…Over two years, about one-fifth of all giant sequoias have been killed in extreme wildfires in California. The numbers shocked ecologists, since the enormous trees can live more than 2,000 years and have evolved to live with frequent, low-intensity fires in the Sierra Nevada. …After the 2020 and 2021 fires, scientists watched the sequoia groves to see if the next generation of trees is emerging to replace their lost parents. In some places, seedlings are filling the forest floor. In others, fewer are emerging from the burned soil. …So in a historic step, the National Park Service has begun replanting some severely burned areas. …A handful of conservation groups are suing to halt the effort, arguing that such intervention shouldn’t occur in an area designated as federal wilderness… Land managers face a key question: As humans take an increasing toll on natural landscapes, how far should we go to fix it?