Efectos de la aplicación de cenizas de caldera de biomasa en el modelo jerárquico de agregación de un suelo forestal bajo condiciones oceánicas

Se ha estudiado los efectos que tiene la aplicación de cenizas de caldera de biomasa, en el modelo jerárquico de agregación (Tisdall y Oades, 1982) y en la estabilización del C orgánico en un suelo forestal situado en la zona templada del País Vasco. Para ello, se aplicaron 3 tratamientos con diferentes dosis de ceniza en muestras de suelo tamizadas a 250 μm procedentes de un huerto semillero de pinus radiata. Estas muestras fueron incubadas durante 3 meses y fraccionadas los días 29, 44, 64, 78 y 92 con la intención de separar los macroagregados grandes (LMagg), de los macroagregados pequeños (Magg), microagregados (magg), limos (silt) y arcillas (clay). Todas las fracciones fueron analizadas para determinar su contenido en C orgánico. Los resultados mostraron que con la aplicación de cenizas, el modelo jerárquico de agregación de suelo se cumple para las fracciones LMagg, Magg y magg, pero no para la fracción silt. Además se ha observado que las cenizas promueven la formación de microagregados aumentado así la capacidad de secuestro de C del suelo, pero en cambio disminuye la proporción de macroagregados, hecho que podría acarrear una disminución en la calidad estructural del suelo.S'ha estudiat els efectes que té l'aplicació de cendres de caldera de biomassa, en el model jeràrquic d'agregació (Tisdall i Oades, 1982) i estabilització del C orgànic en un sòl forestal situat a la zona temperada del País Basc. Per fer-ho, es van aplicar 3 tractaments amb diferents dosis de cendra en mostres de sòl tamisades a 250 μm procedents d'una plantació de pinus radiata. Aquestes mostres van ser incubades durant 3 mesos i fraccionades els dies 29, 44, 64, 78 i 92 amb la intenció de separar els macroagregats grans (LMagg), dels macroagregats petits (Magg), microagregats (magg), llims (silt) i argiles. Totes les fraccions van ser analitzades per determinar el seu contingut en C orgànic. Els resultats van mostrar que amb l'aplicació de cendres, el model jeràrquic d'agregació del sòl es compleix per a les fracciones LMagg, Magg i magg però no per a la fracció silt. A més s'ha observat que les cendres promouen la formació de microagregats augment d'aquesta manera la capacitat de segrest de C del sòl, però en canvi disminueix la proporció de macroagregats, fet que podria implicar una disminució en la qualitat estructural del sòl.The aim of this study was to evaluate the effects of biomass boiler ashes application on the hierarchical model of aggregation and stabilization (Tisdall and Oades, 1982) in a forest soil located in the Basque Country temperate region. To this end, three treatments with different ash doses were applied in a 250 μm sieved soil samples from a pinus radiata forest. Those samples were incubated for 3 months and fractionated at days 29, 44, 64, 78 and 92 to isolate large macroaggregates (LMagg), small macroaggregates (Magg), microaggregates (magg), silt and clay fractions. All fractions were analyzed for organic C content. The results showed that with ash application, the hierarchical model of aggregation holds for LMagg, Magg and magg fractions but not to silt fraction. In addition, results indicate that ashes promote microaggregates formation increasing soil C sequestration but instead, reduce macroaggregates proportion, which could lead to a soil structural quality decrease

Genetic constraints on temporal variation of airborne reflectance spectra and their uncertainties over a temperate forest

Remote sensing enhances large-scale biodiversity monitoring by overcoming temporal and spatial limitations of ground-based measurements and allows assessment of multiple plant traits simultaneously. The total set of traits and their variation over time is specific for each individual and can reveal information about the genetic composition of forest communities. Measuring trait variation among individuals of one species continuously across space and time is a key component in monitoring genetic diversity but difficult to achieve with ground-based methods. Remote sensing approaches using imaging spectroscopy can provide high spectral, spatial, and temporal coverage to advance the monitoring of genetic diversity, if sufficient relation between spectral and genetic information can be established. We assessed reflectance spectra from individual Fagus sylvatica L. (European beech) trees acquired across eleven years from 69 flights of the Airborne Prism Experiment (APEX) above the same temperate forest in Switzerland. We derived reflectance spectra of 68 canopy trees and correlated differences in these spectra with genetic differences derived from microsatellite markers among the 68 individuals. We calculated these correlations for different points in time, wavelength regions and relative differences between wavelength regions. High correlations indicate high spectral-genetic similarities. We then tested the influence of environmental variables obtained at temporal scales from days to years on spectral-genetic similarities. We performed an uncertainty propagation of radiance measurements to provide a quality indicator for these correlations. We observed that genetically similar individuals had more similar reflectance spectra, but this varied between wavelength regions and across environmental variables. The short-wave infrared regions of the spectrum, influenced by water absorption, seemed to provide information on the population genetic structure at high temperatures, whereas the visible part of the spectrum, and the near-infrared region affected by scattering properties of tree canopies, showed more consistent patterns with genetic structure across longer time scales. Correlations of genetic similarity with reflectance spectra similarity were easier to detect when investigating relative differences between spectral bands (maximum correlation: 0.40) than reflectance data (maximum correlation: 0.33). Incorporating uncertainties of spectral measurements yielded improvements of spectral-genetic similarities of 36% and 20% for analyses based on single spectral bands, and relative differences between spectral bands, respectively. This study highlights the potential of dense multi-temporal airborne imaging spectroscopy data to detect the genetic structure of forest communities. We suggest that the observed temporal trajectories of reflectance spectra indicate physiological and possibly genetic constraints on plant responses to environmental change

Efectos de la aplicación de cenizas de caldera de biomasa en el modelo jerárquico de agregación de un suelo forestal bajo condiciones oceánicas

Se ha estudiado los efectos que tiene la aplicación de cenizas de caldera de biomasa, en el modelo jerárquico de agregación (Tisdall y Oades, 1982) y en la estabilización del C orgánico en un suelo forestal situado en la zona templada del País Vasco. Para ello, se aplicaron 3 tratamientos con diferentes dosis de ceniza en muestras de suelo tamizadas a 250 μm procedentes de un huerto semillero de pinus radiata. Estas muestras fueron incubadas durante 3 meses y fraccionadas los días 29, 44, 64, 78 y 92 con la intención de separar los macroagregados grandes (LMagg), de los macroagregados pequeños (Magg), microagregados (magg), limos (silt) y arcillas (clay). Todas las fracciones fueron analizadas para determinar su contenido en C orgánico. Los resultados mostraron que con la aplicación de cenizas, el modelo jerárquico de agregación de suelo se cumple para las fracciones LMagg, Magg y magg, pero no para la fracción silt. Además se ha observado que las cenizas promueven la formación de microagregados aumentado así la capacidad de secuestro de C del suelo, pero en cambio disminuye la proporción de macroagregados, hecho que podría acarrear una disminución en la calidad estructural del suelo.S’ha estudiat els efectes que té l’aplicació de cendres de caldera de biomassa, en el model jeràrquic d’agregació (Tisdall i Oades, 1982) i estabilització del C orgànic en un sòl forestal situat a la zona temperada del País Basc. Per fer-ho, es van aplicar 3 tractaments amb diferents dosis de cendra en mostres de sòl tamisades a 250 μm procedents d’una plantació de pinus radiata. Aquestes mostres van ser incubades durant 3 mesos i fraccionades els dies 29, 44, 64, 78 i 92 amb la intenció de separar els macroagregats grans (LMagg), dels macroagregats petits (Magg), microagregats (magg), llims (silt) i argiles. Totes les fraccions van ser analitzades per determinar el seu contingut en C orgànic. Els resultats van mostrar que amb l’aplicació de cendres, el model jeràrquic d’agregació del sòl es compleix per a les fracciones LMagg, Magg i magg però no per a la fracció silt. A més s’ha observat que les cendres promouen la formació de microagregats augment d’aquesta manera la capacitat de segrest de C del sòl, però en canvi disminueix la proporció de macroagregats, fet que podria implicar una disminució en la qualitat estructural del sòl.The aim of this study was to evaluate the effects of biomass boiler ashes application on the hierarchical model of aggregation and stabilization (Tisdall and Oades, 1982) in a forest soil located in the Basque Country temperate region. To this end, three treatments with different ash doses were applied in a 250 μm sieved soil samples from a pinus radiata forest. Those samples were incubated for 3 months and fractionated at days 29, 44, 64, 78 and 92 to isolate large macroaggregates (LMagg), small macroaggregates (Magg), microaggregates (magg), silt and clay fractions. All fractions were analyzed for organic C content. The results showed that with ash application, the hierarchical model of aggregation holds for LMagg, Magg and magg fractions but not to silt fraction. In addition, results indicate that ashes promote microaggregates formation increasing soil C sequestration but instead, reduce macroaggregates proportion, which could lead to a soil structural quality decrease

Efectos de la aplicación de cenizas de caldera de biomasa en el modelo jerárquico de agregación de un suelo forestal bajo condiciones oceánicas

Se ha estudiado los efectos que tiene la aplicación de cenizas de caldera de biomasa, en el modelo jerárquico de agregación (Tisdall y Oades, 1982) y en la estabilización del C orgánico en un suelo forestal situado en la zona templada del País Vasco. Para ello, se aplicaron 3 tratamientos con diferentes dosis de ceniza en muestras de suelo tamizadas a 250 μm procedentes de un huerto semillero de pinus radiata. Estas muestras fueron incubadas durante 3 meses y fraccionadas los días 29, 44, 64, 78 y 92 con la intención de separar los macroagregados grandes (LMagg), de los macroagregados pequeños (Magg), microagregados (magg), limos (silt) y arcillas (clay). Todas las fracciones fueron analizadas para determinar su contenido en C orgánico. Los resultados mostraron que con la aplicación de cenizas, el modelo jerárquico de agregación de suelo se cumple para las fracciones LMagg, Magg y magg, pero no para la fracción silt. Además se ha observado que las cenizas promueven la formación de microagregados aumentado así la capacidad de secuestro de C del suelo, pero en cambio disminuye la proporción de macroagregados, hecho que podría acarrear una disminución en la calidad estructural del suelo.S'ha estudiat els efectes que té l'aplicació de cendres de caldera de biomassa, en el model jeràrquic d'agregació (Tisdall i Oades, 1982) i estabilització del C orgànic en un sòl forestal situat a la zona temperada del País Basc. Per fer-ho, es van aplicar 3 tractaments amb diferents dosis de cendra en mostres de sòl tamisades a 250 μm procedents d'una plantació de pinus radiata. Aquestes mostres van ser incubades durant 3 mesos i fraccionades els dies 29, 44, 64, 78 i 92 amb la intenció de separar els macroagregats grans (LMagg), dels macroagregats petits (Magg), microagregats (magg), llims (silt) i argiles. Totes les fraccions van ser analitzades per determinar el seu contingut en C orgànic. Els resultats van mostrar que amb l'aplicació de cendres, el model jeràrquic d'agregació del sòl es compleix per a les fracciones LMagg, Magg i magg però no per a la fracció silt. A més s'ha observat que les cendres promouen la formació de microagregats augment d'aquesta manera la capacitat de segrest de C del sòl, però en canvi disminueix la proporció de macroagregats, fet que podria implicar una disminució en la qualitat estructural del sòl.The aim of this study was to evaluate the effects of biomass boiler ashes application on the hierarchical model of aggregation and stabilization (Tisdall and Oades, 1982) in a forest soil located in the Basque Country temperate region. To this end, three treatments with different ash doses were applied in a 250 μm sieved soil samples from a pinus radiata forest. Those samples were incubated for 3 months and fractionated at days 29, 44, 64, 78 and 92 to isolate large macroaggregates (LMagg), small macroaggregates (Magg), microaggregates (magg), silt and clay fractions. All fractions were analyzed for organic C content. The results showed that with ash application, the hierarchical model of aggregation holds for LMagg, Magg and magg fractions but not to silt fraction. In addition, results indicate that ashes promote microaggregates formation increasing soil C sequestration but instead, reduce macroaggregates proportion, which could lead to a soil structural quality decrease

Intraspecific genetic variation of a Fagus sylvatica population in a temperate forest derived from airborne imaging spectroscopy time series

The growing pace of environmental change has increased the need for large‐scale monitoring of biodiversity. Declining intraspecific genetic variation is likely a critical factor in biodiversity loss, but is especially difficult to monitor: assessments of genetic variation are commonly based on measuring allele pools, which requires sampling of individuals and extensive sample processing, limiting spatial coverage. Alternatively, imaging spectroscopy data from remote platforms may hold the potential to reveal genetic structure of populations. In this study, we investigated how differences detected in an airborne imaging spectroscopy time series correspond to genetic variation within a population of Fagus sylvatica under natural conditions. We used multi‐annual APEX (Airborne Prism Experiment) imaging spectrometer data from a temperate forest located in the Swiss midlands (Laegern, 47°28'N, 8°21'E), along with microsatellite data from F. sylvatica individuals collected at the site. We identified variation in foliar reflectance independent of annual and seasonal changes which we hypothesize is more likely to correspond to stable genetic differences. We established a direct connection between the spectroscopy and genetics data by using partial least squares (PLS) regression to predict the probability of belonging to a genetic cluster from spectral data. We achieved the best genetic structure prediction by using derivatives of reflectance and a subset of wavebands rather than full‐analyzed spectra. Our model indicates that spectral regions related to leaf water content, phenols, pigments, and wax composition contribute most to the ability of this approach to predict genetic structure of F. sylvatica population in natural conditions. This study advances the use of airborne imaging spectroscopy to assess tree genetic diversity at canopy level under natural conditions, which could overcome current spatiotemporal limitations on monitoring, understanding, and preventing genetic biodiversity loss imposed by requirements for extensive in situ sampling

Remotely sensed between‐individual functional trait variation in a temperate forest

1. Trait-based ecology holds the promise to explain how plant communities work, for example, how functional diversity may support community productivity. However, so far it has been difficult to combine field-based approaches assessing traits at the level of plant individuals with limited spatial coverage and approaches using remote sensing (RS) with complete spatial coverage but assessing traits at the level of vegetation pixels rather than individuals. By delineating all individual-tree crowns within a temperate forest site and then assigning RS-derived trait measures to these trees, we combine the two approaches, allowing us to use general linear models to estimate the influence of taxonomic or environmental variation on between- and within-species variation across contiguous space. 2. We used airborne imaging spectroscopy and laser scanning to collect individual-tree RS data from a mixed conifer-angiosperm forest on a mountain slope extending over 5.5 ha and covering large environmental gradients in elevation as well as light and soil conditions. We derived three biochemical (leaf chlorophyll, carotenoids, and water content) and three architectural traits (plant area index, foliage-height diversity, and canopy height), which had previously been used to characterize plant function, from the RS data. We then quantified the contributions of taxonomic and environmental variation and their interaction to trait variation and partitioned the remaining within-species trait variation into smaller-scale spatial and residual variation. We also investigated the correlation between functional trait and phylogenetic distances at the between-species level. The forest consisted of 13 tree species of which eight occurred in sufficient abundance for quantitative analysis. 3. On average, taxonomic variation between species accounted for more than 15% of trait variation in biochemical traits but only around 5% (still highly significant) in architectural traits. Biochemical trait distances among species also showed a stronger correlation with phylogenetic distances than did architectural trait distances. Light and soil conditions together with elevation explained slightly more variation than taxonomy across all traits, but in particular increased plant area index (light) and reduced canopy height (elevation). Except for foliage-height diversity, all traits were affected by significant interactions between taxonomic and environmental variation, the different responses of the eight species to the within-site environmental gradients potentially contributing to the coexistence of the eight abundant species. 4. We conclude that with high-resolution RS data it is possible to delineate individual-tree crowns within a forest and thus assess functional traits derived from RS data at individual level. With this precondition fulfilled, it is then possible to apply tools commonly used in field-based trait ecology to partition trait variation among individuals into taxonomic and potentially even genetic variation, environmental variation, and interactions between the two. The method proposed here presents a promising way of assessing individual-based trait information with complete spatial coverage and thus allowing analysis of functional diversity at different scales. This information can help to better understand processes shaping community structure, productivity, and stability of forests

Genomics meets remote sensing in global change studies: monitoring and predicting phenology, evolution and biodiversity

Although the monitoring and prediction of ecosystem dynamics under global change have been extensively assessed, large gaps remain in our knowledge, including a need for concepts in rapid evolution and phenotypic plasticity, and a lack of large-scale and long-term monitoring. Recent genomic studies using the model species Arabidopsis predict that plastic and evolutionary changes in phenology may affect plant reproduction. We propose that three genomic-scale methods would enhance global change studies. First, genome-wide RNA sequencing enables monitoring of diverse functional traits and phenology. Second, sequencing of DNA variants highlights the importance of genetic variation and evolution. Third, DNA metabarcoding provides efficient and unbiased ecosystem monitoring. Integrating these genomic-scale studies with remote sensing will promote the understanding and prediction of biodiversity change