Ecology is the study of interactions between biotic and abiotic factors in a given environment and is concerned with basically four levels of biological organization - organisms, populations, community and biomes. Biome is a community of fauna having similar features for the environment they live in.

Vegetation that is dominated by the continuous cover of grasses is said to be grasslands. The region is covered by small shrubs and herbs rather than tall plants. The mean annual temperature and precipitation in this region is about $0^{\mathrm{o}}\mathrm{C}\mathrm{ }\mathrm{t}\mathrm{o}\mathrm{ }{25}^{\mathrm{o}}\mathrm{C}$ and approximately $25-100\mathrm{ }\mathrm{c}\mathrm{m}$.

Forest region having an abundance of cone-bearing needle leaf evergreen trees with long winter and moderate to high precipitation is considered under coniferous forest. They are found in the region above the tropical region. The mean annual temperature is around $-1^{\mathrm{o}}\mathrm{C}\mathrm{ }\mathrm{t}\mathrm{o}\mathrm{ }{13}^{\mathrm{o}}\mathrm{C}$ and mean annual precipitation is approximately $50-250\mathrm{ }\mathrm{c}\mathrm{m}$.

Below image describes the requirement of MAP and MAT of different forest types.