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.
AND WE'LL ANSWER MORE QUESTIONS
ABOUT FORESTS ON SCIENCE TREK:
THE WEB SHOW.
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QUESTION FOR SCIENCE TREK, IT'S
EASY.
YOU CAN SEND IT AS AN EMAIL OR A
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AND IF YOU'RE AN EDUCATOR, WE'LL
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AND EACH WEEK CHECK OUT MY BLOG
FOR THE LATEST SCIENCE NEWS FOR
KIDS.
YOU'LL FIND ALL THE DETAILS AT
IDAHOPTV.ORG/SCIENCETREK.
THANKS FOR JOINING US.
WE'LL SEE YOU NEXT TIME ON
SCIENCE TREK.
NARRATOR: PRESENTATION OF
(MUSIC)
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