The document describes the major biomes found on Earth, including aquatic and terrestrial biomes. It provides details on the defining characteristics, climates, soils, and common plant and animal species found in freshwater, marine, desert, grassland, forest, tundra and other biomes. Biomes are grouped based on whether they are primarily aquatic or terrestrial, and further broken down by specific biome type within those groups.

1. BIOMES
Major regional ecological community of plants and animals

2. Aquatic Biomes
• Water makes up the largest part of the biosphere, covering nearly
75% of the Earth’s surface.
• The aquatic biome can be broken down into two basic regions:
freshwater (i.e, ponds and rivers) and
marine (i.e, oceans and estuaries).

3. Freshwater Region
• Freshwater is defined as having a low salt concentration—usually less than
1%.
• There are different types of freshwater regions: ponds and lakes, streams
and rivers, and wetlands.
Lakes and ponds
• Lakes and ponds are inland depressions containing standing water varying
in depth from 1 m to over 2000 m.
• Ponds are small shallow bodies of water that rooted plants can grow over
the bottom; lakes are usually large.
• They are divided into zones based on the penetration of light.
• The major zones (from the topmost) are the littoral or shallow water zone,
limnetic or open water zone and the profundal zone

4. Streams and rivers
• These are bodies of flowing water moving in one direction.
• Streams and rivers get their starts at headwaters, which may be springs,
snowmelt or even lakes, and then travel all the way to their mouths, usually
another water channel or the ocean.
• The characteristics of a river or stream change during the journey from the
source to the mouth.
• The water is also clearer, has higher oxygen levels, and freshwater fish
such as trout and heterotrophs can be found there.
• Towards the middle part of the stream/river, the width increases, as does
species diversity—numerous aquatic green plants and algae can be found.
• Toward the mouth of the river/stream, the water becomes murky from all the
sediments that it has picked up upstream, decreasing the amount of light
that can penetrate through the water.

5. Wetlands
• Wetlands are areas of standing water that support aquatic plants.
• Marshes, swamps, and peatlands are all considered wetlands.
• Marsh-dominated by herbaceous vegetation; swamps- forested wetlands;
peatlands- wetlands that is accumulated with decayed organic matter
• Plant species adapted to the very moist and humid conditions are called
hydrophytes (e.g. pond lilies, cattails, sedges, tamarack, and black spruce).
•
• Wetlands have the highest species diversity of all ecosystems. Many
species of amphibians, reptiles, birds (such as ducks and waders), and
furbearers can be found in the wetlands.

6. Marine Regions
• Marine regions cover about three-fourths of the Earth’s surface
• include oceans, coral reefs, and estuaries.
Oceans
• The largest of all the ecosystems, oceans are very large bodies of water
that dominate the Earth’s surface.
• The ocean regions are separated into separate zones: intertidal, pelagic,
abyssal, and benthic.
• The intertidal zone is where the ocean meets the land—sometimes it is
submerged and at other times exposed, as waves and tides come in and
out.
• The pelagic zone includes those waters further from the land, basically the
open ocean.
• The benthic zone is the area below the pelagic zone, but does not include
the very deepest parts of the ocean The deep ocean is the abyssal zone.

7. Coral reefs
• Coral reefs are an accumulation of dead skeletal material
• Coral reefs are widely distributed in warm shallow nutrient-poor waters.
They can be found as barriers along continents, fringing islands, and atolls.
• the dominant organisms in coral reefs are corals.
• Corals are modular animals, anemone-like cylindrical polyps with prey-
capturing tentacles
• It also include several species of microorganisms, invertebrates, fishes, sea
urchins, octopuses, and sea stars.

8. Estuaries
• Estuaries are areas where freshwater streams or rivers merge with the
ocean. It is the place where freshwater joins salt water.
• Estuaries are semienclosed parts of the coastal ocean where seawater is
diluted
• Microflora like algae, and macroflora, such as seaweeds, marsh grasses,
and mangrove trees (only in the tropics), can be found here.
• Estuaries also support a variety of worms, oysters, crabs, and waterfowl.

9. Terrestrial Biomes
• The terrestrial biomes include the desert, chaparral, savanna, temperate
grassland, temperate rain forest, tropical rain forest, temperate deciduous
forest, taiga (coniferous, needle leaf or boreal forests), and tundra (artic and
alpine) biomes.
Distribution of the Earth's eight major terrestrial biomes

10. Desert
• Deserts occupy about 26% of the Earth's surface area.
• Deserts are characterized by low rainfall and generally receive fewer than
10 inches of rain a year..
• Rain itself is infrequent and comes in the form of thunderstorms. Since the
rate of evaporation is high, the rain provides only brief periods of rapid
growth.
• Temperatures vary greatly, creating both "cold" deserts (mean annual
temperature ranges of 0 to 15°C) and "hot" deserts (mean annual
temperatures ranges of 15 to 30°C).
• Desert soils are generally low in organic matter and high in calcium
carbonate and soluble salts. The surface is composed of a mosaic of closely
packed sand, pebbles and boulders. Because of the reduced plant cover,
desert soils are easily eroded by wind and rain.
• Both plants and animals are adapted to scarcity of water either by drought
evasion or by drought resistance

11. Chaparral
• Chaparrals (temperate shrublands) occur predominately in the transition
zones between desert and temperate forest biomes.
• Chaparrals are characterized by hot, dry summers and mild rainy winters.
• Dense, spiny shrubs with tough evergreen leaves dominate these areas.
• The combination of dry summers and dense shrub vegetation create ideal
conditions for frequent fires. Thus, chaparral can be considered a “fire
maintained” ecosystem.
• Chaparral soils are fragile with low to moderate fertility. They are easily
eroded, particularly after a fire.
• To prevent desiccation many plants have adapted by having small leathery
leaves and becoming dormant during the dry season. The animal
biodiversity is high in both vertebrates and invertebrates species.

12. Savanna
• Savannas are tropical grasslands with scattered individual trees.
• Most are found in transitional climate zones between tropical rainforest and
desert biomes.
• Savannas are characterized by warm year-round temperatures. Annual
precipitation occurs during the summer wet season. Fires are frequent
during the dry season.
• Soils are poor, being low in nutrients and permeability. They tend to retain
water near the surface during the wet season.
• Vegetation consists of low-growing grasses, forbs (small broad-leaf plants),
deciduous trees and shrubs that are scattered against an open park-like
landscape. Trees are also adapted to being fire-resistance.
• Savannahs are populated with wandering animals that move in response to
seasonal variation in food and water (e.g. wildebeest, rhinos, water buffalos,
warthogs, gazelles, zebras, giraffes, antelope, and elephants).

13. Temperate Grassland
• Temperate grasslands are characterized by hot summers and cold winters
• grassland soils are very fertile and rich in organic material.
• The soil is held in place by a thick network of intertwining roots of drought-
tolerant perennial grasses.
• Temperate grasslands are dominated by herbaceous vegetation which is
adapted to periodic drought and fire conditions. The grasslands are
generally treeless, with trees and shrubs being limited to the edges of
streams and rivers. Wildflowers are abundant and include anemones,
ranuculus, iris and others.
• A number of grazing mammals prevails. A large variety of small herbivores
such as prairie dogs, mice, rabbits, squirrels, grouse, and meadowlarks
predominate. They intern are preyed upon by fox, wolves, coyotes, ferrets,
snakes and birds of prey (hawks and eagles).

14. Temperate Rain Forest
• Temperate rain forests are dominated by dense stands of large coniferous
trees.
• The ocean moderates the climate so that winters are mild and summers are
cool. Rain and fog from ocean currents create a very moist climate
• Soil is nutrient-poor with high organic content.
• In the North American temperate rain forests large evergreen trees, such as
western hemlock, Sitka spruce, Douglas fir and red woods, dominate.
Epiphytes are common and include several species of mosses, lichens, and
ferns. Deciduous shrubs, such as vine maple are found in open areas.
• a dense vegetation biomass reminiscent of tropical rain forests is present
but dominated by only a few tree species.
• Squirrels, mule deer, elk, and many species of birds, reptiles and
amphibians are the common wildlife in this biome.

15. Tropical Rain Forest
• Tropical rain forests are broadleaf evergreen forests, which contain the
highest diversity of plant and animal species on Earth.
• Because the major tropical rain forests are found near the equator, where
hot moisture-laden air rises and dumps its moisture, they are characterized
by year-round warmth and high rainfall.
• Tropical rain forests soils are often nutrient-poor, acidic, thin, and low in
organic matter. Most of the nutrients are stored in the living biomass of the
rain forest vegetation.
• Because of the warm moist climate and high number of decomposers
(bacteria, fungi, and soil invertebrates), nutrients are quickly recycled by
rapid decomposition.
• There is an enormous number of species residing on this biome
(insectivorous and carnivorous mammals and birds etc.)
• Insects numbers in millions

16. Temperate Deciduous Forest
• Temperate deciduous forests are found where there is sufficient moisture to
support the growth of large trees.
• Deciduous trees have a distinct annual rhythm in which the trees drop their
leaves, become dormant in winter, and produce new leaves each spring.
• Temperate deciduous forests are characterized by seasonally cold winters
and warm summers.
• Soils consist of fertile topsoil, rich in organic material, and a clay-rich lower
layer.
• Temperate deciduous forests are dominated by a few species of broadleaf
deciduous trees such as oak, maple, polar, sycamore, beech, and hickory.
Herbs are found at the lowest level, followed by a layer of shrubs, then by
shade tolerant under story trees and finally the canopy of large mature
trees.
• A rich diversity of birds, mammal, insects and reptiles are found at all levels.
These include deer mice, squirrels, fox, bear, white-tailed deer, opossums
and raccoons. Gone, however are the larger mammals, including the
woodland bison, wolves, mountain lions (puma) and bobcats. Many species
of birds also occur. These include grouse, woodcock, woodpeckers, owls,
hawks, warblers etc.

17. Taiga
• Taigas are also known as coniferous or boreal forest. Covering about 11%
of the earth's land surface, they are the largest terrestrial biome on earth.
• The taiga zone includes a variety of climate conditions, from moderate to
severe. Overall winters are cold and long and summers are mild and short.
Because of low temperatures, evaporative rates are low and drought is
infrequent.
• Taiga soils are thin, nutrient poor, and acidic.
• Taigas are dominated by evergreen conifers such as spruce, fir, cedar,
hemlock, tamarack, and pine. The small, needle-shaped, wax-coated leaves
are adapted to withstand the intense cold and drought of winter. Willows,
aspen, and birch occur sporadically, particularly in new growth areas.
Because of acidic and nutrient-poor soils there are relatively few
herbaceous plants under the thick forest canopy.
• Some of the more common large mammals found in taigas are elk, moose,
wolves, and bears. Smaller mammals include hare, rodents, lynx, wolverine,
porcupines, and squirrels. Several species of resident birds are present,
such as crossbills, nutcrackers, warblers, grouse, and jays. Insects,
particularly flies and mosquitoes are common, but amphibians and reptiles
are less prevalent and may be absent in some areas.

18. Tundra
• Tundra means marshy plain.
• The tundra biome is characterized by an absence of trees, the presence of
dwarf plants, and a ground surface that is wet, spongy, and hummocky.
• Soils of this biome are usually permanently frozen starting at a depth of a
few centimeters to meter or more.
• Within this biome, temperature, precipitation, and evaporation all tend to be
at a minimum. Most tundra locations, have summer months with an average
temperature below 10 degrees Celsius.
• The species diversity of tundra vegetation is relatively small. Plant
communities are usually composed of a few species of dwarf shrubs, a few
grass species, sedges, and mosses.
• The principal herbivores in this biome include caribou, musk ox, arctic hare,
voles, and lemmings. Most of the bird species of the tundra have the ability
to migrate and live warmer locations during the cold winter months. The
herbivore species support a small number of carnivore species like the
arctic fox, snow owl, polar bear, and wolves. Reptiles and amphibians are
few or completely absent because of the extremely cold temperatures.