Birth rate (b) = \(\frac { number\ of\ births\ per\ unit\ time }{ average\ population } \)
Death rate (d) = \(\frac { number\ of\ deaths\ per\ unit\ time }{ average\ population } \)

Fishes undergo aestivation to avoid summer related problems.
Bears undergo hibernation to avoid winter-related problems.

The alpine zone between Timberline and snow zone includes in the descending order, a subs now the zone immediately below the snow zone, a meadow zone in the centre and a shrub zone which gradually merges into the timber zone.

The largest and most nearly self-sufficient biological system is often designated as the Ecosphere, which includes all the living organisms of the Earth, interacting with the physical environment to regulate their distribution, abundance, production and evolution

When resources are in more than adequate to meet the demands of the organisms seeking them, competition does not occur, but when inadequate to satisfy the need of the organisms seeking them, the weakest, least adapted, or least aggressive individuals are often forced to face challenges. This phenomenon is known as the competitive exclusion principle of Hardin.

Migration and Courtship

Warm blooded animals, living in colder climates, tend to have shorter limbs, ears and other appendages when compared to the members of the same species in warmer climates.

1. The characteristic of soil that determines the movement of water through pore spaces is known as soil permeability.
2. Soil permeability is directly dependent on the pore size. Water holding capacity of the soil is inversely dependent on soil porosity.

This is the level of exposure of plants to environmental factors that leads to neither injury nor reduction in growth and yield of crops.

Ecological niche is a term for the position of a species within an ecosystem, describing both the range of conditions necessary for persistence of species, and is ecological role in the ecosystem.