03903naa a2200373 a 450000100080000000500110000800800410001910000150006024501050007526000090018052026350018970000180282470000160284270000270285870000190288570000150290470000260291970000240294570000130296970000150298270000230299770000250302070000130304570000180305870000190307670000140309570000130310970000140312270000150313670000230315170000180317470000160319277303210320813148042008-09-15       2008    bl uuuu     u00u1 u    #d1 aBAROIS, I.  aSoil quality parameters that determine the below ground biodiversity in Los Tuxtlas Veracruz Mexico.  c2008  aIn the frame of the project ?Conservation and sustainable management of below ground biodiversity (GEF/UNEP-CIAT/TSBF)? soil organisms inventories were done in the biosphere reserve of Los Tuxtlas around Santa Martha volcano. 3 Sites (LM, SF and VC) and 4 land use (forest (S), fallow (A), pasture (P) and maize (M) were sampled, in 89 points . The sampled organisms were the biological nitrogen fixators, the mychorrizal fungi, the nematodes, the macrofauna (earthworms, ants, termites, beetles, millipedes, centipedes?). In each point the samples for the microorganisms and nematodes came from a composite soil sample made of 12 cores of 5 cm diameter and 20 cm height. The macrofauna was sampled with monoliths (25x25x30cm), Winkler bags and Pitfall traps. Some chemical parameters (pH, Na, K, Mg. Ca and P Bray), physical (% H,EC, clay, lime, sand, ad, rd, slope) and organic parameters ( C, N, NH4, NO3, litter and deshydrogenase and B-glucosidase activity) were measured in each points from the composed sample. In order to synthesized the results and to evaluate which parameters of the soil determine the diversity of organisms the general indicator of soil quality (GISQ) was build after 4 subindicators that evaluates the physical, chemical, organic matter and the macrofauna data. The construction of the GISQ was made with PCA of each of the 4 sets of variables and a cluster analysis. Also identification of species indicators (Ind Val) and coinertia analysis was carried out. The PCA of the 4 set of variables showed significant separation among sites and among land uses. LM site had the best soil quality, followed by SF and VC. In the land use system S showed the best soil quality and M the lowest, although in some group of variables P and A uses presented a quality near to S. The highest GISQ (1.00-0.85) were from LM but in different land uses (S, A and P); the lowest (0.49-0.21) were in VC in maize and pasture and in SF in maize. The cluster analysis did discriminate 8 groups of the sampling points having a similar GISQ. The Ind Val analysis extracted some species indicators many from the ants and the nematodes and few from the earthworms, termites and mycorrhizal fungi. The co-inertia analysis between soil quality indicators and species richness displayed that some diplopodes and coleoptera and native earthworms required a high soil quality soil. Other coleoptera, ants and exotic earthworms required a less rich soil although with a high quality in organic matter. Finally ,the microorganisms (Rhizobia and mycorrhizal fungi), Nematodes and Chilopoda, were more represented in poor quality soils1 aVELASQUEZ, E.1 aLAVELLE, P.1 aNEGRETE-YANKELEVICH, S1 aGARCÍA, J. A.1 aSANTOS, M.1 aÁLVAREZ-SÁNCHEZ, J.1 aCASTILLO-CAMPOS, G.1 aCRAM, S.1 aFRAGOSO, C1 aFRANCO-NAVARRO, F.1 aMARTÍNEZ-ROMERO, E.1 aMEZA, E.1 aMORÓN, M. A.1 aRODRÍGUEZ, P.1 aROJAS, P.1 aSOSA, V.1 aTREJO, D.1 aVARELA, L.1 aBUENO-VILLEGAS, J.1 aGÓMEZ, J. A.1 aSORMANI, C.  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. Editors: George Gardner Brown; Klaus Dieter Sautter; Renato Marques; Amarildo Pasini. 1 CD-ROM.