Taylor’s power law reveals tree growth uncertainties increase with climate warming

Background/Question/Methods

Although the impact of global warming on tree growth has well been recognized, it is poorly understood how tree growth fluctuates as global warming makes the climate become increasingly unpredictable. Using a global tree-ring dataset, we reconstructed the histories of mean tree growth and growth variation over the past two centuries and modeled their relationships using Taylor’s mean-variance power law.

Results/Conclusions

We found that the 5-year mean and variance in tree growth rate both increased significantly over time, and the variance-mean Taylor’s power law had a global average exponent of 1.5. The exponent was generally larger for species with lower resistance to drought and increased over time as global warming intensifies. Our study shows that warming strongly destabilizes global tree growth and makes forest dynamics less predictable, jeopardizing the functioning of global forest