This document summarizes several major terrestrial biomes: tropical forest, tropical savanna, desert, shrublands, chaparral, temperate forest, grasslands, conifer forest (boreal forest). It describes the characteristic climate, vegetation layers, common plant and animal species, and productivity levels of each biome. Clements and Shelford introduced the concept of classifying terrestrial ecosystems into biomes based on patterns of plant distribution and climate. There are eight major biomes described in the document.

1. TERRESTRIAL BIOMES

2. FE Clements & VE
Shelford
• Introduced in 1939 an approach for
combining the broad scale
distribution of both plants and
associated animals into a single
classification system called
biomes.

3. 8 Major Terrestrial Biomes
• Tropical forest
• Temperate forest
• Conifer forest (Taiga)
• Tropical savanna
• Temperate grasslands
• Chaparral (Shrublands)
• Tundra
• Desert

4. The pattern of terrestrial biomes in
relation to temperature and moisture

5. Classification of terrestrial
ecosystems are based from
• Plant distribution
• Climate
• Annual precipitation

6. Tropical Forest
• Key feature is constant temperature
– Average temperature from one month to the
other is usually within 2C
– However, daytime temp may be 34 C during
the day and 20 C at night.
• Much rain: annual rainfall ranges from
2,000 mm to 15,000 mm (79 – 591 inches;
1.6 inches per day).
• Found in the equatorial zone between
10°N and 10°S where the temperatures are
warm

8. Tropical Forest
• Long Dry Season
– Dry season = 6-8 months
– Many trees drop their leaves during the dry
season not to escape cold, but to prevent
overheating
• Short Dry Season
– Dry season < 3 months
– Tropical rain forest: 2,300 – 5,000 mm of rain
per year (extreme years some places may get
15,000 mm = 50 feet).

9. LAYERS OF TROPICAL
RAINFORESTS
1. Emergent Trees/Layer
2. Canopy Layer
a.High
b.Low Tree Stratum
3. Shrub Understory
4. Ground Layer of Herbs
and Ferns /Forest Floor

10. • Climbing vines grow upward into the
canopy
• Epiphytes grow on trunks and branches
• Stranglers grow downward from the
canopy to the ground
• Buttresses-plant-like outgrowths; prop
roots, provides support to trees
• Floor of laced with roots both large and
small forming a dense mat on the ground

11. Tropical Forest (Rain)
• Huge diversity
– Perhaps 50 - 75% of all organisms on Earth inhabit
theses forests.
– Temperate forest may have 20 - 30 tree species per
hectare (2.47 acres); rain forests can support more
than 350 – 450 tree species per hectare
• To fit that many tress each species may only be
represented once or twice
• Most productive terrestrial biome
– High temp, moisture, uninterrupted growing
season
– Decomposers / nutrient cycling

13. Tropical Rain Forest

14. Tropical Savannas
• Originally used to describe the treeless areas of
South America
• Characterized by a ground cover of grasses with
scattered shrubs or trees
• Has warm continental climate with seasonality
in rainfall
• Mean monthly temperature do not fall typically
below 18°C
• Continuous weathering produces phosphorus-
deficient Oxisols, Alfisols in drie savannas and
Entisols on driest savannas

15. • Consists of two-layer vertical structure (as a
result of ground cover and shrubs and trees)
• PLANT ACTIVITY
– Controlled by seasonal precipitation and changes
in available moisture; leaf litter decomposed
during wet season; woody debris consumed by
termites during the dry season

16. • Home to at least 60 animal species
• Wildebeest and zebra are migratory during dry
season
• Insects:
flies, grasshoppers, locusts, crickets, carabid
beetle, ants and detrital feeding dung beetles
and termites
• Carnivores-lion, leopard, cheetah, hyena and
wild dog
• Scavengers- vultures and jackals

18. Desert
• Lies between 15° and 30° where the air is
caused aloft the Intertropical Convergence
Zone
• Difference in moisture, temperature, soil
drainage, topography, alkalinity, and salinity
create variations in vegetation
covering, dominant plants, and groups of
associated species

19. Types of Deserts
• Cool Desert- Great Basin of North America,
Gobi, Takla Makan, and Turkestan deserts of
Asia and high elevations of hot deserts are
dominated by chenopod shrubs(shrub
steppes/desert scrub)
• Hot desert-range from these lacking
vegetation to ones with some combination of
chenopods, dwarf shrubs and succulents.
– Southwestern North America-the Mojave, the
Sonoran and the Chihuahuan dominated by
creosote bush and bursage

20. Plants
• Desert plants may be deep-rooted woody
shrubs like mesquite and Tamarix, whose
taproots reach the water table
• Larrea and Atriplex are deep-rooted
perennials with superficial laterals that
extend, as far as 15 to 30 m from the stems.
Others have shallow roots often extending no
more than a few centimeter below the surface

22. Animals
• Drought-evading animals adopt an annual
cycle of activity or go into estivation or some
other stage of dormancy during the dry
season (spadefoot toad)
• Includes wide assortment of beetles, ants,
locusts, lizards, snakes, birds, and mammals
• Mammals are mostly herbivorous; grazing
herbivores tend to be generalists or
opportunists

23. • Desert rodents (Heteromyidae) and ants feed
largely on seeds and are important in the
dynamics of desert ecosystem
• Desert carnivores, foxes and coyotes, have
mixed diets
• Omnivory rather than carnivory and complex
food web seems to be the rule in desert
ecosystem

25. Desert

26. Productivity
• Infrequent rainfall coupled with high rates of
evaporation limit the availability of water to
plants and so primary productivity is low
• Desert soils are poorly developed Ardisols and
Entisols and land limits the ability of
vegetation to modify soil environment

27. SHRUBLANDS
• Plant communities where the shrub growth is
dominant or codominant
• Five widely disjunct region between 30° and
40° latitude dominated by evergreen shrubs
and sclerophyllus trees
– Semi-arid regions of Western North America
– Regions bordering the Mediterranean Sea
– Central Chile
– Cape Region of South Africa
– Southwestern and Southern Australia

28. CLIMATE
• Has hot, dry summer with at least one month
of protracted drought, and cool, moist winters
• 65% of annual precipitation falls during the
winter months with temperature average of
10-12°C with a risk of frost
• Persistent flow of dry air during summer
brings several months of hot, dry weather
• Fire is a frequent hazard during the periods.

29. PLANTS AND VEGETATION
• Support similar looking communities of xeric
broadleaf evergreen shrubs and dwarf trees as
“sclerophyllous”(scleros-hard, phyll-leaf)
vegetation with an herbaceous understory
1. Mediterranean Sea in Southern Europe and
North Africa dominated by mixed evergreen
woodland such as holm oak and cork oak
2. Southern Africa – vegetation is known as
fymbos composed of broadleaf protenoid shrubs
that grow to a height of 1.5-2.5 m

30. 3. Southwestern Australia- mediterranean shrub
community known as mallee dominated by low-
growing Eucalyptus, 5-8 m in height with broad
sclerophyllous leaves
4. North America – sclerophyllus shrub community
is known as chaparral (a word Spanish origin
meaning a thicket of shrubby evergreen oaks)
5. Central Chile –mattoral shrub communities occur
in coastal lowlands and on the west –facing slopes
of Andes; mattoral species are evergreen shrubs 1-3
m in height with small sclerophyllous leaves

32. Chaparral

33. ANIMALS
• Mediterranean-parallel and convergent
evolution among bird species and some lizard
species
• NA-mule deer, coyotes, a variety of
rodents, jackrabbits and sage grouse
• Australian mallee-birds including endemic
mallee-fowl which incubates its egg in a large
mound; gray kangaroo and species of wallaby

34. PRODUCTIVITY
• Diverse soil conditions but soils are typically
classified as Alfisols
• Generally deficient in nutrients, litter
decomposition is limited by low temperature
during winter and low soil moisture during the
summer months
• Vary in productivity depending on the annual
precipitation and the severity of summer
droughts

35. TEMPERATE FOREST
• Forests dominated by broadleaf deciduous trees
• North America – mixed mesophytic forested of
the unglaciated Appalachian plateau; the beech-
maple and Northen hardwood forests (with pine
and hemlock) in northern regions , the maple-
basswood forests of the Great Lake states; the
oak-chestnut of central hardwood forests; the
magnolia-oak forests of the Gulf Coast staes; and
the oak-hickory forests of the Ozarks

36. • The Asiatic broadleaf forest (Eastern
China, Japan, Taiwan, Korea) contains a
number of plant species of the same genera
found in NA;broadleaf evergreen species
become increasingly present and in the west
foothills of the Himalayas.
• Southern Europe, their presence reflects the
transition into the mediterranean region.
Evergreen oaks and pines are also widely
distributed I the Southeastern US (associated
with poorly developed sandy soils

37. • In Southern Hemisphere they are found only in the
drier parts of the Southern Andes
• In Southern Chile, broadleaf evergreen rain forests
have developed in an oceanic climate that is virtually
frost-free
• Also found in New Zealand, Tasmania and parts of
Southeastern Australia
• In broadleaf deciduous forests of the temperate
region, the growing season is marked by the autumn
colors of foliage shortly before the trees enter into
their leafless winter period;trees resume growth in the
spring in response to increasing temperature and
longer daylengths; many herbaceous species flower at
this time before the developing canopy casts a heavy
shade on the forest floor.

39. 4 VERTICAL STRATA/LAYERS
1. Upper canopy – dominant tree species
2. Lower tree canopy
3. Shrub layer
4. Ground layer

40. ANIMALS
• Associated vertical stratification and the
growth form of plants
– Arthropods
– Mice, shrews, ground squirrels, and forest
salamanders burrow into soil/litter for shelter and
food
– Larger mammals live on ground layer and feed on
herbs, shrubs and low trees
– Birds move freely among several strata

41. PRODUCTIVITY
• Differences in climate, bedrock, and drainage are
reflected in the variety of soil conditions that are
present
• Soil types: Alfisols, Inceptisols, Uttisols associated
glacial materials in more Northen region
• Influenced largely by temperatures and the
length of the growing season
• Leaf fall in deciduous forests occur over a short
period in autumn, and the availability of nutrients
is related to rates of decomposition and
mineralization

43. GRASSLANDS
• Occupy regions where rainfall is between 250 mm and
800 mm a year; many exist through the intervention of
fire and human activity
• Occur in the midlatitudes in midcontinental regions
where annual precipitation dclines as air masses move
inward from the coastal environments
• Northern Hemisphere – include the prairree of North
America and steppes of Central Eurasia
• Sothern Hemisphere – include pampas of Argentina
and the grassveld of high plateaus of Southern
Africa;smaller areas occur in Southeast Australia and
the drier parts of New Zealand

44. • Northern Hemisphere
– Climate is recurring drought; tallest and most
productive where mean annual precipitation is
greater than 800 mm and mean annual
temperature is above 15°
– 3 Main Types
• Tallgrass prairie- big blue stem growing 1m tall with
flowering stalk
• Mixed-grass prairie- Great Plains;needle grass, grama
grass
• Shortgrass prairie- rod-forming blue grama and blue
grass

46. • Desert grassland (Southeast Texas to Southern
Arizona into Mexico) similar to shortgrass
plains except that three-awn grass replaces
buffalo grass
• Annual grassland (Central valley of California)
associated with mediterranean type climate
characerized by rainy winters and hot, dry
summers. Growth occurs during early
spring, and most plants are dormant in
summer, turning the hills a dry tan color
accented by the deep green foliage of
scattered California oaks

47. • Steppes – treeless except for ribbons and patches
of forest divided into four belts of latitude
• Southern Hemisphere (Southern Africa, Southern
America)
– pampas, the South American grasslands extend
westward in a large semicircle from Buenos Aires to
cover about 15% of Argentina
– With European forage grasses and alfalfa and the
eastern tallgrass pampas have been converted to
wheat and corn
– Velds of Southern Africa occupy eastern part of a high
plateau 1500 m to 2000 m above sea level

48. ANIMALS
• Dominated by herbivorous species
• Vertebrates like large burrowing mammals
and ungulates
• NA-once dominated by herds of bisons and
pronghorned-antelope;prairie dog with
gophers and the mound
• Eurasian steppes and pampas lack herds of
ungulates; 2 major herbivores are pampas
deer, guanaco, small relative of the camel

49. • African grassveld once supported migratory
herds of wildebeest and zebras along with
lion, hyena and leopard; They have been
greatly destroyed and was replaced by sheep,
cattle, and horses
• Australia-marsupial mammals evolved many
forms; dominant grazing animals are
kangaroos (the red and the gray)
• Grasslands evolve under the selective
pressure of grazing which stimulates primary
production

50. • Strata
1. Tall, green ephemeral herbaceous growth
2. Ground layer
3. Below-ground root layer
Grasslands accumulate a layer of mulch that retains
moisture and with continuous turnover of fine
roots, add organic matter to the mineral soil
The soil type is Mollisols where there is a relatively
thick, dark-brown to black surface horizon that is
rich in organic materials

51. CONIFER FOREST
• Dominated by needle-leaf evergreen trees
• Found primarily in broad circumpolar belt
across the Northern Hemisphere and on
mountain ranges where low temperature
limits the growing season
– Central Europe-dominated by Norway spruce
– North America-Engelmann spruce, subalpine
fir, Douglas fir, and panderosa pine and stands of
lodgepole pine

52. Boreal Forest

53. 4 MAJOR VEGETATION TYPES
1. Forest tundra ecotone with open stands of
stunted spruce, lichens, moss
2. Open boreal woodland with stands of lichens
and black spruce
3. Main boreal forest with continuous stands of
spruce and pine broken by poplar and birch
4. Boreal-mixed forest where it grades into the
temperate forest of Southern Canada and the
Northern US

54. CLIMATE
• Cold continental climate with seasonal
variation
• Summers are short, cool and moist
• Winters are prolonged, harsh and dry with
prolonged period of snowfall
• Driest winters are most extreme in Interior
Alaskaand Central Siberia which experience as
much as 100°Cseasonal temperature extreme
• Under the controlling influence of permafrost

55. PERMAFROST
• The perennially frozen subsurface that may be
hundreds of meters deep. It develops where
the ground temperature remain below 0°C for
extended periods of time. Its upper layer may
thaw in summer and refuge in winter. Because
it is impervious to water, it forces all water to
remain and move about it. Thus, the ground
stays soggy even though precipitation is
low,enabling plants to exist in the driest parts
of the Arctic.

56. ANIMAL COMMUNITY
• Caribou, moose (elk in Eurasia), cyclic
snowshoe hare, aboreal red squirrel, quill-
bearing porcupine
• Predators include wolf lynx, pine martins and
owls, migratory neotropical birds (for nesting
ground)
• Habitat for seed-eating birds like
crossbills, grosbeaks, and siskins
• Herbivorous insects line spruce budworm

57. PRODUCTIVITY
• Generally low in comparison to more temperate
forests, limited by low nutrients, cooler
temperatures, and the short-growing season
• Inputs of plant litter are low under the cold, wet
conditions
• Rates of decomposition are low
• Soils are Spodosols characterized by a thick
organic layer; mineral soil beneath mature
coniferous forests are comparatively infertile, and
growth is often limited by the rate at which
mineral nutrients are reccycled through the
ecosystem

58. TUNDRA
• Top of Northern Hemisphere; frozen plain
clothed in sedges, heaths and willows dotted
with lakes and crossed by streams
• Came form the Finnish ‘tunturi’ meaning a
treeless plain
Two Broad Types:
1. Tundra with up to 100% plant cover and wet to
moist soil
2. Polar desert with less than 5% plant cover and
dry soil

59. CONDITIONS UNIQUE TO TUNDRA
1. Permafrost
2. Vegetation
3. Transfer of heat

60. Tundra

61. VEGETATION
• Simple and few and growth is slow; only
species able to withstand constant
disturbance of the soil; buffeting by the wind
and debrasion from wind-carried particles of
soil and ice can survive
• Sphagnum on low ground with cotton grasses
and sedges
• Heath shrubs, dwarf willows and birches,
herbs, mosses and lichens
• Cructose, foliose, lichens on rocks

62. • Plants propagate through vegetative means
• Photosynthetically active on the Arctic tundra about 3
months out of the year as snow cover disappears,
plants commence photosynthetic activity. They
maximize use of the growing season and light even at
midnight.
• Goes into production of new growth but about one
month before the growing season ends
• Most tundra vegetation is underground
• Most shoot ratios of vascular plants range from 3:1 to
10:1
• Roots are concentrated in the upper soil;above ground
parts seldomgrow taller than 30 cm
• Below grouns activity is typically 3x that of the
aboveground productivity

66. Thank you!