02488naa a2200133 a 450000100080000000500110000800800410001910000130006024501050007326000090017852018270018770000190201477303210203313147952008-09-15       2008    bl uuuu     u00u1 u    #d1 aAIRA, M.  aEffects of seabird (Phalacrocorax aristotelis L.) nesting on soil biota and nutrient mineralization.  c2008  aThe existence of nutrient fluxes from water to land, and the consequences for the structure and productivity of terrestrial ecosystems are well known. The activities of seabirds are a type of water-land flux about which little is known, especially during the nesting season when breeding birds move more often between water and land and also spend more time on land than at other stages. We studied the effects that nesting activities of the European shag (Phalacrocorax aristotelis, L.) have on soil biochemical properties and the composition of soil microfauna on the Cíes Islands (NW Spain). We sampled fresh soil inside and outside of the nests (paired samples, n=7). Soil inside the nest had a lower organic matter content, and higher electric conductivity and dissolved organic carbon content than the soil outside the nests. There were no differences in N pools in the soil samples from inside and outside of the nests. Microbial biomass and C mineralization were greater in soil from inside than from outside of the nests. Nesting did not modify the composition of nematode communities (bacterivores, fungivores, omnivores and herbivores), although the soil outside the nest supported a more abundant and diverse nematode community. The present results suggest that nesting did not produce differences in the decomposer community in the soil inside the nest, despite of it seems to be more efficient since C mineralization is greater. However, the lack of differences in most of the variables analyzed, as well as in the composition of nematode populations indicates the instability and high turnover rate of these two soil systems. In fact, it appears that there are no differences in the belowground communities of live organic matter systems (plants) or dead organic matter systems (nests) on the Cíes Islands1 aDOMÍNGUEZ, J.  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.