Soil samples from 0--2. 5,[10][11][12][13][14][15][16][17][18][19][20][20][21][22][23][24][25][26][27][28][29][30] Oturoa, Rotoiti, Stratford, Egmont, Tokomaru, Kokotau, Kaitoke, Otiake, Edendale, and Waikiwi soils were collected in spring and total nematode populations found to be I 097 {)()()-9 595 OOO/m 2 • Over the II sites vertical distribution at the 6 depths (46, 24, II, 7, 9, 3% in successive strata) was most significantly correlated with soil carbon and readily available soil phosphorus. It is considered the causal correlation of nematodes is with root growth. Correlations with soil physical factors are given. A total of37 genera were identified, 14-20 being found at each site. Mean number ofgenera in the strata sampled was 14,13,12,9,10,6. The greatest diversity of genera occurred in Oturoa sand, a soil derived from a 9O-yearold volcanic ash shower. Populations for each genus, depth, and site are given.Complementary distributions found include Aphelenchoides/Aphelenchus, Heterocephalobus/Cephalobus, Anaplectus/Plectus, Monhystera + Chromadoridae/ Rhabditidae + Plectidae. Tylenchida and Dorylaimida also appear to be complementary; the large biomass of the Dorylaimida populations suggests many of them may be directly dependent on plants for food, as are Tylenchida.