For example, intensive recreational facilities such as campgrounds often result in the removal of the local vegetation a fuel wood for camp fires. Because conifers are a common component in mountainous regions where they often dominate, they are particularly vulnerable to the development of winter sport activities such as ski resorts. Over 90% of the major armed conflicts between 1950 and 2000 occurred within countries containing biodiversity hotspots, and more than 80% took place directly within hotspot areas. Civil unrest can have a serious negative impact on biodiversity. The Vit Nam war used poisonous Agent Orange as an aerial forest defoliant in which 14% of the forest cover was affected.