High synchrony of tree growth is followed by a uniform pattern of de-synchronization

Aim: Growth asynchrony in trees increases deviation in the average of forest growth and, consequently, brings uncertainty in modeling forest productivity and other functions. Despite recognition of growth variability among trees, the process of asynchronous growth and its ecological implications are poorly understood. Here we used tree-ring data to show that, although forest growth is influenced by climatic factors, inter-annual growth changes of individual trees often do not respond in a synchronous manner.
Location: China.
Time period: The past five and a half centuries.
Major taxa studied: Forest tree growth.
Methods: We used tree-ring methods and tree-ring data obtained from increment core samples in 1046 juniper trees at 32 sites and 538 pine trees at 20 sites to explore the implications of growth asynchrony in maintaining forest stability in the face of environmental fluctuations.
Results: After highly synchronous growth events, the number of trees keeping continuous growth synchrony declined progressively and, notably, in a relatively uniform pattern.
Main conclusions: We argue that diverse rather than synchronized growth spreads the capacity of trees to respond to disturbances and stresses at the individual level, consequently enhances forest resilience to risks of climate uncertainty. This resilience-acquisition strategy is an inherent and an adaptive property of forest tree growth that is similar to maintaining a diversified financial investment portfolio. This new perspective on widespread asynchronous tree growth sheds insight into assessment of forest health risks under future climate change.