Do mixed forests function better than monocultures?

Starting point

Multiple benefits are attributed to mixed forests, forests in which multiple tree species grow together. Mixed forests are expected to produce more wood, be more resistant to pests and pathogens, be more resilient towards climate change, etc.

The question from forest managers

Data to back up benefits of mixed forests are scarce. Forest managers ask for more knowledge and guidelines on mixed forests.

Tree diversityTree diversity

How do we come to an answer

  • We set up the TREEWEB observatory to study tree diversity effects in mature, real-world forests. The whole food web (primary producers, herbivores, pathogens, predators, detritivores) is studied in forests of one, two or three tree species (different combinations of beech, pedunculate oak, and red oak).
  • We set up the FORBIO tree species diversity experiment in Belgium: small stands of one up to four tree species at three contrasting sites with different environments and forest development stages. We monitor different aspects of ecosystem functioning such as tree growth, herbivors, and nutrient cycling.

The Belgian FORBIO experiment is part of TreeDivNet, a global network of tree diversity experiments. TreeDivNet provides a unique platform to study the effect of tree species diversity in different forest types around the world. The oldest experimental plantation in TreeDivNet was planted in 1999.