Urban planners love streets lined with identical, clonally propagated trees. They look nice and organized and they’re easier to maintain. However, mixed forests are more productive than monocultures. Whether you are looking at a sugar bush or an urban area, diversity is better.
The study was done by Technical University of Munich, Mixed forests: Ecologically and economically superior: Meta-analysis provides facts on mixed-species forest stand productivity for science and practice. It was summarized in ScienceDaily May 2018.
“Mixed-species forests are ecologically more valuable as versatile habitats. They mitigate climate change, as they mean a higher carbon sink."
Data was collected from long-term experiments in France, Georgia, Switzerland and Scotland reviewing 600 studies which analyzed the influence of mixed forests on productivity. They used the increase in volume of trunk wood which was calculated via repeated measurements of the tree diameter, height and trunk shape. Eighty percent of the study areas were monocultures. The data from Bavaria started in the 1870s.
“In light of climate change and the increasing ecological, economic and social requirements that forests need to fulfill, mixed stands will increase in importance throughout the world."