Sun rays penetrate through the bushfire smoke haze in an alpine forest. Although inconvenient and dangerous to humans, bushfires are essential for certain plant species survival. Certain pine species have their seeds enclosed in pine cones, glued shut with strong resin. They require fire to melt the resin and release the seeds. As fire regimes have changed due to human interference, forest composition is changing. In some circumstances the reduced frequency of fires in areas is having a negative impact on forest health as the species which require fire for survival cannot reproduce.