(N/A) Ecology at the organismic level is essentially physiological ecology,which attempts to understand how different organisms are adapted to their environments in terms of both survival and reproduction.
The rotation of the Earth around the Sun and the tilt of its axis cause annual variations in the intensity and duration of temperature,resulting in distinct seasons.
These variations,combined with annual variations in precipitation (rain,snow),result in the formation of major biomes,such as deserts,grasslands,tropical forests,temperate forests,coniferous forests,and tundra,as shown in the figure.
Regional and local variations within each biome lead to the formation of a wide variety of habitats.