This survey was done by the Institut für Geoökologie, Universität Potsdam, Germany, under contract to the Smithsonian Tropical Research Institute, Panama.  We are grateful to the Universität Potsdam for allocating more resources and time than were budgeted.

The survey team received a warm welcome and great logistical support and assistance from STRI staff on BCI and at the Tupper campus, Ancon.  We particularly appreciate the logistic coordination by Señoras Oris Acevedo and Belkys Jiménez, and the hard work of Señor Olivio Apolonio in digging spacious profile pits in stony and compact soils.

Frauke Barthold and Rosina Grimm received financial assistance from the German Academic exchange service (DAAD)

We are grateful to Senor Villarreal of the Ministerio de Desarollo Agropecuaria, Santiago for allowing and facilitating access and copying of the Catapan (1970) 1:20 000 land resource maps.

We received advice from many scientists in the BCI community, and particularly much background to science on BCI from Dr Egbert J Leigh Jr.  Dr E Veldkamp provided useful information on the comparison of the soils of Barro Colorado Island with those at La Selva in Costa Rica.

The soil samples were analysed by in the laboratories of the Institut für Geoökologie and Institut für Chemie, Universität Potsdam, with granulometric analyses performed by the Institut für Geographie, Universität Mainz.

We are grateful to Mr S. Tan of the Sarawak Department of Forestry, Malaysia and Professor I.A.U.N. Gunatilleke of Peradeniya University, Sri Lanka for permission to use unpublished data from the CTFS plots at Lambir and Sinharaja respectively.