Ecuaciones para la estimación de biomasa de frondosas en España

To estimate forest carbon pools from forest inventories it is necessary to have biomass models or biomass expansion factors. In this study, tree biomass models were developed for the main hardwood forest species in Spain: Alnus glutinosa, Castanea sativa, Ceratonia siliqua, Eucalyptus globulus, Fagus sylvatica, Fraxinus angustifolia, Olea europaea var. sylvestris, Populus x euramericana, Quercus canariensis, Quercus faginea, Quercus ilex, Quercus pyrenaica and Quercus suber. Different tree biomass components were considered: stem with bark, branches of different sizes, above and belowground biomass. For each species, a system of equations was fitted using seemingly unrelated regression, fulfilling the additivity property between biomass components. Diameter and total height were explored as independent variables. All models included tree diameter whereas for the majority of species, total height was only considered in the stem biomass models and in some of the branch models. The comparison of the new biomass models with previous models fitted separately for each tree component indicated an improvement in the accuracy of the models. A mean reduction of 20% in the root mean square error and a mean increase in the model efficiency of 7% in comparison with recently published models. So, the fitted models allow estimating more accurately the biomass stock in hardwood species from the Spanish National Forest Inventory data.Para realizar estimaciones de cantidades de carbono acumulado por los bosques, a partir de datos procedentes de inventarios forestales, es necesario disponer de modelos de estimación de biomasa o de factores de expansión. En este trabajo se han ajustado modelos de estimación de biomasa para las principales especies forestales de frondosas existentes en los bosques españoles: Alnus glutinosa, Castanea sativa, Ceratonia siliqua, Eucalyptus globulus, Fagus sylvatica, Fraxinus angustifolia, Olea europea var. sylvestris, Populus x euramericana, Quercus canariensis, Quercus faginea, Quercus ilex, Quercus pyrenaica y Quercus suber. Se han determinado las siguientes fracciones: fuste con corteza, ramas de diferentes tamaños, parte aérea y parte radical. Para cada especie se ajustó un sistema de ecuaciones utilizando la metodología de mínimos cuadrados generalizados conjuntos, que contempla el cumplimiento de la propiedad aditiva entre fracciones. Como variables independientes se utilizaron el diámetro y la altura total del árbol. El diámetro aparece en todos los modelos, no así la altura, si bien su inclusión resulta en una mejora de las estimaciones en los modelos de biomasa de fuste para la mayoría de las especies y en parte de los modelos de ramas. La comparación con otros modelos desarrollados anteriormente para estas especies y ajustados con otra metodología, indica una mejora en la precisión de los aquí presentados. Existe una mejora media del 20% en términos de la raíz del error medio cuadrático y del 7% en la eficiencia del modelo. Así, mediante el uso de estos modelos ajustados se puede estimar con mayor precisión la biomasa y el carbono acumulado por estas especies de frondosas a partir de datos del Inventario Forestal Nacional de España

Neutrino Masses from R-Parity Violation with a Z3Z_3 Symmetry

Peer reviewe

Analysis of inequality in fertility curves fitted by gamma distributions

The aim of this paper is to analyse fertility curves from a novel viewpoint, that of inequality. Through sufficient conditions that can be easily verified, we compare inequality, in the Lorenz and Generalized Lorenz sense, in fertility curves fitted by gamma distributions, thus achieving a useful complementary instrument for demographic analysis. As a practical application, we examine inequality behaviour in the distributions of specific fertility curves in Spain from 1975 to 2009.Peer Reviewe

Complementarity between dark matter direct searches and CEν\nuNS experiments in U(1)′U(1)' models

We explore the possibility of having a fermionic dark matter candidate within $U(1)'$ models for CE$\nu$NS experiments in light of the latest COHERENT data and the current and future dark matter direct detection experiments. A vector-like fermionic dark matter has been introduced which is charged under $U(1)'$ symmetry, naturally stable after spontaneous symmetry breaking. We perform a complementary investigation using CE$\nu$NS experiments and dark matter direct detection searches to explore dark matter as well as $Z^{\prime}$ boson parameter space. Depending on numerous other constraints arising from the beam dump, LHCb, BABAR, and the forthcoming reactor experiment proposed by the SBC collaboration, we explore the allowed region of $Z^{\prime}$ portal dark matter.Comment: Matches published version. 21 pages, 5 figures, 2 table

Estudios sobre Basidiomycetes. VII (Hayedo de Montejo de la Sierra, Madrid)

Fourteen taxons that grow in the beech wood of Montejo de la Sierra (Madrid) are studied. Two of them are reported for the first tim e in Spain: Baeospora myriadophylla (Peck) Sing. and Eichleriella spinulosa Berk. S Curtis.Se estudian un total de 14 táxones que fructifican en el hayedo de Montejo de la Sierra (Madrid). Son nuevas citas para la micoflora espeola: Baeospora myriadophylla (Peck) Sing. y Eichleriella spinulosa Berk. S Curtis

Quark-lepton mass relation and CKM mixing in an A(4) extension of the minimal supersymmetric standard model

An interesting mass relation between down-type quarks and charged leptons has been recently predicted within a supersymmetric SU(3)(c) circle times SU(2)(L) circle times U(1)(Y) model based on the A(4) flavor symmetry. Here we propose a simple extension which provides an adequate full description of the quark sector. By adding a pair of vectorlike up quarks, we show how the CKM entries V-ub, V-cb, V-td and V-ts arise from deviations of the unitarity. We perform an analysis including the most relevant observables in the quark sector, such as oscillations and rare decays of kaons, B-d and B-s mesons. In the lepton sector, the model predicts an inverted hierarchy for the neutrino masses, leading to a potentially observable rate of neutrinoless double beta decay