Abstract niet beschikbaarNematode fauna used as an instrument for assessing biological quality of soils. A joint study of the Department of Nematology, Agricultural University, Wageningen (biotic parametes). To assess the quality of soils an ecological typology based on the free-living nematode fauna is in development. Herefore knowledge on the relationship between the presence of nematodes and the physical and chemical soil parameters is essential. Fifteen different forest ecosystems spread on 30 locations were sampled between 4/4/88 and 26/5/88. This sampling program covered all the sandy soils of the Netherlands. In 71 samples were analysed: water content ; pH, texture, organic matter, nitrate, ammonium, total nitrogen, sodium, calcium, potassium, magnesium, base capacity and CEC. The analysis of the biotic parameters and the interpretation of the data will be published in another paper.DGM/DWB-B Robberse J