The changing of the colour of the autumn leaves is a spectacular, photogenic, natural event in many forests around the world. The myriad of golds, reds, yellows, greens and browns provides a colourful canvas that ushers in the end of summer. This year in the USA, the autumn foliage has been adversely affected by drought conditions. The vibrant colours of the leaves have been dulled by unusually dry weather. Over 80 per cent of America's northwest is undergoing extreme conditions that are not conducive to perfect foliage. The traditional autumnal beauty spots of Massachusetts, Maine, Rhode Island and New Hampshire are experiencing severe drought, and lacklustre colours.
Dr. William Keeton, a forest ecology and forestry professor at the University of Vermont, explained why the adverse conditions were prevalent this year. He said: "It is due to a combination of factors, including good tree growth last year, mild drought and both warm days and cool nights over the last month." He added: "The colours this year are coming about two weeks earlier than normal and will probably go by fast and furiously. Largely, this is because the drought creates physiological stress for the trees." He warned: "The stress is not a good thing and may be a harbinger of things to come with climate change. In terms of fall foliage, drought can cause the leaves to die and fall off earlier."