Forests are biologically diverse systems, representing some of the richest biological areas on Earth. They offer a variety of habitats for plants, animals and micro-organisms. However, forest biodiversity is increasingly threatened as a result of deforestation, fragmentation, climate change and other stressors. Tropical, temperate and boreal forests offer a diverse set of habitats for plants, animals and micro-organisms. Consequently forests hold the majority of the world’s terrestrial species. However these biologically rich systems are increasingly threatened, largely as a result of human activity.