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ECOSYSTEM Aparna Menon Dept of English. Free Powerpoint Templates. Definition. Natural system consisting of the biotic and abiotic factors. Any situation where there is a relationship between organisms and their environment.
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ECOSYSTEMAparnaMenonDept of English Free Powerpoint Templates
Definition • Natural system consisting of the biotic and abiotic factors. • Any situation where there is a relationship between organisms and their environment. • An ecosystem is a community of living and nonliving things considered as a unit. • Ecosystem is a complex set of relationships among the living resources, habitats and residents of an area. It includes plants, trees, animals, fishes, birds, micro-organisms, air, water, soil and people.
Types of Ecosystems • Mainly of two kinds: 1) Terresterial or land based 2)aquatic ecosystems • Natural 1.Terrestrial ecosystems (grasslands, forests, desert ecosystems) 2.Aquatic ecosystem (Ponds, rivers, lakes, sea etc. a.Lentic (Stagnant water) like lake, ponds etc. b.Lotic (Flowing water) like river, ocean, sea, etc. • Artificial 1.A crop land, garden, aquarium, park, kitchen garden.
Components of an Ecosystem An ecosystem consists of two main components • Abiotic or Non-living components. • 1. Inorganic substances • 2. Organic compounds • 3. Climatic factors • Biotic or Living components. • 1. Autotrophs or Producers • 2. Heterotrophs or Consumers • 3. Decomposers or Saprotrophs
BIOTIC COMPONENTS Classified in to three: 1)Producers : green plants capable of photosynthesis. There are microorganisms and bacteria which can produce organic matter even in the absence of light. This process is called chemosynthesis. Photosynthetic plants and chemosynthetic microbes are capable of food production and hence known as producers. 2) Consumers : Organisms which directly or indirectly depend upon plants and other organisms for their food requirements are referred as consumers.
Biotic components Consumers are of different levels : • 1) Primary consumers: all herbivores which directly feed on plants are primary consumers. • 2) Secondary consumers: Carnivores animals feeding on herbivores. Example lion, tiger etc. Omnivores feed on both plant and animals. • 3) Tertiary consumers: Carnivores animals feeding on other carnivorous animals. Snake, Vulture etc
Biotic components • 3) Decomposers: organisms that feed on dead plants and animals. • The decomposers absorb waste and dead matter and thereby maintaining an ecosystem clean and healthy. • The sum total of biological material in all these three biotic components of the ecosystems is referred to as biomass.
Abiotic components • 1) Physical factors: Sunlight, temperature, rainfall, soil type, water availability etc • Abiotic components in a particular area determine the type of organisms that exist in a particular ecosystem. • 2) Chemical factors: elements such as carbon, oxygen, nitrogen etc constitute the chemical factors.
Biotic Components of Ecosystem • Different living organisms constitute the biotic components of an ecosystem. • This refers to large life-forms such as trees or mammals, small life-forms such as insects and algae, and microscopic life-forms such as bacteria. • Biotic, meaning of or related to life, are living factors. Plants, animals, fungi and bacteria are all biotic or living factors.
Producers • Most important components of ecosystem. • Producers are organisms which are able to manufacture organic compounds from inorganic substances from their environment. • Food is produced both for themselves and for other organisms. • They depend directly on the abiotic component for their survival and production of nutrients. • Producers are also known as autotrophs (derived from Greek words: “autos” meaning self and “trophe” meaning nourishment) • They induce into the ecosystem, the energy required for its biological processes.
Producers • Producers extract nutrients from soil or ocean and manufacture their own food using photosynthesis, in the presence of carbon dioxide and sunlight and so energy from sun powers the base of food chain. Producers are also, thus known as primary producers. • An exception occurs in deep-sea hydrothermal ecosystems where there is no sunlight. Here, the primary producers manufacture food through a process called chemosynthesis. • Chemosynthesis is a process certain organisms use to produce energy, akin to photosynthesis, but without the utilization of sunlight. The energy comes from the oxidization (burning) of chemicals which seep up from the Earth's crust. • So, producers are either photo-autotrophs or chemo-autotrophs.
Consumers • Consumers are organisms that obtain nutrients by consuming other organisms. • These organisms are formally referred to as heterotrophs(derived from Greek words “heteros” meaning another/ different and “trophe” meaning nourishment. • A heterotroph is an organism that cannot synthesize their own food and must obtain it ready made. • They can be herbivores, carnivores, omnivores or detritivores.
Herbivores • Animals who derive their required energy directly from consuming the plants and plants only. • Also known as primary consumers. • Herbivores have special digestive systems that let them digest all kinds of plants, including grasses. • Eg. Rabbit, cattle, horse, sheep, insects, etc.
Carnivores • Animals that feed on other animals. • Carnivores generally eat herbivores (secondary consumers), but occasionally eat other carnivores also (tertiary consumers). • Eg: lion, tiger, cats, birds of prey, sharks, frogs, etc.
Predators Scavengers Scavengers eat the food that has been killed and left behind by predators. Eg: vultures, racoons, hyena,etc. Scavengers play an important role in the ecosystem by consuming the carcass of animals that have been left to decompose. Decomposers and detritivores complete this process, by consuming the remains left by scavengers. • A predator is an organism that hunts and kills other organisms for food. • Eg: lions, tigers, sharks, wolves, snakes, etc.
Omnivores • Animals that feed on both plants and animals. • Omnivores often are opportunistic, general feeders with neither carnivore nor herbivore specializations for acquiring or processing food, and are capable of consuming and do consume both animal protein and vegetation. • Many omnivores depend on a suitable mix of animal and plant food for long-term good health and reproduction. • Eg, humans, bear, etc.
Detritivores • They feed on dead plant and animal matter, but perform an additional function which is to return essential nutrients back to the ecosystem in the process. • Detritivores actually eat organic matter. • They are essential for recycling of nutrients: without them dead plant material would not be returned to the soil for new growth • Eg: worms, millipedes, sea stars, crabs, dung flies.
Detritivores • Detritivores consume dead organic material such as carcasses, fallen leaves, dead plants, animal droppings and shed skins. • Having consumed the material, the organism then excretes or egests waste. • This waste contains nutrients which are thus returned to the soil, facilitating new plant growth, or made easier for other organisms to consume. By breaking down dead matter into smaller pieces, detritivores speed up the process of decomposition.
Decomposers/ Saprobes • These are micro-organisms which break-down organic matter into inorganic compounds and derive their nutrition in the process. Decomposers break down complex compound into simpler compounds without eating them. • For example, fungi can grow on organic matter, such as a dead tree trunk or a piece of bread, and breaks it down and absorbing the nutrients without eating the wood or the bread. • These are organisms that aid in decomposition of already dead or dying organisms. • Decomposers secrete enzymes to digest organic matter and then absorb resulting molecules. • Eg: bacteria, fungi, etc.
Abiotic Components of Ecosystem • The nonliving materials in an ecosystem, such as minerals, gases, liquids and chemicals are referred to as abiotic or non-biotic factors. • Abiotic, meaning not alive, are nonliving factors that affect living organisms. Environmental factors in such habitat (pond, lake, ocean, desert, mountain) or weather such as temperature, cloud cover, rain, snow, hurricanes, etc. are abiotic factors.
Abiotic Components of Ecosystem • An abiotic factor is a nonliving condition or thing, such as climate or habitat, that influences or affects an ecosystem and the organisms in it. • Abiotic factors can determine which species of organisms will survive in a given environment.
