Biodiversity COLLEGE OF AGRICULTURAL SCIENCES • COOPERATIVE EXTENSION CENTER FOR BIODIVERSITY RESEARCH, ENVIRONMENTAL RESOURCES RESEARCH INSTITUTE OUR LIVING WORLD: YOUR LIFE DEPENDS ON IT!
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Biodiversity
COLLEGE OF AGRICULTURAL SCIENCES • COOPERATIVE EXTENSION
CENTER FOR BIODIVERSITY RESEARCH, ENVIRONMENTAL RESOURCES RESEARCH INSTITUTE
OUR LIVING WORLD:YOUR LIFE DEPENDS ON IT!
ContentsI. The web of life connects us all 1
II. Humanity depends on the natural diversity of life 2
III. The little things that run the world 4
IV. Biodiversity is a basic economic resource 6
V. Food doesn’t grow in supermarkets 8
VI. Biodiversity, our little-known natural heritage 10
VII. Natural diversity is rapidly declining 12
VIII. What can you do to help? 14
Acknowledgments and further reading 16
“The people have a right toclean air, pure water, and tothe preservation of thenatural, scenic, historic, andesthetic values of theenvironment. Pennsylvania’spublic natural resources arethe common property of allthe people, includinggenerations yet to come. Astrustee of these resources,the Commonwealth shallconserve and maintain themfor the benefit of all thepeople.”
Section 27,Article 1, PennsylvaniaConstitution
Text by Ke Chung Kim
Edited by Eston Martz
Graphic design by Gretl Collins
Cover illustration byLanny Sommese
Project supported by thePennsylvania Wild ResourceConservation Fund
PrefaceOur survival depends on the web of life
created by the interactions of the millions of
different animals, plants, fungi, and other
microscopic organisms that share the Earth
with us. All of these species together make
up our natural heritage, which we call
biological diversity, or “biodiversity.”
Because of human activities that pollute or
destroy natural habitats, we are losing
species at an alarming rate. For the sake of
both present and future generations, we
must protect biodiversity in Pennsylvania,
the nation, and the world.
This publication highlights how our
existence depends on the web of life. We
will explore the diversity of life, see how
closely our lives are linked to those of other
organisms, learn how all species together
make natural processes function, and
discover what we can do to help protect our
natural partners in life. Conserving
biodiversity helps maintain our quality of
life. It is an investment in Pennsylvania’s
future. By actively supporting the
preservation of our rich natural diversity,
we all can play a part in creating a
sustainable society.
— Ke Chung Kim
Center for BioDiversity Research
Environmental Resources Research Institute
The Pennsylvania State University
The Web of Life Connects Us Alldamage or destroy habitats that plants,animals, fungi, and microorganisms need.As a result, many species have been drivento extinction and many others arethreatened.
Pennsylvania alone has lost over 156native plant and animal species since thearrival of European settlers. Today, nearly800 Pennsylvania species are endangered,threatened, or of special concern.
The planet Earth provides the physicalbase for our life-support system, thebiosphere in which all life exists. Surroundedby an envelope of air, along with soil andwater, Earth teems with millions ofdifferent kinds of plants, animals, fungi,and microorganisms. Together, thesespecies make up the natural diversity oflife, or biodiversity. A person strollingthrough a flower garden, a honey beevisiting a flower, a cow grazing on apasture, or a woodpecker pecking on a treetrunk are all parts of the interconnectedwhole of our living world. No species cansurvive alone—we are all connected in anintricate web of life. The interactionsamong the world’s species form the strandsof the web.
Despite all of our technologicaladvances, our survival still dependscompletely on the web of life. The world’sspecies supply basic necessities such asfood, breathable air, and drinkable water,as well as fuel, fibers, building materials,medicines, and natural areas where weenjoy a variety of recreational activities.
Scientists have identified approximately1.7 million different kinds of organisms,but the actual number could be in the tensof millions. Unfortunately, as habitatdestruction and environmentaldegradation continue, many species will belost without our even realizing theyexisted.
Invaluable strands in the web of life arebeing lost at an alarming rate. Since 1600, atleast 1,140 plant and animal species havedisappeared from the planet, and 31,500species are currently endangered orthreatened with extinction. This loss ofbiodiversity has caused massive, destructivechanges in the world’s climates,landscapes, water resources, andatmosphere.
This serious damage to the web of life isa direct result of the activities of anexpanding human population. In the last200 years, the human population hasincreased six-fold—from 1 billion peoplein 1800 to more than 6 billion today. Thishas placed an increased demand onnatural resources, and we continue to
WHAT IS BIODIVERSITY?Biodiversity is the variety and variation
of all species of plants, animals, fungi,
and microbes, including their genetic
makeup, their ecological roles, and their
interrelationships in biological
communities throughout the world
ecosystems. Biodiversity is therefore the
natural biological capital for our life-
support system on the planet Earth.
What does the loss of these strands inthe web of life mean to our health,economy, and future? When a speciesbecomes extinct, a unique partner in ourlife-support system is gone forever. This lossdeprives humanity of a vital resource andweakens the web of life.
We must protect biodiversity becauseour very existence depends on it.Conserving biodiversity protects our life-partners and preserves vital resources thatensure the viability of the web of life. Eachof us can help keep the web intact bydoing simple things to help preservebiodiversity. The first step is to becomebetter informed about how biodiversityaffects our lives.
1
Humanity Depends on the Natural Diversity of LifeWe share Earth with millions of different species of plants, animals, fungi, and microorganisms, and this biodiversity provides us with thebasic necessities of life. The activities of all these organisms together maintain the atmosphere, develop new soils, break down wastes, storeand filter water, pollinate our crops, provide us with food, and protect us from disease. Without these ecological services, we cannot haveabundant food, natural fibers for our clothes, lumber for our homes and furniture, and a clean environment and good health.
The species that inhabit a common area form a natural community. Each species plays a role in the survival of the other partners, andtogether they maintain the life of their natural community. In a group of natural communities, or an “ecosystem,” the complexinteractions of living organisms with their environments sustain their life-support system. When species are lost, ecosystems cannotfunction properly, and the lives of all partners—including humans—are disturbed.
PhotosynthesisTrees, plants, and algae turnthe sun’s energy intocarbohydrates. All animals,including humans, dependdirectly or indirectly onplants for food.
A healthy atmosphereTrees, plants, and algaerelease tons of oxygen andremove carbon dioxidefrom the atmosphere. Treesand plants also store waterand slowly release it backinto the atmosphere. Plantsrecycle over two-thirds ofthe water directly back tothe atmosphere.
Soil development and wastedecompositionInsects, worms, bacteria, and fungi breakdown animal and plant wastes into tinyparticles that enrich soil and help plantsgrow. These tiny organisms keep theworld from being overwhelmed withdead plant and animal remains.
W H Y D O W E N E E D WHAT IS ABIODIVERSITYACCOUNT?
A biodiversity account is
the number of species of
plants, animals, fungi,
and microorganisms
involved in producing
products for human use.
It also may refer to the
number (and kinds) of
species involved in
maintaining ecological
services that support
humans and other
species. The biodiversity
accounts of the products
we use and the
ecological services we
require involve
thousands of species.
2
BIODIVERSITYACCOUNT OFTHE EASTERNWILD TURKEYNo species can exist
without interacting with
other species. The Eastern
Wild Turkey needs a habitat
that includes both mixed
forests and open vegetation
to survive and breed. Many
different plants and
animals within these
habitats provide food and
shelter for wild turkeys.
Turkeys nest in leaf litter
and in fallen logs. They feed
on seeds and nuts of
various trees and shrubs,
and also eat more than 50
species of mosses and
grasses. Wild turkeys also
eat around 267 species of
insects, spiders, snails,
millipedes, and centipedes.
Hundreds of other
organisms are essential to
the existence of the plants
and animals that provide
food and shelter for wild
turkeys. The biodiversity
account of the Eastern Wild
Turkey includes at least 317
species.
OUR INBORN NEED FORNATUREAs early humans interacted with
other species, they learned to use
plants and animals for food and
clothing and as materials for
shelter. This led to the
development of early human
culture, including agricultural and
iron technology. Humans became a
unique species, with both
biological and cultural aspects.
The cultural aspects of human
life—science, technology, and
art—all depend on the biological
base of our environment.
Humans have an innate need
for nature, called “biophilia.” This
love of nature provides inspiration
for art and music and gives us a
sense of environmental ethics. The
splendor of our state’s landscapes
provides a natural setting for
Pennsylvanians to enjoy outdoor
life. However, as natural habitats
are continually transformed for
human use, our inherent need for
nature gets shortchanged.
ACCOUNTING BIODIVERSITYFOR A FURNISHED HOMEIt takes a large number of
organisms to produce the food,
fibers, and materials we use.
Consider how many species it
takes to sustain the trees we use
to construct and furnish an
average home. A single acre of
forest supports—and depends
on—many hundreds of different
species of fungi, bacteria, animals,
and plants. The combined activities
of these different organisms make
the growth and reproduction of
trees possible. The list of all the
species involved in the life cycle of
trees would number in the
hundreds, even thousands.
Water purificationAquatic plants, animals,and microorganisms breakdown wastes and help keepwater clean.
PollinationBees pollinate floweringplants, including manyfruit and vegetable species.Other insects, birds, andbats also pollinate plants.
B I O D I V E R S I T Y ?
3
Pest controlBirds, bats, fish,mammals, amphibians,and predatory insects eatmany of the insect peststhat might otherwisedevastate our crops orharm our health.
The Little Things that Run the WorldThe Earth is full of manydifferent kinds of smallorganisms, including bacteria,algae, protozoa, fungi, slimemolds, lichens, liverworts,mosses, worms, snails, andinsects and their relatives.These small organismstogether make up most ofglobal biodiversity, and theyare found in astronomicalnumbers throughout theworld. Just 2.5 acres of pasturemay contain about 8.5 tons ofdifferent tiny organisms. Weoften overlook theirimportance because of theirsize, but life on Earth couldnot survive without these smallliving things. All naturalcommunities ultimatelydepend on them.
These small organisms dotheir important ecologicalwork “behind the scenes.”Before the invention of themicroscope, we could notobserve their activities and lifecycles. In many cases, we didnot even know theyexisted. Today, wehave a greaterunderstanding ofthe criticalroles “littlethings”play inmaintainingthe web of life.
TINY ORGANISMS ANDFOOD CHAINSTiny organisms are essentiallinks in food chains, the series ofconnections between predatorsand their prey. When a newlyhatched caterpillar feeds onplant leaves and later becomesa butterfly, for example, thefood chain begins. When a birdeats a caterpillar or a butterfly,a link is added to the foodchain. Another link is addedwhen a dragonfly eats an adultbutterfly. A frog eats thedragonfly. A snake eats thefrog. Finally, a hawk eats thesnake. Losing a link in thisfood chain leads to problemsfor the other species.
Other relationships betweentiny organisms and larger onesare not so easily observed. Forexample, bacteria and smallanimals such as termites andearthworms help maintain andenhance soil fertility.
Bacteria are invisible to thenaked eye, but they areessential to life on Earth. Manypeople mistakenly think allbacteria are harmful tohumans, but only a very smallnumber of the estimated 1million species harm humans,animals, or plants. Mostbacteria actually help ussurvive. They:
• help protect us from disease
• help us digest food andeliminate wastes
• make basic elements likecarbon and nitrogenavailable for use by otherliving things
• break down plant andanimal waste, recycling basicnutrients other organismsneed
• help us produce antibioticsand other medicines
Certain bacteria can even beused to clean up oil spills and
other pollutants. A soil-dwelling species, Bacillusthuringiensis, has been used tocontrol insect pests.
Protists (algae, protozoa, andslime molds) are one-celledorganisms that play a majorrole in the world’s ecosystems.For example, algae generate alarge proportion of the world’soxygen and form a key link inaquatic food chains. Otherprotists, like protozoa andslime molds, decomposeorganic matter by feeding onit. Protozoa also feed onbacteria and help prevent theovergrowth of bacterialpopulations.
Fungi play a key role inmaintaining the health of ourecosystems. This unusual groupof organisms includes yeast,molds, and mushrooms. Manymushroom species are animportant source of food forhumans and other animals. Byfeeding on decaying matter,other species of fungi break
down organic materials. Inforests, fungi returnorganic materials to the
soil as they feed on dead treesand leaves. Some
microscopic fungi form
4
INSECTS AND ARTHROPODS: NATURE’SIMPORTANT PARTNERSInsects and their relatives form a vital link in the food chain.
They are the main source of food for many animals. A variety of birds,
bats, reptiles, amphibians, fish, and other vertebrates depend on these
tiny creatures and would die without them. In some parts of the world,
they are an important food source for humans.
Many plants need insects for pollination.
Pollination is necessary for plants, including many fruits and vegetables,
to reproduce. Humans and other creatures depend on plants for food.
Many parasitic and predacious arthropods are natural pest-control
agents.
Spiders, some mite species, praying mantids, ladybeetles, and many
other arthropods feed on the insect pests that cause millions of dollars
in crop damage each year. Many parasitic insects, such as tiny wasps
and tachinid fly species, lay their eggs inside the bodies of insect pests.
As the larvae grow, the pests eventually die.
Insects help decompose dead plants and animals.
Many insects feed on dead organic matter. If they did not, the Earth
would soon be overwhelmed with slowly rotting plants and animals.
Arthropods are natural recyclers that return nutrients to the soil and
help create new soil.
The nutrients that arthropods obtain from feeding on living plants, as
well as dead plants and animals, are returned to the soil, helping to
maintain fertility and create new soil.
associations with the roots ofplants, including almost all treespecies. This partnership helpsboth survive. The plantprovides food for the fungi,while the fungi help the plantabsorb sufficient water andminerals and protect it fromdrought and disease. Manyplants depend on certainfungal species for seedgermination and growth.
Lichens are unusualassociations between a fungusand a photosynthetic organism,such as green algae, that livetogether and make a joint life.Lichens can absorb moisturedirectly from the air and canwithstand prolonged drought.They are commonly found inrelatively moist places. Someare found even in harshenvironments—atop thehighest mountains, or inextreme cold. They oftencolonize areas of bare rock,where they contribute to thebreakdown of rock and theformation of soil. After soilforms, other organisms canbegin to colonize it. Somelichens provide food forinvertebrate animals. They alsoprovide forage for deer, elk,and other grazing animals.
Mosses and liverworts arerelatively simple, small plantsthat provide habitats for smallanimals such as roundwormsand insects. These tiny plantsalso help prevent soil erosion.
Insects and their relatives, suchas spiders, are the mostsuccessful forms of life onEarth. Also known asarthropods, these creaturesmake up more than 65 percentof all known species—there aremore species of insects than allother species of animalscombined. Over 1 millionarthropod species are known,but the actual number thatexists may be closer to 10million. They are foundeverywhere on the planet,including aquatic habitats suchas streams, rivers, ponds, lakes,wetlands, and undergroundwaters.
When we consider all the ways
tiny organisms help maintain life
on earth, it is clear that we must
preserve the conditions they
need to survive. Without these
“little things that run the world,”
humans could not survive.
5
Biodiversity is a Basic Economic ResourceBiodiversity provides the mostbasic economic resources,including food, fuel, timber,fiber, medicines, andrecreation. Plants and animalsprovide a multitude of usefulproducts, such as gums, resins,shellac, rubber, dyes, waxes,spices, and natural pesticides.These products alonecontribute $3 to $8 billion tothe U.S. economy and $84 to$90 billion to the globaleconomy each year. Thebenefits derived from theworld’s ecosystems are valuedat an average of $33 trillion peryear, supporting the generationof the world’s wealth (by globalGross National Product) of $18trillion.
Many medicines and health-care products come fromglobal biodiversity. In theUnited States, the commercialvalue of pharmaceuticalsderived from the world’sspecies is more than $36 billionannually. Worldwide, sales ofover-the-counter drugs basedon plants alone total $84billion per year.
BIODIVERSITYSUPPORTSPENNSYLVANIA’SECONOMYBiodiversity directly
contributes to
Pennsylvania’s economy
through industries and
activities based on natural
resources.
• Pennsylvania agriculture
generates more than $4
billion annually and
provides hundreds of
thousands of jobs.
• Nearly one out of five
Pennsylvanians hunts or
fishes. They spend more
than $1 billion every year
on these activities.
• Almost half of all
Pennsylvanians over age
16 photograph, feed, or
observe wildlife.
Statewide, over $1 billion
is spent annually on
these interests.
• Our forest products
industry is valued at $4.5
billion per year and
employs more than
100,000 people.
• Tourism, our second
largest industry,
generates over $18.7
billion per year and
supports more than
290,000 jobs.
Some native Pennsylvaniaplants have medicinal value.Ginseng root stimulates thecardiovascular and centralnervous systems and also lowersblood sugar, while witch hazel isused to treat bruises and skinproblems such as inflammation.
To date, only 5 percent ofknown plants have beenexamined for their medicinalproperties. Who knows whatcure may be discovered amongthe remaining plant species?However, habitat destructionacross the world threatensmany plants with extinction.Other organisms withmedicinal potential also arethreatened. In view of theirpossible medical value, wecannot afford to lose any morespecies.
Natural ecosystems alsoprovide many indirecteconomic benefits. Forexample, forests play a criticalrole in maintaining our watersupply. By absorbing the bulkof heavy rains and retainingmoisture during dry spells,
these natural water storage areasprovide flood control and lessenthe effects of drought.
Pennsylvania’s forests serveas a 17-million-acre water treat-ment plant and air purificationsystem. Trees and plants inforests release tons of oxygendaily, remove carbon dioxide,and filter and release water backinto the atmosphere. Theextensive root mass in forestsprevents soil erosion, reducingsediment levels in surface water.Trees also keep summertemperatures lower and help toregulate rainfall cycles.
Wetlands act as naturalfiltration systems and removesilt, heavy metals, and othercontaminants from water; theyabsorb and retain rainwater,gradually make it available toplant roots, and move it intoaquifers and surface streams.Natural ecosystems provide allof these benefits at no cost to us.Preserving biodiversity not onlyprovides jobs and maintains oureconomy, it saves money.
6
FORESTS OFPLENTYForests provide
lumbers to build
houses and to make
furniture, and wood
pulp to produce
papers. Pennsylvania’s
forests contain at least
90 species of trees
that can provide the
10,000 board feet of
lumber needed to
construct and furnish
an average American
home. Pennsylvania’s
forests yield over 1
billion board feet of
hardwood timber a
year—more than any
other state.
Pennsylvania has the
largest hardwood
supply in the nation
and supplies nearly 70
percent of the world’s
black cherry lumber
and veneer. The
average American
wood-frame home,
including furnishings,
easily contains at least
50 tree species.
B I O D I V E R S I T Y P R O V I D E S G O O D M E D I C I N E
More than 40 percent of all prescription drugs—and 9 of the top 10 used in the United States—come from plants, animals, fungi, and microorganisms.
MEDICINE USE MATERIAL SOURCE*
Aspirin painkiller willow bark
Penicillin antibiotic bread mold
Vincristine cancer treatment periwinkle
Vinblastine cancer treatment periwinkle
Digitalis heart stimulant foxglove
Quinine anti-malarial Cinchona (coffee family)
Bacitracin antibiotic bacteria
Erythromycin antibiotic bacteria
Streptomycin antibiotic bacteria
Tetracycline antibiotic bacteria
Morphine painkiller opium poppy
Codeine painkiller opium poppy
Taxol ovarian and breast cancer treatment Pacific yew
* Materials from these species are specifically processed to make all prescription drugs.
Natural Purification
Saves $5 To $7 Billion
For many years, the Catskills’
watershed provided clean water to New
York City and surrounding
communities. When the watershed
became polluted due to sewage,
agricultural runoff, and other human
activities, the city faced a choice: build
an artificial filtering system for $6 to
$8 billion, or restore the dynamic
filtering capacity of the Catskills’
natural purification system. The New
York City administration aptly decided
to restore the watershed at a cost of
only $1 billion, saving taxpayers $5 to
$7 billion.
7
Dead plant material provides food forthese tiny living things, and the cycle oflife continues. When we drink the cow’smilk, bacteria in our digestive systems helpus digest it and also provide us with severalB vitamins and vitamin K. All of thesepartners—bacteria, fungi, insects,earthworms, plants, and cows—benefitfrom the activities of other members inthis “cow ecosystem.”
A surprisingly large number of speciesare involved in producing a typical meal.Let’s say you had a hamburger, frenchfries, and an apple pie for lunch. What isthe biodiversity account of this one meal?Ground beef comes from cattle that eatpasture plants, roughage, and storedgrains. Pasture in the eastern U.S. iscomposed of at least five grasses, sevenlegumes, and at least five weed species.Innumerable species, including insects,spiders, earthworms, fungi, bacteria andother microbes, support the life of thesegrasses, grains, and legumes.
The remaining items come directlyfrom at least 15 other species. The breadfor hamburger rolls uses flour from wheat,
Food Doesn’t Grow In SupermarketsAll of our food comes from biodiversity.The world’s species provide fruits,vegetables, legumes, mushrooms, seeds,nuts, grains, milk, cheese, butter, eggs,poultry, fish, meat, and even the spices,syrups, honey, and sugar we add to ourfood. The lives of these species aresustained by close partnerships with otherspecies in their ecosystems. This web of lifelinks all the organisms that provide ourfood supply.
Today, most of us buy food at grocerystores rather than growing or raising itourselves. We rarely see the interactionsbetween species we eventually eat andtheir partner species in a naturalcommunity.
Consider how many species contributeto the life of a dairy cow. When a cow eatsplants, bacteria that live in the cow’sstomach make digestion of the plantspossible. The plants depend on millions ofbacteria, fungi, and insects in the soil todecompose dead vegetation and makenutrients available. Earthworms aerate andhelp create the soil plants need to grow.
sugar from sugar cane, and yeast fungus.French fries are made from potatoes, andone or more corn or soybean species areneeded to make the oil used to fry them. Ifthe hamburger includes lettuce, tomato,pickles, and onion, four more species canbe added to the meal’s biodiversityaccount. Catsup (from tomatoes) andmustard (a plant species) may eachcontain additional spices from plantspecies. The apple pie filling is made fromone or more apple varieties, spices fromseveral plant species, butter or margarinemade from milk or vegetable oil, andsugar. The crust is made of flour fromwheat and vegetable shortening fromseveral plant species.
All of these food items rely on animmense community of other species.Without pollinators, there would be noapples, potatoes, or tomatoes. Countlessother species are necessary for the energyand nutrient recycling that make all plantgrowth possible. The biodiversity accountof this one meal runs into many hundreds,possibly thousands, of species.
A L L O F O U R F O O D C O M E S F R O M B I O D I V E R S I T Y .
Ketchup:
Tomato, spices
(5+ species)
French fries:
potatoes, corn oil,
soybean oil, salt
(3+ species)
Pie filling:
apples, sugar, nutmeg,
cinnamon, lemon juice
(5+ species)
Bun:
wheat, sugar, yeast,
milk (4+ species)
Pie crust:
wheat, sugar, butter,
vegetable oil
(4+species)
The total
biodiversity
account
from all the
ingredients
in this one
meal runs
into many
hundreds.
8
A meal
biodiversity
account based
on terminal
ecosystem
products
adds up to
at least 40
species.
Beef:
cattle feeds,
roughage, grains
(8+ species)
Lettuce (1)Pickle:
(3+ species)
cucumber, dill,
garlic, vinegar
Onion (1) Mayonnaise
(4+ species)
Mustard
(3+ species)
FOOD BIODIVERSITY ACCOUNTIn this country, food is so plentiful and accessible that many of ustake it for granted. Yet, to feed the rapidly increasing humanpopulation, we need to find new food sources and make our cropsmore resistant to disease, drought, and pests. How can this beaccomplished? Biodiversity may help provide an answer.
Many of our crops were domesticated by our ancestorsthousands of years ago. These wild species were originally rich invariation in size, yield, and resistance to drought and disease.Over time, crop varieties were selected for the largest size, highestyields, and the flavors humans prefer. At the same time, othervaluable traits, such as greater resistance to disease, pests, ordrought, were often unknowingly eliminated. This process hasresulted in crop uniformity. Since the individual plants that makeup a modern crop are genetically alike, an entire crop may bewiped out if the plants lack resistance to drought, pests, ordisease. Adding genes from the wild plants our crops weredeveloped from can help modern crop plants withstand insectinfestation, unfavorable weather, or disease.
Currently, only 20 plant species provide 90 percent of theworld’s food. Nearly 80 percent of the global diet comes from justfour plant species: wheat, corn, rice, and potatoes. There are,however, over 30,000 edible plant species. These untapped wildcrop species could be introduced and made part of ouragricultural systems. Sadly, many of these wild plants are rapidlydisappearing worldwide, while 6 billion people must be fed.
To safeguard our food supply, we need to utilize a variety offood species and incorporate the natural strengths of wildrelatives into our staple crops. The wild relatives of many cropplants still survive, but their numbers have steadily decreased.Many species are now threatened with extinction, leading to therapid decline of global genetic stocks.
FOOD FROMTHE WATERMany people enjoy eating a tuna sandwich. Tuna
does not come from a can, but from the ocean. The
tuna is part of a marine ecosystem that includes
many other organisms, and it relies on a number
of these for food. Tuna fish feed on other fishes,
mostly mackerels and herrings. Mackerels feed on
small fishes, crustaceans, squids, worms, and
plankton. Herrings eat mostly plankton, but also
small fishes and crustaceans. Thus, the
biodiversity account of a tuna
easily involves 50 species of
animals as food. Tuna
populations can suffer if
these other marine
animals are lost due to
pollution or other
human
causes.
The marine fish
catch adds $2.5
billion to the U.S.
economy, and $82
billion worldwide,
but modern fishery
practices are not
sustainable. Fish
stocks throughout
the world are being
depleted rapidly by
overfishing,
threatening many
species. Our
marine fish stocks
need to be
safeguarded.
Nearly 80 percent of theglobal diet comes
from just fourplant species:wheat, corn,
rice, andpotatoes.
9
Biodiversity, Our Little-Known Natural HeritageBiodiversity did not developovernight. The great diversityof plants, animals, fungi, andmicroorganisms reflects anevolutionary history that spans3.5 billion years. Over thattime, many species died outand new species replacedthem, shaping the compositionand structure of today’sbiodiversity. Every species,molded over time by geneticforces, other species, and thesurrounding environment,occupies a specific habitat witha definite range of distributionand specific ecological roles toplay in the ecosystem. Togetherthey weave an intricate web oflife, in which every speciesmatters.
More than half of globalbiodiversity occurs in tropicalrain forests, but only a verysmall fraction of this vast
Rivers, lakes, and wetlands provide richresources for biodiversity, although they coverless than 1 percent of the Earth’s surface.
biodiversity is known. Even inNorth America, wherebiodiversity is relatively betterknown, the documentedspecies of insects and arachnidsrepresent barely 50 percent ofthe estimated total of 200,000species. Many of these species,both known and undescribed,have become extinct orendangered.
Rivers, lakes, and wetlandsprovide rich resources forbiodiversity, although theycover less than 1 percent of theEarth’s surface and take uponly 0.01 percent of the world’stotal water resources.Freshwater biodiversityaccounts for more than 12percent of the known species ofanimals and 41 percent of allknown fishes in the world—scientists are continuallydiscovering new species inrivers, lakes, and wetlands.Rivers and lakes in the UnitedStates contain the largestbiodiversity of severalinvertebrates, such ascrayfishes, mussels, snails, andaquatic insects. Freshwaterbiodiversity suffers frompollution much more thanland-based plants and animals.
During a recent event atFrick Park in Pittsburgh, 1,500volunteers explored the area,searching for all the speciesthey could find in one day. Inthis small area, they found1,471 species of plants, animals,and fungi. An estimated 24,000different plants and animalsinhabit Pennsylvania, includingspecies found nowhere else.Unfortunately, many species inPennsylvania have disappeared,and a great number of theremaining species areendangered or threatened.
10
HOW
MAN
Y SPECIES EXIST ON
EARTH?
Over the last250 years, scientistshave documentedapproximately1.75 MILLION SPECIES• 1,320,000 animals• 270,000 plants• 80,000 protozoans• 72,000 fungi• 4,000 viruses• 4,000 bacteria
Global biodiversitylikely includes over
10 MILLION SPECIES,but we have documented only
about 17 percent of them.
Recent estimatessuggest that lessthan 10 percent ofinsects, nematodeworms, and fungiare documented.For bacteria andother microorganismsthe number is evensmaller—less than1 percent.
B I O D I V E R S I T Y I N P E N N S Y L V A N I A
Lichens, Mosses, and
Liverworts
351 lichen species, 350 moss
species, and 115 liverwort species
Fungi
7,447 species
Vascular Plants
2,103 native species
— 116 are believed to have
disappeared from Pennsylvania
— 368 are endangered or
threatened
— 52 are considered rare
Mammals
73 native species
— 11 have disappeared from
Pennsylvania, including the gray
wolf, mountain lion, lynx, bison,
wolverine, moose, marten, and
the marsh rice rat
— 6 are endangered or
threatened
— 3 are considered rare
Reptiles
37 species
— 2 have disappeared from
Pennsylvania
— 5 are endangered or
threatened
Amphibians
36 species
— 1 has disappeared from
Pennsylvania
— 4 are threatened or endangered
Fish
160 native species
— 15 have disappeared from
Pennsylvania
— 21 are threatened or endangered
— 1, the blue pike, may be extinct
Invertebrates
Up to 20,000 species; only 11,702
have been documented
— Invertebrates make up 61 percent
of Pennsylvania’s biodiversity
— Of 65 freshwater mussel species,
over half are endangered or gone
from Pennsylvania
— Approximately 282 species
(including sponges, mollusks,
crayfish, amphipods, pillbugs,
sowbugs, ostracods, and insects)
are considered Species of Special
Concern
— 37 species have disappeared
from the state
Birds
394 species
— 11 are endangered
— 5 are threatened
— 9 are rare
— 1, the passenger pigeon,
is extinct
11
Natural Diversity is Rapidly Declining
What is causing this loss ofirreplaceable natural resourcesand the destabilization of ourlife-support systems? Theprimary culprit is the humanspecies. Our activities degrade,fragment, and destroy habitats.We overexploit naturalresources; we introduce non-native species; and we polluteair, water, and soil. Ouractivities are even causing theworld’s climates to change.
According to the fossilrecord, the average life span ofa species is 4 million years.During the last century,though, as more speciesbecome extinct, the averagelife span of a mammal specieshas dropped to less than 10,000years—the life expectancy oftoday’s mammal is only 100 to1,000 years. Throughouthistory, normally only 1 to 10species became extinct eachyear. Today extinction occurs atan alarming rate—at least1,000 species are lost every
year. This is 100 to 1,000 timesthe normal extinction rate.
During past massextinctions, at least 65 percentof all species became extinct,resulting in drastic changes inthe composition of life formson Earth. Natural communitiesand ecosystems could continueto function because the loss ofspecies occurred gradually overhundreds of thousands ofyears. As species died out, newlife forms arose to help carryout critical ecological services.
The current rapidextinction rate does not giveecological communitiesenough time to replenish theloss of species. Since speciesdepend on one another, achain-reaction of extinctionscan occur as more species in anatural community disappear.This massive decline inbiodiversity threatens the stablefunctioning of ecosystems.
Since the year 1600, morethan 1,100 species havebecome extinct, including 484
Together, millions of differentspecies of plants, animals,fungi, and microorganismssupport the wonders of life.Their intricate interactionsamong themselves and withsurrounding environmentsprovide clean air and water,food, and other materials weneed for survival. Yet every daywe lose more species. We losethem both to extirpation, whena species is gone from one areabut still exists elsewhere, and toextinction, the permanent lossof a species.
animals and 654 plants. Thisdoes not include the largenumbers of species that werenever documented butnevertheless became extinctduring this time.
As of 1994, over 31,000 ofthe world’s species—5,366animals and 26,106 plants—were considered threatenedwith extinction (threatenedspecies), and 4,816 species werein danger of becoming extinct(endangered species). Thesenumbers do not include vastnumbers of tiny organisms thatinhabit threatened habitats, buthave not yet been discoveredand named.
Like the rest of the world,Pennsylvania has experienced aserious decline in biodiversity.Although our state’s populationhas remained around 12 millionpeople for the last 20 years,shifts in where we choose to liveand how we use land posesignificant threats to our nativebiodiversity.
Many of Pennsylvania’snatural habitats have beenfragmented, altered, ordestroyed by urban andsuburban sprawl, lack of zoningand planning at the municipallevel, road construction, andindustrial activities. Thedestruction of 56 percent of ourstate’s wetlands has been amajor cause of loss of species,since 84 percent of nativeamphibians, 46 percent ofnative birds, 44 percent ofnative reptiles, and 37 percentof native vascular plants dependon wetlands. If the loss ofwetlands continues, morespecies will be lost.
Forty percent of Pennsyl-vania’s forests have been clearedto make way for agriculture anddevelopment. Most of theremaining forests are only 80 to
PRIMARY CAUSESOF TODAY’SEXTINCTION
• Increasing human
population and expanding
economic development
place exhaustively high
demands on biological
resources.
• People focus on short-term
solutions and not long-
term consequences when
making decisions.
• Economic markets do not
recognize the value of
biodiversity and ecosystem
functions.
• The use of natural
resources is not properly
regulated.
• Government policies do
not address the exhaustive
use of biological
resources.
• Human migration and
international travel and
trade are rapidly
expanding.
This is 100 to1,000 timesthe normalextinctionrate.
Today atleast 1,000species arelost everyyear.
12
100 years old and lack the richdiversity of species found in“old-growth” forests. Youngerforests do not support speciesthat need the unique conditionsfound in older forests.
Some larger mammals andmany migratory birds requirelarge, unbroken expanses offorest. Road construction anddevelopment have fragmentedour landscape, resulting inboth a loss of species and adecline in the number ofindividuals making up theremaining species.
Pollution is another majorcause of biodiversity loss inPennsylvania. Contaminationfrom industry, agriculture, andother sources degrades naturalhabitats and results in the lossof local populations of manyplants and animals. Fifty-sevenpercent of all endangeredspecies in Pennsylvania becameendangered due to pollution ofaquatic habitats. Pollution is aleading cause of the declines inmany native fish and musselpopulations.
Many species of plants andanimals in rivers, lakes, andwetlands are threatened withextinction. About 40 percent of
freshwater fish and amphibianspecies are also at risk. Thirty-seven percent of 303 species ofAmerican freshwater fishes areat risk of extinction, and 17species have alreadydisappeared during the lastcentury. In Pennsylvania, 13native fish species are at risk.Sixty-seven percent of 300freshwater mussel species inthe Unites States are injeopardy, and 1 in 10 speciesmay already have disappeared.Similarly, half of all crayfishspecies in the United States areat risk of extinction.
E X O T I C I N V A D E R S O F P E N N S Y L V A N I ADATE OF INTRODUCTION
INTO U.S. PLACE OF ORIGIN PROBLEMS CAUSED
Zebra mussel 1988 Asia Outcompetes other aquatic mussels and fish
Chestnut blight fungus 1904 Asia Destroyed chestnut forests
Dutch elm disease fungus 1930 Asia Eliminated most of the American elms in the eastern United States
Purple loosestrife (plant) 1800s Europe Chokes wetlands, eliminating other plants and their associated animal
communities
Brown trout 1884 Europe Outcompetes many native fish, some of which now face local extinction
Gypsy moth 1869 Europe Defoliates native trees, altering the composition of native forests
European starlings 1890 Europe Compete with Eastern Bluebirds for nest sites
House or English sparrows 1853 Europe Compete with Eastern Bluebirds for nest sites
Major threats to freshwaterfishes include nonpoint sourcepollution, invasive plants andanimals, and dams. Nonpointsource pollution includes manydifferent chemicals, nutrients,and sediments from soilerosion caused by agriculture,some forestry activities, urbanand suburban development,and highway construction.When invasive species ofanimals and plants enter ourfreshwater systems, they oftenoutcompete native species forfood and space. Dams createphysical barriers to fish
movement and disturbwatershed systems.
In addition to habitat lossand pollution, the introductionof aggressive, non-indigenousspecies poses a major threat tomany species and habitats.Pennsylvania has had its shareof “exotic invaders,” withdisastrous consequences. Manyof these species have not beenharmful, but some havereproduced and spread to suchan extent that they threatenthe survival of native species.
13
What Can You Do To Help?We all depend on the riches ofbiodiversity to sustain ourhealth, our economy, and ourvery lives. Yet biodiversity inPennsylvania—and the rest ofthe world—is seriously
PRESERVEHABITATSTo protect biodiversity inPennsylvania, we mustprotect natural habitats.
1. Habitats, includingforests, wetlands,grasslands, rivers, andlakes, need to besustainably managed.
2. Fragmentation andalteration of wild areasshould be avoided.
3. Mined and disturbedareas, includingwetlands, need to berestored.
4. Air, water, and soil mustbe protected frompollutants andcontaminants.
5. Invasive, non-nativespecies must be keptout of local ecosystems.
threatened. We must act nowto preserve biodiversity.
Most U.S. citizens areconcerned aboutenvironmental problems.Since we all benefit from the
natural diversity of life,preserving it is everyone’sresponsibility.
You can do many simplethings to improve and sustainthe quality of life we enjoy nowand to safeguard the quality oflife for future generations.
14
W H A T Y O U C A N D O T O H E L P
LEARN MORE ABOUTBIOLOGICAL DIVERSITY• Be aware of the ways biodiversity
enriches the quality of your life.
• Learn to recognize local areas
rich in biodiversity, especially
those that are already threatened.
• Learn more about endangered
species and how they became
endangered.
• Make your daily activities
protective of our natural heritage.
USE SOUNDGARDENING ANDLANDSCAPINGPRACTICES• Plant a variety of native trees,
shrubs, and ground covers in
home landscaping.
• Avoid using liquid fertilizers, toxic
pesticides, and weed killers on
your property.
• Compost food scraps and use
organic gardening methods.
RECYCLE• Recycle when possible and
reduce consumption of
nonrecyclable products.
• Buy recyclable products
whenever possible.
CONSERVE WATERAND PROTECTWATER QUALITY• Avoid unnecessary water use.
• Use environmentally safe
detergents that are
biodegradable and low in
phosphates.
DISPOSE OF WASTEPROPERLY• Dispose of hazardous household
chemical wastes such as motor oil,
antifreeze, paint, paint remover,
toxic cleaning agents, and
pesticides at recycling centers or
community collection points.
• Dispose of batteries and other
manufactured consumer products
properly.
CONSERVE ENERGY• Improve the energy efficiency of
your home to reduce energy
consumption
• Drive an energy-efficient car.
• Carpool or use public
transportation whenever possible.
GET INVOLVED• Support local, national, and global
environmental groups and
organizations that work to protect
biodiversity.
• Work with your elected officials to
safeguard biodiversity.
• Attend public meetings that
address biodiversity issues such as
land development, public water
supply, sewage treatment, and solid
waste management.
• Urge your representatives and other
elected officials to support the
protection of biodiversity.
• Promote biodiversity awareness
programs in schools, 4-H clubs,
scout groups, and other places.
15
Acknowledgments:also wish to thank theEditorial Committeemembers (Rick Carlson,Frank Felbaum, Tom Ford,Caren Glotfelty, JerryHassinger, Robert Hill, andKim Steiner) for theiradvice and patience incompleting this project.
My special appreciationgoes to Lanny Sommese forhis illustration, created forthe accompanying posterthat adorns the covers ofthis publication.
This publication was madepossible with a grant fromthe Pennsylvania WildResource ConservationFund with support of thePennsylvania Department ofConservation and NaturalResources, PennsylvaniaGame Commission,Pennsylvania Fish and BoatCommission, and PennState’s College ofAgricultural Sciences. Thisproject would not havebeen possible without theircontinued interest andsupport, for which I wish toexpress my greatappreciation. My specialthanks go to Robert Hill,former biodiversitycoordinator, PennsylvaniaDepartment ofConservation and NaturalResources, and Frank H.Felbaum, Pennsylvania WildResource ConservationFund, for their support andpatience during thepreparation of thispublication.
— K.C. Kim
The publication of thisbooklet has been delayedbecause of my unexpectedhealth problems and changesof writing/editorial assistantsfor the project since it beganin fall 1997. I have receivedgenerous assistance inreference searching, writing,and editing from ElaineTietjen, Claudia Violette, JoyDrohan, and JenniferChesworth. Their intellectualand editorial contributionshelped shape the perspectivesof this booklet. My specialgratitude is due to Elaine,Claudia, and Joy for theirefforts and assistance.Furthermore, a large numberof my colleagues kindlyreviewed many differentdrafts of the booklet. Mythanks for their kind reviewsare due to John Grehan,Robert Hill, Carolyn Mahan,Bruce McPheron, MaryannFrazier, Shelby Fleischer,Mike Saunders, Les Lanyon,R. P. Withington III, LisaWilliams, and Teresa M.Alberici. The publication ofthis booklet could not havebeen possible without theexcellent editorial andgraphics work of the PennState Information andCommunicationsTechnologies staff,particularly Eston Martz,executive editor, GretlCollins, publications designer,and Howard Nuernberger,photographer. I acknowledgetheir contributions to theproduction of this bookletwith my great appreciation. I
FURTHER READING:
• Baskin, Y. 1997. The Work ofNature. How the Diversity ofLife Sustains Us. Island Press,Washington, D.C.
• Biodiversity: The Fragile Web.National Geographic, Vol.195, No. 2, February 1999.
• Costanza, R., B. G. Norton,and B. D. Haskell (eds.).1992. Ecosystem Health: NewGoals for EnvironmentalManagement. Island Press,Washington, D. C.
• Daily, G. C. (ed.). 1997.Nature’s Services: SocietalDependence on NaturalEcosystems. Island Press,Washington, D.C.
• Di Giulio, R. T. and E.Monosson (eds.). 1996.Interconnections betweenHuman and Ecosystem Health.Chapman & Hall, London,U.K.
• Grifo, F. and J. Rosenthal(eds.). 1997. Biodiversity andHuman Health. Island Press,Washington, D. C.
• Hassinger, J. D., R. J. Hill, G.L. Storm and R. H. Yahner.1998. Inventory andMonitoring Biotic Resources inPennsylvania. PennsylvaniaBiological Survey, UniversityPark, PA.
• Heywood, V. H. and R. T.Watson. 1995. GlobalBiodiversity Assessment.UNEP/CambridgeUniversity Press, Cambridge,U.K.
• Kim, K. C. and R. D. Weaver(eds.). 1994. Biodiversity andLandscapes: A Paradox ofHumanity. CambridgeUniversity Press, New York,NY.
• Mac, M. J., P. A. Opler, C. E.Pucket Haeker, and P. D.Doran. 1998. Status andTrends of the Nation’sBiological Resources. Reston,VA: U.S. Department ofInterior, U. S. GeologicalSurvey. Vol. 1:1-436, Vol.2:437-964.
• Pearce, D. and D. Moran.1994. The Economic Value ofBiodiversity. EarthscanPublications Ltd, London.
• Prugh, T. 1995. NaturalCapital and Human EconomicSurvival. ISEE Press,Solomons, MD.
• Thorne, S. G., K. C. Kim, K.C. Steiner, and B. J.McGuinness. 1995. AHeritage for the 21st Century:Conserving Pennsylvania’sNative Biological Diversity. AReport by the PennsylvaniaBiodiversity TechnicalCommittee. PennsylvaniaFish and Boat Commission,Harrisburg, PA.
• Wilson, E. O. 1984.Biophilia. Harvard UniversityPress, Cambridge, MA.
• Wilson, E. O. (ed.) 1988.Biodiversity. Washington,D.C.: National AcademyPress.
• Wilson, E. O. 1992. TheDiversity of Life. The BelknapPress of Harvard UniversityPress, Cambridge, MA.
16
Penn State College of AgriculturalSciences research, extension, andresident education programs arefunded in part by Pennsylvaniacounties, the Commonwealth ofPennsylvania, and the U.S.Department of Agriculture.
This publication is available fromthe Publications Distribution Center,The Pennsylvania State University,112 Agricultural AdministrationBuilding, University Park, PA 16802.For information telephone (814)865-6713.
Where trade names appear, nodiscrimination is intended, and noendorsement by Penn StateCooperative Extension is implied.
Issued in furtherance of CooperativeExtension Work, Acts of CongressMay 8 and June 30, 1914, incooperation with the U.S.Department of Agriculture and thePennsylvania Legislature. T. R. Alter,Director of Cooperative Extension,The Pennsylvania State University.
This publication is availablein alternative media onrequest.
The Pennsylvania State University iscommitted to the policy that allpersons shall have equal access toprograms, facilities, admission, andemployment without regard topersonal characteristics not relatedto ability, performance, orqualifications as determined byUniversity policy or by state orfederal authorities. It is the policy ofthe University to maintain anacademic and work environmentfree of discrimination, includingharassment. The Pennsylvania StateUniversity prohibits discriminationand harassment against any personbecause of age, ancestry, color,disability or handicap, nationalorigin, race, religious creed, sex,sexual orientation, or veteran status.Discrimination or harassmentagainst faculty, staff, or students willnot be tolerated at The PennsylvaniaState University. Direct all inquiriesregarding the nondiscriminationpolicy to the Affirmative ActionDirector, The Pennsylvania StateUniversity, 201 Willard Building,University Park, PA 16802-2801, Tel814-865-4700/V, 814-863-1150/TTY.
© The Pennsylvania State University2001
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Live a lifestyle that promotes thepreservation of our natural heritage.
Your Life Depends On It
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