The world's biggest and oldest trees are rapidly dying, research shows.
"Their demise will have substantial impacts on biodiversity and forest ecology, while worsening climate change," said ecologist William Laurance of James Cook University in Cairns, Australia.
The "biggest, most magnificent trees" provide critical food and shelter for many birds, insects and mammals.
Laurance said a number of factors are contributing to the deaths, including logging in "virgin" forests and droughts.
Climate change is also a factor, as "their photosynthesis shuts down when it gets too warm, and at night they use more energy because their metabolic rate increases."
And it's only getting worse.
"The largest, oldest trees would progressively die off and tend not to be replaced. Alarmingly, this might trigger a positive feedback that could destabilize the climate: As older trees die, forests would release some of their stored carbon into the atmosphere, prompting a vicious circle of further warming, forest shrinkage and carbon emissions."