Environment

The marine biotic communities can be studied separately for different life zones of the ocean as follows: 1. Biotic communities of oceanic region: The oceanic region or pelagic zone is less rich in species and numbers than the coastal areas, but it has its characteristic species. Many of these are Read more…

Many groups of animals are provided with unique and intrinsic self-regulatory mechanism such as failure of reproduction and self-inflicted mortality for controlling the size of the population. Populations grow when natality exceeds mortality, and the), decline when mortality exceeds natality. However, limitation animal number in a population is brought about Read more…

One property which arises at each new higher level of organi­sation is united, integrated function. Disunited structure means independent function and by extension, competition; while united structure means joint function and by extension, cooperation. For example, the cells can remain structurally independent and can compete for space and raw materials. Read more…

Presumably, each species is fairly well adapted or fit, if it has been in its particular environ­ment for many generations. The range of tolerance of a species may be narrow (i e., species has a low ecological amplitude) or broad (i.e., species has a high ecological amplitude). Thus, orga­nisms are Read more…

Ponds, however, are considered as small bodies of standing water so shallow that rooted plants can grow over most of the bottom. Most ponds and lakes have outlet streams and both are more or less temporary features on the land­scape because filling no matter how slow, is inevitable. The aquatic Read more…

Density gives an idea of competition. If density is more, it means there is more degree of competition between the indivi­duals of the species. Density is expressed as number of individuals per unit area and is calculated as follows: Density = Total number of individuals of the species in all Read more…

The alpine zone (zone which lies between timber line and snow zone) includes in the descending order, a sub-snow zone immediately below the snow zone a meadow zone in the centre and a shrub zone which gradually merges into the timber zone. According to Mani (1957) snow zone of Himalayas Read more…

The rise and fall of these factors very frequently affect the fauna, altering their number and diversity. Some of the important factors of fresh-water environ­ment are following: Pressure, Density and Buoyancy: The pressure imposed on a lake-dwelling organism is the weight of the column of water above it plus the Read more…

Lime mortars are more porous and soft compared to other cement-based systems 19 and can be effectively used as a potential candidate to repair and rehabilitate heritage structures. The sizes of the pores present in lime mortar materials used in the current study are widely vary from >10?m to < Read more…

Kurt Lewin (1951) developed the thought of force-field analysis by looking behaviour within organization as a dynamic and not as a static balance of forces working in opposite directions within the organization. Lewins believes that, any change brought by current situation or condition of the organisation and this cause force Read more…

In the meantime, the reformative trend which was gaining momentum in the field of penology ail around the world also gave filip to the cause of correctional method of treatment of offenders in India. It was realised that confining convicts in closed prison cells hardly serves any useful purpose. The Read more…