Leaf peeping(看),the practice of traveling to watch nature display the fall colors,is a beloved annual activiy,especially in New England.But recent seasons have been disrupled by weather conditions. Typically,by the end of September,leaves take on warmer colors throughout the U.S.This year,many areas haven't even shaken off the green shades of summer.In Maine,where peak conditions typically arrive in September,forest rangers reported less than 70%color change and modest leaf drop.

The reason climate change can be bad for fall foliage( 叶 子 ) has a bit to do with plant biology.Like people,trees must prepare for winter.When fall arrives,and day length and temperature drop,trees respond by ending green substance production and absorbing remaining nutients,causing leaves to lose the original color.Greens give way to yellows,reds and oranges that make for dramatic autumn displays.

Achieving those peak colors is a delicate balance.Warm fall temperatures can make the fall colors appear later.Worse,dry summers can cause leaves to miss the fall color turn altogether.Delay of the start of the fall colors,which has been moving later into the fall,could subsist. "My observations in the last decade have had more years that were later than what we consider historical averages.It can be a trend as the planet

warms,"said foliage expert Jim Salge.

It's not just the plants that suffer."Turning leaves offer an iresistible mass of color —which,by estimate,generates as much as billions of dollars a year in tourism in New England,"said Andy Finton,a forest ecologist.That's another good reason to focus on preserving forests.Leaf peeping can stay part of the area's feature if forests are given enough protection."If we can keep them unharmed,they'll provide things

we've depended on,as well as fall inspiration,"said Finton.