Sierra Nevada forests during drought (IMAGE) University of California - Davis Caption Forests in California's Sierra Nevada face multiple threats, from drought and bark beetles to severe wildfire and other climate-related impacts. Credit Pacific Southwest Forest Service, USDA Usage Restrictions Credit must be given to the creator. Only noncommercial uses of the work are permitted. No derivatives or adaptations of the work are permitted. License CC BY-NC-ND Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.