Drought’s heat killed Southwest’s piñon forests

At this New Mexico site, piñon pines were damaged by 2002 (left) and dead by 2004 (right) in a scorching drought. At sites across four states, a team headed by David Breshears of the University of Arizona in Tucson found that 40 to 80 percent of the pine nut–producing trees died during the drought and its plague of bark beetles.