Biosphere

BIOSPHEREAll life is confined to a thin

veneer on the earth’s surface

called the

Biosphere

• Biosphere is the global ecological system integrating all living beings and their relationships.

• Usually defined as the thin outer layer of the earth capable of supporting life.

Subdivisions of the Biosphere

•Lithosphere•Hydrosphere•Atmosphere

LITHOSPHERE

The rocky material of the earth’s outer shell and is the ultimate source of all mineral elements required by living

organisms.

hydroSPHERE

The hydrosphere includes all water on Earth.

The abundance of water on Earth is a unique feature that clearly distinguishes our "Blue

Planet" from others in the solar system.

Not a drop of liquid water can be found anywhere else in the solar system. It is because

the Earth has just the right mass, the right chemical composition, the right atmosphere, and is the right distance from the Sun that permits water to exist mainly as a liquid.

Most of the water is contained in the oceans

atmOSPHERE

The gaseous component of the biosphere.

Extends up to some 3500 km above the earth’s surface, but all life is

confined to the lowest 8 to 15 km (TROPOSPHERE).

The screening layer in the atmosphere of oxygen-zone

is concentrated mostly between 20 – 25 km.

Greenhouse effectThe greenhouse effect is the rise in

temperature that the Earth experiences because certain gases in the atmosphere

(water vapor, carbon dioxide, nitrous oxide, and methane, for example) trap energy from

the sun. Without these gases, heat would escape back into space and Earth’s average temperature would be about 60ºF colder.

Because of how they warm our world, these gases are referred to as greenhouse gases.

Terrestrial Environments: BIOMES

• A biome is a major biotic unit bearing a characteristic and easily recognized array of plant life.

• A biome is identified by its dominant plant formation but, because animals depend on plants, each biome supports a characteristic fauna.

• A biome,s distinctiveness is determined mainly by climate.

Temperature Deciduous Forest

• This biome occupies the eastern half of the United States and a large portion of Europe.

• It is characterized by: hardwood trees (e.g., beech, maple, oak, hickory) which are deciduous(shed their

leaves in the autumn).• Large stands dominated by a single species are

common. • Deer, raccoons, and salamanders are characteristic

inhabitants. • During the growing season, this biome can be quite

productive in both natural and agricultural ecosystems.

Coniferous Forest• This biome is found in the upper areas of North America and Asia

• Tall mountains have supported vigorous tree growth and a large animal population.

• Many animals like the white tailed deer, Reeve's muntjac, fox, mice, owls, and squirrels are found in this area.

• The weather in this biome is very cold. It is stormy in the winter

and hot. There are usually many lightning storms in the summer.

• There are many plants in this biome, but three dominate more than others. These are: pine, fir, and spruce trees. Mosses are also

found almost anywhere here

Tropical Forest• The Tropical Rain forest contains trees standing 30 to 55

meters in height, creating a continuous canopy of foliage. The enclosed canopy shades the forest floor inhibiting the

development of much undergrowth, creating an open forest formation

• The intense precipitation of the tropical rainforest climate heavily leaches the soil.

• Oxisol soil common to the rain forest are relatively infertile due to intense weathering and a lack of available nutrients. Deforestation and habitat destruction is severely crippling

the rain forest ecosystem.

Grassland

• The Grassland biome is dominated by grasses of a variety of species, all having adapted to the summer drought common to their semiarid habitat.

• Prairies are found on the humid side of the grassland biome and are often referred to as the tall-grass prairie.

• On the drier side of the grassland biome lies the steppe grasslands. Vegetation must cope with the summer soil moisture deficit common to the steppe climate in which this formation class is found.

Tundra• Tundra is the coldest of all the biomes. Tundra comes from

the Finnish word tunturi, meaning treeless plain. Characteristics of tundra include:• Extremely cold climate • Low biotic diversity • Simple vegetation structure • Limitation of drainage • Short season of growth and reproduction • Energy and nutrients in the form of dead organic material • Large population oscillations

Desert

• Deserts cover about one fifth of the Earth's surface and occur where rainfall is less than 50 cm/year.

• There are relatively few large mammals in deserts because most are not capable of storing sufficient

water and withstanding the heat.

• Deserts often provide little shelter from the sun for large animals. The dominant animals of warm deserts

are nonmammalian vertebrates, such as reptiles. Mammals are usually small, like the kangaroo mice of

North American deserts.

Inland Waters

• Of all the worl’ds water, 2.5% is fresh.

• Inland waters exist as running-water, or LOTIC.

(brooks or streams)

• Standing water or LENTIC. (ponds or lakes)

Oceanic Environments

• This is the largest zone in the ocean. • as deep as 11,000 m below the surface. • Sunlight does not penetrate very deep into

the oceanic zone.• Cradle of life

• BETHNIC (seabed)• PELAGIC (open ocean)

Rocky Intertidal Zone

• This zone is located along the shoreline of the world ocean.

• Exposed to air during low tides

• Animals of intertidal communities experience daily fluctuations between marine and terrestial environments.

Rocky Subtidal Zone

• This area is submerged most of the time, exposed briefly during extreme low tides

around full and new moon events.

• This zone provides habitat to a large diversity of plants and animals in contrast to the other

zones.

• It is dominated by red algae and the most common animals found here are the grazers

such as periwinkles and sea urchins.

Nearshore Soft Sediments

• Small creeks in salt marshes are particularly favorable in habitats for many polychaetes, mussels and fishes.

• In calm waters of tropical and subtropical marine coasts, mangrove trees grow in submerged soft sediments, forming thick forests along the shoreline.

Deep-Sea Sediments

• The deep sea includes the continental slope, continental rise and abyssal pain.

• Suspension-feeding invertebrates dominate sandy subtrates.

Hydrothermal Vents

• Hydtrothermal vents occur on abyssal plain in areas of submarine volacanic activity.

• Hydrothermal vents are ephemeral; repeated colonization of newly formed vents propagate these communities.

Pelagic Realm

• The vast open ocean is called the pelagic realm.

• 90% of the total ocean

• Areas of upwelling and convergence of ocean currents are vital sources of nutrient renewal for the surface photic zone.