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Land Biomes

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Title: Land Biomes


1
Land Biomes
  • APES LCHS
  • Dr.E

2
Introduction
  • Biomes are the major regional groupings of plants
    and animals discernible at a global scale
  • distribution patterns are correlated with
    regional climate patterns and identified
    according to the climax vegetation type
  • a biome is composed not only of the climax
    vegetation, but also of immature communities

3
To understand the nature of biomes one needs to
learn
  • Global distribution pattern
  • Where each biome is found and how each varies
    geographically
  • A given biome may be composed of different taxa
    on different continents

4
To understand the nature of biomes one needs to
learn
  • The dominant, characteristic, and unique growth
    forms
  • vertical stratification
  • leaf shape, size, and habit
  • special adaptations of the vegetation

5
To understand the nature of biomes one needs to
learn
  • The types of animals (especially vertebrates)
    characteristic of the biome
  • Their typical morphological, physiological,
    and/or behavioral adaptations to the environment

6
Major Biomes
  • Deserts
  • Forests
  • Grasslands
  • Tundra
  • Aquatic

7
Deserts
  • Deserts cover about one fifth of the Earths
    surface and occur where rainfall is less than 50
    cm/year
  • Most deserts occur at low latitudes
  • Another kind of desert, cold deserts, occur in
    the basin and mountain ranges
  • Most deserts have a considerable amount of
    specialized vegetation, as well as specialized
    vertebrate and invertebrate animals

8
Deserts
  • Soils often have abundant nutrients because they
    need only water to become very productive and
    have little or no organic matter
  • Disturbances are common in the form of occasional
    fires or cold weather, and sudden, infrequent,
    but intense rains that cause flooding

9
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10
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11
Types of Deserts
  • Hot and Dry
  • Semiarid
  • Coastal
  • Cold

12
Hot and Dry Desert
  • Temperature
  • Desert surfaces receive a little more than twice
    the solar radiation received by humid regions and
    lose almost twice as much heat at night
  • Many mean annual temperatures range from 20-25 C
  • The extreme maximum ranges from 43.5-49 C.
    Minimum temperatures sometimes drop to -18 C

13
Hot and Dry Desert
  • Precipitation
  • Rainfall is usually very low and/or concentrated
    in short bursts between long rainless periods
  • Evaporation rates regularly exceed rainfall rates
  • Sometimes rain starts falling and evaporates
    before reaching the ground
  • Rainfall is lowest on the Atacama Desert of
    Chile, where it averages less than 1.5 cm
  • Inland Sahara also receives less than 1.5 cm a
    year
  • Rainfall in American deserts is higheralmost 28
    cm a year

14
Hot and Dry Desert
  • Soils
  • Soils are course-textured, shallow, rocky or
    gravely with good drainage and have no subsurface
    water
  • They are coarse because there is less chemical
    weathering
  • The finer dust and sand particles are blown
    elsewhere, leaving heavier pieces behind

15
Hot and Dry Desert
  • Plants
  • Canopy in most deserts is very rare
  • Plants are mainly ground-hugging shrubs and short
    woody trees
  • Leaves are replete (fully supported with
    nutrients) with water-conserving characteristics
  • They tend to be small, thick and covered with a
    thick cuticle (outer layer)
  • In the cacti, the leaves are much-reduced (to
    spines) and photosynthetic activity is restricted
    to the stems
  • Some plants open their stomata (microscopic
    openings in the epidermis of leaves that allow
    for gas exchange) only at night when evaporation
    rates are lowest

16
Hot and Dry Desert
  • Yuccas

  • Ocotillo
  • Turpentine bush

  • Prickly Pears
  • False mesquite
  • Sotol
  • Ephedras

  • Agaves
  • Brittlebush

17
Hot and Dry Desert
  • Animals
  • The animals include small nocturnal (active at
    night) carnivores
  • The dominant animals are burrowers and kangaroo
    rats
  • There are also insects, arachnids, reptiles and
    birds
  • The animals stay inactive in protected hideaways
    during the hot day and come out to forage at
    dusk, dawn or at night, when the desert is cooler

18
  • Snakes
  • Lizards
  • Tortoise Bighorn Sheep
  • Coyote Ants
  • Tarantula Tarantula Wasp

19
Semiarid Desert
  • Temperature
  • The summers are moderately long and dry, and like
    hot deserts, the winters normally bring low
    concentrations of rainfall
  • Summer temperatures usually average between
    21-27 C
  • It normally does not go above 38 C and evening
    temperatures are cool, at around 10 C.

20
Semiarid Desert
  • Precipitation
  • Cool nights help both plants and animals by
    reducing moisture loss from transpiration,
    sweating and breathing
  • Condensation of dew caused by night cooling may
    equal or exceed the rainfall received by some
    deserts
  • As in the hot desert, rainfall is often very low
    and/or concentrated
  • The average rainfall ranges from 2-4 cm annually.

21
Semiarid Desert
  • Soils
  • ranges from sandy and fine-textured to loose rock
    fragments, gravel or sand
  • fairly low salt concentration, compared to
    deserts which receive a lot of rain (acquiring
    higher salt concentrations as a result)
  • there is no subsurface water.

22
Semiarid Desert
  • Plants
  • The spiny nature of many plants in semiarid
    deserts provides protection in a hazardous
    environment
  • The large numbers of spines shade the surface
    enough to significantly reduce transpiration
  • The same may be true of the hairs on the woolly
    desert plants
  • Many plants have silvery or glossy leaves,
    allowing them to reflect more radiant energy
  • These plants often have an unfavorable odor or
    taste.

23
Semiarid Desert
Creosote bush Bur sage White
thorn
Cat claw Mesquite Brittle bushes
Lyciums
Jujube
24
Semiarid Desert
  • Animals
  • During the day, insects move around twigs to stay
    on the shady side jack rabbits follow the moving
    shadow of a cactus or shrub
  • Naturally, many animals find protection in
    underground burrows where they are insulated from
    both heat and aridity

25
Semiarid Desert
Kangaroo rats Rabbits
Skunks Side-blotched Lizard Mountain Lion Mule
Deer Rattlesnake
Burrowing owls

Western Bluebird
26
Coastal Desert
  • Temperature
  • The cool winters of coastal deserts are followed
    by moderately long, warm summers
  • The average summer temperature ranges from 13-24
    C winter temperatures are 5 C or below
  • The maximum annual temperature is about 35 C and
    the minimum is about -4 C
  • In Chile, the temperature ranges from -2 to 5 C
    in July and 21-25 C in January

27
Coastal Desert
  • Precipitation
  • The average rainfall measures 8-13 cm in many
    areas
  • The maximum annual precipitation over a long
    period of years has been 37 cm with a minimum of
    5 cm

28
Coastal Desert
  • Soils
  • fine-textured with a moderate salt content
  • fairly porous with good drainage.

29
Coastal Desert
  • Plants
  • extensive root systems close to the surface where
    they can take advantage of any rain showers
  • thick and fleshy leaves or stems can take in
    large quantities of water when it is available
    and store it for future use
  • some surfaces are corrugated with longitudinal
    ridges and grooves
  • stem swells so that the grooves are shallow and
    the ridges far apart
  • the stem shrinks as water is used so that the
    grooves are deep and ridges close together.

30
Coastal Desert
  • Salt bush
  • Buckwheat Bush
  • Black bush
  • Rice grass
  • Little Leaf Horsebrush
  • Black Sage
  • Chrysothamnus

31
Coastal Desert
  • Animals
  • Some animals have specialized adaptations for
    dealing with the desert heat and lack of water
  • toads seal themselves in burrows with gelatinous
    secretions and remain inactive for eight or nine
    months until a heavy rain occurs
  • amphibians that pass through larval stages have
    accelerated life cycles, which improves their
    chances of reaching maturity before the waters
    evaporate
  • insects lay eggs that remain dormant until the
    environmental conditions are suitable for
    hatching
  • fairy shrimps also lay dormant eggs.

32
Coastal Desert
  • Chilean Woodstar
  • Caecilians
  • Vultures
  • Mice
  • Fox
  • Scorpions

33
Cold Desert
  • Temperature
  • Cold winters with snowfall and high overall
    rainfall throughout the winter and occasionally
    over the summer
  • Antarctic, Greenland and the Nearctic realm
  • short, moist, and moderately warm summers with
    fairly long, cold winters
  • mean winter temperature is between -2 to 4 C and
    the mean summer temperature is between 21-26 C

34
Cold Desert
  • Precipitation
  • winters receive quite a bit of snow
  • mean annual precipitation ranges from 15-26 cm
  • annual precipitation has reached a maximum of 46
    cm and a minimum of 9 cm
  • heaviest rainfall of the spring is usually in
    April or May
  • rainfall can be heavy in autumn in some areas

35
Cold Desert
  • Soil
  • heavy, silty, and salty
  • relatively porous and drainage is good so that
    most of the salt has been leached out

36
Cold Desert
  • Plants
  • widely scattered
  • areas of shad-scale, about 10 percent of the
    ground is covered
  • some areas of sagebush it approaches 85 percent
  • heights vary between 15 cm and 122 cm
  • deciduous, most having spiny leaves

37
Cold Desert

  • Lichens  
  • Bryophytes
  • Antarctic
    Algae
  •  
  • Snow Algae

  • Kelp

38
Cold Desert
  • Animals
  • population density can range from 14-41
    individuals per hectare
  • all except the jack rabbits are burrowers
  • also applies to carnivores
  • several lizards do some burrowing and moving of
    soil
  • deer are found only in the winter

39
Cold Desert
  • Jack Rabbits Kangaroo Rats
  • Kangaroo Mice
  • Pocket Mice Grasshopper Mice
  • Antelope Ground Squirrels
  • Badger Kit fox
  • Coyote Mule deer

40
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41
Grasslands
  • characterized as lands dominated by grasses
    rather than large shrubs or trees
  • largest land animals due to huge vegetation
  • There are two main divisions of grasslands
  • tropical grasslands called savannas
  • temperate grasslands.

42
Savanna
  • Savanna is grassland with scattered individual
    trees
  • Climate is the most important factor in creating
    a savanna
  • fires maintain an area as a savanna
  • Types of Savannas
  • climatic conditions are called climatic savannas
  • soil conditions not entirely maintained by fire
    are called edaphic savannas
  • derived savanna is the result of people clearing
    forest land for cultivation

43
Savanna
44
Savanna
  • Precipitation
  • always found in warm or hot climates where the
    annual rainfall is from about 50.8 to 127 cm
    (20-50 inches) per year
  • crucial that the rainfall is concentrated in six
    or eight months of the year, followed by a long
    period of drought when fires can occur
  • if the rain were well distributed throughout the
    year, many such areas would become tropical forest

45
Savanna
  • Soils
  • porous, with rapid drainage of water
  • only a thin layer of humus (the organic portion
    of the soil created by partial decomposition of
    plant or animal matter), which provides
    vegetation with nutrients

46
Savanna
  • Plants
  • characterized by a continuous cover of perennial
    grasses, often 3 to 6 feet tall at maturity
  • may or may not also have an open canopy of
    drought-resistant, fire-resistant, or
    browse-resistant trees, or they may have an open
    shrub layer

47
Savanna
  • Animals
  • When the rains come, savanna bunch grasses grow
    vigorously
  • larger grasses may grow an inch or more in 24
    hours
  • a surge of new life at this time
  • for example, many antelope calves are born
  • with so much grass to feed on, mothers have
    plenty of milk
  • calves die if the rains fail to come.

48
Savanna
  • Animals
  • do not all occur in the same savanna
  • giraffes, zebras, buffaloes, kangaroos, mice,
    moles, gophers, ground squirrels, snakes, worms,
    termites, beetles, lions, leopards, hyenas, and
    elephants

49
  • Giraffes Zebras Water buffaloes
  • Cheetah Baboon Ants
  • Crocodile Wild Dog Termites
  • Meerkats Lions Leopards
  • Hyenas Elephants Rhinoceros

50
Temperate Grassland
  • grasses as the dominant vegetation with trees and
    large shrubs absent
  • seasonal drought and occasional fires are very
    important to biodiversity.
  • effects arent as dramatic in temperate
    grasslands as they are in savannas

51
Temperate Grassland
  • Precipitation
  • usually occurs in the late spring and early
    summer
  • annual average is about 50.8 to 88.9 cm (20-35
    inches).

52
Temperate Grassland
53
Temperate Grassland
54
Temperate Grassland
  • Temperature
  • range is very large over the course of the year
  • summer temperatures can be well over 38 C (100
    degrees Fahrenheit
  • winter temperatures can be as low as -40 C (-40
    degrees Fahrenheit)

55
Temperate Grassland
  • Soil
  • deep and dark, with fertile upper layers
  • nutrient-rich from the growth and decay of deep,
    many-branched grass roots
  • rotted roots hold the soil together and provide a
    food source for living plants

56
Temperate Grassland
  • Plants
  • different species of grass grows best in a
    particular grassland environment
  • seasonal drought, occasional fires, and grazing
    by large mammals all prevent woody shrubs and
    trees from invading and becoming established
  • a few trees, such as cottonwoods, oaks, and
    willows grow in river valleys, and some nonwoody
    plants, specifically a few hundred species of
    flowers, grow among the grasses

57
Temperate Grassland
  • Purple needlegrass Blue Grama
  • Buffalo grass
    Galleta
  • Asters
    Blazing Stars
  • Coneflowers
    Goldenrods
  • Sunflowers Clovers
  • Psoraleas
    Wild Indigos

58
Temperate Grassland
  • Animals
  • gazelles, zebras, rhinoceroses, wild horses,
    lions, wolves, prairie dogs, jack rabbits, deer,
    mice, coyotes, foxes, skunks, badgers,
    blackbirds, grouses, meadowlarks, quails,
    sparrows, hawks, owls, snakes, grasshoppers,
    leafhoppers, and spiders

59
Tundra The Not-So Barren Land
  • coldest of all the biomes
  • comes from the Finnish word tunturia, meaning
    treeless plain
  • frost-molded landscapes
  • extremely low temperatures
  • little precipitation
  • poor nutrients
  • short growing seasons

60
Tundra The Not-So Barren Land
61
Tundra The Not-So Barren Land
62
Tundra The Not-So Barren Land
  • Temperature
  • growing season ranges from 50 to 60 days
  • average winter temperature is -34 C (-30 F)
  • average summer temperature is 3-12 C (37-54 F)
    which enables this biome to sustain life

63
Tundra The Not-So Barren Land
  • Precipitation
  • may vary in different regions of the arctic
  • yearly precipitation, including melting snow, is
    15 to 25 cm (6 to 10 inches)

64
Tundra The Not-So Barren Land
  • Soil
  • formed slowly
  • layer of permanently frozen subsoil called
    permafrost exists, consisting mostly of gravel
    and finer material
  • when water saturates the upper surface, bogs and
    ponds may form, providing moisture for plants
  • no deep root systems in the vegetation of the
    arctic tundra, however, there are still a wide
    variety of plants that are able to resist the
    cold climate

65
Tundra The Not-So Barren Land
  • There are about 1,700 kinds of plants in the
    arctic and subarctic
  • adapted to sweeping winds and disturbances of the
    soil
  • short and group together to resist the cold
    temperatures and are protected by the snow during
    the winter
  • carry out photosynthesis at low temperatures and
    low light intensities
  • growing seasons are short and most plants
    reproduce by budding and division rather than
    sexually by flowering

66
Tundra The Not-So Barren Land
  • low shrubs, sedges, reindeer mosses, liverworts,
    and grasses
  • 400 varieties of flowers
  • crustose and foliose lichen

67
Tundra The Not-So Barren Land
  • Animals
  • Strategies evolved to withstand the harsh
    conditions of the tundra can be divided among
    those species that are resident and those that
    are migratory

68
Tundra The Not-So Barren Land
  • Resident
  • small number of bird (e.g., ptarmigan) and mammal
    (e.g., muskox, arctic hare, arctic fox, musk ox)
  • Morphological adaptations
  • large, compact bodies
  • a thick insulating cover of feathers or fur
  • pelage and plumage that turns white in winter,
    brown in summer
  • Physiological adaptations
  • ability to accumulate thick deposits of fat
    during the short growing season
  • insulation and as a store of energy for use
    during the winter, when animal species remain
    active
  • Population adaptations
  • cyclical fluctuations in population size, best
    seen perhaps in the lemming, a small rodent which
    is the major herbivore in the tundra's simple
    food chain
  • predator populations and plant populations
    respond in kind to the peaks and crashes of the
    herbivore populations

69
Tundra The Not-So Barren Land
  • Migratory
  • species such as waterfowl, shorebirds and caribou
    adapt to the tundra by avoiding the most severe
    conditions of winter
  • each year at the end of the short growing season
    they move southward into the boreal forest or
    beyond, but return to the tundra to breed due to
    the long growing season

70
Forests
  • occupy approximately one-third of Earths land
    area
  • account for over two-thirds of the leaf area of
    land plants
  • contain about 70 of carbon present in living
    things
  • are major casualties of deforestation, pollution,
    and industrial usage
  • forest biomes are classified according to
    numerous characteristics, with seasonality being
    the most widely used

71
Types of Forests
  • Tropical
  • Temperate
  • Boreal forests (taiga)

72
Tropical Forests
  • are characterized by the greatest diversity of
    species
  • occur near the equator, within the area bounded
    by latitudes 23.5 degrees N and 23.5 degrees S
  • distinct seasonality
  • winter is absent
  • only two seasons are present (rainy and dry)
  • The length of daylight is 12 hours and varies
    little.

73
Tropical Forests
74
Tropical Forests
75
Tropical Forests
  • Temperature
  • average 20-25 C and varies little throughout
    the year
  • the average temperatures of the three warmest and
    three coldest months do not differ by more than 5
    degrees

76
Tropical Forests
  • Precipitation
  • evenly distributed throughout the year
  • annual rainfall exceeds 2 meters

77
Tropical Forests
  • Soil
  • nutrient-poor and acidic
  • decomposition is rapid
  • subject to heavy leaching

78
Tropical Forests
  • Plants
  • Canopy
  • multilayered
  • Continuous
  • allows little light penetration
  • Flora is highly diverse
  • one square kilometer may contain as many as 100
    different tree species
  • Trees are 25-35 m tall
  • buttressed trunks and shallow roots
  • mostly evergreen, with large dark green leaves.

79
Tropical Forests
  • Plant Adaptations
  • ability to tolerate constant shade
  • adapt strategies to reach sunlight
  • Fungus is a good example of a plant that
    flourishes in warm, dark places created by the
    forest canopy and understory

80
Tropical Forests
  • Lianas

  • Epiphytes (grow on another plant)
  • Ferns

  • Moss

  • Curare
  • Forest Canopy Palms

81
Tropical Forests
  • White-faced Monkey

  • Tree frog
  • Toucan
  • Vine Snake
  • Gecko

  • Vested Anteater
  • Transparent butterfly
  • Jaguar
  • Unicorn
    grasshopper

  • Red-eyed tree frog
  • Silver-throated Tanager
  • Tropical king snake
  • Scorpion

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83
Temperate Forest
  • Temperature
  • Well-defined seasons with a distinct winter
    characterize this forest biome
  • Moderate climate and a growing season of 140-200
    days during 4-6 frost-free months distinguish
    temperate forests
  • Temperature varies from -30 C to 30 C.

84
Temperate Forest
85
Temperate Forest
86
Temperate Forest
  • Precipitation
  • (75-150 cm) is distributed evenly throughout the
    year
  • Soils
  • fertile, enriched with decaying litter

87
Temperate Forest
  • Plants
  • Canopy
  • moderately dense
  • allows light to penetrate
  • resulting in well-developed and richly
    diversified understory vegetation and
    stratification of animals
  • Flora is characterized by 3-4 tree species per
    square kilometer
  • Trees are distinguished by broad leaves that are
    lost annually

88
Temperate Forest
  • Oak
  • Hickory

  • Beech
  • Hemlock
  • Maple

  • Basswood
  • Cottonwood
  • Elm

  • Willow
    Spring-flowering herbs

89
  • Bank Vole
  • Black Bear

  • Gray Squirrel
  • Raccoon

  • White-tailed Deer

  • Wild Boar
  • Cardinal
  • Goshawk

  • Turkey
  • Yellow-bellied Sapsucker

  • Rat Snake
  • Spring Peeper


90
Temperate Forest
91
Temperate Forest
  • Further subdivisions of this group are determined
    by seasonal distribution of rainfall
  • moist conifer and evergreen broad-leaved forests
    wet winters and dry summers (rainfall is
    concentrated in the winter months and winters are
    relatively mild)
  • dry conifer forests dominate higher elevation
    zones low precipitation.Mediterranean forests
    precipitation is concentrated in winter, less
    than 1000 mm per year
  • temperate coniferous mild winters, high annual
    precipitation (greater than 2000 mm)
  • temperate broad-leaved rainforests mild,
    frost-free winters, high precipitation (more than
    1500 mm) evenly distributed throughout the year
  • Only scattered remnants of original temperate
    forests remain

92
Boreal forests, or taiga
  • represent the largest terrestrial biome
  • Occurs between 50 and 60 degrees north latitudes
  • seasons are divided into short, moist, and
    moderately warm summers and long, cold, and dry
    winters
  • length of the growing season in boreal forests is
    130 days

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94
Boreal forests, or taiga
95
Boreal forests, or taiga
  • Temperatures are very low
  • Precipitation is primarily in the form of snow,
    40-100 cm annually
  • Soil is thin, nutrient-poor, and acidic
  • Canopy permits low light penetration, and as a
    result, understory is limited

96
Boreal forests, or taiga
  • The conical or spire-shaped needleleaf trees
    common to the taiga are adapted to the cold and
    the physiological drought of winter and to the
    short-growing season
  • Conical shape - promotes shedding of snow and
    prevents loss of branches.
  • Needleleaf - narrowness reduces surface area
    (transpired), especially during winter when the
    frozen ground prevents plants from replenishing
    their water supply. The needles of boreal
    conifers also have thick waxy coatings--a
    waterproof cuticle--in which stomata are sunken
    and protected from drying winds.
  • Evergreen habit - retention of foliage allows
    plants to photosynthesize as soon as temperatures
    permit in spring, rather than having to waste
    time in the short growing season merely growing
    leaves.
  • Dark color - the dark green of spruce and fir
    needles helps the foliage absorb maximum heat
    from the sun and begin photosynthesis as early as
    possible

97
Taiga Plants
  • Balsam Fir
  • Black
    Spruce Douglas-fir
  • Paper Birch Eastern Red Cedar
    Jack Pine
  • Siberian White Fir
    White Poplar
  • Spruce
  • White Spruce

98
Taiga Animals
  • American Black Bear Bald Eagle
    Bobcat
  • Canadian Lynx Gray Wolf
    Grizzly Bear
  • Long-Eared Owl Red Fox
    River Otter
  • Snowshoe Rabbit
    Wolverine

99
Boreal forests, or taiga
100
Bibliography
  1. http//www.ucmp.berkeley.edu/glossary/gloss5/biome
    /index.html
  2. http//www.enchantedlearning.com/biomes/marsh/fres
    hwater.shtml 
  3. http//mbgnet.mobot.org/ 
  4. http//www.runet.edu/swoodwar/CLASSES/GEOG235/bio
    mes/intro.html
  5. http//archive.globe.gov/sda-bin/wt/ghp/tgL(en)P
    (seasons/Miniinvestigation)
  6. http//www.panda.org/about_wwf/where_we_work/ecore
    gions/global200/pages/home.htm
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