Jan Willem Erisman,^*,** Arjan Hensen,^***,** Wim de Vries,^****,** Hans Kros,^*****,** Tamme van de Wal,^{******,*******} Wim de Winter,^{********,*******} Jan Erik Wien,^{*********,*******} Mark v Elswijk,^{**********,***********} Matthijs Maat,^{**********,***********} Kaj Sanders<sup>************


*</sup>Jan Willem Erisman is head of the Department of Integrated Assessment and program manager for environmental research at the Energy Research Centre of The Netherlands (ECN). His area of research is the atmosphere - biosphere exchange of pollutants and nutrients, instrument development and monitoring, and policy development and evaluation. His address: Head, Department of Integrated Assessment, Energy Research Foundation, ECN, P.O. Box 1, 1755 ZG Petten, The Netherlands. erisman@ecn.nl
^**Their address: Alterra bv., Green World Research, P.O. Box 47, 6700 AA Wageningen, The Netherlands.
^***Arjan Hensen studied physics at Utrecht University with specialization in meteorology and physical oceanography. During his first 5 years at the Energy Research Centre of the Netherlands (ECN) he focused on greenhouse gas research (CO2, CH4 and N2O). More recently he worked on radiation measurements, aerosol forcing, and ammonia deposition and emission measurements. His address: ECN, P.O. Box 1, 1755 ZG Petten, The Netherlands. Hensen@ecn.nl
^****Wim de Vries is senior research scientist, leader of research programs on “Risks of soil pollution and soil remediation” and “Abiotic conditons for nature development” at Alterra Green World Research in the Netherlands. He has both MSc and PhD degrees in soil chemistry and soil physics from the Agricultural University in Wageningen, The Netherlands. W.devries@Alterra.wag-ur.nl
^*****Hans Kros is a soil scientist. He has worked on the development and application of nutrient cycling models at different spatial scales ranging from plot scale towards continental scale. Specific expertise comprises model simplification and building of decision support systems on biogeochemical changes in terrestrial ecosystems. j.kros@Alterra.wag-ur.nl
^******Tamme van der Wal is a graduate of Wageningen University in land- and water management and informatics. He is currently general director of Wageningen Software Labs, a company within Wageningen UR, providing information technology (IT) services for education and science. He is one of the initiators of Play2Learn. This joint venture between Wageningen Software Labs and SERC provides IT support for development of games for policy support and education. T.vanderwal@wisl.nl
^*******Their address: W!SL, P.O. Box 47, 6700 AA Wageningen, The Netherlands.
^********Wim de Winter studied ecology, modeling and fisheries at Wageningen Agricultural University. After a short career in estuarine ecology he shifted to software engineering. Having passed through a few software companies and the university's informatics department he's now a specialist in developing scientific software at Wageningen Software Labs (W!SL). w.p.dewinter@wisl.nl
^*********Jan E. Wien is a project manager in the field of information management and information technology. He has a degree in Agriculture and Information Technology from Wageningen University. He has worked at the Agricultural Economics Research Institute and has experience in economic and environmental modeling, policy evaluation and model integration. Currently, he works at Wageningen Software Labs (W!SL) and is a project manager of various software development projects including support systems for interactive decision making and discussion. j.j.f.wien@wisl.nl
^**********Mark van Elswijk and Matthijis Matt are senior advisors at the Software Engineering Research Centre (SERC) in Utrecht, The Netherlands. They both have collaborated with Wageningen Software Labs (W!SL) in Play2Learn (www.play2learn.nl), an organization specialized in putting complex knowledge into easy-to-use applications, especially games. Elsijk's expertise is in software engineering, software architecture and software quality; Matt is in software architecture and distributed systems. elswijk@serc.nlmaat@serc.nl
^***********Their address: Software Engineering Research Centre (SERC), P.O. Box 424, 3500 AK Utrecht, The Netherlands.
^************Kaj H. Sanders studied environmental sciences at Wageningen Agricultural University. Since 1999 he has been working at the Dutch Ministry for the Environment where he has specialized on effects of acidification and long range transboundary air pollution on nature and on nature management and policy making. His address: Ministry of Housing, Spatial planning and Environment, P.O. Box 250951, 2500 EZ The Hague, The Netherlands. kaj.sanders@minviron.nl