20.11.23~20.11.29 Climate change could bring the start of Autumn forward by almost a WEEK because trees are capturing more carbon causing leaves to fall sooner

1658
소스 이미지 보기

The start of autumn could begin a week sooner in the future due to climate change causing trees to capture more carbon and drop their leaves earlier in the year.
…
However, a new, large-scale study of European trees by the Swiss Federal Institute of Technology has found this trend has started to reverse and leaves are falling earlier.  
The new discovery means instead of autumn starting up to three weeks later, it will start between three and six days earlier over the course of the century.
The presence of leaves on deciduous trees marks the changing of the seasons – and the period of time in which trees store carbon from the air.
Warning winters cause spring leaves to emerge earlier and it a widespread example of a climate-change impact, according to the team behind the study.
…
Dr Zani and colleagues used long-term observations from dominant Central European tree species from 1948 to 2015 and experiments designed to modify carbon uptake to evaluate the related impacts.
The study showed an increased growing-season in spring and summer due to more CO2, light and higher temperatures will lead to earlier leaf shedding – not later.
This is likely because roots and wood cease to use or store leaf-captured carbon at a point – making leaves costly to keep….
‘These findings demonstrate the critical role of sink limitation in governing the end of seasonal activity and reveal important constraints on future growing-season lengths and carbon uptake of trees,’ said Zani.
The results ‘substantially lower our expectations of the extent to which longer growing seasons will increase seasonal carbon uptake in forests,’ she added.
…

An excerpt form   https://www.dailymail.co.uk/sciencetech/article-8990765/Climate-change-bring-start-Autumn-forward-week.html