Plant adaptations to dry environments.

2/10/2015
Plant adaptations to deserts
How to run a Plant
•
1.
2.
3.
4.
CO2
A plant is an integrated
system which:
Obtains water and nutrients
from the soil.
Transports them through the
roots and stems to leaves.
Combines the H2O with CO2
entering the stomata to make
sugar.
Exports energy rich sugar to
where it’s needed for
maintenance, growth, and
reproduction of the plant.
Bananas
H2 O
Water Transport in Plants
Transport in Plants
Oh
Yeah?
1. Animals have circulatory systems.
2. Vascular plants have one way systems.
•
•
Because vascular plants have one way
systems, plants need a lot more water
than same sized animals.
A sunflower plant “drinks” and “perspires”
17 times as much as a human, per unit of
mass.
Good thing
we’ve got
roots!
Transpiration and the Stomata
• Transpiration (= evaporation of water from
leaves) pulls water and minerals up stems AND
provides evaporative cooling, but
• It results in tremendous loss of water, which
must be controlled.
• Conflicting leaf
needs:
1. Avoid
desiccation.
2. Get CO2.
• Leaves are covered by a waxy waterproof cuticle.
Good at 1. but not 2.
• Stomata – pores that let CO2 in when there’s
not too much water stress.
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2/10/2015
Stomata
• The stoma (or pore) is surrounded
by two specialized cells, called
guard cells, which are attached to
one another at their ends.
Photosynthetic Water Use Efficiency
• Fundamental plant problem: the pathway for
diffusion of CO2 into leaves is the same as the
pathway for diffusion of H2O out.
• A plant’s success in dealing with water loss and
CO2 uptake is measured as it’s
Photosynthetic Water Use Efficiency (WUE).
• WUE = amount CO2 fixed to sugar by
photosynthesis per amount H2O lost by
transpiration.
• WUE is extra important in the desert!
Adaptations for dealing with
heat and water loss
• Plants have evolved countless
adaptations for increasing their
water use efficiency:
• Low surface to volume ratio
• Small leaves
• Waxy surfaces to stems and
leaves.
Regulation of stomatal opening
• Stomata typically open in the day
(in response to light) and close at
night.
 This provides CO2 for
photosynthesis during the day, but
saves water at night.
• A low level of CO2 in the leaf
constrains photosynthesis and favors
stomatal opening.
• If the leaf is too dry the stomata
close.
Photosynthetic Water Use Efficiency
• WUE can be increased by a “cautious” regulation of
stomatal opening.
• But this lowers the rate of photosynthesis.
• Result: a tradeoff between WUE and plant growth
rate.
• It’s a little surprising that plants can grow at all in the
desert (and the first land plants certainly didn’t).
Adaptations for dealing with
heat and water loss
• Recessed stomata.
• Hairy surfaces
• Extensive root systems
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2/10/2015
3 general plant strategies for
coping with heat and lack of water
Store Water – Succulent Plants
• Store water
• Tolerate drought
• Escape drought
• Store water in leaves stems or roots
• Examples: Cacti
Store Water – Succulent Plants
• Store water in leaves stems or roots
• Examples:
•
Store Water – Succulent
Plants
Agaves
Store Water – Succulent Plants
• Boojum (Fouquieria columnaris)
Store Water – Succulent Plants
• Succulent plants often have an unusual way of
conducting photosynthesis called CAM.
• CAM plants open their stomata at night but keep
them closed during the day (backwards!)
• This keeps them from drying out, but they need
CO2 to photosynthesize when the sun is out, not
at night!
• The CO2 taken in at night is stored as an acid.
• During the day when stomata are closed they
convert the acid back to CO2 and
photosynthesize.
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2/10/2015
Store Water – Succulent Plants
• CAM plants have about 10 times the
WUE of normal plants (fix 10 X as much
CO2 per unit of water lost).
• Tradeoff is that they grow more slowly.
• They usually have reduced surface area
to minimize water loss.
• Defend their water with spines and toxic
chemicals!
• Often have shallow roots for
rapid water uptake.
Tolerate drought
• Included in this category:
• Drought deciduous shrubs and trees like
bursage and mesquite that tolerate drought by
dropping leaves and going dormant.
Tolerate drought
• Extensive roots - extend 2 to 3 times the
diameter of the plant.
• Take up and use water even
under quite dry conditions.
• They vary in how long it takes to go from
dormancy back to maximal growth:
evergreens - fastest,
• drought deciduous -intermediate,
• grasses and herbs - slowest.
Tolerate drought
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If a cactus dries out it will usually die.
But some plants tolerate drying out very well.
Included in this category:
Evergreen shrubs like creosote bush that can
be active even in very dry times.
Tolerate drought
• Included in this category:
• Perennial herbs and grasses that die back
but live through drought.
Escape drought
• Annual plants specialize to favorable
weather periods and exist only as
seeds in unfavorable periods.
• Winter annuals escape hot summers germinate in fall and reproduce and die
in the spring in areas with winter rain.
• Summer annuals germinate
reproduce and die during summer rain.
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Some Important Plants
• columnar cacti – two defining life forms of
the Sonoran Desert: columnar cacti and
legume trees.
• Columnar cacti are found in arid tropical
habitats throughout Mexico, Central and
South America.
• 41 species in Mexico.
Some Important Plants
• Cardon – Pachycereus
pringlei
• Bigger than saguaro
• Baja California and the
coast of Sonora.
Some Important Plants
• Organ pipe –
Stenocereus thurberi
• Many unbranched stems
from ground level.
• In Arizona, only in and
near Organ Pipe Cactus
National Monument.
• Throughout Sonora and
southern Baja.
Some Important Plants
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4 big ones in the Sonoran Desert:
Cardon
Senita
Organ pipe
Saguaro
Some Important Plants
• Flowers open before
dark and remain open
after dawn.
• Pollinated mostly by
bats
• 3 genders: male, female,
hermaphrodite.
Some Important Plants
• More frost sensitive than
saguaro.
• Flowers open only in the
dark.
• Most pollination and some
seed dispersal done by
nectar feeding bats.
• Delicious fruits sold
commercially in Mexico:
pitaya.
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2/10/2015
Some Important Plants
• Senita – Pachycereus schottii
• Grows kind of like organ pipe, but
fewer ribs on the stem.
• Very arid habitats, fine textured
valley soils.
Some Important Plants
Some Important Plants
• Senita is pollinated by a moth that
deliberately pollinates, then lays eggs in
fruits.
• Highly coevolved mutualism.
Some Important Plants
• Pleated ribs enable
saguaro (and other
cacti) to expand
accordion-style to take
up water.
• Well watered plants are
90% water.
• Thermal inertia of the
massive watery stems
keeps saguaros from
overheating or freezing.
• Saguaro – Carnegia
gigantea
• The only columnar
cactus cold hardy
enough to grow in the
Arizona Upland.
• Largest cactus in USA.
• Best studied plant in
Sonoran Desert.
• Saguaros are limited by freezing.
• There are many more saguaros on the
south facing wall of Gates Pass than on the
north facing wall.
• This snow shot suggest why.
Saguaros are limited by freezing.
South facing slope -many
North Facing slope - few
Snow on Jan 22, 2007
South facing
North Facing
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Some Important Plants
Some Important Plants
• As with most CAM succulents, it has a
very shallow but extensive root system.
• Most roots are no more than 4 in. deep
and extend as far out as the plant is tall.
• CAM metabolism “idles”
during drought.
• With stomata closed, CO2
released from respiration is
recycled to CAM
photosynthesis.
• The O2 released from
photosynthesis is recycled
to respiration.
Some Important Plants
Some Important Plants
• Thus it never goes
completely dormant.
• Can resume full growth 24 –
48 hrs after rain.
• Most rains in the desert are
small with water only
percolating down a few
inches.
• CAM plants like saguaro can
take advantage of these due
to shallow roots and idling
photosynthesis.
Some Important Plants
• Yet bats play a surprisingly small
part in pollination.
• Most is done by white-winged
doves and bees during the day.
• In the northern part of its range
(Tucson), there are not enough
pollen feeding bats to do the job.
• Thus flowers are mysterious.
• Flower during the arid
foresummer (May – June).
• White flower open late at
night and close around mid
afternoon the next day.
• Smell like overripe melons.
• Copious nectar
• All this points to bat
pollination.
Some Important Plants
• Fruits ripen in June and early
July.
• >1,000 seeds in juicy red
pulp.
• Rind splits in to sections and
can be confused for a red
flower.
• Important moist food for
many animals at a time when
not much else is available.
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2/10/2015
Some Important Plants
• Many fruits eaten by whitewing doves.
• But they spend most of their
time on saguaros, so
usually drop the seeds
around saguaros instead of
in nurse plants.
• Birds like verdins that feed
on saguaro but move to
paloverdes and other
shrubs to eat and defecate
are better dispersers.
Some Important Plants
• Only survive after several
wetter than average years.
• Appropriate conditions only
occur several times a century in
the Arizona Upland and even
less frequently in the Lower
Colorado River Valley.
• = Episodic recruitment.
Some Important Plants
• Because Saguaro West did not
have a big cohort of giants, it
didn’t suffer as badly from the
1937 freeze.
• Its plants were giants by the
1970s and suffered from the
freeze of 1978, generating
another scare.
• Saguaros are declining most of
the time, but they are not going
extinct.
Some Important Plants
• Seeds germinate with the
first monsoon rain.
• Seedlings grow very slowly
and mostly die from
desiccation, freezing, or
being eaten.
• nurse plants - shelter from
temperature, drought and
predators.
Some Important Plants
• “Impending doom”
• Because saguaros establish so seldom
but die all the time, there have been
several scares about its impending doom.
• Saguaro National Monument East
established in 1933 around giant old
saguaros born in early 1800s or before.
• Many died in the decade following the
1937 hard freeze.
• Established Saguaro NM West in 1961
partly out of fear of impending doom in
Saguaro East.
Coda
• The newest “eminent disaster”
is the buffelgrass invasion.
• This large African grass can
promote fires in the desert that
Saguaros and other native
desert plants cannot survive.
• We’re in the process of seeing
how this will play out.
• You can volunteer at
buffelgrass.org
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2/10/2015
Some Important Plants
• Creosote – Larrea tridentata
• Most common and widespread shrub in all SW
deserts except Great Basis, where it is excluded by
cold.
Some Important Plants
• Larrea is an evergreen shrub that
photosynthesizes during the dry season and can
grow at any time of year.
• It can maintain a positive balance of photosynthesis
to respiration down to very low water potentials.
Some Important Plants
• Vertical leaves covered by a thick layer of resins that
are responsible for the “smell of rain”.
• Most drought tolerant perennial in North America.
• The last shrub in the driest parts of the Sonoran
Desert.
Some Important Plants
• It acclimates to seasonal changes in temperature:
• Optimum temperature for photosynthesis shifts
from 20C (68F) in January to 30C (86F) in Sept.
• It doesn’t store carbon or nutrients or go into
dormancy.
• It’s moderate growth rate is due to its thin canopy
with low leaf area.
Some Important Plants
Some Important Plants
• Not eaten by many large animals other than
jackrabbits.
• Nurse plant for many other plants.
• Frequent site of rodent burrows.
• Many insects are specialized
to creosote bush:
• creosote katydid
• creosote grasshopper
• Creosote gall midge (& 11
other different galls).
• 22 species of bees feed only
on its flowers.
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2/10/2015
Some Important Plants
• One of the longest lived plants.
• On stable landscapes, it keeps putting out new stems on
the outer edge of the root crown.
• Ring forms and keeps growing.
Some Important Plants
• Ambrosia – drab wind pollinated plants that
are a major cause of hay fever.
• Several species very common throughout
the Sonoran Desert.
• Critical nurse plants – among the few
plants that can colonize exposed ground.
Some Important Plants
• Downside: it takes several weeks to
redeploy their photosynthetic machinery
(leaves).
• So this strategy works best when there are
long predictable wet seasons that are
neither too cold nor too hot.
Some Important Plants
• Ring forms and keeps growing.
• One in the Mojave is 26 ft. across and several thousand
years old.
Some Important Plants
• They are drought deciduous shrubs.
• They lose their leaves in the hottest and
driest seasons.
• They usually have 2 leaf cohorts per year –
monsoon and cool winter.
• Since leaves are absent in arid seasons,
they can have high photosynthetic rates
at the price of low water use efficiency.
Some Important Plants
• The 3 common Ambrosias vary in leaf size
and in drought tolerance.
• Larger leaves have more photosynthesis
and can evaporatively cool, if they have
plenty of water to keep stomata open.
• But they have a deeper boundary layer of
stagnant air at their surface and overheat
when stomata are closed.
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2/10/2015
Some Important Plants
• Small, dissected, or divided leaves have a
smaller boundary layer and lose heat more
effectively by convection (transfer of heat
by moving air).
• They can stay at ambient temperature.
Some Important Plants
• Ambrosia deltoidea – Triangleleaf bursage.
• Moderate sized broadleaf shrub with smaller
leaves (2-6 cm2).
• Almost identical geographic range as canyon
ragweed, but out on plains and bajadas.
• Dominant plant in Arizona Upland with palo verde
and saguaro.
Some Important Plants
• The Sonoran Desert is dominated by
legume trees and columnar cacti.
• The legume trees: Palo verdes
(Parkinsonia), Mesquite (Prosopis),
Ironwood (Olneya tesota).
Some Important Plants
• Ambrosia ambrosioides – canyon ragweed.
• A large broadleaf shrub (10-30 cm2 leaves).
• It is confined to washes and canyon bottoms where it
can get enough water to evaporatively cool these large
leaves.
Some Important Plants
• Ambrosia dumosa – white bursage.
• Small shrub with small dissected leaves (0.1 – 0.2
cm2).
• Dominant with Larrea over the driest areas of the
Lower Colorado River.
• Leaf size in Ambrosias match aridity of habitat.
Some Important Plants
• Palo verde – foothills and
blue
• Blue – needs more water,
restricted to washes.
• Flowers for 2 weeks in April.
• Branches droop to the
ground.
• Short-lived (< 50yrs?)
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Some Important Plants
• foothills – more drought
resistant, hillsides
• Flowers for 2 weeks right
after blue palo verde.
• Branches droop less.
• Long-lived (100’s of years?).
Some Important Plants
• Intermediate in function between deciduous shrubs
and evergreens.
• Photosynthetically active all year.
• Produces leaves only in response to heavy rains.
Mesquite – Prosopis velutina
• Wood is hard and attractive
• Popular smoke flavoring for
food.
• Major traditional food source
for Native Americans
 Inner pods sweet
 Seeds 35% protein
 Meal from seeds is used in
native and modern food.
Some Important Plants
• Palo verdes are stem photosynthetic trees.
• One study showed that 72% of annual carbon gain (growth)
came from stem photosynthesis.
• Chlorophyll concentration is higher in stems than leaves.
• More photosynthesis with less water loss (higher WUE).
Legume Trees
• Mesquite – Prosopis velutina
• Important plant with an
interesting history.
Mesquite – Coevolved with mastodons
and other large (extinct) herbivores
• Ate sweet fruits and dispersed
seeds widely
• Seeds germinated better after
passing through gut.
• Plants lived on hills and valleys.
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Mesquite – Coevolved with
mastodons and other large
herbivores
• Large animals went extinct at
end of Pleistocene.
• Mesquites contracted to flood
plains and washes “bosques”
• Cattle 1880’s act like extinct
animals – mequites begin to
recolonize hillsides.
Mesquite – Coevolved with mastodons
and other large herbivores
Mesquite – Coevolved with mastodons
and other large herbivores
• If grassland is overgrazed
mequites outcompete grasses
and take over.
• Since they suppress fire, the
conversion is permanent.
Plants of the Southwest
• Meanwhile, water tables have
dropped dramatically and flood
plain mesquites have been cut.
• Few mequite bosques left.
Some Important Plants
• Fouquierias – 11 species from arid Mexico
and SW USA.
• Drought deciduous C3 plants that
behave like CAM.
• 5 in the Sonoran desert region: burragei,
columnaris, diguetii, macdougalii, splendens
Some Important Plants
• Boojum – Fouquieria columnaris
• Name comes from a mythical plant in
Lewis Caroll’s The Hunting of the
Snark.
• May live > 100 years.
• > 60 ft. tall
• Nearly endemic to Baja California.
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Some Important Plants
• Ocotillo – Fouquieria splendens
• Widespread in Sonoran and
Chihuahuan Deserts
• Leaf blade becomes spine.
Some Important Plants
• Green parenchyma layer under bark - no stomata.
• Photosynthetically active - recycles CO2 from respiration
(no net carbon gain).
• This photosynthetic idling keeps it from using up stored
nutrients and lets it respond quickly to short rains like CAM
plants.
Some Important Plants
• Opuntias – Chollas and Prickly
Pears
Some Important Plants
• Short shoots permit deployment of
leaves 3 days from rain.
• Very shallow roots for rapid uptake.
• Behaves like CAM plants, but it is C3.
Some Important Plants
• Several hummingbirds migrate
north during the spring and
depend on ocotillo as a nectar
source – reliable spring flowering.
• Flowers often nectar robbed by
verdins and carpenter bees.
Opuntias – Chollas and Prickly Pears
• Chollas (round stem) Now called Cylindopuntia
• Prickly Pears (flat stem)
• Many species (> 300)
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Opuntias – Chollas and Prickly Pears
• Nasty glochids
• Unique to Opuntias
Opuntias –Prickly Pears
• Engelmann Prickly Pear – Opuntia engelmannii
• Most common prickly pear
• It varies so much that scientists aren’t sure if it’s 1
variable species or 2 species that hybridize.
Opuntias –Prickly Pears
• Engelmann Prickly Pear Opuntia engelmannii
• Pads eaten by jackrabbits, packrats, and
javelina.
Opuntias – Chollas and Prickly Pears
• Nasty glochids
Opuntias –Prickly Pears
• Engelmann Prickly Pear – Opuntia engelmannii
• Fleshy fruits taste good and are eaten by many
animals.
• Sold commercially as jelly, syrup, even prickly pear
lemonade or margaritas.
Opuntias –Prickly Pears
• And people!
• Some species of prickly pear have been
developed commercially in Mexico –nopalitos
– good against diabetes and high cholesterol
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2/10/2015
Hmm,
Prickly pear!
,
Opuntias –Prickly Pears
• Spaniard conquistadors were very interested in
prickly pears.
• A little scale insect - cochineal - lives on it that
produces a rich red to purple dye.
• Such dye was rare in Europe and worth a lot of
money.
Opuntias – Chollas
• Chain fruit Cholla – Opuntia fulgida
• Big tree-like cholla recognized by the chains of
fruits.
Opuntias – Other local chollas
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Christmas cholla – Opuntia leptocaulis
Name from the red fruits made around Christmas.
Often grows in with shrubs
Difficult on the unsuspecting hiker.
Opuntias – Chollas
• Seven species of chollas around Tucson
• They naturally hybridize and at least 7 natural
hybrid forms recognized.
Opuntias – Chain Fruit Cholla
• One of the only plants that produces fruits that
never mature and makes flowers coming out of
fruits.
• Seeds seldom germinate.
• Reproduces by falling apart.
• What are those chains for?
Opuntias – Other local chollas
• Pencil cholla – Opuntia arbuscula
• Bigger stems than Christmas cholla
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2/10/2015
Opuntias – Other local chollas
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Cane Cholla – Opuntia spinosior
Staghorn – Opuntia versicolor
Buckhorn - Opuntia acanthocarpa
Thin branched bigger chollas
Opuntias – Chollas and Prickly Pears
• Wood rats (packrats) make nests under prickly
pears or cover nests with cholla joints
• Cactus wrens build their nests in chollas
Opuntias – Other local chollas
• Teddy bear cholla – Opuntia bigelovii
• Try to hug it!
• Asexual clones –seeds usually infertile.
Some Important Plants
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Desert broom -Baccharis sathoroides
Grows naturally in desert washes
“Pioneer” or weed of newly disturbed soil.
In Nov/Dec its fluffy seeds are everywhere!
Male flowers
Female flowers
Some Important Plants
• Brittlebush - Encelia farinosa
• Hemispherical shrub that paints the desert
hillsides yellow when it blooms in the spring.
Brittlebush - Encelia farinosa
• Hemispherical shrub that paints the desert
hillsides yellow when it blooms in the spring.
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Brittlebush - Encelia farinosa
• Tremendous variation in leaves
 the green leaf can absorb 85% of solar
radiation and photosynthesize more.
 the silvery one may reflect more than
60%, including the infrared radiation that
causes heating of leaf tissues but they
photosynthesize less.
Ephedra – Ephedra trifurca
• An ancient relict left over from the age
of dinosaurs – seeds but no flowers
Grasses and Grasslands
• Desert Grasslands border the
Sonoran desert east of Tucson.
• They are a dry extension of the
Great Plains grasslands.
Some Important Plants
• Ephedra – Ephedra trifurca
Mormon tea – Ephedra trifurca
• Potent herbal tea – caffeine and ephedrine
• Ephedrine is a chemical related to
pseudoephedrine, which is Sudafed
Grasses and Grasslands
• Going up toward Mt. Lemmon
or driving from Phoenix to
Flagstaff:
• Oak Juniper Savannah
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Grasses and Grasslands
• There are many native grasses
in the desert too.
• Some are annuals (escape)
• Most are perennials (die back
to resist drought).
purple threeawn (Aristida purpurea
Nutt. var. purpurea)
Sprucetop grama (Bouteloua
chondrosioides)
Reverchon Threeawn (Aristida
purpurea Nutt. var. nealleyi)
Six Weeks Needle Grama
(Bouteloua aristidoides)
Sideoats Grama (Bouteloua
curtipendula)
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Black Grama (Bouteloua eriopoda)
feather fingergrass (Chloris virgata)
Fluff grass
(Erioneuron pulchellum)
Tanglehead (Heteropogon contortus)
Arizona cottontop (Digitaria
californica)
Bush muhly (Muhlenbergia porteri)
–
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Some Important Plants
• Invasive grasses are threatening the Sonoran Desert.
• Mediterranean grass, buffelgrass.
Some Important Plants
• Mediterranean grass (Schismus barbatus) has been
around since at least 1926.
• Widespread and common even in the
driest deserts.
Some Important Plants
• Buffelgrass (Pennisetum ciliare) has been extensively
introduced to Arizona and Sonora for livestock forage
since the 1960s.
• It is rapidly expanding along highways and invading the
desert.
• It is all over Tucson and expanding in the foothills and
mts around Tucson.
Some Important Plants
• It is big and burns easily.
• In Sonora more than 1,000,000 hectares (500,000 acres) of
desert have been purposely converted to buffelgrass.
• Results in drastically reduction of habitat and reduced
species diversity.
• It may destroy large hunks of the saguaro/palo verde desert
here.
Quercus
oblongifolia
• Mexican Blue Oak – Quercus oblongifolia
• the dominant species in lower open oak
woodland.
• It is an important constituent of pinyonjuniper communities.
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Silverleaf Oak, Quercus hypoleucoides
lanceolate leaves - dark green on top
silver white on bottom
commonly found in moist canyons and on
ridges and with conifers in S AZ mountains
• deciduous
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Quercus
arizonica
Quercus emoryi
• Arizona White Oak
• one of the largest southwestern oaks
• Found on sky islands in AZ, NM, Sonora,
Chihuahua
• Sprouts from stumps after moderate fires
• evergreen
• Emory Oak
• grows in dry hills at moderate altitudes
• evergreen
Quercus rugosa
Quercus
gambelii
• Netleaf Oak
• Deep leaf veins
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Gambel Oak
deciduous
small tree or large shrub
widespread in the foothills and lower
mountain elevations
• More widespread and goes further north
Pinus
ponderosa
• Arizona Sycamore or Alamo
• Riparian – desert and sky islands
Platanus
wrightii
• Rocky Mt Ponderosa Pine
• All over the west, up to Canada
• Widespread in mts of SW and along Mogollon
Rim and around Grand Canyon in AZ
• Fire adapted, but doesn’t do well with hot fires
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Pinus
strobiformis
Pinus
discolor
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• Border Pinyon Pine
• Grassy pinyon juniper woodlands
• Makes pine nuts
Southwestern (or Chihuahua) White Pine
Mexico – Sierra Madre
high-elevation pine – growing with other pines
Likes cool moist places but very drought
tolerant
• Huge cone!
• sky islands - a layer cake of biomes each
with its own plants and animals
Pinus
engelmannii
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Apache pine
Mainly Mexican
AZ: south & east of Tucson
Needles up to 15 in. long!!
Abies
concolor
Abies
lasiocarpa
var. arizonica
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White Fir
Long narrow tapering tree
Distintive gray bark
High altitude in AZ, widespread in W US
Corkbark Fir
Looks like white fir, but thick corky bark
Straight leaves in two rows
Grows at treeline in NM and AZ
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2/10/2015
Pseudotsuga
menziesii
• Douglas Fir
• Higher mountains
throughout West
• One of the tallest trees in
USA
• Cones have funny bracks
sticking out
• Not a true fir.
Populus tremuloides
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Quaking Aspen
Most massive living organism?
Huge geographic range?
Great beauty?
A “phoenix” species?
One is ~80,000 yo with
47,000 trees (in Utah)
• Grows in gaps after fire
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