Globally, mountainous areas are rich in biodiversity. They are habitats of many species of plants and animals, and even people. One-tenth of the world’s population dwells in mountainous regions, and mountains contain useful resources such as water, timber, and minerals. However, mountains are also vulnerable eco-systems, and in recent years, they have faced serious environmental destruction. The term “vertical zonation structure” is often used to describe the environmental characteristics of mountain eco-systems. This vertical zonation structure frequently affects residents’ land-use patterns, which makes it useful for determining the locals’ livelihood. This study, which focuses on the mountain village P in Sri Lanka, researches changes in land-use patterns with respect to vertical zonation. Furthermore, changes in livelihoods will be discussed, including non-farm income.