Jatropha curcas (L.) is a perennial plant of the spurge family (Euphorbiaceae). Recently, it has received much attention as a potential source of vegetable oil as a replacement for petroleum, and, in particular, the production of biodiesel. Despite the interest that is being shown in the large-scale cultivation of J. curcas, genetic resources remain poorly characterized and conserved and there has been very little plant breeding for improved traits. At present, the varieties being used to establish plantations in Africa and Asia are inedible. The meal obtained after the extraction of oil cannot, therefore, be used as a source of animal feed. Naturally existing edible varieties are, however, known to occur in Mexico. The toxic components of J. curcas seeds, the potential for plant breeding to generate improved varieties, and the suitability of J. curcas oil as a feedstock for biodiesel production are discussed.
a b s t r a c t Concentrations of 16 polycyclic aromatic hydrocarbons (PAHs), 19 polybrominated diphenyl ethers (PBDEs), 7 polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), isomers and metabolites of dichlorodiphenyltrichloroethane (DDTs) and Hexachlorocyclohexane (HCHs) were measured in the feathers of the Red-billed Chough Pyrrhocorax pyrrhocorax, a rare and protected corvid species inhabiting rural and mountainous areas. Feathers were collected in the wild from seven sites in the Iberian Peninsula, one in La Palma, Canary Islands, Spain and one site in Italy. HCH isomers and HCB resulted always under the detection limit. PAHs were found only in the Italian population (range 39.3-54.6 ng/g wet weight in the three subsamples). For PBDEs, the concentrations ranged from 135 to 11,753 pg/g (mean 1560 ± 3415 pg/g w.w.). Only one sample collected in the most urbanized Spanish site in 1990 exceeded 2000 pg/g. Twenty years later in the same site the concentration resulted very low. Six Spanish areas from the same meta-population, and one island population at La Palma showed a low contamination by pp'DDE (3.2 ± 3.3 ng/g w.w., range for positive samples 1.7-10.1 ng/g w.w.). PCBs were found only in two Spanish locations with the 52 and the 138 congeners. Overall the species showed low to intermediate levels of contamination in feathers probably due to its intermediate trophic position and/or to the integrity of its environment.V.
Sustainable territorial management requires reliable assessment of the impact of conservation policies on landscape structure and dynamics. Euro-Mediterranean regions present a remarkable biodiversity which is linked in part to traditional land use practices and which is currently threatened by global change. The effectiveness of one-decade conservation policies against land use changes was examined in Central Spain (Madrid Autonomous Community). A Markov model of landscape dynamics was parameterized with CORINE Land Cover information and transition matrices were obtained. The methods were applied in both protected and unprotected areas to examine whether the intensity and direction of key land use changes -urbanisation, agricultural intensification and land abandonment-differed significantly depending on the protection status of those areas. Protected areas experienced slower rates of agricultural intensification processes and faster rates of land abandonment, with respect to those which occurred in unprotected areas. It illustrates how simple mathematical tools and models -parameterized with available data-can provide to managers and policy makers useful indicators for conservation policy assessment and identification of land use transitions.Key words: global change; land use and land cover change; traditional and cultural land uses; protected areas and protection categories. ResumenCambio en el uso del suelo en una región Mediterránea metropolitana y su periferia: evaluación de las políticas de conservación mediante datos del CORINE Land Cover y modelos de Markov La gestión sostenible del territorio requiere de análisis realistas sobre el impacto de las políticas de conservación en la estructura y dinámica del paisaje. La región Euro-Mediterránea presenta una biodiversidad remarcable que está unida en parte a las prácticas tradicionales del uso del suelo y que actualmente está amenazada por el cambio global. La efectividad de la implantación de políticas de conservación frente a los cambios en el uso del suelo fue examinada en el centro de España (Comunidad Autónoma de Madrid). Se usaron modelos de Markov para analizar la dinámica del paisaje parametrizados con información del CORINE Land Cover y se obtuvieron las matrices de transición. La metodología se aplicó en áreas protegidas y no protegidas para examinar si la intensidad y dirección de los cambios del uso del suelo claves -urbanización, intensificación agrícola y abandono-difieren significativamente en función del grado de protección. Las áreas protegidas experimentaron menores tasas en el proceso de intensificación agrícola y mayores en el abandono con respecto a las ocurridas en zonas sin protección. Se demuestra cómo modelos y herramientas matemáticas -parametrizados con los datos disponibles-pueden proporcionar a gestores y políticos indicadores útiles para la evaluación de políticas de conservación e identificación de transiciones de uso del suelo.Palabras clave: cambio global; cambios en el uso y cobertura del suelo; usos del suelo tradic...
We compared the breeding phenology and clutch size of Choughs Pyrrhocorax pyrrhocorax in three Spanish areas that differed in feeding habitat, breeding environmental conditions and the distribution and availability of different nesting sites (cliffs or artefacts). The variation in the timing of laying seemed to be related to differences in climatic conditions determined by the altitude. The variation in clutch size was associated with the different use that Choughs made of the feeding areas because of the contrasting availability and distribution of their nesting sites. Within southeastern Madrid, clutch size of the Chough decreased and its variance increased at high nest densities on cliff sites, suggesting that density dependence in fecundity arises from habitat heterogeneity rather than by interference. At high densities, individuals, territories, nest sites or a combination of these may differ in quality, thus promoting differences and increasing the variance in the initial investment of reproductive effort. The syncronization of the onset of laying at increased breeding densities suggests that social influences arising from communal foraging or avoidance of predation by early warning and predator swamping may be acting also. We suggest that nest-site availability and distribution have a major influence on the social organization of Choughs through their breeding and foraging strategies.
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