The huge rainforest of Irian Jaya occupies about 40 million Ha. About 42% of this rainforest has been turned into nature reserves and protected forests and is overseen by the Indonesian government. The largest protected area in the Central Ranges is the 21,500 km2 Gunung Lorentz Nature Reserve in the Snow Mountains. The montane flora is dominated by distinct southern elements, which include extensive forests of Antarctic beech. Of the Nothofagus species, Nothofagus womersleyi and N. stylosa are each known from a single locality. Conifers are represented by the southern gymnosperms, including the podocarps (Podocarpus), Kauri Pine (Agathis), Hoop Pine (Araucaria cunninghamiana var. papuensis), and Klinki Pine (Araucaria hunsteinii), all valuable timber species.
Of the animals, there are 100 endemic species, 45 marsupial species, and 53 bats and rodents, as well as two primitive monotremes, the Short-beaked Echidna (Tachyglossus aculeatus) of the lowlands, and the Long-beaked Echidna (Zaglossus bruijni) of the high mountains. Eight species of cuscus occur here, as well as pygmy possums (Cercatetus caudatus and Distochurus pennatus) and ringtails (Pseudocheirus). There are four species of tree kangaroo (Dendrolagus), as well as forest wallabies (Dorcopsis) and the common Agile Wallaby (Macropus agilis) of the southeastern plains and woodlands. There is an extraordinary variety of chiroptera, with tube-nose bats, flying foxes, sheath-tail bats, horse-shoe bats and mastiff bats.