, local & regional extinction. – 40% (USA) of endangered & 95% (Hawaii) because of invasive

species; $1.4B/year in economic & ecological damage & rising

We Have Moved DisruptiveSpecies into Some Ecosystems


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Stepped Art

Deliberately introduced species

Purpleloosestrife

Europeanstarling

African honeybee(“Killer bee”)

Nutria Salt cedar(Tamarisk)

Marine toad(Giant toad)

Waterhyacinth

Japanesebeetle

Hydrilla European wildboar (Feral pig)

Accidentally introduced species

Sea lamprey(attached to lake

trout)

Argentinafire ant

Brown treesnake

Eurasianruffe

Common pigeon(Rock dove)

Formosantermite

Zebramussel

Asian long-horned beetle

Asian tigermosquito

Gypsy mothlarvae Fig. 9-9, p. 199

These are some of theestimated 7,100 harmfulinvasive species that have

been deliberately oraccidentally introducedinto the United States.

- Have causedecological/economic harm


18/51Fig. 9-10, p. 200

Kudzu vine has overgrown this car in the U.S. state of Georgia.


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• Imported from Japan in the 1930s – Help control soil erosion – grow very rapidly, engulfs hillsides,

gardens, trees, stream banks, cars• Very difficult to kill

– Even with grazing goats & herbicides – which may damage otherplants & contaminate water; Fungus – possible solution

• Could there be benefits of kudzu? – Powdered starch in beverages, gourmet confections, herbal

remedies, leaves nutritious, lessen alcohol intake, fiber for paper

• Kudzu bug – imported from Japan – Can kill Kudzu vine, but spreads even more rapidly, feeds onsoybeans, emits chemical that disturbs & stains human skin,propagate quickly & easily

– Pesticides possible, but may promote resistance, geneengineering to reduce soybean consumption?; wasp to eat bugembryos?

Case Study: The Kudzu Vine &Kudzu Bugs


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• Nonnative invaders – Aircraft, ships, imported food products, cars & trucks, tourists

• Argentina fire ant – introduced in the 1930s – Reduced populations of native ants (up to 90%) – Painful stings can kill (deer fawns, ground-nesting birds, baby

sea turtles, newborn calves, pets & old & young (80) – Pesticide spraying in 1950s & 1960s worsened conditions –

reduced native ants & genetic resistance – Tiny parasitic flies may help control fire ants without harming

native ants or hairy crazy ants but these invade beehives & areresistant to pesticides

Accidentally Introduced Speciescan Disrupt Ecosystems


21/51Fig. 9-11, p. 201

University of Florida researchers hold a 4.6-meter-long (15-foot-long), 74-kilogram (162-pound) Burmese python captured in Everglades National Parkshortly after it had eaten a 1.8-meter-long (6-foot-long) American alligator.


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• Accidentally introduced – Imported as pets but dumped into Everglades wetlands

• Reproduce rapidly and are hard to kill – Live to 20-25 years, up to 5 m length, 77kg, huge appetites,

nocturnal, eats alligators (keystone), domestic pets, farm animals

• Greatly depleted Everglades populations of: – Rabbits, foxes, raccoons, opossums, and deer

• 2012 – illegal to import Burmese pythons, North & South African pythons, yellow anacondas

– Invasive top predator goes to ecosystem with no naturalenemies

Case Study: Burmese PythonsEating through Florida Everglades


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U.S.A. spends $160M annually on eradication/control• Research programs identifying invaders

– Its characteristics, vulnerable ecosystems & predators (control)

• Establishing international treaties banning transferbetween countries – Step up inspection & banning controls, proper cargo ship and

ballast discharging

• Public education about exotic pets & plants• What else can be done to prevent invasive species?

Prevention Is Best Way toReduce Invasive Species Threats


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Fig. 9-12, p. 202


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• Human population growth & overconsumption – Degrading (eliminated, degraded, fragmented) habitat

• Pollution – 1/5 Euro bees, >67M birds, 6-14M fish PA; 20% endangered – Bioaccumulation can cause extinctions of species not directly

affected by pollution – DDT; fish-eating birds, falcons, hawks etc – DDT make bird eggshells fragile – unsuccessful reproduction

• Climate change – Some species will become extinct (polar bear, lemming, arctic

fox, coral polyps) – Some will spread (43 of 61 – Jansson & Nilsson)

Other Species Extinction Causes


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Stepped ArtFig. 9-13, p. 202

DDT in water

0.000003 ppm,or 3 ppt

DDT in smallfish (minnows)0.5 ppm

DDT inzooplankton0.04 ppm

DDT in fish-eatingbirds (ospreys)

25 ppm

DDT in large fish(needle fish)2 ppm

Bioaccumulation and biomagnification: DDT is a fat-soluble chemical that can accumulate in thefatty tissues of animals. In a food chain or web, the accumulated DDT is biologically magnified inthe bodies of animals at each higher trophic level, as it was in the case of a food chain in the U.S.state of New York, illustrated here. (Dots in this figure represent DDT.)Question: How does this story demonstrate the value of pollution prevention?


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• Live only in the Arctic – 60% in Canada, rest in Greenland, Norway, Russia & Alaska – Eats ringed seals (winter), stores fat for summer (low ice)

• Arctic ice is melting – Decreasing habitats – less floating sea ice, shorter time – Polar bears swim farther between ice, less feeding, storing fats

• Weaker females; less reproduction• 30-35% decline by 2050 (20-25,000 in 19 subpopulations) – uneven

population statistics

Case Study: Polar Bears &Climate Change


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Fig. 9-14, p. 204

On floating ice in Svalbard, Norway, a polar bear feeds on its ringed seal prey.Question: Do you think it matters that the polar bear may become extinct duringthis century primarily because of human activities? Explain.


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• Poaching, smuggling of animals, plants – Animal parts (pelt of giant panda, rhinoceros horn, tiger

fur/bones/penis) – Pets (live mountain gorilla, exotic birds: parrots) – Plants for landscaping and enjoyment (orchids, cactus)

• Prevention- research & education – No verifiable evidence horn is aphrodisiac (mostly keratin –

fingernails, hair), sustainable (8cm from base) – Cyanide used to stun tropical fish kill many, also polyps – Worth 16.5 × from ecotourism (hyacinth macaw) – Imported exotic animals may carry: hantavirus, Ebola, Asian bird

flu, herpes B, salmonella

Illegal Killing, Capturing,Selling of Wild SpeciesThreatens Biodiversity


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Fig. 9-15, p. 205

A poacher in South Africa killed this critically endangered northern white rhinoceros for its twohorns. This species is now extinct in the wild. With a rhino horn worth up to $300,000 on the Asianblack market, thieves have been stealing the horns from museums, antique stores, and even

private collections. Question: What would you say if you could talk to the poacher who killed thisanimal for its horns?


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• West and Central African wild animals – Past: sustainable hunting, now: supply cities with exotic meats

• Hunting has driven some species to extinction – Miss Waldron’s red colobus monkey – Potentially spreads HIV/AIDS, Ebola

• Threatened species: – Monkeys, apes, antelope (most hunted), elephants, and hippos

– Alternatives: farmed fish, large rodents: cane rats

Rising Demand for BushmeatThreatens Some African Species


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• 70% of the world’s bird species are declining – 1 in 8 threatened with extinction

• Habitat loss and fragmentation of the birds’ breedinghabitats – Population growth leading to: forests cleared for farms, lumber

plantations, roads, resource usage and housing development

• Intentional or accidental introduction of nonnativespecies – These species (e.g. bird-eating rats, brown tree snakes,

mongooses) eat the birds these kill millions of birds/year

Case Study: A DisturbingMessage from the Birds


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• Exposure to pollutants & industrialization – Oil spills, pesticides, herbicides, toxic lead (shotgun pellets,

angler sinkers) – 23 species of seabirds (e.g. albatross) face extinction as they

drown due to fishing lines & nets• Overexploitation

– For pets (52 of 388 species of parrots threatened)• Birds are indicator species

– Respond quickly to environmental changes & are easy to track &

count – decline indicative of environmental degradation• Birds perform critical ecosystem and economic services

– Pollination, seed dispersal Extinctions could lead to extinctioncascade for many other species

Case Study: Disturbing Messagefrom the Birds (cont’d.)


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Fig. 9-17, p. 206

Endangered natural capital: This endangered Attwater’s prairie chicken lives in a wildlife refugein the U.S. state of Texas.


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• Establishing and enforcing national environmental lawsand international treaties

• Creating protected wildlife sanctuaries• Taking precautionary measures to prevent such harm

9-4 How Can We Sustain Wild

Species and Their EcosystemServices?


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• 1975 – Convention on International Trade in EndangeredSpecies (CITES) – Signed by 178 countries banning hunting, capturing, selling of

threatened/endangered species

– 926 species in extinction danger, 5,000 animals and 29,000threatened plants restricted from international trade – Although reduced international trade, limited effects due to

varying local enforcement (small fines), exemptions, non-signees• Convention on Biological Diversity (BCD)

– Focuses on ecosystems & links biodiversity protection toindigenous people rights – Ratified by 193 countries (not ratified in some key countries like

U.S.A); no severe penalties or enforcement mechanisms• National laws can be important

International Treaties & NationalLaws Help Protect Species


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• Endangered Species Act (ESA) – 1973 and lateramended in 1982, 1985, and 1988 – Identify and protect endangered species in the U.S. and abroad

• National Marine Fisheries Service for ocean species – Responsible for identifying & listing endangered & threatened

species; list/delist based on biological without political/economicfactors; use economic factors to decide on protection

• U.S. Fish and Wildlife Service for all others

Case Study: U.S.A EndangeredSpecies Act


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• Forbids federal agencies (except Defense) fromfunding/authorizing projects that jeopardize endangeredor threatened species

– In 2012, 1,476 species officially listed – ESA requires that all commercial shipments of wildlife

enter/leave country from 1 of 17 designated ports/airports – 120 full-time USFWS inspectors for >200M wild animals – Few illegal shipments are ever caught/confiscated with small

fines

Case Study: The U.S.AEndangered Species Act (cont’d .)


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• Species are listed only when in serious danger – Akin to hospital emergency room taking in most desperate cases

• Conditions for more than half of listed species are stableor improving

– 90% recovering at specified rates, 99% still surviving (ER above)• Budget is about 86 cents per U.S. citizen

– Considered highly productive with such a small budget

• U.S National Academy of Sciences

– Increase funding – Emphasis on recovery plans higher likelihood of getting off list – Establish species habitat & give it maximum protection; focus on

sustainable biodiversity & ecosystem services

Case Study: Is ESA a failure?


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Fig. 9-19, p. 209

The American bald eagle has been removed from the U.S.endangered species list. Here, an eagle is about to catch a fishin its powerful talons.


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• In 1903, Theodore Roosevelt established the first federalwildlife refuge – Pelican Island, Florida – 2009 brown pelican removed from list – 2012 – 560 refuges, >47M annual visitors

• Wildlife refuges – Most are wetland sanctuaries (protect migratory waterfowl) – Are not immune from disturbance: mining, oil drilling, off-road

vehicle usage occur in 60% of them; little funding, poor

maintenance – More needed for endangered plants

Establish Wildlife Refuges& Other Protected Areas


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Fig. 9-20, p. 210

The Pelican Island National Wildlife Refuge in Florida was America’sfirst National Wildlife Refuge.


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• Seed banks – Preserve genetic material of endangered plants – 1,000

collectively hold >3M samples: refrigerated & low humidity – Svalbard Global seed Vault (Arctic) to contain 100M

• Botanical gardens and arboreta – Living plants (1/3 world’s known plants), 3% rare & threatened

plants with space getting limited

• Farms can raise organisms for commercial sale – Alligators (meat, hides, Florida), butterflies (educate visitors,

Papua New Guinea)

Seed Banks, Botanical Gardens,Wildlife Farms Help Protect Species


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• Techniques for preserving endangered terrestrial species – Egg pulling – collect from wild and hatch in Zoo, research center – Captive breeding – bred in captivity before introduction to wild

(peregrine falcon, California Condor) – Artificial insemination – Embryo transfer – implant eggs of 1 species into surrogate mother of

another – Use of incubators – Cross-fostering – rare species raised by parents of similar species

• Ultimately releasing/reintroducing to the wild – Black-footed ferret, golden lion tamarin, Arabian oryx, Condor

• Limited space and funds – Unsuitable habitat, unable to survive wild, poaching, 10,000 members

required for genetic diversity, not gene banks, especially aquariums

Zoos & Aquariums Can ProtectSome Species


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Fig. 9-21, p. 211

The Monterey Bay Aquarium inMonterey,California (USA),contains thistidewater pool,which is used totrain rescued seaotter pups tosurvive in the wild.


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Fig. 9-22, p. 212


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• Precautionary principle – Act to prevent or reduce harm when preliminary evidence

indicates acting is needed; “better safe than sorry”, “look beforeyou leap”

– Species are the primary components of biodiversity• Focus on the preservation of species or ecosystems?

– How to allocate, prioritize resources?

• Which species gets the most attention?

– Most threatened? Keystone? Most human appeal?• Which habitat areas most critical?

The Precautionary Principle


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• Failure to protect honeybees – Loss of vital ecosystem services (Japan, China, pesticide

overuse); pollinate crops by hand – expensive, time-consuming

• Farmers are: – Breeding bees resistant to harmful parasitic mites and fungi – Raising their own colonies – avoid bringing in stressed,

unhealthy honeybees – Improving bee nutrition – by not feeding sugar syrups & pollen

substitutes

Case Study: ProtectingHoneybees and Other Pollinators


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• We are hastening the extinction of wild species anddegrading the ecosystem services they provide by: – Destroying and degrading habitats – Introducing harmful invasive species

– Increasing human population growth, pollution, climate change,and overexploitation

Three Big Ideas


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• We should avoid causing the extinction of wild species – Species provide vital ecosystem and economic services – Their existence should not depend primarily on their usefulness

to us

Three Big Ideas (cont’d.)


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• We can work to prevent the extinction of species and toprotect overall biodiversity and ecosystem services by: – Using laws and treaties – Protecting wildlife sanctuaries

– Making greater use of the precautionary principle

Three Big Ideas (cont’d.)

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Sustaining biodiversity and ecosystem