Natural Resources: Types and Spheres

• Natural resources include air, water, minerals, and biochemical cycles.

What are Natural Resources?

• Natural resources exist independently of human actions.
• Air, sunlight, soil, water, plants, animals, and fossil fuels are examples of natural resources.
• Natural resources occur naturally and can be directly useful or become useful through technology.

Types of Natural Resources

• Natural resources can be classified based on their origin and availability
• Origin based resources can be classified as biotic or abiotic.
• Availability based resources can be classified as exhaustible or inexhaustible

Biotic and Abiotic Resources

• Biotic resources are obtained from the biosphere.
• Examples of biotic include forests, animals, fish, bacteria, and birds.
• Abiotic resources are obtained from the lithosphere, atmosphere, and hydrosphere.
• Examples of abiotic resources include sunlight, minerals, soil, wind, and temperature.

The Four Main Spheres of Earth

• The four main spheres of earth are the lithosphere, hydrosphere, atmosphere, and biosphere.
• Planet Earth's four main components form a complete system.
• These components are land, air, water, and life.
• The names for the components are derived from Greek words.

Lithosphere

• The Lithosphere is also known as the Geosphere, with 'Geo' meaning 'ground'.
• The lithosphere includes the crust and uppermost mantle which form the outer, rigid layer of Earth.
• The lithosphere is the most rigid of Earth's layers.

Hydrosphere

• Hydrosphere has the root word 'hydro', which means 'water'.
• The hydrosphere includes all water on or near Earth like; oceans, rivers, lakes, and atmospheric moisture.
• The hydrosphere extends several miles below Earth's surface and up into the atmosphere as water vapor.
• Earth is the only planet in the Solar System with a hydrological cycle.
• The Hydrosphere makes up about three fourths of the Earth's surface.

Atmosphere

• Atmosphere has the root word 'atmo' meaning 'air'.
• The atmosphere covers the entire Earth like a blanket.

Biosphere

• Biosphere has the root word 'bio' meaning 'life'.
• The biosphere includes the regions of Earth where the atmosphere, hydrosphere, and lithosphere interact to make life possible.
• The biosphere is composed of biotic as well as abiotic components.
• Biotic components include all living organisms.
• Abiotic components include air, water, and soil.

Air

• Air is a mixture of nitrogen, oxygen, carbon dioxide, and water vapor.
• Life on Earth requires this mixture.
• Earth's surface atmosphere is 78% nitrogen, 21% oxygen, 0.03% carbon dioxide and other gases, 0.93% inert gases(Argon), and 0.01% water vapor.

Why Air is Called the Breath of Life?

• Air contains oxygen, which is essential for life
• Plants and animals require oxygen for respiration to convert food into energy.
• Plants utilize carbon dioxide to produce food through photosynthesis.
• Air helps keep Earth's overall temperature stable.

Carbon Dioxide is Fixed in Two Ways

• Green plants transform carbon dioxide into glucose through photosynthesis.
• Marine animals use dissolved carbonates in sea-water to create their shells.

Climate Control and the Role of the Atmosphere

• Air is a bad conductor of heat.
• The atmosphere acts as a protective blanket for organisms.
• The atmosphere keeps the Earth's average temperature fairly steady throughout the day and year.
• The atmosphere prevents temperature spikes during daylight and slows heat escape into outer space at night.
• The moon's surface temperature ranges from -190°C to 110°C because the moon does not have an atmosphere.

The Movement of Air: Winds

• Moving air is called wind.
• Air moves from high to low pressure areas.
• The motion of wind is the result of heating and water vapor creation.
• Air rises when heated by radiation from land or water, particularly as land heats faster than water.
• Low pressure regions are created as air rises, causing air from the sea to move in, thus producing wind.
• The Earth's rotation is a factor that may influence winds.
• Mountain ranges can disrupt wind paths

Formation of Rain

• A large amount of water evaporates into the air when water bodies are heated, biological activities also introduce water vapor into the atmosphere.
• Heated air rises carrying water vapor.
• The air cools and expands as it rises so the water vapor condenses into tiny droplets.
• The water droplets grow bigger via condensation and fall as rain when heavy enough.
• Rainfall patterns are decided by prevailing wind.
• In India, rains are brought by the southwest or northeast monsoons.

Air Pollution

• Air pollutants are agents or substances that pollute the air.
• The presence or absence of certain organisms indicates the air pollution levels.
• Lichens are sensitive to air contaminants like sulphur dioxide.
• Lichens are commonly found growing on tree barks as a thin greenish-white crust.

Water

• Water is known as the fluid of life.
• Water covers 75% of the earth's surface, with 97% as oceans and only 3% as fresh water.
• Water exists in solid, liquid, and gaseous forms in the atmosphere, on land, and underground.
• The chemical formula for water is H2O, it's composed of hydrogen and oxygen.

Importance of Water

• Water's functions are emphasized:
• It is the main constituent of protoplasm.
• It acts as a solvent, allowing mineral salts to be transported throughout plants.
• It provides a medium for various metabolic reactions.
• In metabolic reactions, water acts as a reactant.
• During photosynthesis, it releases oxygen.
• It helps maintain the turgidity of the growing cells.
• It controls the movements of certain plant organs.
• The growth of the cells during elongation is mainly dependent on absorption of water.
• Metabolic end product of respiration is water.
• Places with lots of water tend to have more biodiversity.

Water Pollution

• Water pollution is the addition of undesirable substances to water and removal of desirable substances from water
• Causes of water pollution include the addition of harmful substances, removal of desirable ones, and temperature changes.

Mineral Riches in the Soil

• Nutrients are supplied by the minerals in the Earth's crust, which is its outermost layer.
• Rocks break down into fine particles of soil over a long period of time by physical, chemical, and biological processes.
• Soil is not just soil, it is a mixture including small rock particles, decaying organic matter (humus), microscopic life, air, and water.

Factors or Processes That Make Soil

• Sun: Rocks heat up and expand, then cool down and contract which leads to cracks.
• Water erodes rocks
• Wind carries sand and erodes rocks.
• Living organisms: Lichens, roots of big trees and small plants like moss, are able to grow on the surface now and they cause the rock to break up further.
• Average particle size determines the type of soil

Quality of Soil

• Humus and microorganisms determine soil quality.
• Mineral nutrients in soil depend on the rocks that they are formed from.
• It causes the soil to become more porous, which is a major factor in deciding soil structure.

Factors That Decide The Type of Plant That Will Thrive On a Particular Soil

• Factors include nutrient content of a soil, amount of humus present in it, and the soil depth.

Top Soil

• Topsoil is the topmost soil layer, contains humus, living organisms, and soil particles.

Soil Pollution

• Soil pollution includes the removal of useful components and the addition of harmful substances.
• Pollutants adversely affect soil fertility and kill microorganisms.
• Fertilizers and pesticides destroy the structure of the soil.

Soil Erosion

• Soil erosion includes the removal of the topsoil by wind, flowing water, or other activities.
• Roots of plants prevent soil erosion by firmly holding the soil particles.

Biogeochemical Cycle

• In a biogeochemical cycle matter flows from the non-living environment into living organisms then back out.

The Water-Cycle

• Water evaporates, falls as precipitation, and flows back to the sea via rivers.
• The process in which water evaporates and falls ont the land as rain and later flowsback in to the sea via is called the water cycle

The Various Steps Involved In The Water Cycle In The Biosphere

• Evaporation - occurs as water in seas and oceans turns into water vapor by the suns heat.
• Transpiration - plants absorb water from the soil that becomes used for photosynthesis as well excess water from the plants gets added to the atmosphere as water vapor.
• Water vapor goes back to the atmosphere during respiration in living plants and from the decay of dead plants.
• Condensation - water vapor rises, cools, and condenses into tiny droplets of liquid water.
• Droplets floating in the air combine to make a cloud.
• Wind blows the clouds by moving water to different regions of the Earth.
• Precipitation – As more water droplets form they join together to form bigger water drops in the clouds. These drops become heavy and fall to the earth as rain. Any water that falls frfom the sky (rain, snow, sleet, hail)
• Percolation and Absorption - some of the precipitation soaks into the ground. Underground water percolates through rock or clay layers reaching underground water. On land the water is used by plants, crops, and trees. Water returns and the cycle is complete.

Nitrogen Cycle

• Nitrogen is found in the atmosphere; 78% of the air.
• Organisms can not use nitrogen; it must have a fixed form.
• Step 1: Nitrogen Fixation
  • Lightning
  • Bacteria
• Step 2: Nitrification
  • Nitrification converts the ammonia into nitrite ions and then into nitrates which the plants can take as nutrients.
• Step 3: Ammonification
  • Ammonification is when an animal or plant dies they release wastes from their bodies, nitrogen is released and organic form. Fungi and bacteria convert organic nitrogen into ammonium via Ammonification.
• Step 4: Denitrification
  • Denitrification converts simple nitrogen compounds into nitrogen gas (N2), and it's released back into the atmosphere. When the ammonia is converted back into inert nitrogen, it's called denitrification.

Carbon Cycle

• Carbon exists as graphite and diamonds.
• In combined form, it is found as carbon dioxide in the atmosphere, carbonate and hydrogen carbonate salts in various minerals.
• All life-forms are based on carbon-containing molecules, such as carbohydrates, fats, proteins, nucleic acids, and vitamins.
• The carbon cycle transfers carbon from the atmosphere into the Earth and its organisms, then back again.
• Carbon enters the atmosphere as carbon dioxide through respiration and combustion.

Photosynthesis

• Carbon is incorporated into life-forms through photosynthesis in the presence of Sunlight.
• The processes of nature are consistently adding and removing carbon from the air.

Respiration

• Respiration occurs in plants, animals, and even decomposesr
• Glucose stored inside of plants and animals is released during respiration through the form of CO2, water, and energy.

Decomposition

• Carbon releases into the environment through decomposition of plants, animals, and waste materials.

Combustion

• The burning of fossil fuels provides energy and releases carbon rapidly.
• This carbon mostly enters the atmosphere mostly as carbon dioxide gas.

Movement Of Carbon From The Atmosphere To The Oceans

• The greenhouse effect results in warming when heat is trapped.
• An increase in greenhouse gasses will increase temperatures worldwide.
• Some gases prevent Earth from releasing heat which are greenhouse gases.
• Carbon dioxide is one of the greenhouse gasses to trap heat.

Oxygen Cycle

• Oxygen is an important element for life on Earth.
• Oxygen makes up 65% of the human body, mostly as water (H2O).
• 30% of the Earth and 20% of the atmosphere is oxygen.
• Processes on Earth create and use oxygen, those processes make up the oxygen cycle.
• It is interconnected with the carbon cycle.

Processes That Use Oxygen

• Respiration: Animals take in simple sugars (glucose) and oxygen and release carbon dioxide, water and energy.
• Decomposition: Organic matter (plants, animals) breaks down chemically into all the simple elements that they are made of and these elements return back to the environment.

Processes That Produce Oxygen

• Photosynthesis: Chlorophyll allows green plants/trees to take in carbon dioxide and water, releasing Oxygen, sugar and water vapor.
• Sunlight: Sunlight reacts with water vapor in the atmosphere

Ozone Layer

• Elemental oxygen typically has two atoms, though it can form molecules with three atoms which is known as ozone (O3).
• The ozone layer exists within the stratosphere, between 20 to 30 kilometers above the earth where it contains a relatively high amount of ozone.
• The Ozone absorbs harmful sun emissions preventing damage.

Depletion of Ozone Layer

• The reduction of ozone in the stratosphere is ozone depletion.
• Ozone depletion occurs due to industries that manufacture chlorofluorocarbons (CFCs) used in some products.
• CFCs get into the stratosphere and break apart from sun emissions in ultra violet radiation.
• When CFCs break apart they release one Chlorine atom. These then react with Ozone causing a chemical cycle that destroys areas of the ozone.