BRIEF DISCUSSION OF THE PREVIOUS CLASS (5:12 P.M.)

FUNCTIONS IN ECOSYSTEM (5:24 P.M.)

• Biotic interaction
• Types of Organisms in Ecosystem
• (a) Producers
• These are capable of photosynthesis.
• For example, plants and phytoplankton.
• (b) Herbivores
• These are plant-eating organisms.
• For example, Cow, goat, etc.
• (c) Carnivores
• They feed on herbivores.
• For example, lion, wolf, etc.
• (d) Detrivores/Scavengers
• They feed on dead matter.
• For example, Hyena, Vultures, etc.
• (e) Nectarivores
• They feed on nectar.
• For example, Hummingbird, Sunbird, etc.
• (f) Frugivores
• They eat fruits.
• For example, Parrots, Parakeets, Great Hornbill, Monkeys, etc.
• (g) Gramivores
• They feed mainly on grass.
• For example, Sparrow, Munia, Bluethroat birds, Deers, Horses, Cows, Elephant, Rhinoceros, Indian Bison, etc.
• Types of Organisms Based on Roles
• (a) Flagship species
• Species selected to act as an ambassador, icon, or symbol for the defined habitat, issue, or campaign.
• They are relatively large and charismatic.
• For example, the Tiger, the Great Indian Bustard (Heaviest Flying Bird), etc. 
• (*Note: Sarus Crane is the tallest flying bird.)
• (b) Keystone Species
• It is a species that plays an essential role in the functioning or structure of the ecosystem. Its disappearance may cause significant change.
• They have a disproportionately large impact on the ecosystem, compared to their abundance.
• For example, Wolves in Yellowstone National Park (Yellowstone National Park is the first national park in the world.), Honey Bees, Top Predators, Elephants, etc.
• Elephants are called ecosystem engineers.
• (c) Indicator Species
• They indicate certain processes in the ecosystem.
• They are used to assess the environmental condition or the quality of an ecosystem.
• For example, Lichens indicate air pollution, River Dolphins indicate water pollution, Corals indicate sedimentation, Blackbucks indicate the health of grassland, Himalayan Monal indicates the health of the Himalayan ecosystem, etc.
• (d) Umbrella Species
• These are the dominant species in the ecosystem and are representatives of that ecosystem.
• By protecting the umbrella species, all other species can be easily protected.
• For example, Corals, Kelps, and top predators.
• Ecosystem Services (6:05 P.M.)
• four types of services are provided by the ecosystem:
• (a) Provisioning Services
• The "products" are obtained from the ecosystem.
• For example, Foods, Fibers, Ornamentals, Minerals, etc.
• (b) Regulating Services
• The benefits obtained from the regulation of ecosystem processes.
• For example, Climate Regulation, Flood Prevention, etc.
• (c) Cultural Services
• These refer to the non-material services obtained from the ecosystem.
• For example, Educational, recreational, etc.
• (d) Supporting Services
• These services are necessary for the production of all other ecosystem services.
• For example, Biodiversity, Nutrient Cycle, etc.

BIOGEOCHEMICAL CYCLES (6:11 P.M.)

• The flow of different chemical elements and compounds between different organisms and the physical environment is called as Biogeochemical Cycle.
• These are classified into the gaseous cycles and sedimentary cycles.
• (a) Gaseous Cycle
• In this, the reservoir pool is the atmosphere.
• For example, Carbon Cycle, Nitrogen Cycle, Water Cycle, and Oxygen Cycle.
• (b) Sedimentary Cycle
• The reservoir pool is in the Earth's crust or lithosphere.
• For example, the Sulphur Cycle and Phosphorous Cycle.

WATER CYCLE (6:21 P.M.)

• The water vapour converts into water through the process of condensation.
• This water accumulates around the hygroscopic particles, leading to cloud formation.
• The precipitation would lead to the falling of the water on the surface.
• When water vapour condenses on the ground, it may result in different condensation forms like fog, mist, dew, and frost.
• The water converts into water vapour by absorbing the heat. This process is called evaporation. 
• 

CARBON CYCLE (6:30 P.M.)

• The carbon dioxide present in the atmosphere enters the plants through the process of photosynthesis.
• The equation of photosynthesis is 6CO2+ 6H2O+ Sunlight -> C6H12O6+ 6O2.
• The plants store it in the form of carbohydrates.
• The consumers consume the plants, there by it goes into the consumers.
• The consumers give out carbon dioxide by the process of respiration.
• The plants also perform the respiration to release the carbon dioxide.
• Plants and consumers after their death convert into the soil organic matter.
• This soil organic matter decomposes to release the carbon into the atmosphere.
• Some soil organic matter will convert into fossil fuel.
• This fossil fuel on combustion will release the carbon into the atmosphere.
• The oceans are capable of absorbing the carbon dioxide. They release it back, once they get saturated.
• 

OXYGEN CYCLE

• Plants convert the atmospheric carbon dioxide into the atmospheric oxygen.
• This is taken by the plants and animals which convert it into carbon dioxide (Respiration Process).
• Also, the oxides release the oxygen into the atmosphere.

NITROGEN CYCLE (7:06 P.M.)

• Nitrogen is present abundantly in the atmosphere.
• The conversion of nitrogen into ammonia is called Nitrogen Fixation.
• Nitrogen Fixation is carried out by free-living bacteria in the soil. For example, Azatobacter and Clostridium.
• Nitrogen Fixation is carried out by the symbiotic microbes as well. For example, Rhizobium and Blue Green Algae (Anabena and Spirulena).
• Nitrogen Fixation happens naturally during the lightening as well.
•  It can be carried out by industrial processes as well.
• Ammonia is converted into Nitrite and Nitrate through the process of Nitrification.
• Nitrosomonas converts the ammonia into nitrites.
• Nitrobacter converts the nitrite into nitrates.
• The nitrate is converted into ammonia through the process of Ammonification.
• Nitrate is converted into nitrogen through the process of Denitrification.
• Pseudomonas converts the nitrites and nitrates into the nitrogen.
• 
• Fossil fuels also contain some nitrogen compounds. On combustion, the oxides of the nitrogen reach the atmosphere.
• This further comes down with rain in the form of nitric acid.

PHOSPHOROUS CYCLE (7:28 P.M.)

• The phosphorous is stored in the rocks.
• The phosphorous is released into the soil through the processes of weathering, erosion, etc.
• In the soil, the phosphorous is present in the form of phosphates.
• The plants take this phosphate through the process of assimilation.
• Through consumption, it travels higher in the food cycle.
• From the consumers, it reaches the soil through the process of excretion and decomposition.
• Rain, rivers, and other such agents take away the phosphorous from the soil and deposit it into the basin.
• Through the process of lithification, it again gets stored in the rocks.

SULPHUR CYCLE 

• There is an interaction with the atmosphere, but the reservoir is in the lithosphere.
• It is stored in the form of organic and inorganic forms.
• In the organic form,  it is stored in the form of coal, petroleum, and peat.
• In the inorganic form, it is stored in the form of sulfates and sulfides.
• 

TIGERS (7:40 P.M.)

• The various statuses are Not Evaluated, Data Insufficient, Least Concern, Near Threatened, Vulnerable, Endangered, Critically Endangered, Extinct in Wild, and Extinct.
• Big cats in India are Lion, Tiger, Cheetah, Snow Leopard, and Leopard.
• Jaguar and Puma are not present in India.
• The IUCN status of the tiger is endangered.
• Tiger is in Appendix 1 of the CITES.
• There are several subspecies of tiger,
• It is present in 13 countries, where it is found in the wild. These countries are called Tiger-Range countries.
• India, Nepal, Bangladesh, Bhutan, Myanmar, Thailand, Laos, Vietnam, Cambodia, Malaysia, Indonesia, China, and Russia are such countries.
• India hosts 70% of the world's tigers.
• The various subspecies of tigers can be classified into continental tigers and Island tigers.
• The Royal Bengal Tiger is a continental tiger.
• The Indo-China Tiger is also a continental tiger. 
• The Malayan Tiger is a continental tiger.
• Sumatran and Javan tigers are island tigers. 
• The Bali Tiger is extinct.
• China has a South-China tiger, which is a continental tiger.
• The Amur/Siberian tiger is found in Siberia. It is the biggest species of tiger.
• The tiger is the largest of all the big cats.
• The tiger is very important as it is a keystone, flagship, and umbrella species.

THE TOPIC FOR THE NEXT CLASS: DIFFERENT TYPES OF ECOSYSTEMS, BIOMES, AND WETLANDS.