Ecosystem and its Components
The study of the relationship between organisms and between the organisms and the environment is ecology. The structural and functional unit of ecology is known as the ecosystem. Continuous production and exchange of materials between the living and nonliving components. Plants and animals of a regional climate and soil type interact to produce a characteristic land community known as biome. In biome emphasis is on the biotic community
Tundra Biome Less of tree growth Vegetation is shrubs, grasses, mosses & scattered trees
Dessert Biome Plants are usually ground hugging shrubs and small woody trees. Animals are nocturnal carnivores Climate warm throughout the year and very hot during summer.
Biotiic Component All living components of the environment The biotic component can be categorized as
Autotrophic Component or Producers 2. Heterotrophic Component or Consumers 1.
Autotrophs or Primary producers All those organisms green plants, bacteria and algae which contain chlorophyll and is capable of converting solar energy into chemical energy and storing food stuff in the presence of carbon dioxide and water
Heterotrophs or Consumers All other organism unable to make their own food
but depend on other organism for food to meet their energy needs for survival. Depending on feeding habits they can be classified as a. b. c.
Primary Consumers Secondary Consumers Tertiary Consumers
Secondary and tertiary consumers may be 1.
Predators which hunt, capture and kill their prey
2. Carrion feeders which feed on corpses 3. Parasites which are smaller than host, live either inside or outside the host. Depend on the metabolism of their hosts for their food supply 4. Animals with flexible food habits- omnivores
Saprophytes or Decomposers The dead bodies of producers and consumers are eaten and
broken down into simple inorganic substances by certain microbes. The simple substances are utilized again by producers to prepare food. Water, carbon dioxide, phosphates, nitrogen ,sulphates and organic compounds are by-products of activity of orgnisms
Trophic levels Links in the food chain are known as trophic levels. Energy flows from each level
From lower to higher Loss of energy at each level
Trophic Level in a Grass land Ecosystem
Food Chain A sequence of organism that feed on one another
,form a food chain. Some animals eat only one kind of food and
therefore are of a single food chain.
eaten by
eaten by
eaten by
After death
Food Chain
Man can neither increase the amount of energy nor improve efficiency in energy transfer- but can shorten the food chain.
25,000 cal
Types of Food Chains Grazing food chain
Detritus food chain
Food Web Food chains inter-linked with one another to form a
food web. It constitutes a number of alternate paths for energy flow and provides greater stability to the ecosystem
Bioaccumulation and Biomagnifications refers to how pollution enters a food chain. Here
there is an increase in concentration of a pollutant from the environment to the first organism in a food chain. Refers to the tendency of pollutants to concentrate as they move from one tropic level to the next. the pollutant must Long-lived 2. Mobile 3. Soluble in fats 4. Biologically active 1.
Material Cycling and Energy Flow Energy does not cycle in the ecosystem, its flow is
unidirectional. First law-energy cannot be created or destroyed it can change from one form to another. Energy es from herbivore to carnivore not vice versa The ecosystem can maintain its entity and prevent the
collapse of the system due to unidirectional energy flow
Balance of Nature The component parts like food chain, material cycling and
energy flow are closely interrelated to different organisms thereby maintaining a dynamic equilibrium amongst them. The science of systems of control in an ecosystem is known as cybernetics