Biosphere and biomes & its types.

1. Biosphere
 Ch muneeb
kamran

2. Biosphere
 The biosphere is the life zone of the Earth and includes all
living organisms (animals, plants and microorganisms)
and all organic matter yet to be decomposed.
 The biosphere is composed of biomes.
 Biome is a large region with specific type of climate and
living organisms.
 A biome is characterized by plant life present in it and it's
boundary is defined by the regional climate

3. Biome
There are four major types of biomes:
 Deserts
 Grasslands
 Forests
 Tundra

4. Desert Biomes
 Desert Biome
 Deserts cover about one fifth of the Earth's surface
 Deserts occur where rainfall is less than 50 cm/year
 Deserts have specialized vegetation and animals
 Soils often have nutrients but they need only water to
become very productive
 The dominant animals of warm deserts are non-
mammalian vertebrates, such as reptiles

5. Desert Biome
There are four major types of deserts:
 Hot and dry
 Semiarid
 Coastal
 Cold
 Hot and Dry
 Mean annual temperatures range from 20-25° C
 The mean minimum and maximum temp. ranges from -18 to
49° C
 Sometimes rain starts falling and evaporates before reaching
the ground
 Average rainfall is less than 1.5 cm

6. Desert Biome
 Semiarid Desert
 The average rainfall ranges from 2-4 cm annually
 Temperature range is 10 to 38 ° C
 Coastal Desert
 The maximum annual temperature is about 4 to 35 ° C
 The average annual rainfall measures 8-13 cm
 Cold Desert
 These deserts are characterized by cold winters
with snowfall and high overall rainfall throughout
the winter and occasionally over the summer
 The mean winter temperature is between -2 to 4° C
and the mean summer temperature is between 21-
26° C.

7. Grass lands
 Grasslands
 Lands dominated by grasses rather than large trees
 Grasslands occur where there is enough rain to support
abundant grass but not enough for trees
 In drier grassland, grasses may be less than half a meter tall. In
wetter areas, grasses can exceed 2m
 Where scattered trees occur in grasslands, we call it SAVANNA
 Grassland and Savanna vegetation is adopted to survive drought
and extreme heat or cold
 Most have deep, long lived roots that seek groundwater and that
persist when leaves and stems above ground die back. These
deep roots and annual accumulation of dead leaves on surface
produce thick organic rich soils in many grasslands
 Historically greatest threat to grasslands was conversion of rich
soil to farmland
 Currently greatest threat to grasslands is overgrazing

8. Forest Biomes
 Forest biome
 Forest occupy approx. 1/3 of the Earth’s land area
 Forest biome can be categorized in to THREE major
types:
 Tropical forest
 Temperate forest
 Boreal forest (Taiga)

9. Forest biomes
 Tropical forest
 Occur near the equator
 Temperature is on average 20-25 ̊C and varies very little
throughout the year
 Precipitation is evenly distributed throughout the year with
annual rainfall exceeding 2000mm
 Temperate forest
 Well defined seasons
 Temperature various from -30 to 30 ̊C
 Precipitation (75 – 150 cm) is distributed evenly throughout
the year
 Boreal forest
 Temperature are very low
 Precipitation in the form of snow (40-100 cm annually)

10. Tundra biome
 Coldest of all biome
 Extremely low temperatures
 Little precipitation
 Poor nutrients in soil
 Low biotic diversity
Tundra is separated into two types:
Arctic tundra
Alpine tundra

11. Arctic tundra
 Located in the northern hemisphere
 Has cold, desert-like conditions
 Temperature is -34° C to 12° C
 Annual precipitation rate (rainfall)
15 to 25 cm
 A layer of permanently frozen subsoil
called permafrost exists

12. Alpine tundra
 Located on mountains throughout the
world at high altitude
 Trees are absent/cannot grow
 The night time temperature is usually below
freezing point

13. Biosphere parts
Biosphere is divided
Plant life: Made Earth the livable planet. Plants have a direct
impact on temperature, rocks, atmosphere, oceans. They
are primary producers (autotrophs).
Animal life: 1.5 million known kinds of animals.
Hetrotrophs (Herbivores, omnivores)
Microorganisms, Human being

14. Threats to biosphere