RT info:eu-repo/semantics/article T1 Spatial pattern and variability in soil N and P availability under the influence of two dominant species in a pine forest A1 Rodríguez, Alexandra A1 Durán, Jorge A1 Covelo, Felisa A1 Fernández-Palacios, José María A1 Gallardo, Antonio K1 Pinus canariensis K1 Adenocarpus viscosus K1 Microbial biomass-N K1 Dissolved organic-N K1 Inorganic-N K1 Extractable-P AB The presence of a legume in a nitrogen (N)- limited forest ecosystem may not only create “islands of N fertility” but also affect the phosphorus (P) availability. The main objective of this study was to compare the effect of a pine (Pinus canariensis) and a leguminous (Adenocarpus viscosus) species on the spatial pattern and variability of different labileorganic-N (microbial biomass-N [MB-N] and dissolved organic-N [DON]), as well as inorganic-N (IN) and –P fractions (NH4-N, NO3-N, and PO4-P), in a forest soil of the Canary Islands (Spain). Assuming some litter quantity and quality differences between these two species, we expected to find higher soil labile organic-N concentrations under isolated individuals of P. canariensis than under isolated individuals of A. viscosus. We also expected to find higherconcentrations and spatial dependence (percentage of total variance explained by spatial autocorrelation) ofNO3-N beneath A. viscosus than beneath P. canariensis canopies, and higher spatial scaling of soil variables under the influence of P. canariensis canopies than under the presence of A. viscosus individuals. Moreover, we tested whether the soil variables measured under isolated individuals of both species showed a different spatial variability than the same soil variables measured under overlapping pine canopies inside a pine forest. To test these hypotheses, soil samples under isolated mature individuals of each species were collected in the winter and summer, whereas under a pine forest canopy, the sampling was performed only in the winter. The winter MB-N andDON concentrations were significantly higher beneath the pine individual, whereas the winter NO3-N, NO3-N-to-IN ratio, and PO4-P were significantly higher under the leguminous individual; these differences were not observed in the summer samples. We found higher spatial ranges under the pine than under the legume canopy in the winter sampling, and the spatial dependence of NO3-N was twice as high beneath the legumes as under the pines at bothsampling dates. The soil spatial variability was higher (up to 17 times higher) under isolated individuals than inside the pine forest. The results of this study suggest that both the morphological and physiological characteristics of P. canariensis and A. viscosus, as well as the spatial pattern of P. canariensis, may influence the spatial pattern and variability of soil resources. SN 0032-079X YR 2011 FD 2011 LK http://riull.ull.es/xmlui/handle/915/17677 UL http://riull.ull.es/xmlui/handle/915/17677 LA en DS Repositorio institucional de la Universidad de La Laguna RD 09-nov-2024