The benefits provided by forest ecosystems include: goods such as timber, food, fuel and bioproducts. ecological functions such as carbon storage, nutrient cycling, water and air purification, and maintenance of wildlife habitat.
Like all ecosystems, forests consist of many interacting parts. They include living organisms such as plants, animals, and fungi. Forests also include non-living components that these organisms depend on, such as the soil and climate. As stated in the article, one change, such as pollution, can cause a ripple effect through the ecosystem. Dying lichens are one of the earliest signs of pollution. In turn, the loss of the lichens can cause a decline in species that rely on the lichens for survival.
By the process of cellular differentiation which consists of physical and functional changes of the cell used by processes at the genetic level. The expression of these in each type of cell is different. That is to say that the type of cell follows at a time of development there is differential activation of some genes and repression of others
