Globally, the loss of tropical forests contributes significantly to the greenhouse effect and thus to climate change - by releasing the carbon dioxide bound in the trees. But there is another way: leaves are optimized to absorb carbon dioxide, and trees store it in their wood. In an old forest, however, the uptake of CO2 and the release through the decomposition of dead plants roughly balance each other out. If the biomass of the trees no longer increases, the net effect of a forest on the CO2 balance is therefore small.

The age of forests

Young forests are different: Their trees grow rapidly and they accumulate biomass over decades. Especially where high temperatures and humidity promote tree growth, namely in tropical rainforests. This is shown by a study in Costa Rica: As part of his master's thesis at the University of Vienna, Florian Oberleitner calculated the age of forests near the La Gamba tropical station, the "Austrians' rainforest" in Costa Rica, using aerial photographs. In twelve forests that were between five and 55 years old, he determined and measured all the trees and derived the stored carbon from them. Four years later, Carola Egger repeated the measurements and analyzed the changes in her master's thesis at the University of Natural Resources and Life Sciences. [more]