Explanation:1) Energy or Power: The whole ecosystem is undertaken from the energy of different type – solar power, man power and fuel power including electricity. But solar power is most important which is the natural energy and PROVIDES different type of driving force to all other segments-plants and man. (2) Biotic Factors: The biotic factors of the ecosystem consists of all living organisms found on the earth. These group of factors can be classified into three forms: (i) Consumers, (ii) Producers and (iii) Decomposers or Assimilators. i. Consumers: The consumers as the segments of the ecosystem depend on the plants (producers) for food and energy either DIRECTLY or indirectly. These living organisms are animals and men who belong to this category. The groups of herbivores are primary consumers who directly depend on green plants. The group of carnivores are SECONDARY consumers who indirectly depend on green plants, as they depend on herbivores for their food. Tertiary consumers are those carnivores who depend for their food on the other groups of carnivores. ii. Producers: Plants and trees are said to be the producers on the earth. They use solar energy with other nutrients from the earth and produce fresh oxygen and food for the life of animals. Plants also help to reduce the amount of CO2 in the atmosphere. These living organisms, so called producers, give some positive contribution to the ecosystem. iii. Decomposers: These living organisms-producers and consumers RELEASE a lot of waste during their life. Their dead body when they die becomes a waste on the earth. Micro organisms like bacteria, fungi, etc. play a role as a decomposer on the earth. Consuming this waste, they regenerate the energy out of the waste and back it into the ecosystem. (3) Abiotic or Physical Factors: ADVERTISEMENTS:  Abiotic or physical factors are concerned with the non-living elements found on the earth. In fact, these factors are so important to determine the life of the organisms on the different parts of the earth. These factors are described as under: i. Temperature: It is the optimally regulated temperature on the earth that has developed and supported the life on this planet. The temperature affects the metabolic activities, growth, men, animals, food habits and several other activities. Any change in the temperature which may happen over a long period of time may bring a big challenge to the support of life on the earth. ADVERTISEMENTS:  ii. Topography: The topography represents to the features or the conditions on the surface of the earth. The surface of the earth may have different kinds of features – hilly region, grassland, plateau, desert, ice-caps and plain and smooth region. The soil of the different places also varies. The variety of the soil and surface conditions of the earth determines the vegetation and the quality of life on the particular piece of land. iii. Water: A huge quantity of water is found on the earth which is stored in oceans, rivers, lakes, ponds and in side the land. Water which may be called the “drinking water” on the earth is very limited and not available to the common men. But the quality of water is most essential to the vegetation and the support of life on the earth. iv. Air: The various components of air consist of a number of gases, humidity and wind. It provides the ever important oxygen essential for the life of living organisms on the earth. All these factors determine the living conditions and the habitation pattern among human-beings. Today, air is polluted for the different reasons and the ozone layer has become THINNER, and it has affected the quality of life of the humanity and the health conditions are being deteriorating over the period. v. Light: The sun is the main source of energy and light on the earth. The plants and men use this light as an input in their photosynthesis process and produce oxygen and food which support the life on the earth. Today, the created holes in the ozone layer has permitted ultra-violet rays to enter on the earth and it has become a great challenge to the life on the earth.