02488naa a2200253 a 450000100080000000500110000800800410001902200140006010000180007424500660009226000090015830000230016750000730019052017630026365000200202665000120204665300190205865300210207765300150209865300220211370000190213570000150215477300650216910127242019-10-03       2006    bl uuuu     u00u1 u    #d  a0008-64521 aZERBINO, M.S.  aEarthworms in agro-ecosystems of Uruguay. (Conference Paper).  c2006  c2-s2.0-34249690096  aArticle history: Received November 14, 2005 / Accepted June 9, 2006.  aABSTRACT. This study assessed the richness and abundance of Oligochaeta in two long-term experiments in Uruguay. In one experiment, located in eastern Uruguay (UEPP, INIA Treinta y Tres) we evaluated four different rotations (continuous cropping, short rotation, long rotation, and pasture improvement) under grazing and no tillage conditions. The rotations were compared with adjacent grazed natural grassland. In the other experiment, located in northern Uruguay (UEG, INIA Tacuarembó), we compared two natural grasslands, one under grazing and the other excluded it for 9 years. The community structure differed within the different agroecosystems. At UEPP-INIA Treinta y Tres, richness and abundance were significantly higher in the four crop-pasture rotations than in the natural grassland. Pasture improvement had the highest richness while continuous cropping showed the highest density. Species 1 (Family Ocnerodrilidae) was predominant at the continuous cropping, while sp.2 (Family Lumbricidae) was absent. Both species were recorded at the pasture improvement with similar densities. At UEG-INIA Tacuarembó there were no differences between treatments for richness and total abundance. Species 3 (Family Glossoscolecidae) was the only species affected by grazing. The indicator value index (IndVal) was computed for each species: sp.1 with a value of 39, and sp.2 with a value of 61. These species were associated to continuous cropping and pasture improvement, respectively and could be regarded as detector species. Species 3 with an IndVal value of 97 was associated to the ungrazed area at the UEG-INIA Tacuarembó, and should be regarded as a characteristic species.  @2006 College of Arts and Sciences University of Puerto Rico, Mayagüez.  aAGROECOSISTEMAS  aURUGUAY  aAgroecosystems  aDetector species  aEarthworms  aIndicator species1 aRODRÍGUEZ, C.1 aALTIER, N.  tCaribbean Journal of Science, 2006, Vol. 42, No. 3, 315-324.