[1] He is one of the most cited scientists internationally in the field of silviculture and forest management.

[2][3] He obtained a PhD from Ghent University in 1993 on research about earthworms and litter decomposition in Flemish forests.

He was director of the Royal Institute for the Sustainable Management of Natural Resources and the Promotion of Clean Technology (KINT-IRGT) from 1995 to 1997.

[12] This paper, called Trees, forests and water: Cool insights for a hot world, gives an overview of the important effects of trees on helping to retain water on the ground and to produce cooling moisture, which in turn has a positive impact on food security and climate change adaptation.

[13][14] Muys also demonstrated that the surface temperature can be used to monitor the restoration of degraded tropical forests.