Ecotones are formed due to major or drastic changes in the environment. Here, some sharp boundaries are produced. For example, an area between the areas of forest and a cleared land near it. One of the major reasons for the formation of ecotones is the mountain range. They show a wide variety of climatic conditions that are present on the slope ranges. The terrain can act as an obstruction that provides a boundary between the species. For example, Mont Ventoux of France acts as a boundary between the fauna and flora of northern and southern France.