NARRATOR: PRESENTATION OF

SCIENCE TREK ON IDAHO PUBLIC

TELEVISION IS MADE POSSIBLE

THROUGH THE GENEROUS SUPPORT OF

THE LAURA MOORE CUNNINGHAM

FOUNDATION, COMMITTED TO

FULFILLING THE MOORE AND BETTIS

FAMILY LEGACY OF BUILDING THE

GREAT STATE OF IDAHO; BY THE

IDAHO NATIONAL LABORATORY,

MENTORING TALENT AND FINDING

SOLUTIONS FOR ENERGY AND

SECURITY CHALLENGES; BY THE

FRIENDS OF IDAHO PUBLIC

TELEVISION; AND BY THE

CORPORATION FOR PUBLIC

BROADCASTING.

JOAN CARTAN-HANSEN: FORESTS PLAY

AN ESSENTIAL ROLE IN OUR WORLD,

PROVIDING EVERYTHING FROM A HOME

TO THOUSANDS OF CREATURES AND

FUEL AND RECREATION FOR HUMANS.

BUT THERE'S MORE TO FORESTS THAN

JUST THE TREES.

FIND OUT.

STAY TUNED, SCIENCE TREK IS

NEXT.

(MUSIC)

CARTAN-HANSEN: HI, I'M JOAN

CARTAN-HANSEN, AND WELCOME TO

SCIENCE TREK.

AND WELCOME TO THE UNIVERSITY OF

IDAHO'S COLLEGE OF NATURAL

RESOURCES.

SCIENTISTS ARE STANDING BY TO

ANSWER YOUR QUESTIONS ABOUT

FORESTS.

A LITTLE LATER IN THE SHOW WE'LL

GO INTO MORE DETAIL ABOUT TREES.

BUT FIRST, LET'S LEARN A LITTLE

BIT MORE ABOUT FORESTS.

STUDENT: "FORESTS COVER ABOUT 30

PERCENT OF THE EARTH'S SURFACE."

CARTAN-HANSEN: THAT'S RIGHT.

FORESTS ARE ONE OF OUR WORLD'S

BIOMES.

A BIOME IS A LARGE GEOGRAPHICAL

AREA THAT CONTAINS SIMILAR

PLANTS, ANIMALS, AND

ENVIRONMENTS.

A FOREST IS A COMPLEX COMMUNITY

OF LIFE IN WHICH TREES ARE THE

DOMINANT LIFE FORM.

STUDENT: "THERE ARE THREE BASIC

TYPES OF FORESTS: THE TROPICAL

RAINFOREST, THE TEMPERATE

FOREST, AND THE BOREAL FOREST."

STUDENT: "TYPES OF FORESTS CAN

BE DEFINED BY THE TYPES OF TREES

AND THE AMOUNT OF RAIN."

CARTAN-HANSEN: RAINFORESTS ARE

MOSTLY FOUND AROUND THE EQUATOR.

THEY COVER ABOUT 7 PERCENT OF

THE EARTH'S SURFACE.

RAINFORESTS HAVE THE GREATEST

VARIETY OF TREES.

THEY HAVE TWO BASIC SEASONS, WET

AND DRY.

AND BECAUSE THE CLIMATE IS SO

WARM, RAINFORESTS ARE EVERGREEN,

THAT IS, THE TREES DON'T LOSE

THEIR LEAVES.

RAINFORESTS ARE ALSO SO MOIST

THAT SOME CAN EVEN CREATE THEIR

OWN RAIN.

STUDENT: "TEMPERATE FORESTS GROW

IN NORTH AMERICA, NORTHEASTERN

ASIA, WESTERN AND CENTRAL

EUROPE, AND SOUTH OF THE

EQUATOR.

TEMPERATE FORESTS ENJOY ALL FOUR

SEASONS OF WEATHER."

CARTAN-HANSEN: TEMPERATE FORESTS

HAVE DECIDUOUS AND CONIFER, OR

EVERGREEN TREES.

STUDENT: "DECIDUOUS IS LATIN AND

MEANS 'TO FALL.'

DECIDUOUS TREES LOSE THEIR

LEAVES IN THE FALL AND REGROW

THEM IN THE SPRING."

STUDENT:"CONIFER OR EVERGREEN

TREES HAVE NEEDLES AND KEEP THEM

YEARROUND."

CARTAN-HANSEN: TEMPERATE

DECIDUOUS FORESTS IN NORTH

AMERICA HAVE TREES LIKE OAK,

MAPLE, AND BEECH.

IN THE SOUTHERN HEMISPHERE

TROPICAL DECIDUOUS FORESTS HAVE

A WARMER CLIMATE.

TREES HERE DON'T GROW AS TALL.

THEIR TRUNKS AND BRANCHES TWIST

MORE AND THEIR TREE'S BARK IS

THICKER.

FORESTS, NO MATTER THE TYPE,

HAVE THREE BASIC ZONES: THE TOP

IS CALLED THE "CANOPY"; THAT'S

WHERE BRANCHES JOIN TOGETHER TO

FORM SORT OF A ROOF OVER THE

REST OF THE FOREST.

THE NEXT LEVEL IS THE

"UNDERSTORY"; THAT'S WHERE THE

SMALL BUSHES, PLANTS, AND

SAPLINGS LIVE UNDERNEATH THE

MATURE TREE'S CANOPY.

THE FINAL LEVEL IS THE FOREST'S

"FLOOR."

HERE LIVING THINGS LIKE ALGAE,

FUNGI, LICHEN, MOSS, AND THE

DECAYING PLANTS AND LEAVES

CREATE A SQUISHY CARPET ON THE

FOREST FLOOR.

STUDENT: "HERE'S A FACT FOR YOU:

INSECTS ARE THE ONLY CREATURES

THAT LIVE IN ALL LEVELS OF THE

FOREST."

CARTAN-HANSEN: MORE THAN 5

MILLION LAND SPECIES DEPEND UPON

FORESTS FOR THEIR SURVIVAL.

FORESTS ARE WHERE THEY LIVE,

WHERE THEY FIND FOOD.

FORESTS PROVIDE SERVICES TO

PEOPLE, TOO.

THEY ABSORB CARBON FROM THE

ATMOSPHERE.

THEY GIVE US WOOD FOR FUEL,

FURNITURE, HOUSES AND PAPER.

THEY GIVE US A PLACE TO RECREATE

AND TO ENJOY NATURE.

FORESTS AND THE PLANTS THAT LIVE

IN THEM ARE THE BASIS FOR

MEDICINE AND FOOD.

FORESTS GIVE US THE ABILITY TO

REGULATE TEMPERATURE, AND THEY

CLEAN THE AIR OF POLLUTION.

MOST IMPORTANTLY, FORESTS CLEAN

OUR WATER AND PROVIDE THE OXYGEN

WE BREATHE.

STUDENT: "ONE LARGE TREE CAN

CAPTURE AND FILTER 36,500

GALLONS OF WATER A YEAR."

STUDENT: "AND, TOO, MUCH OF OUR

TREES PROVIDE ENOUGH OXYGEN FOR

ONE PERSON TO BREATHE OVER A

YEAR."

CARTAN-HANSEN: FORESTS ARE SO

IMPORTANT, THEY'VE BEEN CALLED

OUR PLANET'S LUNGS.

BUT THE WORLD'S FORESTS ARE IN

TROUBLE.

MORE THAN 50 PERCENT OF THE

PLANET'S FORESTS HAVE ALREADY

BEEN DESTROYED, AND WE'RE LOSING

FORESTS AT A STAGGERING RATE,

THE EQUIVALENT OF THE SIZE OF 48

FOOTBALL FIELDS, EVERY MINUTE.

SOME FORESTS ARE CLEARED FOR

AGRICULTURAL USES OR MINING.

SOME ARE LOST TO DISEASE AND

PESTS.

LARGE AMOUNTS ARE LOST TO

WILDFIRES.

STUDENT: "WE NEED TO TAKE CARE

OF OUR FORESTS.

WE NEED OUR FORESTS FOR CLEAN

AIR AND CLEAN WATER."

STUDENT: "WE NEED FORESTS FOR

RECREATION AND FOR A HOME FOR

ALL THOSE ANIMALS AND PLANTS."

STUDENT: "SO YOU DO YOUR PART SO

WE ALL HAVE FORESTS TO ENJOY."

CARTAN-HANSEN: AND JOINING ME

NOW TO ANSWER YOUR QUESTIONS

ABOUT FORESTS ARE TARA HUDIBURG,

AN ASSISTANT PROFESSOR IN THE

DEPARTMENT OF FOREST, RANGELAND,

AND FIRE SCIENCES AT THE

UNIVERSITY OF IDAHO; AND DANIEL

JOHNSON, ALSO AN ASSISTANT

PROFESSOR IN THE DEPARTMENT OF

FOREST, RANGELAND, AND FIRE

SCIENCES AT THE UNIVERSITY OF

IDAHO.

THANK YOU BOTH FOR JOINING US.

DAN JOHNSON: THANK YOU FOR

HAVING US.

TARA HUDIBURG: YES, THANK YOU.

CARTAN-HANSEN: OKAY, LET'S GO TO

YOUR QUESTIONS.

(MUSIC)

MARYANN: HI, MY NAME IS

MARYANN.

AND MY QUESTION IS HOW MANY

TYPES OF FORESTS EXIST?

HUDIBURG: THERE ARE THREE MAJOR

FOREST TYPES IN THE WORLD.

WE CALL THEM "BIOMES."

THERE'S THE TROPICAL FOREST

BIOME, THE TEMPERATE FOREST

BIOME, AND THE BOREAL OR THE

TAIGA FOREST BIOME.

THE TEMPERATE FOREST BIOME IS

WHAT WE HAVE IN THE UNITED

STATES.

IT IS AT THE, YOU KNOW, 45 TO

60 DEGREE LATITUDES.

AND ABOVE THE 60 DEGREE LATITUDE

WE HAVE THE BOREAL FOREST, WHICH

IS, THINK ABOUT NORTHERN CANADA

OR MOST OF CANADA AND RUSSIA.

AND THEN THE TROPICAL FORESTS

ARE DOWN BY THE EQUATOR, NORTH

AND SOUTH OF THE EQUATOR.

WITHIN THESE DIFFERENT FOREST

TYPES WE HAVE LIKE SUBLEVELS OF

FORESTS.

SO IN THE TEMPERATE FORESTS WE

HAVE THE DECIDUOUS FORESTS, SO

THE HARDWOOD FOREST THAT EXISTS

ON THE EAST COAST, WHERE DAN IS

FROM.

AND ON THE WEST COAST WE HAVE

CONIFEROUS FORESTS, WHICH IS

WHAT YOU'RE MOSTLY USED TO IN

IDAHO.

TYLER: HI, MY NAME IS TYLER.

HOW MANY SPECIES OF ANIMALS IN

THE RAINFOREST ARE ENDANGERED?

JOHNSON: WELL, GLOBALLY

SPEAKING, THERE'S ABOUT 15,000

ANIMAL SPECIES THAT ARE

ENDANGERED, SO LESS THAN THAT IN

THE RAINFOREST, MAYBE HALF OF

THAT MUCH.

MASON: HI, MY NAME'S MASON.

AND HOW MANY LAYERS ARE IN THE

RAINFOREST?

HUDIBURG: SO THE RAINFORESTS

ACTUALLY HAVE AN ADDITIONAL

LAYER THAT WE DO NOT HAVE IN OUR

FORESTS IN IDAHO.

IT IS CALLED THE "EMERGENT

LAYER."

BUT ALL FORESTS HAVE THE

OVERSTORY CANOPY LAYER, THE

UNDERSTORY, AND THE FOREST

FLOOR.

SOPHIA: HI, MY NAME IS SOPHIA.

AND MY QUESTION IS HOW DO

FORESTS CLEAN WATER?

JOHNSON: FORESTS CLEAN WATER IN

ACTUALLY SEVERAL DIFFERENT WAYS.

WHEN IT RAINS, THAT RAIN

ACTUALLY FILTERS THROUGH THE

CANOPY, WHICH IS WHERE THE

LEAVES ARE, AND THAT'S ONE LEVEL

OF FILTERING.

AND THEN THE WATER CONTINUES ON,

EITHER THROUGH THE CANOPY OR

ALONG THE TRUNKS OF TREES, INTO

THE SOIL AND THEN PERMEATES INTO

THE SOIL, WHICH ACTS AS AN

ADDITIONAL FILTER.

AND THEN THE WATER GOES FROM

THERE INTO THE GROUNDWATER OR

INTO STREAMS.

SO YOU HAVE ONE SET OF FILTERS

IN THE CANOPY, AND THEN YOU HAVE

ANOTHER SET OF FILTERS IN THE

SOIL THAT ACTUALLY CLEAN THE

WATER.

WREN: HI, MY NAME IS WREN.

AND MY QUESTION IS HOW MANY

NATIONAL FORESTS ARE THERE IN

IDAHO?

HUDIBURG: THERE ARE TEN NATIONAL

FORESTS IN IDAHO.

MANY OF THEM ARE IN NORTHERN

IDAHO, IN THE PANHANDLE.

THE CLEARWATER NATIONAL FOREST,

THE ST. JOE NATIONAL FOREST.

A LOT OF NATIONAL FORESTS IN

IDAHO HAVE BEEN GETTING A LOT OF

NATIONAL ATTENTION BECAUSE OF

WILDFIRE IN FORESTS IN IDAHO, SO

YOU'VE PROBABLY HEARD OF A LOT

OF THEM.

ANDY: MY NAME IS ANDY.

AND I HAVE A QUESTION TO TAKE

ABOUT THE FORESTS.

ARE FOREST FIRES GOOD FOR THE

FOREST?

JOHNSON: WELL, IT DEPENDS.

SO IF IT IS A VERY HOT, VERY

SEVERE FOREST FIRE, THAT CAN

ACTUALLY BE BAD FOR FORESTS

BECAUSE IT CAN KILL ALL OF THE

LIVING MATERIAL IN THE SOIL, AS

WELL AS ALL THE TREES.

BUT A MORE MILD, LESS SEVERE

BURN CAN ACTUALLY BE VERY

HEALTHY FOR FORESTS BECAUSE IT

CAN REMOVE FUELS THAT MIGHT

OTHERWISE LEAD TO A MORE SEVERE

FOREST FIRE.

(MUSIC)

CARTAN-HANSEN: THE CANOPY OF A

RAINFOREST CAN BE REALLY THICK.

IT CAN TAKE A RAINDROP TEN

MINUTES TO FALL FROM THE TOP OF

THE CANOPY TO THE RAINFOREST

FLOOR.

AND THE RAINFORESTS IN THE

AMAZON BASIN ARE RESPONSIBLE FOR

A FIFTH OF OUR WORLD'S FRESH

WATER SUPPLY.

(MUSIC)

KAYLA: MY NAME IS KAYLA.

AND MY QUESTION IS WHAT ARE ALL

THE DIFFERENT TYPES OF SOIL THAT

ARE IN FORESTS?

HUDIBURG: SO THERE ARE ACTUALLY

MANY DIFFERENT SOIL TYPES THAT

FORESTS GROW ON.

IT REALLY DEPENDS ON WHERE THOSE

FORESTS ARE LOCATED AND WHAT

TYPE OF VEGETATION IS GROWING

THERE.

THE PARENT MATERIAL, WHICH IS

WHAT IS AVAILABLE AS A SUBSTRATE

TO FORM SOIL THAT TREES GROW ON

IS WHAT KIND OF DETERMINES THE

TYPE OF SOIL THAT WILL BE THERE.

AT THE BEGINNING, IF IT HAS A

LOT OF SAND, IT WILL BE A SANDY

SOIL.

IF IT HAS A LOT OF CLAY, IT WILL

BE A CLAY SOIL.

BUT THESE TYPES OF SOILS AFFECT

HOW MUCH NUTRITION OR NUTRIENT

CONTENT THERE CAN BE IN THE

SOIL.

AND PLANTS NEED NUTRIENTS TO

GROW.

TREES NEED NUTRIENTS TO GROW.

THEY NEED NITROGEN, AND THEY

NEED PHOSPHORUS.

IN GENERAL, WHAT WE REFER TO AS

NUTRIENTRICH SOILS ARE THE SOILS

THAT TEND TO BE UNDER

AGRICULTURE; THAT'S WHY WE GROW

CROPS THERE.

BUT NORTHERN FORESTS, LIKE THE

TEMPERATE FORESTS, THE BOREAL

FORESTS HAVE HIGHER NUTRITION

CONTENT OR HIGHER NUTRIENT

CONTENT, IN GENERAL, THAN

TROPICAL FORESTS.

TROPICAL FORESTS ACTUALLY ARE

VERY NUTRIENTPOOR SOILS.

LEXI: HI, MY NAME IS LEXI.

AND MY QUESTION IS WHAT IS THE

TREELINE?

JOHNSON: SO TREELINE IS THE

POINT AT WHICH TREES STOP

GROWING, OR THERE ARE NO MORE

TREELIKE GROWTH FORMS.

SO THERE'S A COUPLE OF EXAMPLES.

SO AS YOU MOVE HIGHER ON A

MOUNTAIN, IN TERMS OF ALTITUDE,

YOU WILL NOTICE AN ALTITUDE

WHERE TREES STOP GROWING, AND WE

CALL THAT THE "HIGHALTITUDE

TREELINE."

ALSO AS YOU MOVE HIGHER IN

LATITUDE, MOVE FURTHER NORTH,

THERE'S ALSO A HIGHLATITUDE

TREELINE.

SO YOU CAN HAVE EITHER

ALTITUDINAL OR LATITUDINAL

TREELINE.

VARIN: HI, MY NAME IS VARIN.

AND I HAVE A QUESTION FOR THE

FOREST.

WHY DO PEOPLE CUT DOWN TREES

FROM THE FOREST?

HUDIBURG: PEOPLE CUT DOWN TREES

MOSTLY FOR WOOD.

WE DEPEND ON WOOD PRODUCTS FOR

OUR HOUSES, FOR PAPER, AND MANY

OTHER THINGS.

ACTUALLY, THE WOOD PRODUCTS

INDUSTRY HAS EXPANDED INTO

GLUES, RESINS, AND MANY OTHER

TYPES OF THINGS.

SOMETIMES PEOPLE CUT DOWN TREES,

THOUGH, JUST FOR LAND

CONVERSION, SO TO GROW CROPS FOR

FOOD.

THE RATE OF FOREST HARVEST HAS

BOTH INCREASED AND DECREASED,

DEPENDING ON WHERE YOU ARE IN

THE WORLD.

IN THE US IT'S REMAINED

RELATIVELY CONSTANT OVER THE

LAST COUPLE OF DECADES.

MICHAEL: HI, MY NAME IS MICHAEL.

AND MY QUESTION IS WHAT ARE THE

EFFECTS CLIMATE CHANGE HAS ON

NATIONAL FORESTS?

JOHNSON: SO THE EFFECT OF

CLIMATE CHANGE ON FORESTS

DIFFERS DEPENDING ON THE AREA

WHERE THE FOREST IS.

SO IN SOME PLACES CLIMATES ARE

GETTING DRIER, WHICH WOULD HAVE

A NEGATIVE IMPACT ON THE

FORESTS, SO THEY WOULD GROW MORE

SLOWLY.

IN SOME PLACES CLIMATES ARE

GETTING WETTER, WHICH MIGHT HAVE

A POSITIVE EFFECT ON THE

FORESTS; THEY COULD GROW FASTER.

AND LIKEWISE, SOME PLACES ARE

GETTING WARMER, AND SOME PLACES

ARE GETTING COOLER.

SO THE EFFECT OF CLIMATE CHANGE

ON THE FORESTS IS DIFFERENT

DEPENDING ON REGION.

AND I THINK A LOT OF IT IS WE'RE

REALLY UNCERTAIN.

WE DON'T KNOW EXACTLY WHAT'S

GOING TO HAPPEN, AND SO SOME OF

IT'S A LITTLE BIT UNPREDICTABLE.

HUDIBURG: AND ANOTHER THING THAT

CLIMATE CHANGE IS CHANGING IS

THE DISTURBANCE REGIMES.

WE'VE TALKED ABOUT FIRE A LOT

BEING A PART OF DISTURBANCE

REGIMES IN FORESTS.

AND CLIMATE CHANGE MAY BE

INCREASING THE ACTIVITY OF FIRE

IN FORESTS, AND THAT'S OBVIOUSLY

GOING TO AFFECT FOREST GROWTH

BECAUSE IT WILL KILL SOME OF THE

TREES AND THEY CAN NO LONGER

GROW.

THERE ARE ALSO INSECT PATHOGENS,

LIKE BEETLES, THAT MAY BE HAVING

POPULATION INCREASES, WHICH, IF

YOU THINK ABOUT ANY PREDATOR, IF

YOU THINK ABOUT BEETLES BEING A

PREDATOR OF TREES, IF YOU HAVE

AN INCREASED PREDATOR

POPULATION, YOU'RE GOING TO HAVE

INCREASED MORTALITY OF THE PREY,

IN THIS CASE, THE TREES.

AND BEETLES ARE FAVORING THE

WARMER CLIMATES THAT WE'RE

GETTING WITH CLIMATE CHANGE.

(MUSIC)

CARTAN-HANSEN: TREES ARE THE

MOST IMPORTANT PART OF A FOREST,

SO LET'S LEARN A LITTLE BIT MORE

ABOUT THESE AMAZING PLANTS.

STUDENT: "WHAT IS THE OLDEST

THING ON EARTH?"

"WHAT'S THE HEAVIEST?"

"WHAT'S THE TALLEST?"

"IT'S A TREE."

CARTAN-HANSEN: A TREE IS A

PLANT.

IT'S A SPECIAL KIND OF PLANT

BECAUSE IT BUILDS UP STRENGTH BY

PRODUCING WOOD.

TREES HAVE FIVE BASIC PARTS: THE

ROOTS, THE TRUNK, THE BRANCHES,

THE LEAVES, AND THE FLOWERS OR

SEEDS.

STUDENT: "ROOTS ARE WHAT TREES

USE TO COLLECT WATER AND

NUTRIENTS.

THEY ALSO SPREAD OUT TO KEEP THE

TREE STANDING UPRIGHT."

STUDENT: "ROOTS FROM A

150 FOOT TALL TREE STRETCH UNDER

THE EARTH FOR THE AREA THE SIZE

OF A SOCCER FIELD."

CARTAN-HANSEN: THE TRUNK IS THE

TREE'S SUPPORT AND TRANSPORT

SYSTEM.

THE CENTER PART OF THE TRUNK IS

CALLED THE "HEARTWOOD," THE

SUPPORTING PILLAR OF THE TREE.

IT'S MADE UP OF DEAD CELLS.

THE NEXT LAYER IS THE "SAPWOOD."

IT CONTAINS A SYSTEM OF TUBES,

LIKE STRAWS.

IT TRANSPORTS WATER AND

NUTRIENTS FROM THE ROOTS THROUGH

TO THE LEAVES AND THE OTHER

PARTS OF THE TREE.

THE NEXT LAYER IS THE "CAMBIUM."

IT MAKES NEW SAPWOOD AND NEW

BARK EACH YEAR, ALLOWING THE

TREE TO GROW WIDER.

THE OUTSIDE LAYER IS THE TREE'S

"BARK."

THE OUTER BARK PROTECTS AND

INSULATES THE TREE.

THE INNER BARK OR "PHLOEM,"

CARRIES SAP FULL OF SUGAR FROM

LEAVES TO THE REST OF THE TREE.

BARK VARIES A LOT FROM TYPE OF

TREE TO TYPE OF TREE.

SOME OF IT IS SO UNIQUE THAT YOU

CAN IDENTIFY THE TREE JUST BY

LOOKING AT THE BARK.

STUDENT: "YOU CAN TELL HOW OLD

THE TREE IS BY LOOKING AT ITS

TRUNK.

EVERY YEAR A TREE GROWS IT ADDS

A NEW GROWTH RING.

COUNT THE RINGS AND YOU KNOW HOW

OLD THE TREE IS."

CARTAN-HANSEN: THE WAY A TREE

SPREADS ITS BRANCHES DEPENDS

UPON ITS SPECIES.

TREES REACH OUT TO EXPOSE THEIR

LEAVES TO THE SUN.

TOGETHER THE BRANCHES AND THE

LEAVES OR NEEDLES MAKE UP THE

TREE'S CANOPY.

AND LIKE YOU, TREES NEED FOOD,

EXCEPT THAT TREES MAKE THEIR OWN

FOOD.

THEY USE A PROCESS CALLED

"PHOTOSYNTHESIS."

WATER AND NUTRIENTS ARE SENT UP

FROM THE ROOTS TO THE LEAVES.

THE LEAVES TAKE IN CARBON

DIOXIDE FROM THE AIR.

USING ENERGY FROM THE SUN, THE

LEAVES COMBINE THE WATER AND THE

CARBON DIOXIDE TO MAKE SUGARS

THAT THE TREE USES TO FEED

ITSELF.

AND IN THE PROCESS THE LEAVES

RELEASE OXYGEN AND WATER VAPOR

INTO THE AIR.

TREES ALSO PRODUCE SEEDS.

MANY TREES PRODUCE A FLOWER

THAT'S POLLINATED AND GROWS

SEED.

BUT SOME TREES PRODUCE THE FRUIT

WE EAT, LIKE APPLES AND PEARS.

THEIR SEEDS ARE PROTECTED INSIDE

THEIR FRUIT.

STUDENT: "A PINECONE IS A KIND

OF FRUIT.

IT CONTAINS A PINE TREE'S

SEEDS."

CARTAN-HANSEN: THE SEEDS ARE

DISPERSED BY THE WIND OR OTHER

ANIMALS, TAKE ROOT ON THE GROUND

AND START GROWING A NEW TREE.

THERE ARE TWO BASIC KINDS OF

TREES: BROADLEAF AND CONIFER.

BROADLEAF, OR SOMETIMES CALLED

"DECIDUOUS" TREES, HAVE LEAVES

THAT BUD OUT IN THE SPRING AND

GROW FULL AND LUSH IN THE

SUMMER.

THEN THE LEAVES TURN COLOR IN

THE AUTUMN AND DROP TO THE

GROUND.

ALMOST ALL CONIFER TREES HAVE

DARKGREEN NEEDLES THAT STAY ON

YEARROUND.

CONIFER TREES BASICALLY HAVE TWO

KINDS OF NEEDLES.

SOME HAVE SHORT NEEDLES THAT

LOOK AND KIND OF FEEL LIKE

COMBS.

AND OTHERS HAVE LONG NEEDLES

THAT COME IN BUNDLES.

STUDENT: "AND ONE KIND OF

CONIFER TREE DOES CHANGE COLOR

IN THE FALL.

TAMARACKS TURN A BEAUTIFUL

YELLOW AND THEN GO BACK TO GREEN

IN THE SPRING."

CARTAN-HANSEN: TREES PLAY AN

IMPORTANT PART IN THE

ENVIRONMENT AND IN OUR LIVES.

THEY SHADE OUR HOMES, PROTECT

OUR SOIL, AND GIVE ANIMALS AND

PEOPLE A PLACE TO LIVE.

WE GET PAPER, LUMBER, MEDICINE,

FRUIT, NUTS, EVEN MAPLE SYRUP

FROM TREES.

AND ENVIRONMENTAL CAUSES, LIKE

AIR POLLUTION, CLIMATE CHANGE,

DEFORESTATION, AND OVERCROWDING

CAN HARM TREES AND FORESTS.

TREES ARE VERY GOOD AT ADAPTING

TO THE LAND AROUND THEM.

THEY CAN OUTLIVE ALL OTHER

LIVING THINGS.

BUT WE HUMANS NEED TO MAKE SURE

WE PROTECT THE AIR, WATER, AND

SOIL SO TREES CAN GROW.

AND WE NEED TO PLANT TREES AND

TAKE CARE OF OUR FORESTS TO

IMPROVE THE ENVIRONMENT.

TREES ARE ESSENTIAL TO ALL OF

US.

(MUSIC)

NOAH: MY NAME IS NOAH.

MY QUESTION IS WHAT'S THE

BIGGEST FOREST?

HUDIBURG: WHEN WE TALK ABOUT

FORESTS AND WE TALK ABOUT FOREST

TYPES, WE TALK ABOUT BIOMES.

THE BOREAL BIOME OR THE TAIGA

FOREST IS ANOTHER WORD FOR IT IN

THE NORTHERN LATITUDES ON THE

PLANET, IN RUSSIA AND CANADA,

THOSE ARE THE LARGEST FORESTS IN

TERMS OF FOREST TYPE.

AND I BELIEVE THE ACTUAL LARGEST

ONE IS THE ONE IN RUSSIA, NEAR

SIBERIA.

HUNTER: HI, MY NAME IS HUNTER.

AND THE QUESTION IS WHAT CAN

KILL FORESTS?

JOHNSON: THERE ARE A LOT OF

THINGS THAT CAN KILL A FOREST.

FOR EXAMPLE, AN EXTREME WILDFIRE

CAN KILL A FOREST, AN EXTREME

DROUGHT, AN INSECT OUTBREAK, OR

EVEN AN EXTREME HEAT WAVE, ALL

THOSE THINGS CAN KILL A FOREST;

AS WELL AS HUMANS CAN KILL

FORESTS.

AND WE HAVE DONE THIS IN THE

PAST, WHERE WE HAVE REMOVED

FOREST FOR AGRICULTURE USE.

KRIS: HI, MY NAME IS KRIS.

ARE FORESTS JUST IN THE

MOUNTAINS?

JOHNSON: FORESTS ARE NOT JUST IN

THE MOUNTAINS.

ACTUALLY, THEY OCCUR IN LOWLYING

AREAS.

THEY OCCUR IN RIVER BOTTOMS.

THEY OCCUR AT MIDELEVATIONS, AND

IN MOUNTAINS, AS WELL.

SO YOU ACTUALLY FIND FORESTS IN

ALL DIFFERENT TYPES OF LAND

FORMS.

HUDIBURG: FORESTS COVER ABOUT 30

PERCENT OF THE PLANET, THE

TERRESTRIAL LAND MASS, ACTUALLY

BOTH IN THE US AND GLOBALLY,

WHICH IS INTERESTING.

BUT THEY USED TO COVER 60

PERCENT, SO, HISTORICALLY, WE'VE

REMOVED ABOUT HALF THE FOREST

COVER IN THE LAST COUPLE HUNDRED

YEARS FROM THE GLOBE.

THEY COULD BE IN MANY MORE

PLACES THAN WHERE THEY ARE NOW.

WILLIAM: HI, MY NAME IS WILLIAM.

AND MY QUESTION IS HOW MUCH

OXYGEN DOES A TREE PRODUCE?

JOHNSON: SO TREES PRODUCE OXYGEN

BY TAKING CARBON DIOXIDE AND

SUNLIGHT AND FORMING SUGAR AND

PRODUCING OXYGEN AS A BYPRODUCT.

SORT OF LIKE WHEN YOU AND I

BREATHE, WE CONSUME OXYGEN AND

RELEASE CARBON DIOXIDE AS A

BYPRODUCT.

SO ONE MATURE TREE CAN PROVIDE

ABOUT ENOUGH OXYGEN FOR TEN

PEOPLE TO BREATHE.

COOPER: HI, MY NAME IS COOPER.

AND MY QUESTION IS HOW LONG DOES

IT TAKE FOR THE AVERAGE TREE TO

GROW?

HUDIBURG: SO TREES GROW AT

DIFFERENT RATES, DEPENDING ON

WHAT TYPE OF FOREST OR WHAT

SPECIES THEY ARE.

EVEN IN IDAHO WE HAVE DIFFERENT

GROWTH RATES FOR OUR CONIFER

SPECIES OR OUR EVERGREEN TREES.

IF YOU COMPARE GROWTH RATES IN

IDAHO TO GROWTH RATES IN OREGON,

LET'S SAY, LIKE ON THE COAST

RANGE, WHERE THE TEMPERATE

RAINFORESTS ARE, IN THE

TEMPERATE RAINFORESTS A DOUGLAS

FIR TREE REACHES ITS MAXIMUM

GROWTH RATE AND STARTS TO SLOW

DOWN AFTER THAT AT ABOUT 55 TO

60 YEARS OR EVEN 50 TO 60 YEARS;

WHEREAS, IN IDAHO THAT SAME

SPECIES WOULD TAKE AROUND 70 TO

80 YEARS TO REACH ITS MAXIMUM

KIND OF GROWTH RATE.

AND IT'S EVEN MORE DIFFERENT IF

YOU GO TO THE SOUTHEAST WHERE

THERE'S A LONGER GROWING SEASON

THAT IS MORE FAVORABLE, AND IT'S

ALSO MORE FAVORABLE WITHIN THE

GROWING SEASON, WHERE LIKE THE

[INDISCERNIBLE] PINE TREE CAN

REACH ITS MAXIMUM GROWTH AT 30

YEARS' TIME.

CARTAN-HANSEN: WHY DID YOU WANT

TO STUDY ABOUT FORESTS?

JOHNSON: I GREW UP IN THE

EASTERN PART OF THE COUNTRY, IN

THE FOOTHILLS OF NORTH CAROLINA.

AND AROUND THE HOUSE THAT I GREW

UP IN THERE WERE SEVERAL

THOUSAND ACRES OF FOREST, AND SO

THAT'S WHERE I SPENT MOST OF MY

TIME AS A KID.

AND, YOU KNOW, EVEN EARLY ON I

REALIZED THAT AS I MOVED FROM

ONE PLACE TO ANOTHER IN THE

FOREST, THE TREE TYPES OR THE

SPECIES CHANGED.

AND SO AS I GOT OLDER, I

REALIZED THAT THAT WAS SOMETHING

THAT I WAS INTERESTED IN

FIGURING OUT MORE ABOUT, WHICH

IS WHY DO SOME SPECIES LIVE HERE

AND NOT THERE.

AND SO THAT'S WHAT LED TO WHAT I

CURRENTLY DO, WHICH IS I STUDY

HOW DIFFERENT STRESSORS SHAPE

DIFFERENT PLANT COMMUNITIES OR

EXACTLY WHY A PLANT GROWS HERE

AND NOT THERE.

AND SO IT WAS JUST A VERY

NATURAL SORT OF QUESTION TO HAVE

AS A KID THAT I'M STILL PURSUING

AS AN ADULT.

(MUSIC)

CARTAN-HANSEN: THE FOREST FLOOR

IS ONE OF THE MOST IMPORTANT

PARTS OF THE FOREST ECOSYSTEM.

IT'S WHERE DECOMPOSITION TAKES

PLACE, MAKING THE SOIL RICH FOR

PLANTS TO GROW.

IT'S WHERE MOST ANIMALS AND

INSECTS LIVE.

AND THE STUFF YOU FIND ON THE

FLOOR, IT HAS A NAME, IT'S

CALLED "DUFF."

(MUSIC)

KIRSTIN: HI, MY NAME IS KIRSTIN.

AND I'M FROM INDIAN HILLS,

POCATELLO, IDAHO.

AND MY QUESTION IS HOW CAN YOU

TELL HOW OLD A TREE IS BY

COUNTING ITS RINGS?

JOHNSON: SO TREES PUT ON ONE NEW

RING EVERY YEAR.

AND THE REASON THAT THEY DO THAT

OR THE WAY THAT THEY DO THAT IS

EARLY IN THE SPRING THEY PUT ON

A VERY LIGHTCOLORED BAND OF

WOOD, WHICH WE CALL "EARLY

WOOD."

AND THEN AS THE SEASON

PROGRESSES AND IT BEGINS TO HAVE

LESS AND THERE BEGINS TO BE LESS

WATER AND TEMPERATURES START TO

COOL, THEN THAT WOOD BECOMES

DENSER AND DENSER AND DARKER.

AND WE CALL THAT THE "LATE

WOOD."

AND AT THE VERY END OF THAT LATE

WOOD, TREE GROWTH STOPS FOR THAT

YEAR.

AND THEN THE FOLLOWING SPRING

THEY'LL START AGAIN WITH A NEW

LAYER OF EARLY WOOD.

AND SO WE CAN COUNT THOSE RINGS

AND TELL EXACTLY HOW MANY YEARS

OLD A TREE IS.

HUDIBURG: YOU CAN ALSO TELL HOW

MUCH IT GREW BECAUSE THE RING

WIDTH IS RELATED TO HOW MUCH

WOOD GROWTH THERE WAS.

COLE: MY NAME IS COLE.

AND MY QUESTION IS HOW DO YOU

STOP WILDFIRES?

JOHNSON: WELL, ONCE A WILDFIRE

HAS ALREADY STARTED, WHAT WE TRY

TO DO IS WE TRY TO SUPPRESS THAT

WILDFIRE, WHICH MEANS WE TRY TO,

INITIALLY, SLOW IT DOWN BY

REMOVING FUELS, FOR EXAMPLE, OF

DEAD THINGS IN THE UNDERSTORY,

DEAD WOOD, DEAD LIMBS, THINGS

LIKE THAT.

BUT ALSO BY SPRAYING WATER ON

THE FIRE, DROPPING SAND ON THE

FIRE.

WE DO ALL THOSE THINGS TO

INITIALLY TRY TO SLOW IT DOWN,

OR SUPPRESS IT, AND THEN

EVENTUALLY TO STOP IT FROM

BURNING.

SO THAT'S THE SUPPRESSION OF

WILDFIRE.

BUT WE ALSO WANT TO PREVENT

WILDFIRES FROM STARTING IN THE

FIRST PLACE, AND SO THINGS THAT

WE CAN DO TO PREVENT WILDFIRES

IS, AGAIN, REMOVING THE FUELS IN

THE UNDERSTORY THAT COULD BURN,

BUT ALSO BEING VERY CAREFUL

ABOUT WHERE WE MAY LAY DOWN A

MATCH AFTER WE THINK IT'S BEEN

PUT OUT OR EXTINGUISHING A

CAMPFIRE.

THINGS LIKE THAT CAN GO A LONG

WAY IN TERMS OF PREVENTING

WILDFIRES.

JACKSON: MY NAME IS JACKSON.

AND MY QUESTION IS DOES ANYONE

LIVE IN THE FOREST?

HUDIBURG: I GREW UP IN THE

FOREST.

I GREW UP IN PORT ANGELES,

WASHINGTON, AND OUR PROPERTY

BOUNDARY WAS WITH THE OLYMPIC

NATIONAL PARK.

AND SO WE COULD JUST BE IN THE

OLYMPIC NATIONAL PARK WHENEVER

WE WANTED TO, AS CHILDREN.

I BELIEVE DAN ALSO GREW UP IN

THE FOREST.

JOHNSON: I GREW UP IN THE WOODS,

AS WELL.

MY PARENTS, THEIR HOUSE WAS

BORDERED BY SEVERAL THOUSAND

ACRES OF FOREST, AND SO I GREW

UP IN THE WOODS.

AND I GUESS PROBABLY ONE OF THE

REASONS THAT TARA AND I DO WHAT

WE DO IS BECAUSE WE GREW UP IN

THE WOODS.

AND WE'RE NOT ALONE; THERE ARE A

LOT OF PEOPLE IN THE US, AS WELL

AS OTHER COUNTRIES, THAT CHOOSE

TO LIVE IN THE FOREST BECAUSE

THEY LIKE THE AESTHETICS OF

BEING INSIDE A FOREST.

CARTAN-HANSEN: IF A STUDENT IS

INTERESTED IN A JOB IN FORESTRY,

WHAT SHOULD HE OR SHE STUDY IN

SCHOOL?

JOHNSON: IT HELPS TO HAVE JUST A

NATURAL PASSION FOR TREES AND

FOR FORESTS.

BUT AS BACKGROUND MATERIAL,

MATH, I KNOW THIS IS PROBABLY

NOT A VERY POPULAR ANSWER BUT

MATH IS VERY IMPORTANT, PHYSICS

IS VERY IMPORTANT, CHEMISTRY,

ALL OF THE BASIC HARD SCIENCES

LEAD TO A VERY GOOD FOUNDATION

THAT CAN PREPARE YOU TO STUDY

TREES.

BECAUSE TREES, AT THEIR CORE,

PARDON THE PUN, BUT AT THEIR

CORE, IT ALL COMES DOWN TO

PHYSICS AND CHEMISTRY.

HUDIBURG: SO IN ADDITION TO

PHYSICS AND CHEMISTRY AND MATH,

YOU SHOULD ALSO TAKE BIOLOGY.

SO IN BIOLOGY YOU WILL LEARN HOW

TREES GROW AND HOW DIFFERENT

TREES GROW AT DIFFERENT RATES.

CARTAN-HANSEN: I'M SORRY WE'VE

RUN OUT OF TIME.

MY THANKS TO TARA AND DANIEL FOR

ANSWERING STUDENTS QUESTIONS.

HUDIBURG: THANK YOU FOR HAVING

US.

WE BOTH REALLY HAD FUN AND

APPRECIATED IT.

JOHNSON: THIS WAS A GOOD TIME.

THANK YOU VERY MUCH.

CARTAN-HANSEN: MY THANKS ALSO TO

THE FOLKS HERE AT THE UNIVERSITY

OF IDAHO'S COLLEGE OF NATURAL

RESOURCES FOR HOSTING US.

YOU CAN LEARN MORE ABOUT FORESTS

AND LOTS OF OTHER SCIENTIFIC

TOPICS ON THE SCIENCE TREK

WEBSITE.

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THANKS FOR JOINING US.

WE'LL SEE YOU NEXT TIME ON

SCIENCE TREK.

NARRATOR: PRESENTATION OF

(MUSIC)

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