Lecture 2-1 PDF - Types of Ecosystems

TYPES OF ECOSYSTEMS 1- Natural ecosystems :These operate themselves under natural conditions. Based on habitat type, Natural ecosystems can be further classified into two types: A-Terrestrial ecosystems :These ecosystems are related to land. Ex: Grassland ecosystem, forest ecosystem, desert ecosy...

TYPES OF ECOSYSTEMS 1- Natural ecosystems :These operate themselves under natural conditions. Based on habitat type, Natural ecosystems can be further classified into two types: A-Terrestrial ecosystems :These ecosystems are related to land. Ex: Grassland ecosystem, forest ecosystem, desert ecosystem, etc,. B-Aquatic ecosystems :These ecosystems are related to water. ١ Aquatic ecosystems are further sub classified into two types based on salt content: Fresh water ecosystems (a)Running water ecosystems, Ex: Rivers, Streams… (b)Standing water ecosystems, Ex: Pond, lake… Marine ecosystems Ex: Seas 2- Man-made or Artificial ecosystems: Artificial ecosystem are operated (or) maintained by man. Ex: Croplands, gardens… ٢  FUNCTION OF ECOSYSTEM Functions of an ecosystem are of three types: Primary function: The primary function of all ecosystems is the manufacture of carbohydrates (photosynthesis). Secondary function: The secondary function of all ecosystems is the distribution energy in the form of food to all consumers. Tertiary Function: All living organisms die at a particular stage. These dead organisms are decomposed to initiate the third function of ecosystem namely “cycling.” ٣  The functioning of an ecosystems may be understood by studying the following terms: Energy and material flow. Food chains Food webs Ecological pyramids ٤  ENERGY FLOW IN THE ECOSYSTEM Energy is the most essential requirement for all living organisms. Solar energy is the only source of energy to our planet earth. Solar energy is transformed to chemical energy in photosynthesis by the plants (producers). Some amount of chemical energy is used by the plants for their growth and the remaining is transferred to consumers by the process of eating. ٥ ٦  FOOD CHAINS A food chain is the order of events in an ecosystem, where one living organism eats another organism, and later that organism is consumed by another larger organism A food chain always starts with plant and ends with animal. When the organisms die, they are all decomposed by microorganism (bacteria and fungi) into nutrients that can again be used by the plants. At every level, nearly 80-90% of the potential energy gets lost as heat. ٧ A food chain ٨ ٩  FOOD WEB Food web is the interlocking of various food chains in an ecosystem. In a food web, many food chains are interconnected, where different types of organisms are connected at different tropic levels, so that there are a number of opportunities of eating and being eaten at each tropic level. Grass may be eaten by herbivores such as insects or rats or deers, etc ,.and these herbivores may be eaten by carnivores) such as snake or fox or tiger. ١٠ ١١