10. Steps in decomposition
Fragmentation
Leaching
Catabolism
Humification
Mineralization
NUTRIENT CYCLE
• A nutrient cycle (or ecological
recycling) is the movement and
exchange
of organic and inorganic matter back
into the production of living matter.
• The process is regulated by food
web pathways
that decompose matter into mineral
nutrients. Nutrient cycles occur
within ecosystems.
11.
12.
13.
14.
15.
16.
17.
18.
19. Food chains were first introduced by the african-arab scientist and
philosopher al-jahiz in the 9th century and later in a book published in 1927
by Charles Elton, who also introduced the food web concept.
Flow of energy in an ecosystem is one way process.The sequence of
organism through which the energy flows, is known as food chain. A food
chain also shows how the organisms are related with each other by the food
they eat. Each level of a food chain represents a different trophic level.
A common metric used to quantify food web trophic structure is food chain
length
21. (I)GRAZING FOOD CHAIN
• This type of food chain starts from the living green plants
goes to grazing herbivores, and on to carnivores. Ecosystems
with such type of food chain are directly dependent on entry
of solar energy.
• This type of chain thus depends on autotrophic energy(Energy
from photosynthesis & chemosynthesis) capture and the
movement of this captured energy to herbivores.
• The phytoplankton's →zooplanktons →Fish sequence or the
grasses →rabbit →Fox sequences are the examples, of
grazing food chain.
22. (II)DETRITUS FOOD CHAIN
• This type of food chain goes from dead organic matter into
microorganisms and then to organisms feeding on detritus
(detrivores) and their predators. Such ecosystems are thus less
dependent on direct solar energy.
• These depend chiefly on the entry of organic matter produced in
another system. For example, such type of food chain operates in the
decomposing accumulated litter in a temperate forest.
25. Autotroph Heterotroph
Produce own food Yes No
Food chain level Primary Secondary and tertiary
Types Photoautotroph, Chemoautotroph Photoheterotroph,
Chemoheterotroph
Examples Plants, algae, and some bacteria Herbivores, omnivores, and
carnivores
Definition Plants are the prime example
of autotrophs, using
photosynthesis
All other organisms must make use
of food that comes from other
organisms in the form of fats,
carbohydrates and proteins.These
organisms which feed on others
are called heterotrophs.
What or How they eat ? Produce their own food for energy. They eat other organisms to get
proteins and energy.
26. TYPES OF FOOD WEB
• These food webs simply indicate a
feeding relationship.
TOPOLOGICAL
WEBS
• Flow webs, include information on
the strength of the feeding
interaction.
FLOWWEBS
• In interaction the arrows show how
one group influences another.
INTERACTION
WEB
27. • Soil food web
• Aquatic food web
• Food web in forest
• Food web of grassland
• Food web in terrestrial and aquatic ecosystem
DIFFERENT FOOD WEBS
34. Pyramid of Biomass
• The biomass of the members of the food chain
present at any one time forms the pyramid of the
biomass. Pyramid of biomass indicates
decrease of biomass in each tropical level from
base to apex.
36. ABIOTIC FACTORS BIOTIC FACTORS
Sun: Provides light for photosynthesis Producers: Plants that are a source of food
and/or O2
Soil: Provides minerals and nutrients for
plants(producers) to grow.
Primary Consumers: Herbivores that feed on
producers
Water: Helps in Photosynthesis, hydration of
flora and fauna, maintains optimum climate
Secondary Consumers: Carnivores that feed on
primary consumers and/ or other secondary
consumers
Air: Provides CO2 for photosynthesis and O2
for respiration
Decomposers: Organisms that decompose
dead matter and supply minerals and other
substances for the improvement to the soil
39. DECIDUOUS FORESTS TROPICAL
RAINFOREST
Trees here have large,
flat leaves that drop off
in the fall and new
leaves grow in spring
These trees grow in
places that are hot and
wet all year.
Leaves change colour
with the seasons
The forest has three
layers: canopy,
understory, forest floor.
These grow in places
with hot, wet summers
and cool, dry winters.
Trees are very tall and
leaves are always green
40. COASTAL FORESTS CONIFEROUS FOREST
Grows in places where
there is lots of rain.
Grows in places with
very cold winters and
cool summers.
Temperature is not too
hot or too cold, just
cool.
The leaves look like
needles so they don’t
need much water
Has three layers:
canopy, understory,
forest floor
Seeds grow in cones.
Get less rain than all the
other forests
41. FEATURES - FOREST CANOPY/ FOREST FLOOR / FOREST SOIL
Forest Canopy FOREST FLOOR FOREST SOIL
• Since trees reach different heights
in different forests and there can
be many layers of trees, defining
the canopy is a difficult task.
• However, the canopy is
considered the uppermost layer of
plants, including all of the
additional plant and animals living
in that layer.
• The maximum height of the
canopy can vary dramatically.
• The forest floor is where
decomposition takes place.
Decomposition is the process by
which fungi and microorganisms
break down dead plants and
animals and recycle essential
materials and nutrients.
• Also, many of the largest
rainforest animals are found on
the forest floor.
The most common soil definition is
"Soils as a media for plant growth“
• Recycling system for nutrients
and organic waste
• Modifier of the atmosphere
• Habitat for soil organisms
• Engineering medium
• System for water supply and
purification
44. CLIMATE & FAUNA
• The desert is the hottest biome on Earth. It
also has its extremes. It can be over 50
degrees during the day and below 32
degrees at night.
• Less than 25 cm or rainfall every year. The
amount of rainfall varies, but when it rain
• After a storm, the desert may not see any
rain for weeks or months.
• The animals include snakes, owls, mice,
armadillo lizards, fennec foxes, gila
monsters, bats, and vultures.
45. FLORA LIFE OF DESERTS
• There are several plants that are able to survive
in the desert.
• Most plants survive by their long roots to reach
underground water sources.
• A Variety of cactuses - Prickly Pear, Dragon
Tree,Octillo Plant, Desert Spoon,Boojum etc.
• Some desert flora include shrubs eg. Prickly
Pearls, Desert Holly and the Brittlebush.
• Most desert plants are drought- or salt-tolerant
eg. Xerophytes
• Other desert plants have long Taproots eg.
Turnip
48. • The temperate grasslands (also called prairies,
steppes, pampas and veld) are found in all four
corners of the world
• The largest expanse is the Great Plains of North
America
• Grasslands are defined by their semiarid climates,
with 10-30 inches of precipitation annually (mostly
in snow form depending on latitude)
• Temperatures range from -40 to over 70 F
Butterfly weed
Prairie dog
49. • Also known as tropical grasslands. They are
found in a wide band on either side of the
equator on the edges of tropical rainforests.
• The savanna is characterized by very hot
temperatures and distinctive wet and dry
periods
• During the winter less than 4 inches of rain
can fall but they can receive over 25 inches
during the summer months
Gum-Arabic tree
Emu
50. • Savanna gets more rainfall(20-50inches)
than a temperate grassland(20-35inches)
annually
• The grass grows better on Savanna
Grassland than in the Temperate Grassland
• The soils in Temperate Grassland is rich in
Nutrient and is suitable for cultivation
where as in Savanna, Soils are frequently
nutrient poor and dry but contain many
valuable minerals
Savanna Grassland
Temperate Grassland
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54.
55. 1-Ponds Ecosystem 2-Fresh water Ecosystem 3-Marine ecosystem
These are a specific type of
freshwater ecosystems that are
largely based on
the autotroph algae which provide
the base trophic level for all life in
the area.
Freshwater ecosystems are a subset
of Earth's aquatic ecosystems.
Seawater has an average salinity of
35 parts per thousand of water.
Actual salinity varies among
different marine ecosystems.
The largest predator in a pond
ecosystem will normally be a fish and
in-between range smaller insects
and microorganisms.
They
include lakes and ponds, rivers, strea
ms and springs, and wetlands.
Marine ecosystems cover
approximately 71% of the Earth's
surface and contain approximately
97% of the planet's water.They
generate 32% of the world's
net primary production.
It may have a scale of organisms
from small bacteria to big creatures
like water snakes, beetles, water
bugs, frogs, tadpoles, and turtles.
This is important for the
environment.
They can be contrasted with marine
ecosystems, which have a
larger salt content.
They are distinguished from
freshwater ecosystems by the
presence of dissolved compounds,
especially salts, in the water.
Approximately 85% of the dissolved
materials
in seawater are sodium and chlorine
