Fire scars on a giant sequoia tree in CaliforniaDavid McNew/Getty ImagesScars on trees left by fires hundreds of years ago are helping scientists understand past wildfire trends across North America and giving clues to how blazes might unfold with further climate change.Fire scars are small wounds made when fires burn near trees but dont kill them. They provide rich details about past wildfires and their underlying causes, says Chris Guiterman at the University of Colorado, Boulder.For dendrochronologists examining fire scars, every