Adventitious bud (Bot.) A bud from any part of the stem, leaves or roots that is not connected with the strands of bud-bearing tissue arising from the axis of the leaves.
Aeration, Soil (Ped.). The process by which air and other gases in the soil are renewed. The rate of soil aeration depends largely on the size and number of soil pores and on the amount of water clogging the pores. A soil with many large pores open to permit rapid aeration is said to be well aerated, while a poorly aerated soil either has few large pores or has most of those present blocked by water. (SSSA).
Aerobic. Applied to soil organisms that can live only in the presence of oxygen and to conditions in which free oxygen is available. Anton. Anaerobic.
Aestivation (a) The process of passing a period of hot season or prolonged drought in an inactive state. (Also spelt Aestivation). Cf. Hibernation
After-ripening. Biochemical or physical changes occurring in seeds, bulbs, tubers and fruits after harvesting when ripe in the ordinary way; often necessary for subsequent germination or growth. (BCFT ).
Alpine. (Ecol.) A term applied to the zone of vegetation where winter is severe, snowfall heavy, the mean annual temperature below 45°F. and the mean January temperature below 30°F. In India, alpine zone occurs in the Himalayas at altitudes above 3030.0m.
Anaerobic. Applied to organisms that can live without free oxygen and to conditions in which free oxygen is not available. Anton. Aerobic.
Artificial Reproduction. The result of artificial regeneration, seedling or growth obtained by sowings, planting , etc.
Aspect.(a) The direction towards which a slope faces. CfExposure. (b) (Ecol.). The seasonal appearance of a community, e.g., Spring aspect, Summer aspect etc.
Associate. (a) (Ecol). Applied to any of the dominant species associated with a given species in a plant Association . (b) Also applied loosely to all species, dominant or otherwise, associated with a given species in a crop (Deprec.).