Gianoli E.,University of Concepción |
Gianoli E.,University of Santiago de Chile |
Gianoli E.,University of La Serena |
Saldana A.,University of Concepción |
And 2 more authors.
Journal of Vegetation Science | Year: 2010
Question: Are vines light-demanding species? Location: Temperate evergreen rain forest of southern Chile (401390S, 721110W). Methods: In 45 plots of 25m2 distributed in treefall canopy gaps, secondary forest stands and oldgrowth forest (15 plots per light environment), all climbing and non-supported vines were counted and identified to species level, and canopy openness was quantified using hemispherical photographs. Vine abundance and diversity (species richness and Simpson's index) were compared in the three light environments and similarity between vine communities was estimated using Jaccard's similarity coefficient. We also determined the relationship between light niche breadth and local dominance at the species level. Results: In total there were 2510 vine individuals of 14 species. Canopy openness was significantly different in the three light environments. Species richness, diversity, community composition and density of vines were similar in treefall gaps, secondary and old-growth forest. Of the seven more common vine species, which accounted for 91% of all vines, three had even distribution, two were more abundant in the shaded understorey, and two had higher density in well-lit sites. Local dominance of vine species and niche breadth were not significantly associated. Conclusions: Our study in a temperate rain forest questions the widespread notion of vines as pioneer-like species, which may be a consequence of the abundance of some lianas in disturbed sites of tropical forests. Functional arguments are needed to justify a general hypothesis on light requirements of vines, which constitute a vast group of species. © 2009 International Association for Vegetation Science.
Lopez-Jamar J.,University of Castilla - La Mancha |
Casas F.,Institute Investigacion en Recursos Cinegeticos |
Diaz M.,Institute Recursos Naturales |
Morales M.B.,Autonomous University of Madrid
Bird Conservation International | Year: 2011
Local changes in land use can influence patterns of habitat selection by farmland birds, thus biasing predictions of population responses to land use changes based on wildlife-habitat or niche modelling. This study, based in arable farmland in south-central Spain, determined whether habitat selection (use of agricultural habitats and the distance to roads, tracks and buildings) by Great Bustards Otis tarda varied between two nearby areas with differing land uses. The western sector has experienced a process of land abandonment and infrastructure development linked to an airport project that started in 1998 and finished in 2009, while the eastern sector maintains extensive dry farmland systems. Great Bustards avoided ploughed fields and selected short- and long-term fallows. Selection of fallows was more intensive in the sector suffering recent land-use changes, where these substrates were more abundant. Great Bustards were distributed further from roads, paths and buildings than would be expected if individual birds selected habitats at random. Avoidance of infrastructure was strongest in the area suffering recent land-use changes. Local patterns of habitat selection seemed to change in relation to agricultural abandonment and infrastructure development. Consequently, conservation measures based on knowledge of broad patterns of habitat use and selection such as agri-environmental schemes may fail to ensure steppe bird conservation locally if such local effects are overlooked. Specifically, schemes should include landscape-scale restrictions on the development and use of infrastructure (roads, tracks and buildings). Analyses of the patterns and causes of local and regional changes in habitat selection are essential to conserve populations of endangered farmland birds. Copyright © 2011 BirdLife International.
Ramirez-Valiente J.A.,Instituto Nacional Of Investigacion Y Tecnologia Agraria Y Alimentaria |
Valladares F.,Institute Recursos Naturales |
Valladares F.,Rey Juan Carlos University |
Huertas A.D.,University of Granada |
And 2 more authors.
Tree Genetics and Genomes | Year: 2011
Increased drought severity is expected in the Mediterranean Basin over the twenty-first century, but our understanding of the potential of most forest tree species to cope with it remains uncertain. In this study, (1) we examined the potential effects of long-term selection and the capacity to respond to future changes in selective pressures in three populations of cork oak (Quercus suber L.). For this purpose, we evaluated the response to dry conditions of 45 open-pollinated trees originating from populations in Morocco, Portugal, and Spain. Growth, leaf size, specific leaf area (SLA), carbon isotope discrimination (Δ13C), leaf nitrogen content (Nmass), and total chlorophyll content (Chlmass) were measured in 9-year-old plants. (2) We also investigated the relationships between functional traits and aboveground growth by regression models. Plants presenting larger and more sclerophyllous leaves (low SLA and high leaf thickness) exhibited higher growths, with results suggesting that these traits are subjected to divergent selection in this species. Heritability estimates were moderately high for Δ13C (0.43 ± 0.25-0.83 ± 0.31) and stem diameter (0.40 ± 0.15-0.71 ± 0.28) for the tree populations. For the rest of the traits (except for annual growth), heritability values varied among populations, particularly for height, leaf size, leaf thickness, and Nmass. Our results suggest that natural selection has led to local adaptations and has also affected the genetic variance intrapopulation in these cork oak populations, although studies with a higher number of populations should be carried out across different years. Additionally, the absence of significant genetic correlations and the fact that correlated traits did not undergo opposing selection provided little evidence for constraints on evolution caused by genetic correlations. © 2010 Springer-Verlag.
Tejedor-Cano J.,Institute Recursos Naturales |
Prieto-Dapena P.,Institute Recursos Naturales |
Almoguera C.,Institute Recursos Naturales |
Carranco R.,Institute Recursos Naturales |
And 4 more authors.
Plant, Cell and Environment | Year: 2010
Gain of function approaches that have been published by our laboratory determined that HSFA9 (Heat Shock Factor A9) activates a genetic program contributing to seed longevity and to desiccation tolerance in plant embryos. We now evaluate the role(s) of HSFA9 by loss of function using different modified forms of HaHSFA9 (sunflower HSFA9), which were specifically overexpressed in seeds of transgenic tobacco. We used two inactive forms (M1,M2) with deletion or mutation of the transcription activation domain of HaHSFA9, and a third form (M3) with HaHSFA9 converted to a potent active repressor by fusion of the SRDX motif. The three forms showed similar protein accumulation in transgenic seeds; however, only HaHSFA9-SRDX showed a highly significant reduction of seed longevity, as determined by controlled deterioration tests, a rapid seed ageing procedure. HaHSFA9-SRDX impaired the genetic program controlled by the tobacco HSFA9, with a drastic reduction in the accumulation of seed heat shock proteins (HSPs) including seed-specific small HSP (sHSP) belonging to cytosolic (CI, CII) classes. Despite such effects, the HaHSFA9-SRDX seeds could survive developmental desiccation during embryogenesis and their subsequent germination was not reduced. We infer that the HSFA9 genetic program contributes only partially to seed-desiccation tolerance and longevity. © 2010 Blackwell Publishing Ltd.
Ortego J.,CSIC - National Museum of Natural Sciences |
Bonal R.,Institute Investigacion en Recursos Cinegeticos IREC CSIC |
Munoz A.,Institute Recursos Naturales
Journal of Heredity | Year: 2010
Large-scale forest fragmentation can increase interpopulation genetic differentiation and erode the genetic variability of remnant plant populations. In this study, we analyze the extent of clonality and the genetic variability and structure within a holm oak (Quercus ilex) population from Central Spain at 3 patches showing different degrees of fragmentation. For this purpose, we have typed 191 individuals (105 adults and 86 saplings) at 9 microsatellite loci. Microsatellite markers revealed an extensive clonal structure in this species, with most analyzed clumps constituting a single "genet", which in some cases extended over a considerable area (up to 318 m2). The maximum distance between "ramets" tended to be higher in the extremely fragmented patch, suggesting that intensive management and environmental perturbation has favored clonal propagation. We have also found evidence that fragmentation has contributed to reduce genetic variability and increase genetic differentiation in holm oak saplings, indicating that the younger cohorts are suffering some negative genetic consequences of long-term population fragmentation. Finally, analyses of fine spatial genetic structure have revealed significant kinship structures up to 20-50 m that were particularly patent in the 2 less fragmented patches. Overall, our findings point to long-term genetic shifts in population structure of holm oaks in fragmented landscapes; however, further research is required on pollen dispersal and gene flow in this species. © 2010 The American Genetic Association. All rights reserved.
Maestre F.T.,Rey Juan Carlos University |
Castillo-Monroy A.P.,Rey Juan Carlos University |
Bowker M.A.,U.S. Geological Survey |
Ochoa-Hueso R.,Institute Recursos Naturales
Journal of Ecology | Year: 2012
Recent studies have suggested that the simultaneous maintenance of multiple ecosystem functions (multifunctionality) is positively supported by species richness. However, little is known regarding the relative importance of other community attributes (e.g. spatial pattern, species evenness) as drivers of multifunctionality. We conducted two microcosm experiments using model biological soil crust communities dominated by lichens to: (i) evaluate the joint effects and relative importance of changes in species composition, spatial pattern (clumped and random distribution of lichens), evenness (maximal and low evenness) and richness (from two to eight species) on soil functions related to nutrient cycling (β-glucosidase, urease and acid phosphatase enzymes, in situ N availability, total N, organic C, and N fixation), and (ii) assess how these community attributes affect multifunctionality. Species richness, composition and spatial pattern affected multiple ecosystem functions (e.g. organic C, total N, N availability, β-glucosidase activity), albeit the magnitude and direction of their effects varied with the particular function, experiment and soil depth considered. Changes in species composition had effects on organic C, total N and the activity of β-glucosidase. Significant species richness×evenness and spatial pattern×evenness interactions were found when analysing functions such as organic C, total N and the activity of phosphatase. The probability of sustaining multiple ecosystem functions increased with species richness, but this effect was largely modulated by attributes such as species evenness, composition and spatial pattern. Overall, we found that model communities with high species richness, random spatial pattern and low evenness increased multifunctionality. Synthesis. Our results illustrate how different community attributes have a diverse impact on ecosystem functions related to nutrient cycling, and provide new experimental evidence illustrating the importance of the spatial pattern of organisms on ecosystem functioning. They also indicate that species richness is not the only biotic driver of multifunctionality, and that particular combinations of community attributes may be required to maximize it. © 2011 The Authors. Journal of Ecology © 2011 British Ecological Society.
Babot E.D.,Institute Recursos Naturales |
Rico A.,Institute Recursos Naturales |
Rencoret J.,Institute Recursos Naturales |
Kalum L.,Novozymes AS |
And 5 more authors.
Bioresource Technology | Year: 2011
The ability of two natural phenols to act as mediators of the recombinant Myceliophthora thermophila laccase (MtL) in eucalypt-pulp delignification was investigated. After alkaline peroxide extraction, the properties of the enzymatically-treated pulps improved with respect to the control. The pulp brightness increased (3.1 points) after the enzymatic treatment with MtL alone, but the highest improvements were obtained after the MtL treatment using syringaldehyde (4.7 points) and especially methyl syringate (8.3 points) as mediators. Likewise, a decrease in kappa number up to 2.7 points was obtained after the MtL-methyl syringate treatment, followed by decreases of 1.4 and 0.9 points after the treatments with MtL-syringaldehyde and MtL alone, respectively. On the other hand, removal of the main lipophilic extractives present in eucalypt pulp was observed after the above laccase-mediator treatments. Finally, the doses of both MtL and methyl syringate were reduced, and results compatible with industrial implementation were obtained. © 2011 Elsevier Ltd.
San Cristobal A.G.,CSIC - Institute of Agricultural Sciences |
Castello R.,CSIC - Institute of Agricultural Sciences |
Martin Luengo M.A.,Institute Ciencias Of Materiales |
Vizcayno C.,Institute Recursos Naturales
Applied Clay Science | Year: 2010
Kaoliniferous sand and washed industrial kaolin obtained from it were calcined (750°C) or milling prior to activation with NaOH. The changes were characterized by pH, cation exchange capacity (CEC), water capacity after calcination (WCC), particle size distribution (PSD) and specific surface area (SBET), as well as by X-ray diffraction (XRD), Fourier transform infrared (FTIR), thermal methods (TGA and DTA), and scanning and transmission electron microscopy (SEM and TEM). Alkali activation of thermally or mechanically modified kaolin increased the cation exchange capacity from 2.4 to 292.8 and from 3.0 to 279.9cmolkg-1 (samples WT and WM respectively). Alkali activation of mechanically modified kaoliniferous sand (OMA), and thermally and mechanically modified washed kaolin (WTA and WMA), yielded zeolite A. An unnamed zeolite, forming microspheres of 0.8-2.3μm in size, was also formed in mechanically modified kaoliniferous sand (OMA), washed kaolin (WA) and calcined washed kaolin (WTA) after alkali-activation. Structural disorder in the mechanically modified washed kaolin (WMA) favored the formation of a single type of zeolite. © 2010 Elsevier B.V.
Ramirez-Valiente J.A.,Instituto Nacional Of Investigacion Y Tecnologia Agraria Y Alimentaria |
Ramirez-Valiente J.A.,Technical University of Madrid |
Sanchez-Gomez D.,Technical University of Madrid |
Aranda I.,Instituto Nacional Of Investigacion Y Tecnologia Agraria Y Alimentaria |
And 3 more authors.
Tree Physiology | Year: 2010
Plants distributed across a wide range of environmental conditions are submitted to differential selective pressures. Long-term selection can lead to the development of adaptations to the local environment, generating ecotypic differentiation. Additionally, plant species can cope with this environmental variability by phenotypic plasticity. In this study, we examine the importance of both processes in coping with environmental heterogeneity in the Mediterranean sclerophyllous cork oak Quercus suber. For this purpose, we measured growth and key functional traits at the leaf level in 9-year-old plants across 2 years of contrasting precipitation (2005 and 2006) in a common garden. Plants were grown from acorns originated from 13 populations spanning a wide range of climates along the distribution range of the species. The traits measured were: leaf size (LS), specific leaf area (SLA), carbon isotope discrimination (Δ13C) and leaf nitrogen content per unit mass (Nmass). Inter-population differences in LS, SLA and Δ13C were found. These differences were associated with rainfall and temperature at the sites of origin, suggesting local adaptation in response to diverging climates. Additionally, SLA and LS exhibited positive responses to the increase in annual rainfall. Year effect explained 28% of the total phenotypic variance in LS and 2.7% in SLA. There was a significant genotype × environment interaction for shoot growth and a phenotypic correlation between the difference in shoot growth among years and the annual mean temperature at origin. This suggests that populations originating from warm sites can benefit more from wet conditions than populations from cool sites. Finally, we investigated the relationships between functional traits and aboveground growth by several regression models. Our results showed that plants with lower SLA presented larger aboveground growth in a dry year and plants with larger leaf sizes displayed larger growth rates in both years. Overall, the study supports the adaptive value of SLA and LS for cork oak under a Mediterranean climate and their potentially important role for dealing with varying temperature and rainfall regimes through both local adaptation and phenotypic plasticity. © The Author 2010. Published by Oxford University Press. All rights reserved.
Coba De La Pena T.,Institute Recursos Naturales |
Redondo F.J.,Institute Recursos Naturales |
Manrique E.,Institute Recursos Naturales |
Lucas M.M.,Institute Recursos Naturales |
Pueyo J.J.,Institute Recursos Naturales
Plant Biotechnology Journal | Year: 2010
Several recent studies have demonstrated that the expression of a cyanobacterial flavodoxin in plants can provide tolerance to a wide range of environmental stresses. Indeed, this strategy has been proposed as a potentially powerful biotechnological tool to generate multiple-tolerant crops. To determine whether flavodoxin expression specifically increased tolerance to salt stress and whether it might also preserve legume nitrogen fixation under saline conditions, the flavodoxin gene was introduced into the model legume Medicago truncatula. Expression of flavodoxin did not confer saline tolerance to the whole plant, although the sensitive nitrogen-fixing activity was maintained under salt stress in flavodoxin-expressing plants. Our results indicate that flavodoxin induced small but significant changes in the enzymatic activities involved in the nodule redox balance that might be responsible for the positive effect on nitrogen fixation. Expression of flavodoxin can be regarded as a potential tool to improve legume symbiotic performance under salt stress, and possibly other environmental stresses. © 2010 The Authors. Plant Biotechnology Journal © 2010 Society for Experimental Biology and Blackwell Publishing Ltd.