Timber iQ February - March 2019 // Issue: 42 | Page 10

NEWS Trees and climate change: faster growth, lighter wood The wood density of European trees has been decreasing continuously since 1870. Wood from commercially farmed trees offers renewability, carbon neutrality and versatility required for green innovation. T rees are growing more rapidly due to climate change. This sounds like good news. After all, this means that trees are storing more carbon dioxide from the atmosphere in their wood and hence taking away the key ingredient in global warming. But is it that simple? A team from the Technical University of Munich (TUM) analysed wood samples from the oldest existing experimental areas spanning a period of 150 years – and reached a surprising conclusion. The team led by Hans Pretzsch, Professor for Forest Growth and Yield Science at the TUM, examined wood samples from several hundred trees and analysed every single annual ring using a high-tech procedure — a total of 30 000 of them. "The heart of the LignoStation is a high- 8 FEBRUARY / MARCH 2019 // frequency probe which scans each sample in steps of a hundredth of a millimetre," says Pretzsch, explaining the analysis procedure. "By doing so, we measure the specific weight of the wood with an accuracy and resolution which until recently was unthinkable." The wood samples come from the oldest experimental forest plots in Europe which were created at the same time the TU Munich was founded 150 years ago. The samples were taken from common European tree species such as spruces, pines, beeches and oaks. "We have detailed knowledge of the history of every single plot and tree," says Pretzsch. "This allows us to rule out the possibility that our findings could result from the forest being managed differently now when compared to 100 years ago." www.timberiq.co.za