Climate change is impacting when the growing season in nature begins in the spring and when it ends in the autumn. Previous research has shown that changes to the climate seem to be affecting different species of trees in different ways, and that the changes vary in different regions. Although this is an important issue that is fundamentally affecting the ecosystem, little is known about how climate change affects the autumn leaf development of different tree species. Therefore the Autumn Experiment was an important experiment.
Altogether over 10,000 pupils sent in reports on more than 2,000 trees from 378 different locations in Sweden. Using the observations, researchers could examine the differences between various tree species and regions. The researchers also compared the pupils’ reports with observations made 100 years ago and with satellite imagery. From the researchers’ point of view, the Autumn Experiment was a unique opportunity to get reports from thousands of research assistants around the whole of Sweden.
The Autumn Experiment was a collaboration between researchers at the Swedish University of Agricultural Sciences, Umeå University, Lund University and VA (Public & Science). It was carried out as part of ForskarFredag – the Swedish events during the European Researchers' Night.
How does a tree know it is autumn? How is climate change affecting when the leaves of Swedish deciduous trees turn colour in the autumn? Are there variations in autumn leaf development between different tree species and in different locations in Sweden? Is it possible to study autumn using satellite images? These are the questions that the mass ‘Autumn Experiment’ was helping scientists to answer.