LAKE TAHOE, Calif. _ The sugar pine, with its foot-long cones and feathery branches that stretch out high above the forest, used to be one of the most common trees standing guard over Lake Tahoe's clear waters. But drought, bark beetles and climate change have ravaged this beloved conifer, whose population was already diminished by logging, development and other human activities.
From 2012 to 2016, drought and bark beetles killed more than 129 million trees in California, most of them conifers in the Sierra Nevada. On the drier, south-facing slopes on this basin's north side, sugar pines were hit especially hard as mountain pine beetles attacked the water-starved trees, tunneling through their bark until many of them died.
"You had literally side-by-side sugar pines, one alive, one dead," said University of California, Davis forest biologist Patricia Maloney.
But it's not the dead trees that interested Maloney. It was the survivors.
She wanted to know how they managed to stay healthy and green despite experiencing the same parched conditions that killed their neighbors. She thinks it has to do with innate characteristics that gave them a selective advantage over their peers.
Maloney is now leading an effort to plant thousands of seedlings descended from drought-surviving sugar pines from around Lake Tahoe, hoping they carry genes that make them more resilient to drought, waning snowpack and other impacts of global warming.
It's part of a growing recognition by scientists and land managers that the planet is warming so rapidly they can no longer just restore ecosystems to their previous state, but must step in and accelerate how plants and animals adapt.
