Ecology and Environment

Section 2
Ecosystems
 Topics
• Ecotone and edge effect • Equatorial rainforest biome
• Biomes • Tropical monsoon climate
• Tundra biome • Types of Indian forests
• Taiga biome • Indian grasslands
• Savannah • Marine biome
• Temperate grassland • Mangroves
• Mediterranean shrub lands • Coral reefs
• Desert biome • Wetlands
 Ecotone
• An ecotone is a zone of junction or a transition area between two
biomes (diverse ecosystems).
• Ecotone is the zone where two communities meet and integrate.
• For e.g. the mangrove forests represent an ecotone between
marine and terrestrial ecosystem.
• Other examples
– Grassland (between forest and desert)
– Estuary (between fresh water and salt water)
– Riverbank or marshland (between dry and wet).
Characteristics of Ecotone
• It may be narrow (between grassland and forest) or wide (between
forest and desert).
• It has conditions intermediate to the adjacent ecosystems. Hence it
is a zone of tension.
• Usually, the number and the population density of the species of an
outgoing community decreases as we move away from the community
or ecosystem.
• A well-developed ecotone contains some organisms which are
entirely different from that of the adjoining communities.
Edge Effect – Edge Species
• Edge effect refers to the changes in population or community structures
that occur at the boundary of two habitats (ecotone).
• Sometimes the number of species and the population density of some of the
species in the ecotone is much greater than either community. This is
called edge effect.
• The organisms which occur primarily or most abundantly in this zone are
known as edge species.
• In the terrestrial ecosystems edge effect is especially applicable to birds.
• For example, the density of birds is greater in the ecotone between the
forest and the desert.
Ecocline
• Ecocline is a zone of gradual but continuous change from one
ecosystem to another when there is no sharp boundary between
the two in terms of species composition.
• Ecocline occurs across the environmental gradient (gradual
change in abiotic factors such as altitude, temperature
(thermocline), salinity (halocline), depth, etc.)
• An ecocline refers to the gradient change of physicochemical
characteristics between two ecosystems, while an ecotone is a
designated new zone created in combination between two
homogenous ecosystems.
• Thus, this is the key difference between ecocline and ecotone. It is
important to study these concepts in ecology as this leads to
species differentiation and diversity in different geographic
locations.
 Biomes
• Biomes are groups of ecosystems that share similar climatic
conditions and same kind of abiotic and biotic factors spread over
a large area.
• Either terrestrial or aquatic
 Ecozones
• Ecozones are the Biogeographic division of the Earth’s land
surface, based on distributional patterns of terrestrial organisms.
Since they include only terrestrial part of biosphere, they are
called Terrestrial Ecozones also.
• Both biomes and Ecozones are groups of ecosystems, however, an
Ecozone comprises only land parts of Earth surface, while the
biomes comprise both aquatic and land parts.
 Tundra
• Coldest biome.
• Finnish word tunturia, meaning treeless plain.
• Frost-molded landscapes
• Tundra is separated into:
– Arctic tundra
– Antarctic tundra
– Alpine tundra
SOIL
• Dead organic material functions as a nutrient pool.
• The two major nutrients are nitrogen and phosphorus.
• Poor nutrients
• Least developed soil profile.
• Soil depth is very less.
• Soil is formed slowly.
• A layer of permanently frozen subsoil called permafrost exists.
 Climate
• Extremely cold climate
• Little precipitation in the form of snow
• Limitation of drainage
• Short summer and long winter
 Biodiversity
• Low biodiversity
• Simple vegetation structure
• Simple food web
• Short season of growth and reproduction
• Animal populations fluctuate throughout the seasons due to
migration
• Hibernation and migration
• No deep root systems
• Adapted to low temperature and sunlight.
• All of the plants are adapted to sweeping winds and disturbances
of the soil.
• Plants are short and group together to resist the cold
temperatures.
• They can carry out photosynthesis at low temperatures and low
light intensities.
• Most plants reproduce by budding and division rather than
sexually by flowering.
 Arctic tundra
• The growing season ranges from 50 to 60 days.
• The average winter temperature is -34° C, but the average
summer temperature is 3-12° C.
• Precipitation, including melting snow, is 15 to 25 cm.
 Antarctic
• Too cold and dry to support vegetation.
• In some portions of Antarctica, there are areas of rocky soil that
support plant life.
• The major difference between Arctic and Antarctic Tundra is that
Antarctic lacks a large mammal fauna due to physical isolation
from other continents.
 Alpine tundra
• The growing season is approximately 180 days
• Unlike the arctic tundra, the soil in the alpine is well drained.
 Issues
• Permafrost – carbon dioxide sink
• Extremely fragile because of the lack of abundant plant life.
• Extinction of just one species has the capability to destroy the
entire ecosystem
• Oil and mineral extraction
• Global warming and related feedback loops
Arctic Greening
 2019 prelims
Which of the following statements are correct about the deposits of ‘methane
hydrate?
1. Global warming might trigger the release of methane gas from these deposits.
2. Large deposits of ‘methane hydrate’ are found in Arctic Tundra and under the
seafloor.
3. Methane in atmosphere oxidizes to carbon dioxide after a decade or two.
Select the correct answer using the code given below.
(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
• How does the Cryosphere affect global climate? (2017 GS 1)
• How can the mountain ecosystem be restored from the negative
impact of development initiatives and tourism? (Answer in 250
words) 15 Marks
• Needle leaf forest.
• Some of the animals in the taiga hibernate in the winter, some fly
south if they can, while some just cooperate with the environment,
which is very difficult.
• Taiga is the Russian word for forest and is the largest biome in the
world. It stretches over Eurasia and North America. The taiga is located
near the top of the world, just below the tundra biome.
• The winters in the taiga are very cold with only snowfall. The summers
are warm, rainy, and humid.
• The taiga is also known as the boreal forest.
• Boreal was the Greek goddess of the North Wind.
• It does have millions of insects in the summertime. Birds migrate there every
year to nest and feed.
• The average temperature is below freezing for six months out of the year. The
winter temperature range is -54 to -1° C.
• Temperature range in the summer gets as low as -7° C . The high in
summer can be 21° C.
• The summers are mostly warm, rainy and humid.
• They are also very short with about 50 to 100 frost free days.
• The total precipitation in a year is 30 - 85 cm .
• The forms the precipitation comes in are rain, snow and dew.
• Most of the precipitation in the taiga falls as rain in the summer.
• The soil in Taiga is young with little development and profile. This
is mainly because of the fact that cold hinders the development of
soil. The taiga soil is also poor in nutrients.
• The soil is acidic due to the falling pine needles, the forest floor
has only lichens and some moss growing on it.
• Diversity of soil organisms in the boreal forest (southern Taiga) is
high, comparable to the tropical rainforest. The Taiga soils are
dominated by the microscopic fungi. These microscopic fungi play
an important role in the decomposition.
• The main seasons in the taiga are winter and summer.
• The spring and autumn are so short
• There are some lichens and mosses, but most plants are coniferous
trees like pine, white spruce, hemlock and douglas fir.
• Coniferous trees are also known as evergreens. They have long, thin
waxy needles.
• The wax gives them some protection from freezing temperatures and
from drying out.
• The dark color of evergreen needles allows them to absorb heat from
the sun and also helps them start photosynthesis early.
• Evergreens in the taiga tend to be thin and grow close together. This gives
them protection from the cold and wind.
• Evergreens also are usually shaped like an upside down cone to protects the
branches from breaking under the weight of all that snow. The snow slides
right off the slanted branches.
• The roots of Taiga Trees are shallow, which is basically to take advantage of the
young thin soils
• The taiga is susceptible to many wildfires. Trees have adapted by growing thick
bark.
• The fires will burn away the upper canopy of the trees and let sunlight reach
the ground. New plants will grow and provide food for animals that once could
not live there because there were only evergreen trees.
• Fires are thought to be important for forest productivity in the
boreal, as burning the organic leaf litter layer releases nutrients,
which then become more and more limited due to low
decomposition rates as the litter layer builds up again over the
following years.
• Fire allows penetration of sunlight into the ground layer, thereby
ensure flourished ground level plant growth
• Animals of the taiga tend to be predators like the lynx and members of
the weasel family like wolverines, bobcat, minks and ermine.
• They hunt herbivores like snowshoe rabbits, red squirrels and voles.
Red deer, elk, and moose can be found in regions of the taiga where
more deciduous trees grow.
• Many insect eating birds come to the taiga to breed.
• They leave when the breeding season is over. Seed eaters like finches
and sparrows, and omnivorous birds like crows stay all year long.
 SAVANNAH BIOME
• Tropical grassland
• A savanna is a rolling grassland scattered with shrubs and isolated
trees, which can be found between a tropical rainforest and desert
biome.
• In Savannah, the trees are sufficiently small or widely spaced so
that the canopy does not close.
• Savannah covers approximately 20% of the Earth’s land area. The
largest area of Savannah is in Africa.
• Like Taiga, the forest fires are common in Savannahs also but that
is mainly because of human interference and not because of the
natural reasons as the lightning in case of Taiga Biome.
• In Savannahs, these fires are usually confined to the herbaceous
layer and do little long term damage to mature trees.
• These fires either kill or suppress tree seedlings, thus preventing
the establishment of a continuous tree canopy which would
prevent further grass growth.
• Two very different seasons in a savanna; a very long dry season
(winter), and a very wet season (summer).
• In the summer there is lots of rain.
• Every day the hot, humid air rises off the ground and collides with
cooler air above and turns into rain.
• African savannas have large herds of grazing and browsing hoofed
animals. Each animal has a specialized eating habit that reduces
compitition for food.
• East African savannas covered with acacia trees.
• The Serengeti Plains of Tanzania are some of the most well known.
Here animals like lions, zebras, elephants, and giraffes and many types
of ungulates(animals with hooves) graze and hunt.
• South America also has savannas, but there are very few species that
exist only on this savanna.
• The Llanos of the Orinoco basin of Venezuela and Columbia is flooded
annually by the Orinoco River.
• Plants have adapted to growing for long periods in standing water.
• Brazil's cerrado is an open woodland of short twisted trees. The
diversity of animals is very great here.
• Eucalyptus trees take the place of acacias in the Australian savanna.
There are many species of kangaroos in this savanna but not too much
diversity of different animals
• Plants in savannah have long tap roots that can reach the deep water
table, thick bark to resist annual fires, trunks that can store water, and
leaves that drop of during the winter to conserve water.
• The grasses have adaptations that discourage animals from grazing on
them; some grasses are too sharp or bitter tasting for some animals,
but not others, to eat.
• Different species will also eat different parts of the grass. Many
grasses grow from the bottom up, so that the growth tissue
doesn't get damaged by grazers.
• Many plants of the savanna also have storage organs like bulbs
and corms for making it though the dry season.
• Most of the animals on the savanna have long legs or wings to be able to go on
long migrations. Many burrow under ground to avoid the heat or raise their
young.
• Animals don't sweat to lose body heat, so they lose it through panting or
through large areas of exposed skin, or ears, like those of the elephant.
• There are over 40 different species of hoofed mammals that live on the
savannas of Africa. Up to 16 different species of browsers (those who eat
leaves of trees) and grazers can coexist in one area. They do this by having
their own food preferences, browsing/grazing at different heights, time of day
or year to use a given area, and different places to go during the dry season.
• Overgrazing and farming.
• Llanos in Venezuela,
• Campo cerrado in brazil, and
• Pantanal of southern brazil.
 PYQ - 2021
• The vegetation of savannah consists of grassland with scattered small trees,
but extensive areas have no trees. The forest development in such areas is
generally kept in check by one or more or a combination of some conditions.
Which of the following are such conditions.
1. Burrowing animals and termites
2. Fire
3. Grazing herbivores
4. Seasonal rainfall
5. Soil properties
Select the correct answer using the code given below
(a) 1 and 2
(b) 4 and 5
(c) 2, 3 and 4
(d) 1, 3 and 5
 Temperate Grasslands
• The most important characteristic of the Temperate Grasslands is that they
have almost no trees and large shrubs and have grasses as the dominant
vegetation.
• The amount of rainfall is less in temperate grasslands than in Savannahs.
• The Veldts of South Africa
• Pustaz of Hungary
• Pampas of Argentina and Uruguay
• Steppes of the former Soviet Union
• Prairies of Central North America
• Downs of Australia
• Canterbury plains of New zealand
• Temperate grasslands have hot summers and cold winters.
• Rainfall is moderate.
• The amount of annual rainfall influences the height of grassland
vegetation, with taller grasses in wetter regions.
• As in the savanna, seasonal drought and occasional fires are very
important to biodiversity. However, their effects aren’t as dramatic in
temperate grasslands as they are in savannas.
• The soil of the temperate grasslands is deep and dark, with fertile
upper layers. It is nutrient-rich from the growth and decay of deep,
many-branched grass roots.
• The seasonal drought, occasional fires, and grazing by large mammals
all prevent woody shrubs and trees from invading and becoming
established.
• However, a few trees, such as cottonwoods, oaks, and willows grow in
river valleys, and some non woody plants, specifically a few hundred
species of flowers, grow among the grasses.
• The various species of grasses include purple needle grass, blue grama,
buffalo grass, and galleta.
Precipitation in the temperate grasslands usually occurs in the late
spring and early summer.
• The annual average is about 50.8 to 88.9 cm.
• The temperature range is very large over the course of the year.
• The fauna include gazelles, zebras, rhinoceroses, wild horses,
lions, wolves, prairie dogs, jack rabbits, badgers, blackbirds,
grouses, meadowlarks etc.
• Prairies are grasslands with tall grasses while steppes are
grasslands with short grasses.
 Mediterranean Shrublands (Chaparral Biome)
• Mediterranean Shrublands or Chaparral biome
– Coasts of the Mediterranean sea
– California
– Central Chile
– South-western part of South Africa
– South-western parts of Australia.
• Total annual precipitation ranges between 40 and 90 cms per year.
• Many plants are adapted to withstand drought.
• The Mediterranean climate has hot and dry summers and mild-wet
winters.
• This biome is well adapted to frequent fires, for many of its
characteristically deep rooted plants have the ability to re-sprout from
their roots after a fire.
• The dominant shrubs that occupy these regions are stunted and tough
in their ability to with-stand hot summer drought and due to this, the
chaparral vegetation is also known as sclerophyllous. s
• Mediterranean biome is characterized by shrubs.
• In most regions these shrubs are evergreen and have small,
leathery (sclerophyllous) leaves with thick cuticles.
• Many typical members of the shrub flora are aromatic (for
example, sage, rosemary, thyme, and oregano) and contain highly
flammable oils.
• Mediterranean regions have long been impacted by humans
especially through the use of fire and the grazing of livestock.
• In the Mediterranean proper–Europe, North Africa, and Asia
Minor, they are known as Maquis.
• In Chile, they are known as Matorral
• In Australia, they are Mallee scrub
• Cork-oak, olive, fig, and citrus fruits.
• In Australia the bulk of the eucalyptus species is sclerophyllous in
form and structure.
 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.
 Hot and Dry Desert
• The four major North American deserts of this type are the
Chihuahuan, Sonoran, Mojave and Great Basin.
• Plants include: yuccas, ocotillo, turpentine bush, prickly pears,
false mesquite, sotol, ephedras, agaves and brittlebush.
 PYQ - 2018
• Which of the following leaf modifications occur(s) in the desert areas
to inhibit water loss?
1. Hard and waxy leaves
2. Tiny leaves
3. Thorns instead of leaves
Select the correct answer using the code given below.
a) 2 and 3 only
b) 2 only
c) 3 only
d) 1, 2 and 3
EQUATORIAL RAIN FOREST
• Dominated by broad-leaved trees that form a dense
upper canopy (layer of foliage) and contain a diverse array of
vegetation and other life.
• Temperature is uniform through out the year
• Diurnal range is small
• No winter and no seasons
• Distinct dry season is absent
• Precipitation max at eqinox
• Selvas of amazon
• Growing season – all the year
• Tropical hardwood – mahagony, aini, ebony etc
• Thick canopy
• Mangroves
• Undergrowth is not dense
• The rainforest biome remains warm all year and must stay frost-
free. The average daily temperatures range from 20°C to 25°C.
• Rainforests receive the most rain of all of the biomes in a year! A
typical year sees 2,000 to 10,000 mm of rain per year.
• Vines, palm trees, orchids, ferns
• Soil : Rainforest soils are nutrient-poor or oligo trophic because nutrients are
not stored in them for very long.
• The heavy rains that occur in rainforests wash organic material from the soil.
• Although decomposition occurs rapidly in the hot, moist conditions, many
of the dead, fallen leaves and other organic detritus are swept away before
releasing all of their nutrients.
• In addition, rainwater seeps into the ground and leaches away nutrients.
Nevertheless, the high diversity of decomposers, such as bacteria and fungi
accelerates the decomposition process enough that the nutrients released by
decomposition are taken up quickly by the plants, instead of being stored in
the soil.
 PYQ - 2023
Consider the following statements:
Statement-I: The soil in tropical rain forests is rich in nutrients.
Statement-II: The high temperature and moisture of rain forests cause tropical
dead organic matter in the soil to decompose quickly.
Which one of the following is correct in respect of the above statements?
(a) Both Statement-I and Statement-II are correct and Statement-II is the correct
explanation for Statement-I
(b) Both Statement-I and Statement-II are correct and Statement-II is not the
correct explanation for Statement-I
(c) Statement-I is correct Statement-II is incorrect
(d) Statement-I but is incorrect but Statement-II is correct
• Biodiversity: Tropical rainforests are areas of extremely high
biodiversity compared to other ecosystems.
• Biologists estimate that tropical rainforests contain about 50% of
the world’s terrestrial plant and animal species, yet they
encompass only about 6% of the world’s land area.
• While tropical rainforests around the world have many similarities
in their climates and soil composition, each regional rainforest is
unique. You will not find precisely the same species living in all the
tropical rainforests around the world.
• Primates are iconic examples of tropical rainforests and of the
diversity between different regional tropical rainforests.
• Primates are a group of animals that include humans, great apes,
and monkeys.
• Central and South America has howler, spider, capuchin and
squirrel monkeys, while Africa has vervet monkeys, baboons,
chimpanzees and gorillas.
• Madagascar is the unique home of lemurs, and Asia has
proboscis monkeys, macaque monkeys, langurs, gibbons and
orangutans.
• Lumbering or shifting
cultivation
• Why commercial lumbering is
difficult?
• Plantation boom
Major tribes
• Congo basin –
pygmies
• Malasia – orang
asli
 PYQ - 2021
• “Leaf litter decomposes faster than in any other biome and as a result
the soil surface is often almost bare. Apart from trees, the vegetation is
largely composed of plant forms that reach up into the canopy
vicariously, by climbing the trees or growing as epiphytes, rooted on
the upper branches of trees.” This is the most likely description of
• (a) coniferous forest
(b) dry deciduous forest
(c) mangrove forest
(d) tropical rainforest
Tropical monsoon climate
• Occur within 5° to 30° N and S of the equator.
• On-shore [sea to land] tropical monsoons occur in the summer
and off-shore [land to sea] dry monsoons in the winter.
• They are best developed in the Indian sub-continent, Burma,
Thailand, Laos, Cambodia, parts of Vietnam and south China and
northern Australia.
Temperature
• Monthly mean temperatures above 18 °C.
• Temperatures range from 30-45° C in summer. Mean summer temperature is about
30°C.
• In winters, temperature range is 15-30° C with mean temperature around 20-25° C.
Precipitation
• Annual mean rainfall ranges from 200-250 cm. In some regions it is around 350 cm.
• Places like Cherrapunji & Mawsynram receive an annual rainfall of about 1000
cm. [They lie on the windward side of the Meghalaya hills, so the
resulting orographic lift (orographic rainfall) enhances precipitation. Also, they are
located between mountains which enhances cloud concentration due to funneling
effect]
Seasons
• Seasons are chief characteristics of monsoon climate.
– The cool, dry season (October to February)
– The hot dry season (March to mid-June)
– The rainy season (mid-June to September)
– The Retreating Monsoon
 TYPES OF INDIAN FORESTS
(i) Tropical Ever green and Semi Evergreen forests
(ii) Tropical Deciduous forests
(iii) Tropical Thorn forests
(iv) Montane forests
(v) Littoral and Swamp forests.
 Tropical Evergreen and Semi Evergreen Forests
• Western slope of the Western Ghats, hills of the northeastern
region and the Andaman and Nicobar Islands.
• They are found in warm and humid areas with an annual
precipitation of over 200 cm and mean annual temperature above
22 C.
• Tropical evergreen forests are well stratified, with layers closer to
the ground and are covered with shrubs and creepers, with short
structured trees followed by tall variety of trees.
• In these forests, trees reach great heights up to 60 m or above.
• There is no definite time for trees to shed their leaves, flowering
and fruition. As such these forests appear green all the year
round.
• Species found in these forests include rosewood, mahogony, aini,
ebony, etc.
• The more common trees that are found here are the jackfruit,
betel nut palm, jamun, mango, and hollock.
 Semi Evergreen Forests
• Found in the less rainy parts of the regions where moist evergreen
forests are found; Western Ghats, Andaman and Nicobar Islands,
and the Eastern Himalayas.
• Trees: Such forests have a mixture of moist evergreen and moist
deciduous trees.
– The under growing climbers provide an evergreen character to these
forests.
– Main species are white cedar, hollock and kail.
 PYQ - 2016
• ‘Gadgil Committee Report’ and ‘Kasturirangan Committee Report’,
sometimes seen in the news, are related to
• a) Constitutional reforms
b) Ganga Action Plan
c) Linking of rivers
d) Protection of Western Ghats
 Dry evergreen
– Found in the Shivalik Hills and foothills of the Himalayas up to a height
of 1000 metres in the north.
• Found along Andhra Pradesh and Karnataka coast in the south.
– Climatic Conditions: Usually have a prolonged hot and dry season and a
cold winter.
– Trees: Have mainly hard-leaved evergreen trees with fragrant flowers,
along with a few deciduous trees.
• Trees have a varnished look.
• Some of the more common ones are the pomegranate, olive, and oleander.
 Tropical Dry Evergreen Forests
• Along the coasts of Tamil Nadu.
• Annual rainfall of 100 cm [mostly from the north-east monsoon winds in
October – December].
• Mean annual temperature is about 28°C.
• The growth of evergreen forests in areas of such low rainfall is a bit strange.
• Short statured trees, up to 12 m high, with complete canopy.
• Bamboos and grasses are not conspicuous.
• The important species are jamun, tamarind, neem, etc.
• Most of the land under these forests has been cleared for agriculture or
casuarina plantations.
 Tropical Deciduous Forests

• Most widespread forests in India.

• Also called the monsoon forests.
• Spread over regions which receive rainfall between 70-200 cm.
• On the basis of the availability of water, these forests are
further divided into moist and dry deciduous.
 Moist Deciduous Forests
– Region: These forests are found in the north-eastern states along
the foothills of Himalayas, eastern slopes of the Western
Ghats and Odisha.
– Rainfall: Found in the regions which record rainfall between 100-200 cm.
– Trees: Tall trees with broad, branched trunks.
• Some of the taller trees shed their leaves in the dry season.
• Teak, sal, shisham, hurra, mahua, amla, semul, kusum, and sandalwood etc. are
the main species of these forests.
 Dry deciduous forest
• Covers vast areas of the country, where rainfall ranges between 70 -100 cm.
• On the wetter margins, it has a transition to the moist deciduous, while on the
drier margins to thorn forests.
• Found throughout the northern part of the country except in the north-east.
• In the higher rainfall regions of the Peninsular plateau and the northern Indian
plain, these forests have a parkland landscape with open stretches in which
teak and other trees interspersed with patches of grass are common.
• As the dry season begins, the trees shed their leaves completely and the forest
appears like a vast grassland with naked trees all around.
• Tendu, palas, amaltas, bel, khair , axlewood, etc. are the common trees
 PYQ - 2023
Consider the following trees:
1. Jackfruit (Artocarpus heterophyllus)
2. Mahua (Madhuca indica)
3. Teak (Tectona grandis)
How many of the above are deciduous trees?
(a) Only one
(b) Only two
(c) All three
(d) None
Source
• NCERT : India Physical Environment Class XI
• Difficulty level - moderate
 Tropical Thorn Forests
• Areas which receive rainfall less than 50 cm.
• These consist of a variety of grasses and shrubs. It includes semi-arid
areas of south west Punjab, Haryana, Rajasthan, Gujarat, Madhya
Pradesh and Uttar Pradesh.
• In these forests, plants remain leafless for most part of the year and
give an expression of scrub vegetation.
• Important species found are babool, ber, and wild date palm, khair,
neem, khejri, palas, etc. The trees do not grow beyond 10 metres.
• Tussocky grass grows upto a height of 2 m as the under growth.
 Montane Forests
• In mountainous areas, the decrease in temperature with
increasing altitude leads to a corresponding change in natural
vegetation.
• Mountain forests can be classified into two types, the northern
mountain forests and the southern mountain forests
 Montane Wet Temperate Forests
– Region: Occur in the northern and southern India.
• In the North, it is found in the region to the east of Nepal into Arunachal
Pradesh, at a height of 1800–3000 metres, receiving a minimum rainfall of 200
cm.
• In the South, it is found in parts of the Nilgiri Hills, the higher reaches of Kerala.
– Trees: The forests in the northern region are denser than in the South.
• This is because over time the original trees have been replaced by fast-growing
varieties such as the eucalyptus.
• Rhododendrons, Champa and a variety of ground flora can be found here.
 Montane Subtropical Forests
– Climatic Conditions: Found in the region where average rainfall is 100-
200 cm and temperature varies between 15°C to 22°C.
– Region: Found in north-western Himalayas (except Ladakh and Kashmir),
Himachal Pradesh, Uttarakhand, Sikkim and Arunachal Pradesh.
– Trees: Chir (Pine) is the main tree but Oak, Jamun and Rhododendron are
also found in these forests.
 Himalayan Forests
• Himalayan Moist Forests:
– Region: Found in Jammu & Kashmir, Himachal Pradesh, Uttarakhand and
northern hilly parts of Bengal.
– Elevation: Found in the belt where altitude varies between 1000-2000 m.
– Trees: Oak, chestnut, chir, sal, shrubs and nutritious grasses.
• Himalayan Dry Temperate:
– Region: J&K, Chamba, Lahaul & Kinnaur districts (Himachal Pradesh) and
Sikkim.
– Trees: Mainly coniferous; deodar, oak, chilgoza, maple, olive, mulberry
and willow.
 Alpine and Subalpine Forests
– Elevation: In the higher reaches, there is a transition to Alpine forests
and pastures occurring at altitudes of 2,500-4,000 m.
• Sub alpine forests extend from Kashmir to Arunachal Pradesh between 2900 to
3500 metres.
– Trees: In the Western Himalayas, the vegetation consists mainly of
juniper, rhododendron, willow, and black currant.
• In the eastern parts, red fir, black juniper, birch, and larch are the common trees.
 The northern mountain forests
• The Himalayan ranges show a succession of vegetation from the
tropical to the tundra, which change in with the altitude.
• Deciduous forests are found in the foothills of the Himalayas.
• It is succeeded by the wet temperate type of forests between an
altitude of 1,000-2,000 m.
• In the higher hill ranges of northeastern India, hilly areas of West
Bengal and Uttarakhand, evergreen broad leaf trees such as oak
and chestnut are predominant.
• Between 1,500-1,750 m, pine forests are also well-developed in this
zone, with Chir Pine as a very useful commercial tree.
• Deodar , a highly valued endemic species grows mainly in the western
part of the Himalayan range. Deodar is a durable wood mainly used in
construction activity. Similarly, the chinar and the walnut, which
sustain the famous Kashmir handicrafts, belong to this zone.
• Blue pine and spruce appear at altitudes of 2,225-3,048 m.
• At many places in this zone, temperate grasslands are also found. But
in the higher reaches there is a transition to Alpine forests and
pastures.
• Silver firs, junipers, pines, birch and rhododendrons, etc. occur
between 3,000-4,000 m.
• However, these pastures are used extensively for transhumance
by tribes like the Gujjars, the Bakarwals, the Bhotiyas and the
Gaddis.
• At higher altitudes, mosses and lichens form part of the tundra
vegetation.
• The southern slopes of the Himalayas carry a thicker vegetation
cover because of relatively higher precipitation than the drier
north-facing slopes.
• More sunlight
• More soil formation
• Gentle slop
 The southern mountain forests
• Found in three distinct areas of Peninsular India viz; the Western
Ghats, the Vindhyas and the Nilgiris.
• As they are closer to the tropics, and only 1,500 m above the sea level,
vegetation is temperate in the higher regions, and subtropical on the
lower regions of the Western Ghats, especially in Kerala, Tamil Nadu
and Karnataka.
• The temperate forests are called Sholas in the Nilgiris, Anaimalai and
Palani hills.
• Some of the trees of this forest include, magnolia, laurel, cinchona
and wattle.
• Such forests are also found in the Satpura and the Maikal ranges.
 PYQ-2015
• Which one of the following regions of India has a combination of
mangrove forest, evergreen forest and deciduous forest?
• (a) North Coastal Andhra Pradesh
(b) South-West Bengal
(c) Southern Saurashtra
(d) Andaman and Nicobar lslands
 PYQ - 2019
• Consider the following States:
1. Chhattisgarh
2. Madhya Pradesh
3. Maharashtra
4. Odisha
With reference to the States mentioned above, in terms of percentage of forest
cover to the total area of State, which one of the following is the correct
ascending order?
(a) 2-3-1-4
(b) 2-3-4-1
(c) 3-2-4-1
(d) 3-2-1-4
 Sehima-Dichanthium Type
• Key species include Sehima nervosum, Heteropogon contortus, Dichanthium
annulatum and Themeda triandra
• The best development is seen with a rainfall of 500 to 900 mm.
• Therefore, the semi-arid tracts of Maharashtra, Gujarat, Andhra Pradesh,
Karnataka and Tamil Nadu are typical examples of this cover type.
• Grazing and fire are causing species pattern change in this grassland. (sehima
disappearing)
• Rollapadu grassland of Andhra, Gnanganga dry grassland of Buldhana district
in Maharashtra, Sailana grassland in Ratlam district of Madhya Pradesh and
Velavadar salt grassland of Gujarat are some of the important sites in this
zone.
 Dichanthium-Cenchrus-Lasiurus Type
• Spread over northern parts of Gujarat, Rajasthan, western Uttar
Pradesh, Delhi, and semi-arid Punjab
• Key species include Dichanthium annulatum, Cenchrus ciliaris, C.
biflorus, Lasiurus sindicus and Atylosia scarabaeoides.
• The rainfall ranges from about 100 mm in the extreme west to
about 750 mm towards the eastern boundary of this cover type.
• Sewan (Lasiurus sindicus) grassland in Jaisalmer and Banni in
Kachchh district.
 Phragmites-Saccharum-Imperata Type:
• Alluvial plains of the Ganga and the delta plains of Bengal and the
Assam Valley
• Key species include Phragmites australis, Saccharum spontaneum,
Imperata cylindica and Desmostachya bipinnata.
• The water table is high and soil is poorly drained. Rainfall is
moderate (500 mm) to high (up to 5000 mm) in this region.
• Though this region contains some of the wet grasslands of the
Terai and Bhabar, some areas are semi-arid, especially in southern
Uttar Pradesh and Bihar due to the north-south moisture gradient.
 Themeda-Arundinella Type:
• Covering the northern plains to the outer humid hills of the
Himalayas, in Assam, Manipur, West Bengal, Uttar Pradesh,
Punjab, Himachal Pradesh, and Jammu and Kashmir
• Key species include Themeda anaethera, Arundinella bengalensis,
Bothriochloa bladhii, B. pertusa, Heteropogon contortus and
Chrysopogon fulvus
 Temperate-Alpine Type:
• Spread over the higher altitudes of Jammu and Kashmir,
Uttaranchal, Himachal Pradesh, West Bengal, and Assam,
• Key species include Dactylis glomerata, Bromus inermis, Festuca
pratense and Themeda anaethera.
• Based on the altitude gradient, several community types have
been recognized. In the Central Himalaya, five distinct types of
bugiyals (high-altitude grasslands) have been identified locally by
the seminomadic bhotias. These are:
• Dug or dudh bugiyal
• Bas bugiyal
• Mot bugiyal
• Dhania bugiyal
• Dhati bugiyal
• Another unique type of grassland type is the Shola grassland of
the Western Ghats.
• Shola grasslands are unique as they are confined to the high
altitude (>1700 m) in the Western Ghats and interspersed with
tropical forests (generally found in the mountain folds and
valleys).
• Shola grasslands are maintained by fire and frost and appear to
be climax vegetation and Niligir Tahr is found in the shola
grasslands and no where else in the world.
 Importance of grasslands
• Ecotone region
• Biodiversity (Indian Wild Ass, Great Indian Bustard, Pygmy Hog
etc)
• Carbon sequestration
• Soil stabilization and erosion control
• Economic benefits
 Grassland threats
• One of the most neglected ecosystems and are increasingly under
threat of being exploited and destroyed for economic gains or
being treated as wastelands.
• Many natural grasslands like wet grasslands of Terai and Shola
grasslands of the Western Ghats, dry grasslands of Deccan are
being converted to plantations even in Protected Areas (PAs).
• Land-filling
• Over grazing
• Habitat destruction or fragmentation
• Uncontrolled growth of invasive species (Parthenium Or Congress
Grass, Lantana Camara, Prosopis Juliflora)
• Climate change and desertification pressure
• Spread of natural deserts
• Unscientific afforestation programs
• Increased soil salinity
• Agricultural chemicals
 Great Green Wall of Africa
• It aims to restore Africa’s degraded landscapes and transform
millions of lives in one of the world’s poorest regions, the Sahel.
• The African initiative is still only 15% complete.
• Once fully completed, the Wall will be the largest living structure
on the planet – an 8,000 km natural wonder of the world
stretching across the entire width of the continent.
• African countries during the UNCCCD COP14 sought global
support in terms of finance to make the Wall a reality in the
continent’s Sahel region by 2030.
 Green Wall of India
• Ambitious plan to create a 1,400km long and 5km wide green belt
from Gujarat to the Delhi-Haryana border.
• The plan is inspired by Africa’s ‘Great Green Wall’ project.
• The overarching objective of India’s Green Wall will be to address the
rising rates of land degradation and the eastward expansion of the
Thar desert.
• The green belt being planned from Porbandar to Panipat will help in
restoring degraded land through afforestation along the Aravali hill
range. It will also act as a barrier for dust coming from the deserts in
western India and Pakistan.
 Marine biome
• Marine regions cover about three-fourths of the Earth's surface
and include oceans, coral reefs, and estuaries.
• Marine algae supply much of the world's oxygen supply and take
in a huge amount of atmospheric carbon dioxide.
Littoral Zone:
• This zone forms the banks or boundary of the water. Many of the
plants are rooted in the muddy floor and their leaves form a good
hideout for insects and fish. There is a lot of fish, frogs, reptiles, and
insects in this zone.
Limnetic Zone:
• It is the zone after the Littoral zone, extending a few meters into the
water body. Fish swim freely here, with some plants floating on the
water. There is enough sunlight here, and algae and plankton usually
thrive here.
Profundal Zone:
• This zone extends beyond the Limnetic zone and is a deeper region of
the water. Here, there is usually very little or no sunlight. It is cooler.
Living things in this region depend on drifting organic matter for food.
Benthic Zone:
• This is the deepest region of the water body and farthest from the
banks. There is no sunlight in this region, and therefore very little or no
photosynthesis occurs here. Organisms that live here include worms,
bacteria, decomposers, and other scavengers.
 Types of Ocean Organisms
Plankton
• Plankton are organisms that cannot swim but that float along with
the current. The word "plankton" comes from the Greek for
wanderer. Most plankton are microscopic, but some are visible to
the naked eye.
 Phytoplankton
• Phytoplankton, also known as microalgae, are similar to terrestrial
plants in that they contain chlorophyll and require sunlight in order to
live and grow.
• Some phytoplankton are bacteria, some are protists, and most are
single-celled plants.
• Because they need sunlight, phytoplankton live in the photic zone.
Phytoplankton are responsible for about half of the total primary
productivity on Earth.
• Among the common kinds are cyanobacteria, silica-
encased diatoms, dinoflagellates, green algae, and chalk-
coated coccolithophores.
 PYQ - 2021
Consider the following kinds of organisms:
1. Copepods
2. Cyanobacteria
3. Diatoms
4. Foraminifera
• Which of the above are primary producers in the food chains of
oceans?
A. 1 and 2
B. 2 and 3
C. 3 and 4
D. 1 and 4
 Nekton
• Nekton are aquatic animals that can move on their own by
“swimming” through the water. They may live in the photic
or aphotic zone. They feed on plankton or other nekton. Examples of
nekton include fish and shrimp.
• Neuston, group of organisms found on top of or attached to the
underside of the surface film of water. The neuston includes insects
such as beetles and water striders, some spiders and protozoans, and
occasional worms, snails, insect larvae, and hydras. It is distinguished
from the plankton, which only incidentally becomes associated with
the surface film.
 Benthos
• Animals that live on the sea floor are called benthos.
• Typical benthic invertebrates include sea anemones, sponges,
corals, sea stars, sea urchins, worms, bivalves, crabs etc.
 Plants and Algae
• The few true plants found in the oceans include salt marsh grasses
and mangrove trees. Although they are not true plants, large
algae, which are called seaweed, also use photosynthesis to make
food. Plants and seaweeds are found in the neritic zone where the
light they need penetrates so that they can photosynthesize.
 Seagrasses
• Flowering plants that grow submerged in shallow marine
waters like bays and lagoons.
• These have tiny flowers and strap-like or oval leaves.
• Found in shallow, salty and brackish waters in many parts of the
world, from the tropics to the Arctic Circle, except Antarctica.
• Sexual Reproduction Method – submarine pollination.
• Asexual Reproduction Method: reproduce asexually by branching
off at their rhizomes
• Sea Cow Grass, Thready Seagrass , Needle Seagrass , Flat-tipped
Seagrass, spoon seagrass, ribbon seagrass
 Marine Invertebrates
• The variety and number of invertebrates, animals without a
backbone, is truly remarkable.
• Marine invertebrates include sea slugs, sea anemones, starfish,
octopi, clams, sponges, sea worms, crabs, and lobsters. Most of
these animals are found close to the shore, but they can be found
throughout the ocean.
 Fish

• Fish are vertebrates

Fish adaptations
• Scales for protection.
• Gills for extracting oxygen from the water.
• A swim bladder that lets them rise and sink to different depths. Rays
lack swim bladders).
• Ectothermy (cold-bloodedness) so that their bodies are the same
temperature as the surrounding water.
• Bioluminescence: light created from a chemical reaction that can
attract prey or mates in the dark ocean.
 Reptiles
• Only a few types of reptiles live in the oceans and they live in
warm water.
• Sea turtles, sea snakes, saltwater crocodiles, and marine iguana
that are found only at the Galapagos Islands sum up the marine
reptile groups.
• Sea snakes bear live young in the ocean, but turtles, crocodiles,
and marine iguanas all lay their eggs on land.
 Marine Mammals
• Mammals are endothermic (warm-blooded) vertebrates that give
birth to live young; feed them with milk; and have hair, ears, and a
jaw bone with teeth.
Marine mammal adaptations
• For swimming: streamlined bodies, slippery skin or hair, fins.
• For warmth: Fur, fat, high metabolic rate, small surface area to
volume, specialized blood system.
• For salinity: kidneys that excrete salt, impervious skin.
Mangroves
• Mangroves are a group of trees and shrubs that live in the coastal
intertidal zone.
• There are about 80 different species of mangrove trees. All of
these trees grow in areas with low-oxygen soil, where slow-
moving waters allow fine sediments to accumulate.
• Mangrove forests only grow at tropical and subtropical latitudes
near the equator because they cannot withstand freezing
temperatures.
 Adaptations
Salt Excretion
• Some mangroves are able to grow in soils that reach salinities up to 75
parts per thousand (ppt), about two times the salinity of ocean water.
However, most mangroves do better in ranges between 3 and 27 ppt.
• In species from the genera Rhizophora (the red mangrove)
and Bruguiera, the plants create a barrier and can almost completely
exclude the salt from entering their vascular system—over 90 percent
of the salt from seawater is excluded.
• Some mangroves, like this Avicennia germinans, get rid of excess salt
from the water by excreting it through their leaves.
Root Aeration
• The soil where mangroves are
rooted poses a second challenge
for plants as it is severely lacking in
oxygen.
• Pneumatophores help the tree
gain access to oxygen even when
the roots are partially submerged.
Physical Stability Adaptations
• Root adaptations make it possible for mangroves to live in the soft
sediments along the shoreline Root adaptations increase stability
of mangrove trees in the soft sediments along shorelines.
• Red mangroves have prop roots descending from the trunk and
branches, providing a stable support system.
Reproductive Adaptations
• All mangrove trees share two reproductive adaptations – viviparity and
propagule dispersal. Similar to terrestrial plants, mangroves reproduce
by flowering with pollination occurring via wind and insects.
• Once pollination occurs, the seeds remain attached to the parent tree.
They germinate into propagules before dropping into the waters
below. This ability is referred to as “viviparity”. The propagules either
take root in the sediments near the parent tree or are dispersed with
the tides and currents to other shorelines.
 Types of mangroves
1. Red Mangrove or 'Red Mango‘ ( Rhizophora mangle )
– More close to water body
– They have prop roots and stilt roots
2. Black Mangroves or 'Courida‘ (Avicennia germinans)
– Close to inland than red mangroves
– Pneumatophores are present
3. White Mangrove ( Laguncularia racemosa )
– Looks like tropical tree than red and black mangroves
– Lives in solid land but inundated with salt water periodically.
– The leaves have adapted to their salty environment by
developing special openings (glands) that allow salt to pass
from inside the tree to the outside.
– The leaves are then coated with speckled white salt crystals
which are what gives this species its name- white mangrove.
Importance of Mangroves
 IMPROVED FISHERIES / FISH PRODUCTION
• Mangroves serve as a nursery ground for many species of juvenile
fish, crustaceans, mollusks, and more. These ecosystems are
particularly important for reef fish.
• It is estimated that up to half of local fish catches are in some way
dependent on mangroves. Some of these are commercially
important species, thus contributing to food security, local
livelihood sustainability and biodiversity.
• Local coastal fisheries as well as commercial coastal and offshore
fisheries.
Atlantic spadefish (Chaetodipterus faber) amongst the roots of red
mangrove trees (Rhizophora mangle) in the Belize Cays
 Increased Human Wellbeing
• Mangroves help to provide food security through the provision of
several other food products, including honey, algae, fruit, salt, and
leaves for livestock feed for local communities.
• “almost 80% of global fish catches are directly or indirectly
dependent on mangroves”.
• Mangroves also provide ideal locations for aquaculture.
• Mangrove forests also provide water purification services and aid
in the detoxification of wastes.
• Aesthetics, culture, spirituality, and recreation.
• Provide significant buffering against coastal erosion, storm surge,
and sea level rise.
 Climate Mitigation
• Mangroves absorb large amounts of carbon dioxide from the
atmosphere during photosynthesis and are able to store this
carbon, often referred to as “blue carbon,” for extended periods
of time, in the plant structure and in the soil beneath them.
• Incredibly efficient carbon sinks/stores, absorbing carbon at a
much faster rate than terrestrial forests, and locking this carbon
away for a much longer period of time.
• Store 3 to 4 times more carbon than tropical forests.
• Meaning that destroying existing mangroves releases far more
carbon dioxide back to the atmosphere.
• Sea level rise will lead to the loss of more mangrove forests across
the globe, leading to increased carbon emissions to the ocean and
atmosphere as these forests are destroyed, and thus further
exacerbation of climate change.
 Climate Adaptation
• As coastal vulnerability increases, it is crucial that climate adaptation
and risk reduction measures be put in place. Mangroves may play an
important role in climate adaptation in coastal communities.
• Mangrove forests offer significant protection from coastal erosion,
storm surge, and sea level rise, all of which may lead to potentially
devastating and life-threatening flooding along the coast.
• Mangroves are already being utilized in some ecosystem-based
adaptation (EBA) projects, which seek to use nature to promote
resilience to climate impacts.
 Biodiversity
• Mangroves support a large number of threatened and endangered
species, such as the hawksbill turtle, the Bengal tiger, and several
water bird species, for example.
• Key habitats for many migratory birds that rely on the forests as
stop-overs along their migratory paths.
• Mangroves provide refuge for corals from ocean acidification,
thus contributing to the survival of these important species.
• They also contribute to the survival of other nearby ecosystems
through their sediment trapping and filtration processes. Mangroves
therefore indirectly support the species to which these adjacent
ecosystems provide a home.
• Mangroves may provide protection to corals from rising sea
temperatures as a result of climate change. Warmer ocean waters can
lead to deadly bleaching of corals, which also leads to the death of the
organisms that live within and depend upon coral reefs.
• Mangroves may prove to be very beneficial in protecting coral
biodiversity and their dependent species, through the provision of
shade and a buffer against rising ocean acidity.
Concerns
 Pollution
• Mangroves act as natural filters of runoff to the ocean.
• Urban runoff, agriculture and oil spills can interfere with the exchange
between mangrove roots and the atmosphere and soil.
• Oil can suffocate mangroves by coating their roots.
• An overabundance of nutrients like potassium and nitrogen from
urban runoff can disturb mangrove growth
• The pollution load varies for different mangrove forests as well as
among species. For example, Avicinnea is one of the most tolerant
species to heavy metals. In India, the A. marina has increased in
numbers, likely due to its resistance to pollution, thus causing a decline
in biodiversity.
 AGRICULTURE
• Cleared away for agricultural lands, often for palm oil plantations
and rice paddies
• Indonesia and Malaysia, two countries abundant in mangroves,
are responsible for 85% of the world’s palm oil production
• Affected by the chemicals and fertilizers used in on plantations
that runoff into the environment.
• Water may be diverted for crops, through dams and irrigation,
which may change the salinity or amount of water in mangrove
habitats.
 AQUACULTURE
• Mangrove deforestation.
• Most of the shrimp is farmed in southeast Asia where 90% of the world’s
aquaculture industry is located and where 70% of Indonesia’s 3.7 million hectares
of mangroves are damaged or degraded by aquaculture.
• Converting mangroves to aquaculture releases a lot of carbon dioxide as well.
Converting mangroves to shrimp farms will accelerate annual increase in blue
carbon emissions, or carbon stored in coastal and marine ecosystems.
• Fertilizers, waste and antibiotics are used in the farming process and can
negatively impact human health when shrimp is consumed and damage
surrounding mangroves.
• Shifting aquaculture
 Salinity & Sedimentation
• Dams, irrigation and other alterations to landscape can alter the
water, salinity and sedimentation levels of mangrove ecosystems which
can contribute to mangrove decline.
• Irrigation or a newly constructed dam may alter freshwater flow into
the mangroves, increasing its salinity.
• While mangroves have various adaptation techniques to deal with
salinity, such as filtering at the root level or storing excess salt in leaves
and shedding them, high salinity can cause dehydration, imbalances in
nutrition and changes in iron levels that can negatively impact
mangroves.
• A moderate amount of sedimentation is beneficial for mangroves,
bringing nutrients from upstream areas and increasing the
amount of soil that the mangroves grow on.
• High sedimentation rates exceeding 1 cm/year can be caused by
upstream deforestation.
• Too much sediment can smother the mangroves, blocking the
exchange of oxygen between the roots, soil and atmosphere
which can cause root damage or oxygen deficiency.
 Climate Change
• Climate change will lead to the degradation or destruction of
mangroves as a result of sea level rise, changing precipitation
patterns, higher temperatures, and stronger, more frequent
storms.
• Mangroves help to defend the coastline from sea level rise and
have their own mechanisms for adapting to a changing sea level.
However, they may not be able to keep pace with the rate of sea
level rise brought on by climate change, thereby leading to their
demise.
• Climate change will also lead to the destruction of coral reefs, which
protect mangroves from wave action and have a symbiotic
relationship with mangrove forests. The destruction of coral reefs will
further harm mangroves, and vice versa, leading to reduced coastal
protection and significant loss of biodiversity.
• Without mangroves, climate change impacts will be greater and more
destructive for coastal communities, who currently rely on mangrove
forests for protection from storms, sources of food, and livelihood
sustainability. The world can expect to see more climate-related deaths
because of mangrove loss.
 Coastal Development
• Coastal tourism increases, mangroves are cleared to make way for
infrastructure, businesses, hotels, and homes.
• Development in the coastal zone also leads to mangrove destruction indirectly
through the increased pollution, altered hydrology, and harmful human
contact that can result.
• Additionally, coastal development too close to mangrove habitat can limit
their ability to migrate landward as sea levels rise, diminishing their resilience
and therefore the resilience of the communities that they protect.
• Ironically, destruction of mangroves for development puts the new
construction at even higher risk to damage from storms, leading to increased
economic losses.
 Overfishing / Overharvesting
• Ever-increasing global and coastal population which creates higher
demand, an increase in poverty levels, globalization of industry
(which means that locals must compete with commercial
demands for the same resources), and increased coastal tourism.
• The current state of exploitation leads to food insecurity,
livelihood insecurity, and increased conflict among local
populations – in other words, a highly unsustainable state.
 Natural hazards
• Cyclones, typhoons and strong wave action
• Browsing and trampling by wildlife (e.g. deer, which are
numerous in the Middle Andamans) and livestock, especially in
areas close to human habitation
• Infestation by barnacles which attach to young seedlings,
interfering with respiration and photosynthesis and delaying
seedling growth.
• Damage by oysters to the young leaves and plumules
of Rhizophora and Ceriops plants
• Crabs, which attack young seedlings, girdle the root collars and eat the
fleshy tissues of the propagules.
• Gastropods that eat young leaves and flowers of mangroves, a big
problem in the Middle Andamans;
• Insect pests such as wood borers, caterpillars and beetles
• Weeds such as Acrostichum aureum and Acanthus species, which often
occupy deforested mangrove areas and restrict the regrowth
• Drying and mortality of mangrove trees
• Intensity of insect infestation is higher under mono-cropping but can
be controlled by raising mixed plantations
 Problems caused by humans
• Indiscriminate conversion of mangroves on public lands for
aquaculture (e.g. for prawn culture at Chorao, Goa), agriculture,
mining (e.g. along the Mapusa estuary in Goa), human habitation and
industrial purposes;
• Encroachment on publicly owned mangrove forest lands, e.g.
cultivation of paddy observed on government land along estuaries in
Goa, which involved uprooting of natural and planted seedlings;
• Illegal large-scale collection of mangrove fruits (Xylocarpus
granatum, Xylocarpus moluecensis, Nypa fruticans and Heritiera
littoralis), which hinders their natural regeneration.
• Discharge of industrial pollutants into creeks, rivers and estuaries,
which is a major problem in some regions of the world but is relatively
less severe in Goa and the Middle Andamans;
• The traditional use of dragnets in fishing, which often hampers
regeneration of mangroves because young seedlings get entangled in
the nets and are uprooted;
• Movement of barges (used in Goa for carrying iron ore) which give rise
to strong waves that sometimes damage the young mangrove
seedlings;
• Obstruction and diversion of water for culvert construction, e.g. at
Shyamkund in the Middle Andamans.
Coral reefs
Distribution of cold corals
Coral Bleaching
• When corals face stress by changes in conditions such as
temperature, light, or nutrients, they expel the symbiotic algae
zooxanthellae living in their tissues, causing them to turn
completely white. This phenomenon is called coral bleaching.
• The pale white colour is of the translucent tissues of calcium
carbonate which are visible due to the loss of pigment producing
zooxanthellae.
• Corals can recover if the stress-caused bleaching is not severe.
• Coral bleaching has occurred in the Caribbean, Indian, and Pacific
oceans on a regular basis.
• Rise in Sea Temperature: Most coral species live in waters close to the
warmest temperature they can tolerate i.e., a slight increase in ocean
temperature can harm corals. El Nino and global warming are elevating
the sea temperature.
• Ocean Acidification: Due to rise in carbon dioxide levels, oceans
absorb more carbon dioxide. This increases the acidity of ocean water
and inhibits the corals ability to create calcareous skeletons, which is
essential for their survival.
• Subaerial Exposure: Low tides, sea level drops and tectonic uplift can
result in sudden exposure of coral to the atmosphere.
• Solar radiation and ultraviolet radiation: Changes in tropical weather
patterns result in less cloud cover and more radiations which induce
coral bleaching.
• Infectious Diseases: Penetration of bacterium like vibrio shiloi inhibits
photosynthesis of zooxanthellae. These bacteria become more potent
with elevated sea temperatures.
• Chemical Pollution: Increased nutrient concentrations affect corals by
promoting phytoplankton growth, which in turn supports increased
numbers of organisms that compete with coral for space.
• Increased Sedimentation: Land clearing and coastal construction
result in high rates of erosion and a higher density of suspended
silt particles which can
– Smother corals when particles settle out (sedimentation),
– Reducing light availability (turbidity) and
– potentially reducing coral photosynthesis and growth.
• Human Induced Threats: Over-fishing, pollution from agricultural
and industrial runoff, coral mining, development of industrial
areas near coral ecosystems, use of sun screen lotions.
• Fresh Water Dilution: Following intense storms or heavy rainfall,
increased freshwater precipitation can cause rapid dilution,
decreasing water salinity. Such events, can cause bleaching in
small, near shore areas.
• Xenobiotics: Exposure of coral to chemical contaminants such as
copper, herbicides and oils can cause zooxanthellae loss. Such loss
is often highly localized, only occurring where xenobiotics (foreign
substances) come into contact with coral.
• Invasive species – Snowflake coral
 PYQ - 2018
• Consider the following statements:
1. Most of the world’s coral reefs are in tropical waters.
2. More than one—third of the world’s coral reefs are located in the
territories of Australia, Indonesia and Philippines.
3. Coral reefs host far more number of animal phyla than those hosted
by tropical rainforests.
Which of the statements given above is/are correct?
• (a) 1 and 2 only
(b) 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
 PYQ - 2022
• “Biorock technology” is talked about in which one of the
following situations?
• (a) Restoration of damaged coral reefs
(b) Development of building materials using plant residues
(c) Identification of areas for exploration/extraction of shale gas
(d) Providing salt licks for wild animals in forests/protected areas
 Wetlands
• According to most widespread definition wetlands are defined as:
"lands transitional between terrestrial and aquatic eco-systems
where the water table is usually at or near the surface or the land
is covered by shallow water".
• Ramsar Convention on Wetlands define wetlands as: "areas of
marsh, fen, peatland or water, whether natural or artificial,
permanent or temporary, with water that is static or flowing,
fresh, brackish or salt, including areas of marine water the depth
of which at low tide does not exceed six metres".
Functions
• Water storage;
• Storm protection and flood mitigation
• Drought buffering
• Shoreline stabilization and erosion control
• Groundwater recharge and discharge
• Water purification
• Retention of nutrients, sediments, and pollutants
• Stabilization of local climate conditions, particularly rainfall and
temperature
Values
• Economic benefits, including
– Water supply (quantity and quality)
– Fisheries (over two thirds of the world’s fish harvest is linked to the health of wetland
areas)
– Agriculture, through the maintenance of water tables and nutrient retention in
floodplains
– Timber and other building materials
– Energy resources, such as peat and plant matter
– Wildlife resources
– Transport
– Other wetland products, including herbal medicines
– Recreation and tourism opportunities.
– It is estimated that more than a billion livelihoods worldwide are wholly or largely
dependent on wetlands
• Culture and religion
 PYQ - 2022
• “If rainforests and tropical forests are the lungs of the Earth, then
surely wetlands function as its kidneys.” Which one of the following
functions of wetlands best reflects the above statement?
• (a) The water cycle in wetlands involves surface runoff, subsoil
percolation and evaporation.
(b) Algae form the nutrient base upon which fish, crustaceans,
molluscs, birds, reptiles and mammals thrive.
(c) Wetlands play a vital role in maintaining sedimentation balance and
soil stabilization.
(d) Aquatic plants absorb heavy metals and excess nutrients.
 Ramsar
• The Convention on Wetlands is an intergovernmental treaty adopted
on 2 February 1971 in the Iranian city of Ramsar, on the southern
shore of the Caspian Sea.
• Major obligations of countries which are party to the Convention are:
– Designate wetlands for inclusion in the List of Wetlands of International
Importance.
– Promote, as far as possible, the wise use of wetlands in their territory.
– Promote international cooperation especially with regard to transboundary
wetlands, shared water systems, and shared species.
– Create wetland reserves.
• February 2 is celebrated as International Wetlands Day as the Ramsar
Convention was signed on February 2, 1971.
• The Ramsar Convention works with the collaboration of the following
organizations:
– International Union for Conservation of Nature (IUCN).
– Birdlife International.
– International Water Management Institute (IWMI).
– Wetlands International.
– Wildfowl & Wetlands Trust (WWT)
– WWF International
• The United Nations Educational, Scientific and Cultural Organization (UNESCO)
serves as Depositary for the Convention, but the Ramsar Convention is not part
of the United Nations and UNESCO.
Five major wetland types
• Marine (coastal wetlands including coastal lagoons, rocky shores, seagrass
beds and coral reefs)
• Estuarine (including deltas, tidal marshes and mudflats, and mangrove
swamps)
• Lacustrine (wetlands associated with lakes)
• Riverine (wetlands along rivers and streams)
• Palustrine (meaning “marshy” – marshes, swamps and bogs).
 Ramsar Classification System for Wetland Type – for
reference only
Marine/Coastal Wetlands
• kelp beds, sea-grass beds, tropical marine meadows, Coral reefs.
• Rocky offshore islands, sea cliffs, sand bars, spits Intertidal mud,
sand or salt flats.
• Intertidal marshes, mangrove swamps, nipah swamps, lagoons.
• Karst and other subterranean hydrological systems.
 Inland Wetlands
• Deltas, rivers, waterfalls, Permanent freshwater lakes, oxbow lakes.
• Seasonal/intermittent freshwater lakes includes floodplain lakes.
• Permanent freshwater marshes/pools; ponds (below 8 ha), marshes
and swamps on inorganic soils; with emergent vegetation water-logged
for at least most of the growing season.
• Peat lands
• Alpine wetlands, Tundra wetlands, temporary waters from snowmelt.
• Freshwater springs; oases.
• Geothermal wetlands.
 Human-made wetlands

• Aquaculture ponds
• Irrigated land
• Salt exploitation sites; salt pans
• Water storage areas; reservoirs/dams.
• Excavations; mining pools.
• Waste water treatment areas
• Canals and drainage channels.
• The world’s first Site – Cobourg Peninsula in Australia
• The largest Sites are Ngiri-Tumba-Maindombe in the Democratic
Republic of Congo and Queen Maud Gulf in Canada
• The countries with the most Sites are the United Kingdom with
170 and Mexico with 142.
• Bolivia has the largest area under Ramsar protection; Canada,
Chad, Congo and the Russian Federation.
• What is wetland? Explain the Ramsar concept of ‘wise use’ in the
context of wetland conservation. Cite two examples of Ramsar
sites from India. (150 words, 10 marks, 2018)
• Wise use of wetlands is the maintenance of their ecological
character, achieved through the implementation of ecosystem
approaches , within the context of sustainable development.
• “The wise use of wetlands is their sustainable utilization for the
benefit of mankind in a way compatible with the maintenance of
the natural properties of the ecosystem”
• Ramsar “Wise use concept” requires that wetlands’ ecological character should be
maintained within the framework of sustainable development. This concept
recognizes that:
• Developmental activities are inevitable in wetland areas such as construction of
roads, electricity infrastructure, schools and hospitals for poor families.
• Economic activities are also inevitable in wetland areas such as fisheries, farming
and tourism.
• Such activities aid in human development and economic development in a wetland
area.
• And for these activities, wetland’s land, water and bio-resources will have to be used.
• However, these resources should not be used in a manner that wetland’s ecological
character is harmed.
The practical applications of “Wise Use” concept are as following:
• Use of Water: Farmers in wetland region require freshwater for cultivation of paddy,
fruits and vegetables. But, it should not lead to overexploitation of freshwater else
wetland’s regenerative capacity will suffer. Fish, reptiles and amphibians will die.
Therefore, Government may impose legal ‘upper limits / ceiling’ on water use.
• Use of Land: Wetlands purify air and water, they moderate adverse weather impacts
and thus protect human health. However, mining, infrastructure and transportation
services harm wetlands, and thereby indirectly harm human health. Hence, the ‘land’
of wetland should be generally not used for such activities.
• Use of Biomass: Fishing is one of the primary occupation of people in Wetland area.
But excessive fishing, especially during reproduction season will harm wetland’s
foodweb. Hence, government may impose restriction and encourage aquaculture
and ‘rice-fish’ management practices.
Criteria for Identifying Wetlands of International Importance – for
reference only
• Group A. Sites containing representative, rare or unique wetland
types - natural or near-natural wetland type.
• Group B. Sites of international importance for conserving
biological diversity
• Criteria based on species and ecological communities
• Criterion 2: supports vulnerable, endangered, or critically
endangered species or threatened ecological communities.
• Criterion 3: supports populations of plant and/or animal species
important for maintaining the biodiversity.
• Criterion 4: supports plant and/or animal species at a critical stage
in their life cycles, or provides refuge during adverse conditions
Specific criteria based on water birds
• Criterion 5: regularly supports 20,000 or more water birds.
• Criterion 6: regularly supports 1% of the individuals in a
population of one species or subspecies of water bird.
Specific criteria based on fish
• Criterion 7: supports a significant proportion of indigenous fish
subspecies, species or families, life-history stages, species
interactions and/or populations.
• Criterion 8: important source of food for fishes, spawning ground,
nursery and/or migration path.
Specific criterion based on other taxa
• Criterion 9: regularly supports 1% of the individuals in a
population of one species or subspecies of wetland-dependent
non-avian animal species.
 The Montreux Record
• The Montreux Record is a register of wetland sites on the List of
Wetlands of International Importance where changes in ecological
character have occurred, are occurring, or are likely to occur as a result
of technological developments, pollution or other human interference.
It is maintained as part of the Ramsar List.
• Indian Entries
– Keoladeo National Park, Rajasthan
– Loktak Lake, Manipur
– Chilka Lake (Odisha) was placed in the record but was later removed from it.
 Wetland (Conservation and Management) Rules, 2017

• The updated rules will supersede the 2010 rules.

• Constitution of State Wetland Authority: in every state and Union
Territory to be headed by the Environment Minister of the
respective state.
– One expert each in the fields of hydrology, socioeconomics, landscape
planning, fisheries, and wetland ecology.
– They will determine the ‘wise use principle’ that shall govern the
management of wetlands.
• The SWA shall:
– Develop a comprehensive list of activities to be regulated and permitted within
notified wetlands and their zone of influence.
– Recommend additional prohibited activities for specified wetlands.
– Define strategies for better use of wetlands.
– Recommend measures for wetland conservation and for raising awareness
among its stakeholders and local communities with respect to the importance
of wetlands.

Setting up of National Wetland committee: NWC will replace the Central

Wetlands Regulatory Authority and shall be headed by the secretary to
MoEFCC.
 National Wetland Committee (NWC) – Purpose
• Monitoring the implementation of rules
• Advising the central government on appropriate policies and action
programs for conservation and wise use of wetlands.
• Recommending designation of Wetlands of International importance
under the Ramsar Convention.
• Advice collaboration with international agencies on issues related to
wetlands.
• Setting up a digital inventory: It is compulsory for all the state
authorities to prepare a list of all the wetlands. Based on this, a digital
inventory for wetlands will be created and updated every 10 years.
• Prohibited activities: The rules prohibit the discharge of unwanted
waste from villages, towns, cities, industries, etc., and solid waste
dumping into the wetlands. Conversion of wetland area for non-
wetland purposes, construction of a permanent structure on
notified wetlands is banned.
• These rules shall apply to wetlands notified by the State
government, Central government, Union territory Administrations,
and those classified as wetlands of international importance
under the Ramsar convention.
Changes in Policy
• The 2017 Wetland Rules have been criticised for doing away with strong
wetland monitoring systems and omitting important wetland types.
• The 2010 and 2017 Rules for wetlands both emphasise that the ecological
character of wetlands ought to be maintained for their conservation.
• ‘Ecological character’ refers to processes and components which make the
wetland a particular, and sometimes unique, ecosystem.
• Under the new Rules, no authority to issue directions, which are binding in
nature to desist from any activity detrimental to wetland conservation, has
been prescribed to State wetland authorities.
 Challenges in the New Policy
• Challenges ahead in identifying wetlands
• Understanding the historic spread and ecological character will be important.
• In the 2010 Rules, some related criteria were made explicit, such as natural
beauty, ecological sensitivity, genetic diversity, historical value, etc. These have
been omitted in the 2017 Rules. There are a few reasons why this is
problematic.
• First, there is multiple interest around wetlands. Multiple interests also have
governance needs, and this makes it absolutely necessary to identify and map
these multiple uses.
• Secondly, it is crucial to identify ecological criteria so that the wetlands’
character can be maintained.
• The key to wetland conservation is but conserving or managing the
integrity of the wetland ecosystem.
• Finally, restriction of activities on wetlands will be done as per the
principle of ‘wise use’, determined by the State wetland authority.
Whether wise use will include maintaining ecological character
remains to be seen.
• Salt pans as ‘wetlands’ have been omitted from the new Rules.
• They were identified as wetlands in the 2010 Rules, as they are often
important sites of migratory birds and other forms of biodiversity.
• The omission in the 2017 Rules suggests that while saltpans do exist as
wetlands, they do not require any conservation or ecological balance.
 PYQ - 2019
• Consider the following statements:
1. Under Ramsar Convention, it is mandatory on the part of the Government of India
to protect and conserve all the wetlands in the territory of India.
2. The Wetlands (Conservation and Management) Rules, 2010 were framed by the
Government of India based on the recommendations of Ramsar Convention.
3. The Wetlands (Conservation and Management) Rules, 2010 also encompass the
drainage area or catchment regions of the wetlands as determined by the authority.
Which of the statements given above is/are correct?
(a) 1 and 2 only
(b) 2 and 3 only
(c) 3 only
(d) 1, 2 and 3