Category: Subjects

There is a circulation of chemical nutrients like oxygen, carbon, nitrogen, phosphorus, calcium, and water, etc. through the physical and biological world; between the atmosphere, hydrosphere, lithosphere, and biosphere. These cycles are known as biogeochemical cycles. These cycles are natural pathways of the circulation of essential elements of life. For the survival of the major… Continue reading BIOGEOCHEMICAL CYCLES

Ecological pyramids are the diagrammatic representations of the feeding relationship and energy transfers in the ecosystem. They are of three types: Pyramid of Numbers, Pyramid of Biomass and Pyramid of Energy. Pyramid of Numbers: It represents the relationship between number of individuals of primary producers and consumers at different trophic levels. It can be upright… Continue reading Ecological Pyramids

Food Chains A food chain describes how energy and nutrients move through an ecosystem. It basically shows who eats what in the ecosystem. Thus, the transfer of energy from the source in plants through a series of organisms by eating and being eaten constitutes food chains. At each transfer, a large proportion of energy is… Continue reading Food chains and Food webs

The term ecological niche was developed by Charles Elton. Ecological niche may be defined as ‘the functional role and position (micro-habitat) of species in its ecosystem, including what resources it uses, how and when it uses the resources, and how it interacts with other species. The ecosystem stability depends upon the diversity of the niche.… Continue reading Ecological niche

F.E. Clement postulated the concept of Vegetation/Ecological succession which is the process of change in the species structure of an ecological community over time. The time scale can be decades (after a wildfire), or even millions of years after a mass extinction (Permian, Triassic, cretaceous). The development of vegetation community in any ecosystem or habitat… Continue reading Ecological succession

Ecosystem functions through the input of energy mainly solar radiation. L. Lindeman has formulated principles about the relationship between trophic levels within a natural ecosystem. Principle 1: As the distance between the organisms of a given trophic level and the initial source of energy (trophic level one) increases, the probability of the organisms to depend… Continue reading Principles of ecosystem function?

“Ecosystem” term was first coined by A.G. Tansely, in the year 1935. In simple terms, it is a community of living and non-living things that work together. The living and non-living things continuously exchange materials and energy between them. It forms the structural and functional unit of the biosphere (sphere of life). Ecosystem varies greatly… Continue reading What is an Ecosystem?

What is Environment? The word Environment means ‘surroundings’ (environs). Therefore, the environment of an individual, object, or system includes all of the other entities – both living (biotic) and non-living (abiotic)-with which it is surrounded. In an environment. What are the different types of environment? Primarily, the environment can be categorised into two: Natural Environment:… Continue reading What is Environment?