This document provides information about three main terrestrial ecosystems: grasslands, forests, and deserts. It begins with an introduction to terrestrial ecosystems and their key features. It then discusses grasslands in more detail, including the types of grasslands, vegetation, evolution, climates, biodiversity, human impacts, and example animal species. Forest ecosystems are then examined, covering definitions, evolution, ecology, and example plant and animal species. Finally, it briefly touches on desert ecosystems, their vegetation and example animal species. The document aims to highlight the salient features and differences between these three major terrestrial biomes.

1. ON
SUBMITTED BY –
SURBHI YADAV
BSC BIOSCIENCE
Terrestrial ecosystem:-
salient features of
grassland forest &
desert ecosystem
PRESENTATION
SUBMITTED TO – DR.
RASHMI TRIPATHI MA’aM

2. SYNOPSIS
 Terrestrial
Ecosystem :- GRASSLAN
DFORES
T
DESERT

3. introduction

4. A community of organisms and their environment that occurs on the land
masses of continents and islands. Terrestrial ecosystems are
distinguished from aquatic ecosystems by the lower availability of water
and the consequent importance of water as a limiting factor. Terrestrial
ecosystems are characterized by greater temperature fluctuations on
both a diurnal and seasonal basis than occur in aquatic ecosystems in
similar climates. The availability of light is greater in terrestrial
ecosystems than in aquatic ecosystems because the atmosphere is more
transparent in land than in water. Gases are more available in terrestrial
ecosystems than in aquatic ecosystems. Those gases include carbon
dioxide that serves as a substrate for photosynthesis, oxygen that
serves as a substrate in aerobic respiration, and nitrogen that serves as
a substrate for nitrogen fixation. Terrestrial environments are
segmented into a subterranean portion from which most water and ions
are obtained, and an atmospheric portion from which gases are obtained
and where the physical energy of light is transformed into the organic
energy of carbon-carbon bonds through the process of photosynthesis.

5. Terrestrial ecosystems occupy 55,660,000 mi² (144,150,000
km²), or 28.26% of Earth's surface. Although they are
comparatively recent in the history of life (the first terrestrial
organisms appeared in the Alchi period, about 425 million years
ago) and occupy a much smaller portion of Earth's surface than
marine ecosystems, terrestrial ecosystems have been a major
site of adaptive radiation of both plants and animals. Major plant
taxa in terrestrial ecosystems are members of the division
Magnoliophyta (flowering plants), of which there are about
275,000 species, and the division Pinophyta(conifers), of which
there are about 500 species. Members of the division Bryophyta
(mosses and liverworts), of which there are about 24,000
species, are also important in some terrestrial ecosystems.
Major animal taxa in terrestrial ecosystems include the classes
Insecta(insects) with about 900,000 species, Aves (birds) with

6. Organisms in terrestrial ecosystems have adaptations that
allow them to obtain water when the entire body is no
longer bathed in that fluid, means of transporting the water
from limited sites of acquisition to the rest of the body,
and means of preventing the evaporation of water from
body surfaces. They also have traits that provide body
support in the atmosphere, a much less buoyant medium
than water, and other traits that render them capable of
withstanding the extremes of temperature, wind, and
humidity that characterize terrestrial ecosystems. Finally,
the organisms in terrestrial ecosystems have evolved many
methods of transporting gametes in environments where
fluid flow is much less effective as a transport medium.

7. The organisms in terrestrial ecosystems are integrated into a functional
unit by specific, dynamic relationships due to the coupled processes of
energy and chemical flow. Those relationships can be summarized by
schematic diagrams of trophic webs, which place organisms according to
their feeding relationships. The base of the food web is occupied by green
plants, which are the only organisms capable of utilizing the energy of the
Sun and inorganic nutrients obtained from the soil to produce organic
molecules. Terrestrial food webs can be broken into two segments based
on the status of the plant material that enters them. Grazing food webs
are associated with the consumption of living plant material by herbivores.
Detritus food webs are associated with the consumption of dead plant
material by detritivores. The relative importance of those two types of
food webs varies considerably in different types of terrestrial
ecosystems. Grazing food webs are more important in grasslands, where
over half of net primary productivity may be consumed by herbivores.
Detritus food webs are more important in forests, where less than 5% of
net primary productivity may be consumed by herbivores.

8. There is one type of extensive terrestrial ecosystem due solely
to human activities and eight types that are natural
ecosystems. Those natural ecosystems reflect the variation of
precipitation and temperature over Earth's surface. The
smallest land areas are occupied by tundra and temperate
grassland ecosystems, and the largest land area is occupied by
tropical forest. The most productive ecosystems are
temperate and tropical forests, and the least productive are
deserts and tundras. Cultivated lands, which together with
grasslands and savannas utilized for grazing are referred to as
agroecosystems, are of intermediate extent and productivity.
Because of both their areal extent and their high average
productivity, tropical forests are the most productive of all
terrestrial ecosystems, contributing 45% of total estimated

9. G
rassland

10. MAJOR AREAS UNDER GRASSLANDS

11. Grasslands are areas where the vegetation is
dominated by grasses (Poaceae), however sedge
(Cyperaceae) and rush (Juncaceae) families can
also be found. Grasslands occur naturally on all
continents except Antarctica. Grasslands are
found in most ecoregions of the Earth. For
example, there are five terrestrial ecoregion
classifications (subdivisions) of the temperate
grasslands, savannas, and shrublands biome
(ecosystem), which is one of eight terrestrial
ecozones of the Earth's surface

12. Contents
1 Vegetation
2 Evolution
3 Climates
4 Biodiversity and conservation
5 Human impact and economic importance
6 Types of grasslands
6.4.1 Tropical and subtropical
6.4.2 Temperate
6.4.3 Flooded
6.4.4 Montane
6.4.5 Tundra
6.4.6 Desert and xeric Animals

13. The Konza tallgrass prairie in the Flint Hills of northeastern
V
egetationGrassland vegetation can vary in height from very short, as in chalk grassland, to
quite tall, as in the case of North American tallgrass prairie , South American
grasslands and African Savanna.

14. Graminoids are among the most versatile life forms. They
became widespread toward the end of the Cretaceous
period, and fossilized dinosaur feces (coprolites ) have been
found containing phytoliths of a variety of grasses that
include grasses that are related to modern rice and bamboo.
The appearance of mountains in the western United States
during the Miocene and Pliocene epochs, a period of some
25 million years, created a continental climate favorable to
the evolution of grasslands. Existing forest biomes declined,
and grasslands became much more widespread. Following the
Pleistocene ice ages, grasslands expanded in range in the
hotter, drier climates, and began to become the dominant
EVOLUTION

15. Grasslands often occur in areas with annual precipitation
between 600 mm (24 in) and 1,500 mm (59 in) and average
mean annual temperatures ranges from −5 and 20 °C
(Woodward et al. 2004). However, some grasslands occur in
colder (−20 °C) and hotter (30 °C) climatic conditions
.Grassland can exist in habitats that are frequently disturbed
by grazing or fire, as such disturbance prevents the
encroachment of woody species. Species richness is
particularly high in grasslands of low soil fertility such as
serpentine barrens and calcareous grasslands, where woody
encroachment is prevented as low nutrient levels in the soil
may inhibit the growth of forest and shrub species.
CLIMATE

16. Grasslands dominated by unsown wild-plant communities
("unimproved grasslands") can be called either natural or "semi-
natural" habitats. The majority of grasslands in temperate
climates are "semi-natural". Although their plant communities
are natural, their maintenance depends upon anthropogenic
activities such as low-intensity farming, which maintains these
grasslands through grazing and cutting regimes. These
grasslands contain many species of wild plants, including grasses,
sedges, rushes and herbs; 25 or more species per square meter
is not unusual. Chalk downlands in England can support over 40
species per square meter. In many parts of the world, few
examples have escaped agricultural improvement (fertilising,
BIODIVERSITY & CONSERVATION

17. Human impact and economic importaNCE
A restored grassland ecosystem at Morton Arboretum in
Illinois.

18. Grassland vegetation often remains dominant in a particular area usually due to
grazing, cutting, or natural or manmade fires, all discouraging colonisation by and
survival of tree and shrub seedlings. Some of the world's largest expanses of
grassland are found in African savanna, and these are maintained by wild herbivores
as well as by nomadic pastoralists and their cattle, sheep or goats . Grasslands may
occur naturally or as the result of human activity. Grasslands created and maintained
by human activity are called anthropogenic grasslands. Hunting peoples around the
world often set regular fires to maintain and extend grasslands, and prevent fire-
intolerant trees and shrubs from taking hold. The tallgrass prairies in the U.S.
Midwest may have been extended eastward into Illinois, Indiana, and Ohio by human
agency. Much grassland in northwest Europe developed after the Neolithic Period,
when people gradually cleared the forest to create areas for raising their livestock .
The professional study of grasslands falls under the category of rangeland
management, which focuses on ecosystem services associated with the grass-
dominated arid and semi-arid rangelands of the world. Rangelands account for an
estimated 70% of the earth's landmass; thus, many cultures including those of the
United States are indebted to the economics that the world's grasslands have to
offer, from producing grazing animals, tourism, ecosystems services such as clean
water and air, and energy extraction

19. These grasslands are classified with
tropical and subtropical savannas and
shrublands as the tropical and subtropical
grasslands, savannas, and shrublands
biome Notable tropical and subtropical
grasslands include the Llanos grasslands
of South America.
Tropical and subtropical

20. TEMPERATE
Negri Nepote Temperate Grasslands in New
Jersey

21. Mid-latitude grasslands, including the prairie and Pacific
grasslands of North America, the Pampas of Argentina,
Brazil and Uruguay, calcareous downland, and the steppes
of Europe. They are classified with temperate savannas
and shrublands as the temperate grasslands, savannas, and
shrublands biome. Temperate grasslands are the home to
many large herbivores, such as bison, gazelles, zebras,
rhinoceroses, and wild horses. Carnivores like lions, wolves
and cheetahs and leopards are also found in temperate
grasslands. Other animals of this region include: deer,
prairie dogs, mice, jack rabbits, skunks, coyotes, snakes,
fox, owls, badgers, blackbirds (both Old and New World
varieties), grasshoppers, meadowlarks, sparrows, quails,
hawks and hyenas.

22. Similar to montane grasslands, polar Arctic tundra can
have grasses, but high soil moisture means that few
tundras are grass dominated today. However, during the
Pleistocene ice ages, a polar grassland known as steppe-
tundra occupied large areas of the Northern Hemisphere.
These are in the tundra biome.
Desert and xeric
Also called desert grasslands, this is composed of sparse
grassland ecoregions located in the deserts and xeric
shrublands biome.
TUNDRA

23. Animals
Mites, insect larvae, nematodes and earthworms inhabit deep soil, which can
reach 6 metres (20 ft) underground in undisturbed grasslands on the richest
soils of the world. These invertebrates, along with symbiotic fungi, extend
the root systems, break apart hard soil, enrich it with urea and other natural
fertilizers, trap minerals and water and promote growth. Some types of fungi
make the plants more resistant to insect and microbial attacks . Grassland in
all its form supports a vast variety of mammals, reptiles, birds, and insects.
Typical large mammals include the blue wildebeest, American bison, giant
anteater and Przewalski's horse . While grasslands in general support diverse
wildlife, given the lack of hiding places for predators, the African savanna
regions support a much greater diversity in wildlife than do temperate
grasslands . There is evidence for grassland being much the product of animal
behaviour and movement ; some examples include migratory herds of antelope
trampling vegetation and African bush elephants eating acacia saplings before
the plant has a chance to grow into a mature tree.

29. importance
Grasslands provide home to many different animals
that were hunted & domesticated.
They are used as grazing area for cattle of
Rugler community.
They maintain biodiversity.
Protect restored habitat for many plants and
animals including pheasants, ducks, songbirds &
endangered species.

30. Forest
Ecosystem

31. A forest is a large area dominated by trees.Hundreds of more precise
definitions of forest are used throughout the world, incorporating factors
such as tree density, tree height, land use, legal standing and ecological
function.According to the widely used.Food and Agriculture Organization
definition, forests covered four billion hectares (15 million square miles) or
approximately 30 percent of the world's land area in 2006 . Forests are the
dominant terrestrial ecosystem of Earth, and are distributed across the
globe.Forests account for 75% of the gross primary productivity of the
Earth's biosphere, and contain 80% of the Earth's plant biomass . Forests at
different latitudes and elevations form distinctly different ecozones: boreal
forests near the poles, tropical forests near the equator and temperate
forests at mid-latitudes . Higher elevation areas tend to support forests
similar to those at higher latitudes, and amount of precipitation also affects
forest composition . Human society and forests influence each other in both
positive and negative ways. Forests provide ecosystem services to humans and
serve as tourist attractions. Forests can also affect people's health. Human
activities, including harvesting forest resources, can negatively affect forest

33. Etymology
Since the 13th century, the Niepołomice Forest in Poland has had special
use and protection. In this view from space, different coloration can
indicate different functions . The word forest comes from Middle English,
from Old French forest (also forès) "forest, vast expanse covered by
trees"; first introduced in English as the word for wild land set aside for
hunting without the necessity in definition for the existence of trees.
Possibly a borrowing (probably via Frankish or Old High German) of the
Medieval Latin word foresta "open wood", foresta was first used by
Carolingian scribes in the Capitularies of Charlemagne to refer specifically
to the king's royal hunting grounds. The term was not endemic to Romance
languages (e.g. native words for "forest" in the Romance languages evolved
out of the Latin word silva "forest, wood" (English sylvan); cf. Italian,
Spanish, Portuguese selva; Romanian silvă ; Old French selve ) ; and
cognates in Romance languages, such as Italian foresta, Spanish and
Portuguese floresta, etc. are all ultimately borrowings of the French word.

34. Evolution
The first known forests on Earth arose in the Late Devonian
(approximately 380 million years ago), with the evolution of
Archaeopteris . Archaeopteris was a plant that was both
tree-like and fern-like, growing to 10 metres (33 ft) in
height. Archaeopteris quickly spread throughout the world,
from the equator to subpolar latitudes . Archaeopteris
formed the first forest by being the first known species to
cast shade due to its fronds and forming soil from its roots.
Archaeopteris was deciduous, dropping its fronds onto the
forest floor. The shade, soil, and forest duff from the
dropped fronds created the first forest . The shed organic
matter altered the freshwater environment, slowing it down
and providing food. This promoted freshwater fish.

35. Temperate rainforest inTasmania's Hellyer Gorge
Forests account for 75% of the gross primary productivity of the Earth's
biosphere, and contain 80% of the Earth's plant biomass. Forest ecosystems can
be found in all regions capable of sustaining tree growth, at altitudes up to the
tree line, except where natural fire frequency or other disturbance is too high,
or where the environment has been altered by human activity.
ecology

36. The latitudes 10° north and south of the equator are mostly
covered in tropical rainforest, and the latitudes between 53°N and
67°N have boreal forest. As a general rule, forests dominated by
angiosperms (broadleaf forests) are more species-rich than those
dominated by gymnosperms (conifer, montane, or needleleaf
forests), although exceptions exist . Forests sometimes contain
many tree species within a small area (as in tropical rain and
temperate deciduous forests), or relatively few species over large
areas (e.g., taiga and arid montane coniferous forests). Forests are
often home to many animal and plant species, and biomass per unit
area is high compared to other vegetation communities. Much of
this biomass occurs below ground in the root systems and as
partially decomposed plant detritus. The woody component of a
forest contains lignin, which is relatively slow to decompose
compared with other organic materials such as cellulose or

37. Even, dense old-growth stand of beech trees (Fagus sylvatica) prepared to be
regenerated by their saplings in the understory, in the Brussels part of the Sonian
Forest.
A forest consists of many components that can be broadly divided into two categories
that are biotic (living) and abiotic (non-living) components. The living parts include trees,
shrubs, vines, grasses and other herbaceous (non-woody) plants, mosses, algae, fungi,
insects, mammals, birds, reptiles, amphibians, and microorganisms living on the plants
and animals and in the soil
Components

38. Biogradska forest in
Montenegro
Spiny forest at Ifaty, Madagascar,
featuring various Adansonia (baobab)
species, Alluaudia procera(Madagascar
ocotillo) and other vegetation

39. A forest is made up of many layers. Starting from the ground level and moving up,
the main layers of all forest types are the forest floor, the understory and the
canopy. The emergent layer exists in tropical rainforests. Each layer has a
different set of plants and animals depending upon the availability of sunlight,
moisture and food.
•Forest floor contains decomposing leaves, animal droppings, and dead trees.
Decay on the forest floor forms new soil and provides nutrients to the plants.
The forest floor supports ferns, grasses, mushroom and tree seedlings.
•Understory is made up of bushes, shrubs, and young trees that are adapted to
living in the shades of the canopy.
•Canopy is formed by the mass of intertwined branches, twigs and leaves of the
mature trees. The crowns of the dominant trees receive most of the sunlight.
This is the most productive part of the trees where maximum food is produced.
The canopy forms a shady, protective "umbrella" over the rest of the forest.
•Emergent layer exists in the tropical rain forest and is composed of a few
Layers:-

40. A dry sclerophyll forest in Sydney, which is dominated by
eucalyptus trees.
types

41. Forests can be classified in different ways and to different degrees of
specificity. One such way is in terms of the biome in which they exist, combined
with leaf longevity of the dominant species (whether they are evergreen or
deciduous). Another distinction is whether the forests are composed
predominantly of broadleaf trees, coniferous (. needle-leaved) trees, or mixed.
•Boreal forests occupy the subarctic zone and are generally evergreen and
coniferous.
•Temperate zones support both broadleaf deciduous forests (e.g., temperate
deciduous forest) and evergreen coniferous forests (e.g., temperate coniferous
forests and temperate rainforests). Warm temperate zones support broadleaf
evergreen forests, including laurel forests.
•Tropical and subtropical forests include tropical and subtropical moist forests,
tropical and subtropical dry forests, and tropical and subtropical coniferous
forests.
•Physiognomy classifies forests based on their overall physical structure or
developmental stage (e.g. old growth vs. second growth).
•Forests can also be classified more specifically based on the climate and the
dominant tree species present, resulting in numerous different forest types
(e.g., Ponderosa pine/Douglas-fir forest).

42. 633,397
637,293
675,538
678,333
610,000
620,000
630,000
640,000
650,000
660,000
670,000
680,000
1997 1999 2001 2003
FOREST
COVER
TREND ANALYSIS OF FOREST GROWTH IN INDIA (ALL FIGURES IN
Sq. km)

43. (a) Temperate Forest Ecosystem:-
The temperate forest ecosystem is very important on
Earth. Temperate forests are in regions where the
climate changes a lot from summer to winter. Tropical
rain forests are in regions where the climate stays
constant all year long. Temperate forests are almost
always made of two types of trees, deciduous and
evergreen. Deciduous trees are trees that lose their
leaves in the winter.

44. Evergreens are trees that keep them all year
long, like pine trees. Forests can either be one
or the other, or a combination of both. A fourth
kind of forest is a temperate rain forest. These
are found in California, Oregon and Washington
in the United States.
These forests are made of redwoods and
sequoias, the tallest trees in the world. The
amount of rainfall in an area determines if a
forest is present. If there is enough rain to
support trees, then a forest will usually develop.
Otherwise, the region will become grasslands.

45. BIOME TYPE % OF LAND
FOREST 32
RANGELAND&
PASTURE
26
DESERT 20
CROPLAND 11
TUNDRA & WETLANDS 09
URBAN AREAS 02
TOTAL 100
WORLD LAND USE PATTERN
(FAO IN MILLER,2004)

46. (b) The Tropical Rain Forest Ecosystem:
Tropical rain forests are one of the most important areas on Earth.
These special ecosystems are homes to thousands of species animals
and plants. Contrary to popular belief, rain forests are not only
densely packed plants, but are also full of tall trees that form a
ceiling from the Sun above. This ceiling keeps smaller plants from
growing. Areas where sunlight can reach the surface are full of
interesting plants.
Do you know where rain forests get their name? They are so named
because they receive a lot of rain – an average of 80 inches a year.
The temperature doesn’t change very much during the year. It is
always warm and muggy. The famous Amazon jungle is located in
Brazil, in South America. This particular forest is called the
Neotropics. Other large blocks are located in Central and West
Africa.

48. (i) Insects of the Tropical Rain Forest:
The most feared and well known spider in the world resides in the jungle. Ta-
rantulas are one of the creepiest animals you will ever see. Most species of
tarantula have poisonous fangs for killing prey and for protection.
Although some are life-threatening to humans, others are harmless. Army
ants are just one species of ant in the rain forest. They are called army ants
because they march in a long, thick line through the jungle. They only stop
when the young larvae reach pupil stage. Once the queen lays its eggs, the
ants start marching again.
Beautiful butterflies fill the forest, but at one time these insects weren’t so
pretty. Butterflies start out as caterpillars, which tend to be a tad on the
ugly side. They go through metamorphosis, which is the process of changing
into a butterfly. Centipedes aren’t so lucky. They don’t turn into butterflies,
but instead roam the forest looking for food. Some centipedes use poison to
kill their prey.

49. (ii) Tropical Rain Forest Birds:
The birds of the rain forest are the most beautiful in the world. A wide range of
colors can be seen darting through the trees as the forest tops come to life. Many
species of tropical birds are kept as pets because of their looks.
Hundreds of species of parrot live in the rain forest. The scarlet macaw is just one
of these. It is also one of the longest, stretching to a length of 3 feet from its
head to the tip of its tail. When these macaws eat a poisonous fruit, they eat a
special type of clay that neutralizes the poison.
Toucans are also very interesting birds. They have large beaks that they use to
reach fruit they can’t get to. Scientists estimate there are 33 species of toucan in
the rain forest. Not every tropical bird was blessed with looks. The hoatzin looks
more like a peacock without the pretty tail.
Hoatzins are terrible flyers – crash landings are common practice. The brown kiwi is
a flightless bird that looks more like a rodent with a long beak and feathers. Kiwis
live on the ground instead of the trees. They have special claws used for running,
digging and defence.

50. (iii) Tropical Rain Forest Mammals:
Birds aren’t the only creatures that fly through the rain forests. Several
species of flying mammals live in the jungle. From the harmless fruit bat to
the unique flying squirrel, the tropical rain forests are full of surprises.
The Indian flying fox is one of the largest bats in the world. Its wings can
spread out to 5 feet in width. Unlike bats in other parts of the world, these
bats do not live in caves. They prefer to .hang in trees during the day.
Hundreds or even thousands of bats can be spotted in a single tree.
Vampire bats live in the Amazon jungle in South America. The famous
stories of blood-sucking bats probably originated here. These bats do in
fact drink the blood of their victims. They usually attack farm animals, but
have also enjoyed the blood of humans. But vampire bats only drink a very
small amount of fluid

51. (iv) Tropical Rain Forest Reptiles:
The tropical rain forests of the world are full of reptiles. Reptiles are cold
blooded, which means their body temperature depends on their environment. So, it
is important for them to stay in warm climates. Snakes are reptiles, and the rain
forests are home to many. The mamba family is the most poisonous of all. They kill
their prey by injecting poison with their sharp fangs.
Anacondas make up another snake family. They are some of the longest creatures
in the world, as they can reach 30 feet in length. Anacondas prefer to wrap
themselves around their prey and squeeze, rather than inject poison. Anacondas
swallow their prey whole and sleep while the food is digesting. Chameleons are
interesting lizards that can change color.
This enables them to blend in with their surroundings. Not only is this a great
disguise from predators, it is also an easy way to sneak up on their prey.
Chameleons only eat insects. Geckos are very neat creatures. The flying gecko can
glide from tree to tree to escape from predators. Their grip is so strong, that if
you tried to pull one off a window, the glass would break before the gecko would
let go.

52. (v) Tropical Rain Forest Primates:
Monkeys and their cousins are all primates. Humans are also primates. There are
many species of monkeys in the tropical rain forests of the world. Monkeys can
be divided into two groups: new world monkeys and old world monkeys. New world
monkeys live only in South and Central America. Spider monkeys live in the rain
forests in the Andes Mountains.
They look very strange with their long noses. Spider monkeys eat mostly fruit
and nuts, so they are called frugivores. They are joined by the howler monkeys.
These primates are so named because they have a special sac that makes their
sounds louder.
Old world monkeys live only in Africa and Asia. The colobus monkey is one such
kind. These monkeys are called foliovores because they eat leaves. They live in
small groups of 15, but other primates live in larger groups of up to 200. There
are too many species. Chimpanzees, orangutans and gorillas are all called pongids.
These primates are more famous than the others. Gorillas are too big to climb
trees, so they are found on the forest floor.

53. (c) Boreal or Taiga Forests:
The boreal forest ecosystem is the contiguous green belt of conifer and
deciduous trees that encircles a large portion of the Northern Hemisphere.
In North America, the boreal forest stretches across most of northern
Canada and into Alaska. It has long been identified as one of the world’s
great forest ecosystems.This forest ecosystem covers roughly 35% of
Canada’s land mass and is the single largest land based ecosystem in North
America. It also contains a significant proportion of Canada’s biodiversity
and has long been recognized as an important global carbon sink.Although
the boreal is relatively unknown, it is important as the “great lung” of North
America, “breathing in” carbon dioxide and “exhaling” oxygen into the
atmosphere. In short, the boreal forest manages to do what the rain forest
of the Amazon does but with only the fraction of the flora and fauna.

54. This forest ecosystem houses the largest and smallest
mammal species (wood bison & pygmy shrews) of the North
American continent. The Boreal forest has many things:
great lakes and northern rivers; vast bogs, fens and other
organic wetlands. The rich wildlife diversity of the Boreal is
a joy to behold: woodland caribou and lynx; whooping cranes
and wood bison; northern owls; woodpeckers with three
rather than four toes; colorful wood warblers . The Boreal
has more than 5,000 species of conspicuous and colorful
fungi, celebrated far more in Scandinavia and Siberia than
in North America. Then there are the precious old-growth
forests, the richest and most biologically diverse of the
Boreal forest communities that are essential for so many
Boreal species.

55. Tropic rainforest
Temperate
rainforests

56. Structure of Forest Ecosystems:
Different organisms exist within the forest layers.
These organisms interact with each other and their
surroundings. Each organism has a role or niche in
sustaining the ecosystem.
Some provide food for other organisms; others
provide shelter or control populations through
predation:

57. Producers:
All living organisms’ intake energy in order to
survive. In a forest ecosystem, trees and other
plants get their energy from sunlight. Plants
produce their own food, in the form of
carbohydrates. Plants are, therefore, called the
primary producers, since they produce the basic
foodstuffs for other organisms within food chains
and food webs. Photosynthesis is the chemical
reaction that allows plants to produce their own

58. Consumers:
Animals cannot produce their own food. They must consume
food sources for die energy they need to survive. All animals,
including mammals, insects, and birds, are called consumers.
Consumers rely on plants and other animals as a food source.
Details of these animals in a forest ecosystem have been
given earlier.Primary consumers only eat plants and are
referred to as herbivores. Secondary consumers are
referred to as carnivores and feed on herbivores. Tertiary
consumers are carnivores that feed on other carnivores.

59. Decomposers:
Leaves, needles, and old branches fall to the forest
floor as trees grow. Eventually all plants and animals
die. So what happens to all of this plant and animal
material? Does it sit on the forest floor forever?
Thankfully no. These materials are decomposed by
worms, microbes, fungi, ants, and other bugs.
Decomposers break these items down into their
smallest primary elements to be used again.
Decomposers are important in that they sustain the
nutrient cycle of ecosystems.

61. Clearing and burning of the forests for
agriculture,cattle rearing and timber extraction.
Clear cutting and conversion of forest land in hilly
areas for agriculture,plantation and housing.
Forests affected by acid deposition originating from
industries.
Pesticides spraying to control insects in forest
plantation leads to poisoning all the way up the food
chain and unintended loss of species.
ImpactofhumanactivitiesandnaturalforcesontheforestofIndia

63. Conservation of
Forest EcosystemUse resources
carefully
Alternate source
of energy for fuel
wood
Afforestation
NP & Wildlife
Sanctuaries
Control

64. Humans are part of
Forest Ecosystem:
Humans are consumers. We get food and
materials from forests. Because of this, we are
a part of the forest ecosystem. Human
consumption alters forest ecosystems. Human
intervention may be necessary to sustain forest

65. Desert Ecosystem:
Types, Characteristic,
Structure and Function of
Desert Ecosystem

67. Valle de la Luna ("Valley of the
Moon") in the Atacama Desert
of Chile, the world's driest hot
desert
Sand dunes in the Rub' al
Khali("Empty quarter") of
Saudi Arabia
The Agasthiyamalai hills cut off Tirunelveli in India from the monsoons, creating a rainshadow
region.

68. Deserts usually have a large diurnal and seasonal temperature range, with
high daytime temperatures falling sharply at night. The diurnal range may
be as much as 20 to 30 °C (36 to 54 °F) and the rock surface experiences
even greater temperature differentials.During the day the sky is usually
clear and most of the sun's radiation reaches the ground, but as soon as
the sun sets, the desert cools quickly by radiating heat into space. In hot
deserts, the temperature during daytime can exceed 45 °C (113 °F) in
summer and plunge below freezing point at night during winter. Such large
temperature variations have a destructive effect on the exposed rocky
surfaces. The repeated fluctuations put a strain on exposed rock and the
flanks of mountains crack and shatter. Fragmented strata slide down into
the valleys where they continue to break into pieces due to the relentless
sun by day and chill by night. Successive strata are exposed to further
weathering. The relief of the internal pressure that has built up in rocks
Weatheri
ng:-

69. One square centimeter
(0.16 sq in) of windblown
sand from the Gobi Desert
Exfoliation also occurs when the outer
surfaces of rocks split off in flat flakes. This
is believed to be caused by the stresses put
on the rock by repeated expansions and
contractions which induces fracturing parallel
to the original surface. Chemical weathering
processes probably play a more important
role in deserts than was previously thought.
The necessary moisture may be present in
the form of dew or mist. Ground water may
be drawn to the surface by evaporation and
the formation of salt crystals may dislodge
rock particles as sand or disintegrate rocks
by exfoliation. Shallow caves are sometimes
formed at the base of cliffs by this means.
As the desert mountains decay, large areas of

70. The process continues and the end products
are either dust or sand. Dust is formed from
solidified clay or volcanic deposits whereas
sand results from the fragmentation of harder
granites, limestone and sandstone.There is a
certain critical size (about 0.5 mm) below
which further temperature-induced weathering
of rocks does not occur and this provides a
minimum size for sand grains.As the mountains
are eroded, more and more sand is created. At
high wind speeds, sand grains are picked up off
the surface and blown along, a process known
as saltation. The whirling airborne grains act as
a sand blasting mechanism which grinds away
solid objects in its path as the kinetic energy
of the wind is transferred to the ground.The
sand eventually ends up deposited in level areas
known as sand-fields or sand-seas, or piled up
in dune.
Exfoliation of weathering rocks in

71. -10
0
10
20
30
40
50
day 1 night 1 day 2 night 2
temp.
Temperature

72. 0
5
10
15
20
25
30
yr 1 yr 2 yr 3 yr 4
percipita
tion
How the desert is unique and precipitation
The desert is
unique because
most deserts
are found next
to rainforests
and it covers
one third of the
WORLD.

73. Types and Characteristic
Features:
One can find at least one desert on every continent except Europe and Antarctica. Each
desert is different in some way, but they all have one thing in common. In order for an
area of land to be considered a desert, it must receive less than 10 inches of water a
year. Clouds are scarce in these regions, and we all know that without clouds, there can’t
be rain, snow or any other precipitation. But clouds also serve another purpose – they
block out some of the Sun. The desert gets mighty hot during the day because the Sun
beats down on the sand. At night, the desert gets very cold, because there aren’t clouds
around to keep the heat from escaping to the atmosphere.
There are plenty of differences between the deserts of the world. Some deserts are
made of very fine, red sand, others consist of sand mixed with pebbles and rocks. The
desert sand started out as rock, but years of weathering by wind and water has created
dunes in the deserts. These sands are mostly minerals, and sometimes oil can be found
hidden deep within the rocks.

74. Structure and Function:
The different components of a desert
ecosystem are:
(A) Abiotic Component:
The abiotic component includes the nutrients
present in the soil and the aerial environment.
The characteristic feature of the abiotic
component is lack of organic matter in the soil and
scarcity of water.

75. (B) Biotic
Component:
The various biotic
components representing
three functional groups

76. (a) Producer
organisms:
The producers are mainly shrubs or bushes, some grasses and a
few trees. Surprisingly, there are many species of plants that
survive in the desert. Most of them are succulents, which mean
they store water. Others have seeds that lay dormant until a
rain awakens them. Regardless, these plants find a way to get
water and protect themselves from the heat. The most famous
desert plant is the cactus. There are many species of cacti. The
saguaro cactus is the tall, pole shaped cactus. The saguaro can
grow up to 40 feet tall. It can hold several tons of water inside
its soft tissue. Like all cacti, the saguaro has a thick, waxy layer
that protects it from the Sun. Other succulents include the
desert rose and the living rock. This strange plant looks like a
spiny rock. It’s disguise protects it from predators. The
welwitschia is a weird looking plant. It has two long leaves and a
big root. This plant is actually a type of tree and it can live for
thousands of years. There are many other kinds of desert

77. (b)
Consumers:
These include animals
such as insects and
reptiles. Besides them,
some rodents, birds and

78. Desert
Insects and
Arachnids:
There are plenty of insects in the desert.
One of the most common and destructive
pests is the locust. A locust is a special
type of grasshopper. They travel from
place to place, eating all the vegetation
they find. Locusts can destroy many crops
in a single day.Not all desert insects are
bad, though. The yucca moth is very

79. There are also several species of ants in the
desert. The harvester ants gather seeds and
store them for use during the dry season. And
the honey pot ants have a very weird habit. Some
members of the colony eat large amounts of
sugar, so much that their abdomens get too large
for them to move. The rest of the colony feeds
off this sugar.There are also arachnids in the
desert. Spiders are the most notable arachnids,
but scorpions also belong in this group. Some
species of scorpions have poison in their sharp
tails. They sting their predators and their prey

80. Desert Reptiles:
Reptiles are some of the most interesting creatures of the desert. Reptiles can
withstand the extreme temperatures because they can control their body tem-
peratures very easily. You can put most of the desert reptiles into one of two
categories: snakes and lizards.Many species of rattlesnakes can be found in the
desert. Rattlesnakes have a noisy rattle they use to warn enemies to stay away. If the
predator isn’t careful, the rattlesnake will strike, injecting venom with its sharp fangs.
Other desert snakes include the cobra, king snake and the hognose.
Lizards make up the second category of desert reptiles. They are probably the most
bizarre looking animals in the desert. While some change colors and have sharp scales
for defense, others change their appearance to look more threatening.
One such creature is the frilled hazard. When enemies are near, the lizard opens its
mouth, unveiling a wide frill. This makes the hazard look bigger and scarier. The
shingle back has a tail with the same shape as its head. When a predator bites at the
tail, the shingle back turns around and bites back. There are only two venomous lizards
in the world, and one of them is the gila monster. It has a very painful bite.

81. Desert
Birds:Like the other inhabitants of the desert, birds come up
with interesting ways to survive in the harsh climate. The
sand grouse has special feathers that soak up water. It
can then carry the water to its young trapped in the
nest.
Other birds, like the gila woodpecker, depend on the
giant saguaro as its home. This woodpecker hollows out a
hole in the cactus for a nest. The cool, damp inside is
safe for the babies.The roadrunner is probably the most
well known desert bird. Roadrunners are so named
because they prefer to run rather than fly. Ostriches
also prefer to use their feet. Even the young depend on
walking to find food and water. The galah is one of the

82. Desert Mammals:
There are several species of mammals in the
desert. They range in size from a few inches to
several feet in length. Like other desert wildlife,
mammals have to find ways to stay cool and drink
plenty of water. Many desert mammals are
burrowers.They dig holes in the ground and stay
there during the hot days. They return to the
surface at night to feed. Hamsters, rats and
their relatives are all burrowers. Not only do the
burrows keep the animals cool, they are also a
great place to store food.Of course, not all
animals have in holes in the ground. The kangaroo
and spiny anteater both live in the Australian
desert region. Spiny anteaters are unusual
mammals because they lay eggs.The desert is also
full of wild horses, foxes and jackals, which are
part of the canine family. And we can’t forget the
cats. Lions are found all over the deserts of

83. Camels – The
Cars of the
Desert:
Camels could be included in the mammal section.
Camels are the cars of the desert. Without
them, people would have great difficulty
crossing the hot terrain. There are two types of
camels: Bactrian and dromedary. The main
difference between the two is the number of
humps. Dromedaries have one hump, and
Bactrian have two. Both kinds are used by
people, but only Bactrian’s are found in the wild.
Camels are great for transportation because
they use very little water. Camels can withstand
very high temperatures without sweating. They

84. (c)
Decomp
osers:
Due to poor vegetation the
amount of dead organic
matter is very less. As a
result the decomposers are
very few. The common
decomposers are some

85. We think desert as a non arable waste land but it
contains lot of minerals which can be harvested by
making judicial use of it.
The top soil is fertile but very susceptible to
erosion. It can be saved by afforestation.
Minerals like silica, gypsum, borates are very
commonly found.
It’s a very big area which should be converted into
arable.
Importance for man

86. RANK DESERT AREA(in km²) AREA(in mi²)
1 Antarctic Desert (Antarctica) 14,200,000 5,500,000
2 Arctic Desert(Arctic) 13,900,000 5,400,000
3 Sahara Desert (Africa) 9,100,000 3,500,000
4 Arabian Desert (Middle East) 2,600,000 1,000,000
5 Gobi Desert (Asia) 1,300,000 500,000
6 Patagonian Desert(SouthAmerica) 670,000 260,000
7 GreatVictoria Desert (Australia) 647,000 250,000
8 Kalahari Desert (Africa) 570,000 220,000
9 Great Basin Desert (North America) 490,000 190,000
10 Syrian Desert (Middle East) 490,000 190,000
The ten largest deserts

87. Referen
ces:-
https://en.wikipedia.org/wiki/Terrestrial_ecosystem
study.com/academy/.../what-is-a-terrestrial-ecosystem
https://www.slideshare.net/littlemegan/terrestrial-ecosystems
https://www.soinc.org/sites/default/files/uploaded_files
https://en.wikipedia.org/wiki/Grassland
https://www.slideshare.net/KyrmenMarsh517/kyrmen-marsh
https://en.wikipedia.org/wiki/Desert
edugreen.teri.res.in
Environmental Studies : From crisis to cure
en.wikipedia.org/wiki/Grassland
biodiv.wri.org
environment- guides.com
http://www.geocities.com
http://www.enchantedlearning.com
http://www.blueplanetbiomes.org
http://www.mbgnet.net

89. The end…!!