A new study from Umeå University has revealed that trees' circadian clocks guide their growth and the timing of seasonal events like the appearance of leaves in spring. The researchers investigated ...

Add Yahoo as a preferred source to see more of our stories on Google. Most people associate circadian rhythms and internal clocks with humans and animals, but plants have them too. And a new study ...

Leonardo da Vinci seems first to have noticed that widths of tree rings vary in wet and dry years, but there is a big gap between his discovery and a history of tree rings that chronicles Midwest ...