02990naa a2200205 a 450000100080000000500110000800800410001910000230006024501200008326000090020352022190021265000120243165000190244365000090246270000200247170000170249170000250250870000160253377302350254915714762009-01-27       2008    bl uuuu     u00u1 u    #d1 aVENDRAME, P. R. S.  aSoil macrofauna under pastures in the brazilian cerrado regionbthe influence of mineralogy and chemical fertility.  c2008  aVarious processes exercise influence on the soil macrofauna through intervention in the physical, chemical or biological characteristics of the ecosystem. The aim of this study was to evaluate the potential influence of different levels of chemical fertility associated to different contents of kaolinite and gibbsite on the soil macrofauna under pastures in the Brazilian Cerrado region. In this regard, a region to study was selected in the Federal District (near Brasília) and in the city of Formosa, Goiás state. A chemical pre-analysis was carried out of the soils to determine the exchangeable Ca and Mg as well as those of kaolinite and gibbsite through thermogravimetric analysis (TGA) with the aim of calculating the ratio kaolinite / kaolinite+gibbsite (RKGb). These two parameters (Ca + Mg and RKGb) allowed the choice of four groups of soils, which were: Group I (Ca + Mg from 0.5 to 1.0 cmolc kg-1 and RKGb from 0.4 to 0.6); Group II (Ca + Mg from 0.5 to 1.0 cmolc kg-1 and RKGb from 0.8 to 1.0); Group III (Ca + Mg from 2.0 to 4.0 cmolc kg-1 and RKGb from 0.4 to 0.6) and Group IV (Ca + Mg from 2.0 to 4.0 cmolc kg-1 and RKGb from 0.8 to 1.0). Macrofauna was sampled following the TSBF method, collecting blocks of 25 × 25 × 30 cm where, after manual collecting, all of the individuals were counted which afterwards were identified as belonging to groups. The data were submitted to a principal component analysis (PCA) with the aim of grouping the variables which came closest to explaining the behavior of the macrofauna in the four soil groups selected. The groups identified in decreasing order of total density are: Isoptera, Hymenoptera, Oligochaeta, Coleoptera, Diplopoda, Chilopoda, Diptera, Hemiptera, Lepidoptera, Araneae, Homoptera, Symphyla, Scorpione e Pseudoscorpione. The frequency of individuals in the litter is very low and represents less than 1% of the total; the greatest concentration of macrofauna in soils under pastures in the Cerrado region occurs in the superficial layer 0-10 cm. The predominance of Isoptera is more accentuated in the soils having low chemical fertility (low Ca + Mg) and there is a higher density of Oligochatea (earthworms) in soils with high RKGb.  aCerrado  aFauna Edáfica  aSolo1 aMARCHÃO, R. L.1 aBRITO, O. R.1 aGUIMARÃES, M. de F.1 aBECQUER, T.  tIn: INTERNATIONAL COLLOQUIUM ON SOIL ZOOLOGY, 15; INTERNATIONAL COLLOQUIUM ON APTERYGOTA, 12., 2008, Curitiba. Biodiversity, conservation and sustainabele management of soil animal: abstracts. Colombo: Embrapa Florestas. 1 CD-ROM.