Tropical rainforests are defined by high precipitation, temperature, and humidity. They support a high level of biodiversity despite covering a small area of the planet. Plants and animals in rainforests have adapted to the dense canopy structure through traits like buttresses, prop roots, epiphytic growth, and camouflage. However, human activities like deforestation, overexploitation, mining, agriculture, and introducing invasive species are degrading many rainforests and reducing biodiversity.

1. TROPICAL RAINFORESTS
Defining Characteristics
Agra, Joseph Yzrael
Arsenio, Jesher Joshua

2. Introduction
• Rain forests are called "cradles of diversity".
• They spawn and support 50 percent of all living
organisms on Earth even though they cover less than 5%
of Earth's surface.
• A rainforest's importance is truly incomprehensible
when it comes to species diversity.

3. Tropical Rainforests

4. Tropical Rainforests

5. Introduction
• Sunlight is a major limiting factor.
• There is no annual rhythm to the forest; rather each
species has to evolve its own flowering and fruiting
seasons.
• A variety of strategies have been successful in the
struggle to reach light to adapt to the low intensity of
light beneath the canopy.

6. Distribution

7. Location
• Tropical rainforests mainly occur inside the World's
equatorial regions.
• Tropical rainforests are restricted to the small land area
between the latitudes 22.5° North and 22.5° South of the
equator - between the Tropic of Capricorn and the Tropic
of Cancer.

8. Location
• The largest unbroken stretch of rainforest is found in the
Amazon river basin of South America.
• Over half of this forest lies in Brazil, which holds about
one-third of the world's remaining tropical rainforests.
• Another 20% of the world's remaining rainforest exists
in Indonesia and Congo Basin, while the balance of the
world's rainforests are scattered around the globe in
tropical regions.

9. Precipitation and Temperature

10. Precipitation and Temperature
• An important characteristic of tropical rainforests is
moisture.
• Tropical rainforests usually lie in tropical zones where
solar energy produces frequent rainstorms.

11. Precipitation and Temperature
• Rainforests are subject to heavy rainfall, at least 80", and
in some areas over 430" of rain each year.
• High volumes of rain in rainforests can cause local
streams and creeks to rise 10-20 feet over the course of
two hours.
• Mean monthly temperatures are above 64 ° F;

12. Precipitation and Temperature
• There is usually a brief season of reduced precipitation.
In monsoonal areas, there is a real dry season, but that is
more than compressed for with abundant precipitation
the rest of the year.

13. Structure
• Most of life in the tropical rainforest exists vertically in
the trees, above the shaded forest floor - in the layers.
• Each tropical rainforest canopy layer harbors its own
unique plant and animal species interacting with the
ecosystem around them.
• The primary tropical rainforest is divided into at least
five layers: the overstory, the true canopy, the
understory, the shrub layer, and the forest floor.

14. Structure

15. Forest Floor
• The area is mostly shade. Barely and direct light
reaches this level, thus almost no plants grow in this
area as a result.
• Since hardly any sun reaches the forest floor things
begin to decay quickly.
• A leaf that might take one year to decompose in a
regular climate will disappear in 6 weeks.
• Giant anteaters live in this layer.

16. Forest Floor

17. Understory Layer
• Little sunshine reaches this area so the plants have to
grow larger leaves to reach the sunlight.
• The plants in this area seldom grow to 12 feet.
• Many animals live here including jaguars, red-eyed tree
frogs and leopards. There is a large concentration of
insects here.

18. Understory Layer

19. Canopy Layer
• This is the primary layer of the forest and forms a roof
over the two remaining layers.
• Most canopy trees have smooth, oval leaves that come
to a point. It's a maze of leaves and branches.
• Many animals live in this area since food is abundant.
Those animals include: snakes, toucans and treefrogs.

20. Canopy Layer

21. Emergent Layer
• The tallest trees are the emergents, towering as much
as 200 feet above the forest floor with trunks that
measure up to 16 feet around.
• Most of these trees are broad-leaved, hardwood
evergreens. Sunlight is plentiful up here.
• Animals found are eagles, monkeys, bats and
butterflies.

22. Emergent Layer

23. Biotic Factors

24. Animal Adaptations
• The tropical rainforest is a wet, warm forest of
trees that grow very closely together. The canopy
in the rainforest can release gallons of water
each year into the atmosphere. The resulting
moisture hangs over the forest, keeping the
interior warm and humid. Animals living in the
rainforest have had to adapt to these wet, warm
conditions and have had to find niches that
allow them to thrive. They do this by altering
species characteristics to fit the tall trees, the
constant humidity and the rainforest floor.

25. Animals in the canopy: Primates
• Long arms to swing from tree to tree in the
canopy, avoiding predators on the ground

26. The Aye-Aye
• Nocturnal feeder, to avoid dangerous predators
by day.
• Large eyes allow more light in at night
• Builds nests on top of trees in the canopy
• Have a longer middle finger to reach within
holes in tree trunks

28. Birds
• Have large beaks to lose more heat. Birds in
tropical regions can afford to have larger beaks
than birds in temperate regions.
• Differently sized beaks allow for different
adaptations according to use

29. • Large beaks for cutting up pieces of fruit and
nuts
▫ Toucan

30. • Hooked beaks to tear small prey apart
▫ Philippine Eagle

31. • Long thin beaks to reach within small holes on
trees
▫ Black-cheeked Woodpecker

32. Insects
• Camouflage allow longer survivability
▫ Leaf-mimicking treehopper

33. Farming
• Leafcutter ants climb tall trees and cut small
pieces of leaves which they carry back to their
nest. The leaf pieces they carry are about 50
times their weight. The ants bury the leaf
pieces, and the combination of the leaves and
the ants' saliva encourages the growth of a
fungus, which is the only food these ants eat.

35. Predators
• Camouflage allow predators to hunt undetected
• They blend with the color of the leaves and trees

36. • Jaguar’s spots

37. • Amazon Horned Frog

38. Bright Colors
• Warn prospective predators to stay away from
them
▫ Poison arrow frogs
▫ Native Central and South American tribes used to
wipe the ends of their arrows onto the frog's skin
to make their arrows deadly poisonous.

40. Plant Adaptations
• Bark
▫ In drier, temperate deciduous forests a thick bark
helps to limit moisture evaporation from the tree's
trunk. Since this is not a concern in the high
humidity of tropical rainforests, most trees have a
thin, smooth bark.

42. Lianas
• Lianas are climbing woody vines that drape
rainforest trees. They have adapted to life in the
rainforest by having their roots in the ground
and climbing high into the tree canopy to reach
available sunlight. Many lianas start life in the
rainforest canopy and send roots down to the
ground.

44. Drip tips
• The leaves of forest trees have adapted to cope
with exceptionally high rainfall. Many tropical
rainforest leaves have a drip tip. It is thought
that these drip tips enable rain drops to run off
quickly. Plants need to shed water to avoid
growth of fungus and bacteria in the warm, wet
tropical rainforest.

46. Buttresses
• Many large trees have massive ridges near the
base that can rise 30 feet high before blending
into the trunk. Buttress roots provide extra
stability, especially since roots of tropical
rainforest trees are not typically as deep as those
of trees in temperate zones.

48. Prop and stilt roots
• Prop and stilt roots help give support and are
characteristic of tropical palms growing in
shallow, wet soils. Although the tree grows fairly
slowly, these above-ground roots can grow 28
inches a month.

50. Epiphytes
• Epiphytes are plants that live on the surface of
other plants, especially the trunk and branches.
They grow on trees to take advantage of the
sunlight in the canopy. Most are
orchids, bromeliads, ferns, and Philodendron
relatives. Tiny plants called epiphylls, mostly
mosses, liverworts and lichens, live on the
surface of leaves.

52. Pitcher plants
• Pitcher plant vines in the family Nepenthaceae
have leaves that form a pitcher, complete with a
lid. Sweet or foul-smelling nectar in the pitcher
attracts insects, especially ants and flies, that
lose their grip on the slick sides and fall into the
liquid. Downward-pointing hairs inside the
pitcher prevent the insects' escape. The insects
are digested by the plants and provide nutrients.
Pitcher plants are not epiphytes but climbers
rooted in the soil.

54. Abiotic Factors
• Abiotic factors are those non-living, inert
elements of an ecosystem that interact with the
living components. The way that the abiotic
factors interact with a particular ecosystem
determines the types of plants and animals that
can live in that ecosystem. The abiotic factors of
the rainforest biome are the amount of
water, sunlight, temperature and soil, and
climate.

55. Water
• The rainforest normally receives no less than 80
inches of rainfall annually. This is one of the
most visible abiotic factors of the rain forest. The
air under the canopy layer is still and very humid
as a result. The trees also give off water through
their leaves in a process called transpiration.
This process can account for as much as half of
the precipitation in a rain forest.

57. • Transpiration – loss of water vapor from parts of
plants (leaves, stems, roots)

58. Sunlight
• Light is the main source of energy in the rain
forest. Plants use chlorophyll to change energy
from sunlight into chemical energy through
photosynthesis.

59. • In the rain forest, most of the sunlight is
absorbed by the upper canopy, made up of trees
between 60 and 100 feet tall.

60. • Only about 1 percent of the sunlight that strikes
the top of the rain forest reaches to the forest
floor. Plants are adapted to these conditions --
plants in the understory have large leaves to
better absorb the weaker light, while those in the
upper canopy have small leaves to reduce water
loss in the strong sunlight.

62. Soil
• The rain forest soil is shallow and thin, with few
nutrients and soluble minerals. The heavy rains
common in rain forests wash away the nutrients
in the soil. As a result, the nutrients in a rain
forest are largely found in the roots and leaves of
living plants, and in the decomposing vegetation
on the forest floor, rather than in the soil.

64. Temperature and Climate
• The temperature in a rain forest rarely gets
higher than 93 degrees F or drops below 68
degrees. The high and constant temperatures
increase the rate of evaporation and keep
humidity high. Warm temperatures also allow
growth to occur quickly. As animal and insect
life does not need to expend energy keeping
warm, it can spend more energy on reproduction
and reproduce with greater frequency. This
explains some of the abundance of life in the
rain forest.

65. • This temperature is attributed to the location of
rainforests. They are near the equator, and so
they receive a high amount of solar radiation.
• Humid because of high amount of rainfall and
solar energy.
• Stays mostly the same all throughout the year.

66. TROPICAL RAINFORESTS:
HUMAN IMPACT

67. HUMAN IMPACT
• Several human activities have lead to the degredation of
many tropical rainforest biomes.
• These are mainly:
▫ Deforestation
▫ Overexploitation
▫ Introduction of Non-native Species

68. HUMAN IMPACT
I. DEFORESTATION
▫ In general, deforestation, for whatever cause leads to
habitat fragmentation and species displacement.
▫ This disrupts the forest ecosystem and might
ultimately lead to a loss of biodiversity.

69. HUMAN IMPACT
I. DEFORESTATION
▫ On a larger scale, this causes a reduction in the
number of plant life that capable of converting carbon
dioxide in the atmosphere into oxygen, thus
contributing to global warming.

70. HUMAN IMPACT
CAUSES OF DEFORESTATION
▫ Mining and Industry
 Mining and industrial development lead to direct
forest loss due to the clearing of land to establish
projects.
 Roads are constructed through previously
inaccessible land, opening up and fragmenting the
rainforest.

71. HUMAN IMPACT
CAUSES OF DEFORESTATION
▫ Mining and Industry
 Severe water, air and land pollution occurs from
mining and industry.

72. HUMAN IMPACT

73. HUMAN IMPACT
CAUSES OF DEFORESTATION
▫ Damming and Irrigation
 The construction of dams destroys the forest and
often displaces organisms from their original habitat.
 The rates of waterborne diseases increase rapidly.
 Dams also trap silt, which may lead to coastal
errosion.

74. HUMAN IMPACT
CAUSES OF DEFORESTATION
▫ Damming and Irrigation
 The irrigation and industrial projects powered by
dams leads to salination of soils and industry leads
to pollution.

75. HUMAN IMPACT

76. HUMAN IMPACT
CAUSES OF DEFORESTATION
▫ Land Conversion
 Forests are cut down in order to make way for the
conversion of forest land to agricultural
areas, ranches, residential spaces or for other urban
uses.
 Continual agricultural use often renders the soil
extensively depleted which severely decreases the
probability of recovery for these forests.

77. HUMAN IMPACT
CAUSES OF DEFORESTATION
▫ Land Conversion
 Urbanization upstream from or near forests may
introduce pollutants which would endanger and
damage the forest ecosystem.

78. HUMAN IMPACT

79. HUMAN IMPACT
II. OVEREXPLOITATION
▫ Overexploitation of any resource, through whatever
means, disrupts the balance of the forest ecosystem.
▫ Depending on what type of organisms are taken
out, the ecological impact may vary (i.e. keystone vs
dominant species).

80. HUMAN IMPACT
REASONS FOR OVEREXPLOITATION
▫ Logging
 Large areas of rainforest are destroyed in order to
make use of several trees selected for their timber.
 The heavy machinery used to penetrate the forests
causes extensive damage. These may also be a
source of pollution.

81. HUMAN IMPACT

82. HUMAN IMPACT
REASONS FOR OVEREXPLOITATION
▫ Tourism
 Rainforests are being threatened by excessive, poorly
managed and loosely regulated tourism.
 Tourism is not inherently a detrimental, conversely
tourism, specifically eco-tourism, serves a noble
purpose of informing tourists of environmental
issues and advocacies.

83. HUMAN IMPACT
REASONS FOR OVEREXPLOITATION
▫ Tourism
 However, tourism is often used to make easy profit.
Some forested areas are opened without prior
enlistment of proper management strategies.
 If left as such, this may leave the rainforest exposed
to physical pollutants (i.e. littering).

84. HUMAN IMPACT
REASONS FOR OVEREXPLOITATION
▫ Tourism
 Infrastructure development and noise pollution may
also disturb the inhabiting species and may disrupt
the ecosystem.
 There is also a heightened risk of disease
introduction.

85. HUMAN IMPACT

86. HUMAN IMPACT
REASONS FOR OVEREXPLOITATION
▫ Poaching and Hunting
 Causes a decline in tropical rainforest biodiversity.
 Some species are hunted merely for their
fur, plumage or other parts while others are
captured, shipped and sold as pets.

87. HUMAN IMPACT
REASONS FOR OVEREXPLOITATION
▫ Poaching and Hunting
 This greatly disrupts the the forests
ecosystems, often driving these species and several
other species that are dependent on them to the
brink of extinction.

88. HUMAN IMPACT

89. HUMAN IMPACT
II. INTRODUCTION OF INVASIVE SPECIES
▫ An invasive species is a species living outside its native
distributional range, which has arrived there by human
activity, either deliberate or accidental.
▫ Most introduced species are damaging to the
ecosystem they are introduced into since they may
invade ecological niches and thus may displace native
species.

90. HUMAN IMPACT
III. INTRODUCTION OF INVASIVE SPECIES
▫ Only several introductions have resulted with no
negative effects and even fewer have been proven to
be, in fact, beneficial.

91. HUMAN IMPACT
SUMMARY
• Deforestation • Introduction of Invasive
▫ Mining and Industry Species
▫ Damming and
Irrigation
▫ Land Conversion
• Overexploitation
▫ Logging
▫ Tourism
▫ Poaching and Hunting