Patient zero was probably in Puna, a lush, wild district not far from Volcanoes National Park on Hawaii’s Big Island. In 2010, the U.S. Forest Service and University of Hawaii started getting calls from distraught landowners in the area about ohia trees on their properties. Ohias, the bright, flowered trees that dominate nearly 50 percent of the island-state’s forests, are known for their ability to thrive nearly anywhere across the archipelago. But a swath of them had withered mysteriously and died in a matter of weeks.
Animal assemblages are often viewed as a product of the ecosystems in which they live, but in reality they are often the reason an ecosystem looks the way it does. The roles of animals in shaping ecosystems are so important that two special issues recently published in PNAS and Ecography focus specifically on megafauna (literately translated as ‘large animal’) and the important roles they play in ecosystems, as well as what we may have lost through their extinctions across much of the globe.
While much of the country is dealing with rain and snow, California is still dry. One hundred percent of the state is in some form of drought, and a new study just released by the Carnegie Institution for Science has now put a number on what the drought has done to California’s iconic forests. A high-tech flying laboratory has been soaring over California, measuring the impact of four years of drought.
“There’s a lot of red on this screen, which is a sign that we’re over an area that’s in trouble,” scientist Greg Asner told CBS News.
New maps reveal the extreme impact the years-long drought has had on California’s trees and offer a prognosis for future forest health.
Up to 58 million trees have been severely stressed by the drought and related factors, such as rising temperatures and a plague of bark beetle infestations. If the drought persists, hundreds of millions of trees throughout the state could die, according to a study published this week in Proceedings of the National Academy of Sciences.
The past four years of punishing drought have badly hurt California’s forests. Rain was scarce, the days were too hot, and this year’s wildfire season was the worst anyone has seen in years, burning up nearly 10 million acres across the West. For the first time, a team of researchers has measured the severity of the blow the drought dealt the trees, uncovering potential future destruction in the process. The resulting paper, published Monday in the Proceedings of the National Academy of Sciences, is a rich visual testament to just how much California needs its trees and how close the state is to losing 58 million of them.
In the summer of 2014, biologist Nathan Stephenson was surveying giant sequoias in a clearing in Sequoia National Park. He looked up at the crown of a mature giant sequoia, hundreds of years old, and noticed that half of its leaves had turned brown.
Biologist Greg Asner first heard the numbers in April, but they did little to prepare him for what he saw.
THE VIEW OUT THE WINDOW WAS BAD ENOUGH. As his research plane flew over groves of California’s giant sequoias, some of the world’s tallest trees, Greg Asner could see the toll the state’s four-year drought had taken. “It looked wicked dry down there,” he said. But when he turned from the window to the video display in his flying lab, the view was even more alarming. In places, the forest was bright red. “It was showing shocking levels of stress,” he said.
California’s historic drought has created a long list of problems for the Golden State, including killing millions of trees in the Sierra Nevada Mountain Range. Now even the iconic giant sequoias, which can live thousands of years, are starting to show signs that they’re not getting enough water.