Botany: Biomes
I.
Biomes
A. Biomes -
_______________________________________________________
_________________________________________________________________
_________________________________________________________________.
1. Biomes
are terrestrial. Land makes up only ¼ of
earth’s surface area.
B. Similar environments support similar biotic
communities
1.
Biomes are the next higher level of ecological organization above
ecosystems
2.
Biomes represent a number of interacting ecosystems
3.
Biomes have similar vegetation
a. The greater the differences in environments
within a biome, the
greater the
differences among the organisms that inhabit them.
C. ______________________________ and _____________________________
are the major
determinants of the vegetation in an area
1. A biome is a large, relatively distinct
terrestrial region characterized by
a particular
combination of climate, soil, plants, and animals that is
approximately
the same regardless of where it occurs in the world.
2. Cooler temperatures encountered in mountain’s higher altitudes
promote biomes normally seen at high latitudes.
3. In general, as one moves north from the equator (or higher in altitude),
one sees the following sequence of biomes…
a.
b.
c.
d.
4. The mountain coniferous forest is called the ___________________
__________________________________________________________.
5. The tundra near the peak is called the _________________________
__________________________________________________________.
II. Terrestrial Biomes
A. Tundra
1. The Arctic tundra encircles the earth just south of the ice-covered polar
seas in the Northern Hemisphere.
a. Arctic tundra covers about ____________ of the earth's land
surface.
b. These cold, boggy plains are _____________ much of the year.
c. Snow melts here seasonally, providing plentiful ____________
in summer
d. Tundras are characterized by ___________________________
_____________________________________________________
2. Climate
a. Cold with an annual average temperature of -28˚C (_______˚F)
1) Winter average = -34˚C (_______˚F)
a) Extreme low = -70˚C (_______˚F)
2) Summer average = 3 to 16˚C (_______ to _______˚F)
a) Extreme high = 27˚C (_______˚F)
b. Only the topmost layer of earth thaws during the summer; the __________________________________, 10 to 20 cm to 1 m
beneath this layer, is always frozen.
1) Trees are not found in the tundra because the growing
season is too short, their roots cannot penetrate the
permafrost, and they cannot become anchored in the boggy
soil of summer.
2) The tundra is the most fragile of all biomes due to the harsh
and relatively sparse vegetation. High winds occasionally tear
away chunks of matted vegetation. Such damage is known as
a _________________.
3) It may take a decade or more for succession to repair the
blowout.
c. Tundra receives about 20 cm (_________________________)
of rainfall annually
d. Short growing season of 2 to 3 months
(____________________ days), but the days are long during this
period
3. Vegetation
a. In the summer, the ground is nearly completely covered with
_____________________ and ____________________________,
but
there are also numerous patches of ______________________
and ________________________.
b. _________________________________________________
(no more than 50 cm (2 feet) tall) flower and seed quickly while
there is plentiful sun for photosynthesis.
c.
When high winds tear away matted vegetation of
tundra, the
resulting barren patch is called a blow out.
4. Other facts
a. The ______________________ tundra is a similar community
that occurs above the __________________________________ on
mountain ranges.
1) However, there is generally no permafrost or extremes
in day length
2) There are high winds and changing seasons
b. Soils are thin & nutrient poor
c. The tundra regenerates very slowly after it has been disturbed
d. Animal life of the tundra
1) A few animals that are highly adapted to cold live in the
tundra year-round (e.g. ___________________________
__________________________________).
2) During the summer the tundra contains numerous
__________________________________ and
__________________________________.
B. __________________________________ – a.k.a. northern coniferous or
boreal forests
1. Adjacent to the arctic tundra (only in northern hemisphere), this
coniferous
forest extends in a broad belt across northern
2. Climate
a. Cold winters, cool summers with an annual average temperature
of -10 to 14˚C (_______ to _______˚F)
1) Winter average = -54 to -1˚C (_______ to _______˚F)
2) Summer average = -1 to 21˚C (_______ to _______˚F)
b. Precipitation of 50 to 100 cm (______________________)
occurs mostly in _______________________
3. Vegetation
a. Contains great stands of ____________________,
____________________, ____________________, and
____________________; These trees have drought resistant
adaptations. Helps them survive ____________________ when
roots cannot absorb water because the ground is frozen.
1) Needle-like leaves with minimal surface area (that also
can withstand the heavy weight of snow)
2) trees have thick protective leaves and bark.
b. There is a limited understory of plants; floor is covered by low-
lying ____________________ and ____________________
beneath needles.
4. Other facts
a. Because leaf litter (needles) accumulate beneath the trees, &
decay slowly because of the cold temperatures, the soil is relatively
____________________ & ____________________
b. Near mountain tops, it is called a montane coniferous forest.
1) Main vegetation is conifers, without much understory
c. Along the
____________________________________________________.
1) Has the largest trees in existence, some as old as 800
years.
2) Winters are ____________________ & summers are
____________________
3) High yearly rainfall; 200 to 380 cm
(____________________ inches)
4) High humidity with ____________________ from
ocean
5) Well developed understory of ____________________,
____________________, ____________________, &
____________________
d. Animal life of the taiga
1) Birds harvest seeds of conifers; bears, deer, moose,
beaver and muskrat live around cool lakes and streams.
2) Major carnivores include wolves, wolverines, and
mountain lions.
C. Temperate Deciduous Forests
1. These are found south of the taiga in eastern
Asia, and much of
2. The climate is moderate
a. Summers are ____________________ & winters are
____________________; 4˚C (____________________), but can
have sub-freezing temperatures.
b. Precipitation is relatively even throughout the year, but most
falls in ____________________
1) annual rainfall 75-225 cm (________________ inches).
c. Seasons are well-defined with a growing season that ranges
between ____________________ days.
3. Vegetation
a. ____________________________ trees have broad leaves,
which they lose in the fall and grow again in the spring.
1) ex. Oak, maple, beech, hickory, birch & other ________
____________________ (There used to be chestnuts before
blight killed them)
b. Enough sunlight penetrates the canopy to support a well-
developed
understory composed of shrubs, a
layer of herbaceous
plants, and then often a ground cover of mosses and ferns.
4. Other facts
a. Topsoil is ____________________ in organic matter
b. Less than ____________________ of the original forest
remains; it was cleared for _______________________________,
____________________, and ____________________
c. As agriculture has moved west, much of the farm land has
reverted (through ____________________) back to forest
d. Animal life of the temperate deciduous forest
1) The stratification beneath the canopy provides a variety
of habitats for insects and birds.
2) The deciduous forest also contains many
____________________, which provide food for bobcats,
wolves, foxes.
3) The deciduous forest also contains deer and black bears.
4) In contrast to the taiga, the winters are not so cold,
allowing many ____________________ and
____________________ to survive.
D. Grasslands
1. Grasslands occur toward the center of continental masses, where rainfall
is greater than ____________________ but is generally insufficient to
support ____________________.
a. Temperate grasslands include the Russian
____________________, the South American ________________,
and North American ____________________.
2. Climate
a. In temperate areas where rainfall is between 25 to 100 cm (10
and 39 inches) a year, grassland is the _______________________
____________________ because it is too wet for
____________________ and too dry for ____________________.
b. Summers are hot, up to 45˚C (_______˚F); winters are cold,
down to -45˚C (__________˚F)
3. Vegetation - Grasses are the dominant plant form. The extensive root
systems of grasses allows them to recover quickly from grazing, flooding,
drought, and sometimes fire. There are also annual wild flowers. There
are few trees, except near rivers or streams.
a. A tall-grass prairie occurs where moisture is not quite
sufficient to support trees. Tall perennial grasses 5 m (15 feet) tall.
b. A short-grass-prairie survives on less moisture and is between
a tall-grass prairie and desert. Short perennial grasses.
4. Other facts
a. Natural grasslands once covered over _______________ of the
earth's land surface.
1) Most grasslands have now been utilized to grow crops,
especially ______________ and ____________________.
*They are the most important agricultural areas in the
world.*
b. Prairies once contained large herds of ____________________
and _______________________________.
c. ____________________ is tropical grassland that contains
some drought deciduous trees.
1) This biome has no marked hot or cold seasons, but
does have dry and rainy seasons.
2) Savanna contains the greatest variety and numbers of
herbivores (e.g., antelopes, zebras, wildebeests, etc.).
3) This supports a large population of carnivores (e.g.
lions, cheetahs, hyenas, and leopards).
4) Any plant litter not consumed by grazers is attacked by
termites and other decomposers.
d. Animal life of the grasslands
1) Grazing and burrowing species are the dominant forms
of animal life.
2) Mice, prairie dogs, and rabbits, and animals that feed on
them (e.g. hawks, snakes, etc.)
E. Deserts
1. Deserts are found in regions where annual rainfall is less than
____________________ and primarily at latitudes about
____________________ north or south where winds pick up moisture and
ascend. Deserts are characterized by _____________________________
that utilize ___________________________________________.
a. Hot low deserts occur where evaporation & transpiration exceed
rainfall. In the
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1) ____________________ desert occupying a relatively small region of extreme south-central California and most of the southern half of Arizona, east to almost the New Mexico line. (Note the characteristic Saguaro cacti.) (Photo
from: http://whoyoucallingaskeptic.files.wordpress.com/2009/12/sonoran-desert.jpg)
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2) ____________________ desert occupying a
small area of southeastern New Mexico and extreme western Texas, extending
south into a vast area of (Note the creosote bushes and yucca.) (Photo
from: http://www.chihuahuandesert.org/images/lech.creo.cdDesert.jpg)
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3) ____________________ desert occupying a
portion of southern Nevada, extreme southwestern Utah and of eastern (Note the characteristic Joshua tree.) (Photo
from: http://www.susankramer.com/desert1.JPG)
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b. Cold deserts occur as a result of a rain shadow – few
precipitation clouds get over mountain ranges.
1)
windward side of the mountains creating a cold desert
region west of the
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2) The ___________________________ desert
occupies the northern three-quarters of Nevada, western and southern Utah, to
the southern third of Idaho and the southeastern corner of (Note the dwarfed shrubs.) (Photo
from: http://www.desertmuseum.org/images/gbdes02.jpg)
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3) This desert is dominated by sagebrush and birds
dependent on it.
2. Climate
a. Because of a lack of cloud cover, the days are _____________
and the nights are ____________________.
b. Low humidity results in large daily temperature extremes.
c. Precipitation is less than 25 cm (10 inches)
3. Vegetation
a. The
vegetation.
b. However, most
have a variety of plants, all adapted to
heat
and scarcity of water (e.g. succulents).
c. Low deserts have ____________________ & drought tolerant
____________________ with thick cuticles, water storage tissues
in stems & leaves (cacti), reduced leaves or no leaves, shallow
roots (cacti), deep taproots (mesquite), defensive spines, thorns, or
toxins
d. Cold deserts have sagebrush and low shrubs
4. Other facts
a. Soil is nutrient ____________________
1) Not enough moisture for degradation of organic
material
2) Some are high in minerals because of lack of rain
3) Soils are subject to __________________________
____________________ (the sparse vegetation leaves
much of the desert soil exposed)
b. Animal life includes arthropods (e.g., insects and arachnids),
reptiles (e.g., lizards and snakes), running birds, rodents (e.g., the
kangaroo rat), and a few larger birds and mammals (e.g., hawks
and coyote).
F. ____________________ (an example of a shrubland)
Red
shanks chaparral in foreground right, chamise chaparral in bloom background
left. Above Noble Canyon, Pine Valley area, Cleveland National (Chaparral)
Forest. Photo courtesy of California
Chaparral Institute.
1. Shrubland is dominated by shrubs with small but thick
____________________ leaves that are often coated with a thick, waxy
cuticle, and with thick underground stems that survive the dry summers
and frequent fires.
a. Shrubland is found in parts of
b. Dense shrubland in
very dry, is chaparral.
2. Climate
a. ____________________ climate with hot, dry summers & cool,
rainy winters
b. Low humidity, large daily temperature extremes, low
precipitation
3. Vegetation
a. Evergreen
broadleaf shrubs, drought resistant pine
and scrub
oak
1) Vegetation has thick, leathery leaves that cut down on
transpiration in the hot dry summers.
2) Plants form dense thickets
b. Lacks an understory and ground litter, but the vegetation is
highly ____________________.
1) The seeds of many species require the heat and scarring
action of fire to induce germination.
4. Other facts
a. Chaparral is lush & green during ____________________ rainy
season.
b. Many of the plants go ____________________ during the hot
dry summers.
c. Vegetation is adapted to fires, which are a constant threat in the
dry summer season
d. In the winter, heavy rains can produce ____________________
G. Tropical Rainforests
1. Tropical rain forests are found in regions near equator & cover ______
of the earth’s surface.
a. This biome contains the oldest continuously living vegetation
because, unlike other biomes, the plants of the tropical rainforests
were sheltered from glaciations.
b. Greatest species diversity & total biomass of any biome.
2. Climate
a. Little seasonal variation in temperatures between 25°- 35° C
(______°F – _________° F)
b. Plentiful rainfall, 200 to 450 cm (_____ to _______ inches)
c. HIGH humidity
3. Vegetation
a. VERY diverse. Broad leaved evergreen trees with shallow
roots.
1) Multilayered canopy, divided into stories according to
their height
2) Upper two stories are trees. The upper story consists of
the tallest trees; 80 m (260 feet).
3) Most trees are in the middle layer; 50 m (160 feet)
b. There is little understory because of the dense shade
c. ____________________ are air plants that grow on other
plants; they have roots of their own to absorb moisture and
minerals leached from the canopy. (e.g. _____________________)
d. Vines grow on the trees, reaching for the sunlight
4. Other facts
a. Soil is very ____________________ because minerals are
leached by heavy precipitation & decay is very rapid (nutrients are
quickly taken up by existing vegetation).
b. Some tropical forests in
Central and South American are seasonal and have deciduous trees
that shed leaves in dry season.
c. Animal life of the tropical rainforests
1) Although there is animal life on the ground (e.g., pacas,
agoutis, peccaries, armadillos, and coatis), most animals
live in the trees and many spend their entire life in the
canopy.
2) Insects are so abundant in tropical rain forests that the
majority have not been identified yet.
3) Termites are critical in the decomposition of wood.
4) The various birds tend to be brightly colored.
5) Amphibians and reptiles are well represented by many
species of frogs, snakes, and lizards.
6) Lemurs, sloths, and monkeys feed on fruits in tropical
rain forests.
7) The largest carnivores are the cats (e.g., jaguars in South