TORONTO -- A based on European forest trees indicates that climate change is leading to longer growing seasons and causing leaves to fall earlier in the year.
Using a combination of experiments and long-term observational research dating back to 1948, scientists from the Swiss Federal Institute of Technology and University of Munich found that leaves are likely to fall three to six days sooner by the end of the 21st century, rather than lengthening by one to three weeks as current models have predicted.
Researchers say this predicted pattern will limit the capacity of temperate forests to mitigate climate change through carbon uptake.
In conducting their research, scientists obtained more than 430,000 phenological observations from 3,855 sites across Central Europe from 1948 to 2015.
According to the study, elevated carbon dioxide, temperature and light levels are causing an increase in spring and summer photosynthetic productivity. Leaves are emerging earlier and they鈥檙e also falling sooner than expected.
The new findings reveal the critical constraints on future length of growing-seasons and carbon uptake of trees.
Natural Resources Canada says forests can act as either carbon sources or carbon sinks, which means that a forest can either release more carbon than it absorbs or it can absorb more carbon than it releases.
鈥淔or decades we鈥檝e assumed that growing seasons are increasing and that the autumn leaf-off is getting later,鈥� co-researcher and professor at ETH Zurich Thomas Crowther told . 鈥淗owever, this research suggests that as tree productivity gets higher, the leaves actually fall earlier.鈥濃��
