Characteristics of temperate rain forests

so I'd like to bring on one of our the

first of our temperate rainforest

experts now I'd like to introduce dr.

Rick Meinzer he is a research ecologist

with the Forest Service's Pacific

Northwest Research Station and dr. mines

are wanted to tell us a little bit about

the temperate rainforest

okay thanks Patti well this Alaskan

rainforest that were in is similar to

the one you heard about in Puerto Rico

in that it's wet here it much more

precipitation falls and the vegetation

can use but beyond that there are some

big differences that I'll talk about the

rainfall part of the precipitation in

this forest falls as snow during the

winter and it's more seasonal than in

the tropical forest as a rule during the

summer there's often a dry period and

that dry period gets longer as you go

further south to the rain forests in

Washington and Oregon and you also heard

a little bit about the role of wind in

the forests in Puerto Rico well we

certainly don't have hurricanes here but

we do have high winds a couple of days

ago we had some 80 mile an hour winds

and these winds play a role in shaping

the forest because they occasionally

knock trees down and those trees that

have fallen formed gaps in the forest

that allow trees that have been hanging

around on the understory to grow up and

become part of the forest canopy another

important difference is in the number of

species in the forest this forest around

us here has basically about three

species of trees that dominated Sitka

spruce Western hemlock and red cedar

whereas in a small area of tropical

forests it's not uncommon to have more

than a hundred species of trees and

hundreds of species of shrubs and other

plants the types of trees in this forest

also differ these trees are conifers

meaning that they that they bear cones

instead of flowers and tropical trees of

course in tropical forests are flowering

other differences are that conifers have

needle-like leaves this is a hemlock

branch here with small needle-like

leaves and we call tropical trees

broadleaf trees for obvious reasons they

have big broad leaves another one of the

differences between conifers

tropical trees is you can't see it from

the outside but it's in the wood most of

us think of wood is a pretty solid thing

we build furniture and houses out of it

but if you look at it under the

microscope it's actually porous and

that's because the water that comes from

the soil up to the leaves in the canopy

moves through wood and the plumbing that

the water moves through and conifers is

really different from broadleaf tropical

trees conifers have small little cells

about the length of an eyelash called

tracheids in the wood and the water

moves up through the tracheids it's very

different in broadleaf trees they have

these little building blocks of their

plumbing system these little hollow

cylinders that are stacked and and to

form vessels another big difference is

in the height of the trees the tallest

temperate rainforest trees are up to 350

feet tall that's in the coast redwood

area about 700 miles south of here

whereas the tallest tropical trees are

only about half that height about 150

feet tall or so and despite the fact

that these forests have a lot of water

for a tree that's 350 feet tall it's a

big problem to get water to the top it

has to move all the way from the roots

hundreds of feet up to the leaves water

is really heavy if you've ever tried to

carry a five-gallon bucket of water very

far you know how heavy it is so these

trees are pulling columns of water

hundreds of feet tall up to the top and

that's a pretty risky proposition

because if that water column separates

the top of the tree

dies all around me here hanging around

on the trees you see epiphytes epiphytes

are just simply plants that grow on

other plants and in a temperate

rainforest like this the epiphytes tend

to be pretty simple plants we've got a

lot of mosses around here there's a moss

this branch is heavily laden with mosses

and the other type of epiphyte that's

really common here is lichens and here

you see kind of a hairy little lichen

and lichens are pretty neat because

they're sort of a cooperative

arrangement between two life-forms in

between a fungus and what we call a

cyanobacteria which is a Bluegreen

bacteria that can do photosynthesis and

these lichens are really Hardy because

when the

first is dry when it stops raining for a

few days these dry out and they go

dormant but as soon as it rains they

absorb water and they can do their

photosynthesis right away in just a few

minutes the epiphytes and tropical

forests are mostly flowering plants

orchids and bromeliads there are about

10,000 species of orchids at least

worldwide and many a couple thousand

species of Borrelia adds if bromeliads

are in the same family as pineapple if

you in the forest like this if you try

to walk a hundred feet in a straight

line from here to another point you find

out that it's really hard to do it you

run into a lot of biomass biomass is

simply living in dead biological

material with trees these trunks that

are around me here I've probably been

here for many decades and the reason why

temperate forests have so much biomass

hanging around is because there's so

much cooler you heard earlier that it's

about 85 degrees in Puerto Rico today

it's only about 40 degrees here so with

those kinds of temperatures this biomass

decomposes really slowly the bacteria

and fungi that make it decay work really

slow in conditions like this also from

down here this forest is hundreds of

feet tall it's hard to see what's going

on in the upper canopy but what we did

was we took a trip into the upper canopy

of a forest that's about seven or eight

hundred miles from here in a canopy

crane in Washington and we're going to

show you that in this video that follows

okay we're going to take a trip into the

upper canopy of an old-growth temperate

rainforest we're here at the Wind River

canopy crane in Washington State and

this is a joint project between the u.s.

Forest Service in the university of

washington and ken bible here is with

the university of washington he's a

scientist one of the big differences

between the tropical and the temperate

rain forests is just the shape of the

tops of the trees you saw in the

tropical trees that the Crown's of the

trees of the tops are umbrella shaped or

hemispherical shape while these

temperate trees these conifers have very

long narrow crowns that go down maybe

more than a hundred feet down into the

canopy and that's a pretty good

adaptation for where these forests grow

because they grow in the northern

latitudes the light angles are quite low

in the fall and the spring and that's a

good adaptation to trap light so what

we're going to do is take a trip down

the crown of this tall Douglas fir tree

it's over 200 feet tall and the crown is

very deep it's maybe over a hundred feet

long from top to bottom so they'll be

leaves carrying out photosynthesis all

the way from the top of this tree down

into the forest because that's one

different thing about this forest from

the tropical forest in that light

penetrates very deeply into the canopy

whereas if you go much below the top of

the canopy and a tropical forest there's

very little light in both tropical and

temperate forests the upper canopy here

is where a lot of the action is in terms

of what the forest does the forest sucks

up incredible amounts of carbon dioxide

from the air during photosynthesis and

gives off a large amount of water vapor

and with our regard to water here we are

more than 200 feet above the ground so

the water has to get from the soil to

the upper branches of these trees and we

found that in these old conifers like

Douglas fir it could take two to three

weeks for water to get from the forest

floor up to the top of the tree and in

work that we've done in tropical forests

we find that it's much quicker it may

only take a day or two for water to get

to the tops of the trees part of that's

because the trees are shorter but it's

also because these trees have different

systems inside for conducting water

tropical trees have pretty large tubes

to conduct water and the water

really quickly these conifers like

Douglas fir have very small little tubes

and the water moves slowly in terms of

photosynthesis one thing that we do at

the top of the canopy is to measure

photosynthesis with portable instruments

like this this is a little chamber that

we can seal around the the leaves the

foliage like this and air circulates

between this chamber and a main

instrument and we can actually tell how

much carbon dioxide these needles are

taking up and an interesting thing about

these temperate conifers in this

rainforest is that they can be active

year-round as long as it's above

freezing they can do their

photosynthesis almost like a tropical

forest which is active year-round if you

go into a more interior forest say in a

place like Montana or Wyoming the trees

go completely dormant during the winter

but not these one thing we notice in

these tree crowns because they're so

long is the leaves or the foliage that

changes a lot going from the bottom to

the top near the bottom it's the needles

are flattened and pretty wide and large

and as we go toward the top of the tree

you'll probably notice in this fir tree

that the needles become shorter and

they're kind of more erect they stand up

straight and part of that's due to the

difference in light between the bottom

and the top of the tree but part of its

due to water and how difficult it is for

the tree to get water from the bottom to

the top of the tree because it's so hard

to get water at the top when the needles

are growing in the spring they don't

expand as much as near the bottom so

that's part of the reason why they're

smaller just wanted to summarize a few

features of rain forests this one is

cold and wet the one in Puerto Rico is

warm and red wet and the number of

species here is much lower than the

number of species in a forest like the

one in Puerto Rico the trees here are

much taller than tropical trees they

have very different shaped crowns long

pointed crowns tropical trees or more

umbrella shape they have different kinds

of plumbing the trees here have a

different kind of a vascular system as

we call it and the rates of decay are

much slower in this forest that's why

there's a lot of biomass and dead logs

hanging around thanks a lot dr. Meinzer

that was really

interesting and I learned a lot about

temperate rainforests they're just

amazing places and the Tongass where we

are today is is is an amazing place and

it contains most of the old temperate

remaining forests in North America it's

an important place for the plants and

animals that live here and to all

Americans too it's especially important

to all the communities in southeast

Alaska that depend on the forest for

their drinking water for wood for food

for fuel wood for recreation and for the

beautiful scenery that's here that's

really quite remarkable today although

it's still not 85 degrees