1. Expertise in (inter)nationale organisaties:
- Plaatsvervangend hoofd Afdeling Ecologie en Fysiologie van Planten
Faculteit Aard en Levenswetenschappen, VU (2003-2005)
-Lid Bestuur Institute Ecological Sciences VU (1998-2005)
- Voorzitter facultaire Onderwijscommissie Biologie VU (1990-1994)
- Voorzitter facultaire Veiligheidscommissie Biologie VU (2000-2002)
- Lid Bestuur faculteit Biologie VU (1985-1989, portefeuillehouder Onderwijs)
- Lid Bestuur Faculteit Biologie VU (1994-1998, portefeuillehouder onderzoek)
- Lid landelijke Onderzoeksschool SENSE (School for Economic and Natural Sciences in
the Environment)
- Lid International Plant Parasite Society (treasurer, 2000-2005)
- Lid Editorial Board International Journal Ecotoxicology (2000-2004)
- Lid Editorial Board International Journal Environmental Pollution (2002-2006)
- Dutch representative and Member of management Committee EU COST Action 837 -
Plant biotechnology for the removal of organic pollutants and toxic metals in wastewaters
and contaminated sites (1998-2003)
- Dutch representative and Member of Management Committee EU COST Action 859
Phytotechnologies to promote sustainable land use and improved food safety (2004-2009)
- Dutch representative and Member of Management Committee EU COST Action 849
Parasitic Plant Management in Sustainable Agriculture (2001-2006)