also present within Jarrah Forest. Many of these invertebrate species are responsible for nutrient recycling, an essential element of Western Australia's biodiversity. In particular, the insect group Apocrita, which includes wasps, bees, and ants, are a keystone group that, through predation and parasitism, keep other invertebrate populations controlled. The loss of Apocrita could be detrimental to the invertebrate community and to the jarrah forest ecosystem. Rare and endandered native bees include Leioproctus douglasiellus and Neopasiphae simplicior. History The first evidence of human habitation of the region was 50,000 years ago at Devil's Lair by ancestors of today's Aboriginal people. The Noongar are the Aboriginal inhabitants of the bioregion. The Noongar comprised 14 groups, which spoke distinct but mutually-intelligible languages. Aboriginal populations were generally denser on the coastal plain and along the coastal forest edge, and in the interior woodlands and shrublands, particularly near permanent streams and river estuaries. Population was sparse in the forested areas of the south. The Aboriginal inhabitants deliberately set fires to manage the land and vegetation. Evidence from lake and estuarine sediments and firsthand accounts suggest that fire intervals in well-settled areas were frequent – from one to ten years – compared to unoccupied forests and offshore islands, where fire intervals were 30 to 100 or more years. Frequent burning reduced woody cover and encouraged the growth of low shrubs, herbs, and grasses, fostering open woodlands, shrublands, and savannas and limiting areas of dense forest and thicket. Settlement of the region by Europeans began in the 19th century. Forests were logged for timber, and areas cleared for agriculture and pasture. The Noongar were dispossessed from much of the land, and the fire regime changed from one of deliberately-set low-intensity fires to one of general fire suppression, with accidental or lightning-set fires which are less frequent but often more intense. Jarrah (Eucalyptus marginata) is considered one of the best general purpose hardwoods in the world. The British started logging the jarrah forest in the 1840s to produce timber for use in construction, transport and power, and to protect water supplies. Logging was largely unregulated until the release of the Forests Act of 1918. The following 50 years saw forest management expand to include water quality and yield, soil management, rehabilitation of mined forest, recreation and nature conservation. Today jarrah is harvested for high quality furniture and flooring. Environmental threats Most of Jarrah Forest has been cleared for