In the Southwest U.S., the recent years' severe drought conditions could become normal and trigger one of the worst tree mortality rates of the past 1,000 years, according to a study published by the journal Nature Climate Change.
In the Southwest U.S., the recent years' severe drought conditions could become normal and trigger one of the worst tree mortality rates of the past 1,000 years, according to a study published by the journal Nature Climate Change.
To complete their study the team, comprising scientists from the Los Alamos National Laboratory as well as scientists from various U.S. universities, looked at tree-ring data in the Southwest from the year 1000 to 2007. While the Southwest has endured several "mega droughts" over that time period, the scientists wrote, the long-term drought that began in the late 1990s could end up being the worst yet and may even be a signal for drier periods in the future.
Taking other factors like bark-beetle outbreaks and wildfires into consideration, the scientists concluded that tree mortality rate over the next 40 years will be worse than at any time over the past 1,000 years. "With increasing drought stress, our forests of tomorrow will hardly resemble our forests of yesterday," said Henri Grissino-Mayer, a geography professor at the University of Tennessee, Knoxville and one of the authors of the study.
