Land Biomes

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Land Biomes

• APES LCHS
• Dr.E

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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

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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

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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

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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

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Major Biomes

• Deserts
• Forests
• Grasslands
• Tundra
• Aquatic

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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

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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

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Types of Deserts

• Hot and Dry
• Semiarid
• Coastal
• Cold

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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

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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

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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

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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

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Hot and Dry Desert

• Yuccas
• 
  Ocotillo
• Turpentine bush
• 
  Prickly Pears
• False mesquite
• Sotol
• Ephedras
• 
  Agaves
• Brittlebush

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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

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

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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.

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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.

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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.

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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.

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Semiarid Desert
Creosote bush Bur sage White
thorn
Cat claw Mesquite Brittle bushes
Lyciums
Jujube
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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

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

Western Bluebird
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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

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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

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Coastal Desert

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

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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.

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Coastal Desert

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

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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.

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Coastal Desert

• Chilean Woodstar
• Caecilians
• Vultures
• Mice
• Fox
• Scorpions

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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

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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

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Cold Desert

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

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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

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Cold Desert

• 
  Lichens  
• Bryophytes
• Antarctic
  Algae
•  
• Snow Algae
• 
  Kelp

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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

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Cold Desert

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

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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.

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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

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Savanna
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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

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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

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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

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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.

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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

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

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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

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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).

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Temperate Grassland
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Temperate Grassland
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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)

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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

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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

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Temperate Grassland

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

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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

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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

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Tundra The Not-So Barren Land
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Tundra The Not-So Barren Land
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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

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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)

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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

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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

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Tundra The Not-So Barren Land

• low shrubs, sedges, reindeer mosses, liverworts,
  and grasses
• 400 varieties of flowers
• crustose and foliose lichen

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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

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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

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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

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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

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Types of Forests

• Tropical
• Temperate
• Boreal forests (taiga)

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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.

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Tropical Forests
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Tropical Forests
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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

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Tropical Forests

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

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Tropical Forests

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

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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.

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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

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Tropical Forests

• Lianas
• 
  Epiphytes (grow on another plant)
• Ferns
• 
  Moss
• 
  Curare
• Forest Canopy Palms

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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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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.

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Temperate Forest
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Temperate Forest
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Temperate Forest

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

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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

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Temperate Forest

• Oak
• Hickory
• 
  Beech
• Hemlock
• Maple
• 
  Basswood
• Cottonwood
• Elm
• 
  
• Willow
  Spring-flowering herbs

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• Bank Vole
• Black Bear
• 
  Gray Squirrel
• Raccoon
• 
  White-tailed Deer
• 
  Wild Boar
• Cardinal
• Goshawk
• 
  Turkey
• Yellow-bellied Sapsucker
• 
  Rat Snake
• Spring Peeper

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Temperate Forest
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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

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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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Boreal forests, or taiga
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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

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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

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Taiga Plants

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

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Taiga Animals

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

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Boreal forests, or taiga
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Bibliography

1. http//www.ucmp.berkeley.edu/glossary/gloss5/biome
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2. http//www.enchantedlearning.com/biomes/marsh/fres
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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
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