Environment and Ecology short notes for UPSC Civil Service Examination. Aquifer: An underground layer of rock or sand that contains water. Asbestos: A fibrous silicate mineral used as construction material and insulation. It is very dangerous to health when the fibres are inhaled. Autotroph: Green plant or producer that makes its own food. Abiotic components or conditions: The non-living components or conditions of an ecosystem such as the natural resources and the atmospheric conditions. Abyssal zone: The cold and dark zone at the bottom of the ocean. Acid rain: Rain, mist, or snow formed when atmospheric water droplets combine with a range of man-made chemical air pollutants. Adaptation: Adjustment in natural or human systems in response to actual or expected climatic stimuli or their effects, which moderates harm or exploits beneficial opportunities. Agro forestry: A system of land use that combines growing crops along with trees. Albedo: The reflection of light f...