In only the autotrophs can produce their own food and the others are dependent on this production. All the living organisms in an ecosystem are interrelated in terms of feeding and being fed thus forming a definite chain known as food-chain. Food chains are of two main types: 1. Grazing food-chain: Starting with autotrophic plants [...]
It is the most powerful weather event on the earth, disrupting weather pattern across half of the earth’s surface. The most recent El Nino began to develop in 1989 and lingering until 1995. It resulted in unusual weather and short term climate changes that caused losses in crops and commercial fishing.
The BOD test is an indirect measure of the biodegradable organic matter in an aqueous sample. The test is indirect because oxygen used by microbes as they degrade organic matter is measured. Generally the test is performed over a 5 day period (BOD5) of 20°C in 300 ml bottles incubated in the dark to prevent [...]
A large terrestrial or aquatic ecosystem characterized by distinctive kinds of plants and animals and maintained by a distinct climate and soil conditions. Such as the desert biome is characterized by low annual rainfall, high rate of evaporation, resulting in dry environmental conditions. Special adaptations allow organisms to survive in this condition. Other examples of [...]
The term is used to describe the growth and accumulation of living organisms on the surfaces of submerged artificial structures as opposed to natural surfaces. It results in increased costs of recovery of normal functioning of man made structures such as ships, buoys, floats, pipes, cables etc. Biofouling may be of two types- Microfouling- microorganisms [...]
Organic matter produced within an ecosystem is known as autochthonous material. Organic matter entering a stream, lake or ocean but derived from an adjacent terrestrial ecosystem is identified as allchthonous material.
A term with alternative definitions, not all of them synonymous. To state two (i) the ‘occupation’ of ‘profession’ of an organism or species, or (ii) the range of conditions, resource levels and densities of other species allowing the survival, growth and reproduction of an organism or species. Hence, if each condition, resource or other species [...]
A term referring to the theory that when a group of people collectively own a resource, individuals acting in their personal self-interest will inevitably overtax and destroy the resource. The theory was introduced by Garrett Hardin (1968) to modern discussions of population growth. Many global environment problems like ozone layer depletion are the consequences of [...]
An ecosystem focuses is any spatial or organisational unit which includes a community of living organisms and non-living substances of environment interacting to produce and exchange of materials between the living and non-living parts. It may be as small as a puddle or as large as the entire earth (biosphere or ecosphere). Further, an ecosystem [...]
Pollution may be defined as any change in the physicochemical or biological attributes of the environment that causes a disturbance in normal life process and comfort of all organisms including human beings. Biodegradable Pollutants: Animal excreta, manures and some daily requirements. Non biodegradable Pollutions: Heavy metals, Organo-chlorine Pesticides and some organic compounds in daily use.
Dr. Amlan Kumar Mitra, Biology Guide Since 2009
