Fire has been a constant visitor to Tasmanian forests for millions of years. It has shaped the evolution of many plant species and communities. In fact, many species are not only adapted to fire, but actually have features that help to promote it. Fire is an essential part of the life cycle of many plant communities, including dry eucalypt forests and wet eucalypt forests. Fire behaves differently, however, in each of these systems. A key difference between eucalypts and rainforest trees is that eucalypts are adapted to, and take advantage of major, widespread disturbances of the forest canopy, especially those caused by fire. Individual trees of different species can withstand the effects of fire to varying degrees, but all eucalypt forest types depend on it to some extent for regeneration. Eucalypt seed release is triggered by fire, when tough, woody capsules empty their contents onto a nutrient-rich ash seedbed from which all the understorey competition for light, water and nutrients has been removed. Browsing animals are driven out for a time, and the heat-treatment of soil reduces the numbers of plant-eating insects and soil organisms during the short but crucial early growth period.