Dieback is a state where trees show they are under great stress, where they begin to lose their leaves, then their twig and small branches, large branches, and finally die. Individual, scattered trees do this all the time, but when large numbers dieback together it is sign of a major problem. Often however the fieback happens slowly and noone notices until dying trees cover hundreds of hectares. Early observation of patches of dead or dying back trees will help us find where the problems are, and hopefully help restore the forests and woodlands to health.