Biomes Flashcards
Biosphere
The biosphere includes all the living components of the earth. It consists of all plants and animals, including all the microorganisms that live on the planet earth and their interactions with the surrounding environment.
Life on earth found where
Life on the earth is found almost everywhere. Living organisms are found from the poles to the equator, from the bottom of the sea to several km in the air, from freezing waters to dry valleys, from under the sea to underground water lying below the earth’s surface.
Major realms of the environments
Lithosphere, atmosphere, hydrosphere, biosphere.
Biosphere and interaction with the environment
The biosphere and its components are very significant elements of the environment. These elements interact with other components of the natural landscape such as land, water and soil. They are also influenced by the atmospheric elements such as the temperature, rainfall, moisture and sunlight. These interactions are important to the growth, development and evolution of the organism.
ecology
Literally, ecology is the study of the earth as a ‘household’, of plants, human beings, animals and microorganisms. They all live together as interdependent components.The study of interactions between life forms (biotic) and the physical environment (abiotic) is the science of ecology.
Ecological systems
The interactions of a particular group of organisms with abiotic factors within a particular habitat resulting in clearly defined energy flows and material cycles on land, water and air, are called ecological systems.
Habitat
A habitat in the ecological sense is the totality of the physical and chemical factors that constitute the general environment.
Ecosystem
A system consisting of biotic and abiotic components is known as ecosystem.
Types of Ecosystems
Ecosystems are of two major types: terrestrial and aquatic. Terrestrial ecosystem can be further classified into ‘biomes’. Aquatic ecosystems can be classed as marine and freshwater ecosystems. Marine ecosystem includes the oceans, estuaries and coral reefs. Freshwater ecosystem includes lakes, ponds, streams, marshes and bogs.
Biome
A biome is a plant and animal community that covers a large geographical area. The boundaries of different biomes on land are determined mainly by climate.
Structure of an ecosystem
The structure of an ecosystem involves a description of the available plant and animal species. From a structural point of view, all ecosystems consist of abiotic and biotic factors.
Abiotic and biotic factors
Abiotic factors include rainfall, temperature, sunlight, atmospheric humidity, soil conditions, inorganic substances (carbon dioxide, water, nitrogen, calcium, phosphorus, potassium, etc.). Biotic factors include the producers, the consumers (primary, secondary, tertiary) and the decomposers.
Discuss producers, consumers and decomposers
The producers include all the green plants, which manufacture their own food through photosynthesis. The primary consumers include herbivorous animals like deer, goats, mice and all plant-eating animals. The carnivores include all the flesh-eating animals like snakes, tigers and lions. Certain carnivores that feed also on carnivores are known as top carnivores like hawks and mongooses. Decomposers are those that feed on dead organisms (for example, scavengers like vultures and crows), and further breaking down of the dead matter by other decomposing agents like bacteria and various micro- organisms. The producers are consumed by the primary consumers whereas the primary consumers are, in turn, being eaten by the secondary consumers. Further, the secondary consumers are consumed by the tertiary consumers. The decomposers feed on the dead at each and every level.
Foodchain, flow of energy
the sequence of eating and being eaten and the resultant transfer of energy from one level to another is known as the food-chain. For example, a plant eating beetle feeding on a paddy stalk is eaten by a frog, which is, in turn, eaten by a snake, which is then consumed by a hawk. Transfer of energy that occurs during the process of a foodchain from one level to another is known as flow of energy.
Food web
Food chains are not isolated, in fact interconnected. As a result, the food- chains get interlocked with one another. This inter- connecting network of species is known as food web.
Types of food chains
The grazing food chain starts with producers, typically green plants, that convert sunlight into energy through photosynthesis. The detritus food chain begins with detritus, which consists of decomposing organic matter, such as fallen leaves, dead organisms, and waste products. This chain emphasises the role of decomposers and detritivores in recycling nutrients back into the ecosystem. Loss of energy at each level in both.
Types of Biomes
There are five major biomes — forest, desert, grassland, aquatic and altitudinal biomes.
Biogeochemical Cycles and types
These cyclic movements of chemical elements of the biosphere between the organism and the environment are referred to as biogeochemical cycles. There are two types of biogeochemical cycles : the gaseous and the sedimentary cycle. In the gaseous cycle, the main reservoir of nutrients is the atmosphere and the ocean. In the sedimentary cycle, the main reservoir is the soil and the sedimentary and other rocks of the earth’s crust.
What is carbon
It forms the basic constituent of all the organic compounds.
The Carbon Cycle
The carbon cycle describes the movement of carbon through the atmosphere, biosphere, lithosphere, and hydrosphere. Key processes include photosynthesis (where plants convert CO₂ into organic matter), respiration (which releases CO₂), decomposition (returning carbon to the soil), and combustion (burning fossil fuels). Oceans also absorb CO₂, and over geological timescales, carbon can become sequestered in rocks.
Plants and carbon relationship
fixation of carbon dioxide from the atmosphere through photosynthesis. Such conversion results in the production of carbohydrate, glucose that may be converted to other organic compounds such as sucrose, starch, cellulose, etc. Here, some of the carbohydrates are utilised directly by the plant itself. The remaining carbohydrates not being utilised by the plant become part of the plant tissue. During this process, more carbon dioxide is generated and is released through its leaves or roots during the day.
Fixation
Fixation refers to the process of converting a substance into a more stable or usable form.
How much insolation is fixed during photosynthesis?
Out of the total solar insolation that reaches the earth’s surface, only a very small fraction (0.1 per cent) is fixed in photosynthesis.
Oxygen cycle
Oxygen is the main by-product of photosynthesis (biggest source). It is involved in the oxidation of carbohydrates with the release of energy, carbon dioxide and water. The cycling of oxygen is a highly complex process. Oxygen occurs in a number of chemical forms and combinations. It combines with nitrogen to form nitrates and with many other minerals and elements to form various oxides such as the iron oxide, aluminium oxide and others.
Denitrification
There are still other types of bacteria capable of converting nitrates into free nitrogen, a process known as denitrification
The Nitrogen Cycle
- Nitrogen makes up about 78% of the atmosphere and is essential for organic compounds like amino acids, nucleic acids, and proteins.
- Only certain soil bacteria and blue-green algae can utilize nitrogen directly from the atmosphere; most nitrogen must be fixed first. About 90% of fixed nitrogen is biological, primarily through soil microorganisms. Nitrogen is also fixed by lightning and some marine organisms.
- Once fixed, green plants assimilate nitrogen, which is then consumed by herbivores. Decomposing dead plants and animals, along with nitrogenous waste, are converted into nitrites by soil bacteria. Other bacteria can further convert nitrites to nitrates for plants, while some can denitrify nitrates back into free nitrogen.
Other mineral cycles
In addition to carbon, oxygen, nitrogen, and hydrogen, various minerals like phosphorus, sulfur, calcium, and potassium are essential nutrients for life. These minerals originate from inorganic sources and are found as salts in soil water, lakes, and oceans. They enter the water cycle through weathering of the Earth’s crust and are returned via sedimentation. Living organisms obtain these minerals from their environment, while animals derive them from the plants and animals they consume. After death, minerals are returned to soil and water through decomposition, completing the cycle.
Ecological Balance
Ecological balance is a state of dynamic equilibrium within a community of organisms in a habitat or ecosystem. It can happen when the diversity of the living organisms remains relatively stable. Gradual changes do take place but that happens only through natural succession.
Succession
refers to the gradual process of change and development in an ecological community over time. It involves a series of stages where different species of plants, animals, and microorganisms colonise and modify the environment, leading to a more complex and stable ecosystem.
Disturbing of Ecological balance
may be disturbed due to the introduction of new species, natural hazards or human causes. Human interference has affected the balance of plant communities leading to disturbances in the ecosystems. Such disturbances bring about numerous secondary successions.
Forest Biomes subtypes
Tropical ( Equatorial and Deciduous), Temperate, Boreal
Discuss Equatorial forests biome
Region- 10°N-S
Climate- year-round warm temperatures and abundant rainfall, minimal temperature fluctuations.
Soil-Acidic, poor in nutrients
Flora and Fauna-Multi-layered canopy tall and large trees. Mahogany, teak, and balsa
Discuss Tropical Deciduous forests biome
Region-10°-25°N-S
Climate-a hot, dry season and a wet monsoon season.
Soil-Rich in nutrients
Flora and Fauna- Teak, sal, bamboo
Discuss Temperate Forests biome
Region-Velds, Praires, Pampas, Steppes, Downs
Climate- four distinct seasons: spring, summer, autumn, and winter.
Soil-Fertile, enriched with decaying litter
Flora and Fauna-Moderately dense broad leaved trees. With less diversity of plant species. Oak, Beach, Maple etc. are some common species. Squirrels, rabbits, skunks, birds, black bears, mountain lions etc.
Discuss Boreal forests biome
Region-Broad belt of Eurasia and North America (parts of Siberia, Alaska, Canada and Scandinavia) also known as taiga,
Climate- Long cold winters, short, dry summers. Precipitation mostly snowfall 400 -1,000mm
Soil-Acidic and poor in nutrients, thin soil cover
Flora and Fauna-Evergreen conifers like pine, fur and spruce etc. Woodpeckers, hawks, bears, wolves, deer, hares and bats are common animals
Desert Biome constituents
A. Hot and Dry desert
B. Semi arid desert
C. Coastal desert
D. Cold desert
Discuss Hot and Dry Deserts
Region-Sahara, Kalahari, Marusthali, Rub-el-Khali
Climate- Temp. 20 - 45°C. Rainfall is less than 50 mm
Soil-Rich in nutrients with little or no organic matter
Flora and Fauna- Scanty vegetation; few large mammals, insects, reptiles and birds
Discuss Semi arid deserts
Region-Marginal areas of hot deserts
Climate- 21 - 38°C. Rainfall is less than 50 mm
Soil-Rich in nutrients with little or no organic matter
Flora and Fauna- Scanty vegetation; few large mammals, insects, reptiles and birds
Discuss Coastal desert
Region-Atacama
Climate- 15 - 35°C. Rainfall is less than 50 mm
Soil-Rich in nutrients with little or no organic matter
Flora and Fauna-Scanty vege- tation; few large mammals, insects, reptiles and birds
Discuss cold desert
Region-Tundra climatic regions
Climate- 2 - 25°C Rainfall is less than 50 mm
Soil-Rich in nutrients with little or no organic matter
Flora and Fauna-Rabbits, rats, antelopes and ground squirrels
Types of grassland biomes
A. Tropical Savannah
B. Temperate Steppe
Discuss Tropical Savannah grasslands
Region-Large areas of Africa, Australia, South America and India
Climate- dry season, wet monsoon
Soil-Porous with thin layer of humus.
Flora and Fauna-Grasses; trees and large shrubs absent; giraffes zebras, buffalos, leopards, hyenas, elephants, mice, moles, snakes and worms etc., are common animals
Discuss Temperate Steppe grasslands
Region-Parts Of Eurasia and North America
Climate-4 distinct seasons
Soil-Thin flocculated soil, rich in bases
Flora and Fauna-Grasses; occasional trees such as cotton- woods, oaks and willows; gazelles, zebras, rhinos wild horses, lions, varieties of birds, worms, snakes etc., are common animals
Types of aquatic biomes
A. Freshwater B. Marine
Discuss Freshwater Aquatic biomes
Region- Lakes, streams, rivers and wetlands
Climate- Temperatures vary widely with cooler air temperatures and high humidity
Soil-. Water, swamps and marshes
Flora and Fauna-Algal and other aquatic and marine plant communities with varieties of water dwelling animals
Discuss Marine Aquatic biomes
Region-Oceans, coral reefs, lagoons and estuaries
Climate-Temperatures vary widely with cooler air temperatures and high humidity
Soil-Water, tidal swamps and marshes
Flora and Fauna-Algal and other aquatic and marine plant communities with varieties of water dwelling animals
Discuss Altitudinal biomes
Region-Slopes of high mountain ranges like the Himalayas, the Andes and the Rockies
Climate-Temperature and precipitation vary depending upon latitudinal zone
Soil-Regolith over slopes
Flora and Fauna-Deciduous to tundra vegetation varying according to altitude
