By Huw GRIFFITH When ferocious wildfires tore through California’s prized giant sequoia forests, they killed towering trees that have lived there for thousands of years — and perhaps changed the nature of the groves forever. Now the US National Park Service (NPS) wants to give Mother Nature a helping hand, planting lab-grown seedlings it says will kick-start the return of these magnificent stands. “The goal is to reestablish enough sequoias in the first few years […]