Forests are the dominant terrestrial ecosystem of the earth, and are distributed across the goble.Forests account for 75% of the gross primary productivity of the Earth’s biosphere, and contain 80% of the earth’s plant biomass. There are three broad categories of forest definitions in use;administration,land use, and cover use .A forest is made up of many layers .Starting from the ground level and moving up, the main layers of all forest types are the forest floor, the understory and the canopy. The emergent layer exists in tropical rainforests. Each layer has a different set of plants and animals depending upon the availability of sunlight, moisture and food. Forests may provide a diversity of ecosystem services including recycling carbon dioxide into oxygen, acting as a carbon sink, aiding in regulating climate, purify water, mitigating natural hazards such as floods, and serving as a genetic reserve.
