Stand Delineation of Pinus sylvestris L. Plantations Suffering Decline Processes Based on Biophysical Tree Crown Variables: A Necessary Tool for Adaptive Silviculture

Many planted Pinus forests are severely affected by defoliation and mortality processes caused by pests and droughts. The mapping of forest tree crown variables (e.g., leaf area index and pigments) is particularly useful in stand delineation for the management of declining forests. This work explores the potential of integrating multispectral WorldView-2 (WV-2) and Airborne Laser Scanning (ALS) data for stand delineation based on selected tree crown variables in Pinus sylvestris plantations in southern Spain. Needle pigments (chlorophyll and carotenes) and leaf area index (LAI) were quantified. Eight vegetation indices and ALS-derived metrics were produced, and seven predictors were selected to estimate and map tree crown variables using a Random Forest method and Gini index. Chlorophylls a and b (Chla and Chlb) were significantly higher in the non-defoliated and moderately defoliated trees than in severely defoliated trees (F = 14.02, p < 0.001 for Chla; F = 13.09, p < 0.001 for Chlb). A similar response was observed for carotenoids (Car) (F = 14.13, p < 0.001). The LAI also showed significant differences among the defoliation levels (F = 26.5, p < 0.001). The model for the chlorophyll a pigment used two vegetation indices, Plant Senescence Reflectance Index (PSRI) and Carotenoid Reflectance Index (CRI); three WV-2 band metrics, and three ALS metrics. The model built to describe the tree Chlb content used similar variables. The defoliation classification model was established with a single vegetation index, Green Normalized Difference Vegetation Index (GNDVI); two metrics of the blue band, and two ALS metrics. The pigment contents models provided R2 values of 0.87 (Chla, RMSE = 12.98%), 0.74 (Chlb, RMSE = 10.39%), and 0.88 (Car, RMSE = 10.05%). The cross-validated confusion matrix achieved a high overall classification accuracy (84.05%) and Kappa index (0.76). Defoliation and Chla showed the validation values for segmentations and, therefore, in the generation of the stand delineation. A total of 104 stands were delineated, ranging from 6.96 to 54.62 ha (average stand area = 16.26 ha). The distribution map of the predicted severity values in the P. sylvestris plantations showed a mosaic of severity patterns at the stand and individual tree scales. Overall, the findings of this work underscore the potential of WV-2 and ALS data integration for the assessment of stand delineation based on tree health status. The derived cartography is a relevant tool for developing adaptive silvicultural practices to reduce Pinus sylvestris mortality in planted forests at risk due to climate change

La sección de cartas al editor : un planteamiento científico y social en la didáctica de las ciencias

En este artículo demostramos la importancia que las Cartas al editor tienen en la construcción del conocimiento científico y su aplicación a la enseñanza de las ciencias. Se analiza el estado de la sección de Cartas al editor de las revistas editadas en el mercado español que comprenden la siguiente temática: divulgación científica y tecnológica, divulgación cultural e investigación. Aportamos estrategias de trabajo en el aula con el uso de las Cartas al editor en las revistas orientadas todas ellas a facilitar al alumno el desarrollo de ideas adecuadas sobre la construcción real de la ciencia y el conocimiento científico. Finalmente argumentamos la escasa presencia de la sección de Cartas al editor en un porcentaje notable de las revistas consultadas.In this article, we have demonstrated the importance of «Letters to the Editor» in the building up of scientific knowledge and its application to Science teaching. The state of the Letters to the Editor section has been analyzed in the sphere of journals published in Spain comprising the following topics: the dissemination of science and technology, the dissemination of culture, and research. We propose some classroom work strategies based on the use of «Letters to the Editor», which are directed towards encouraging students to develop appropriate ideas on the real construction of science and scientific knowledge. Finally, we have revealed the scant presence of a «Letters to the Editor» section in a considerable percentage of the journals consulted

Experimental Radial Profiles of Early Time (\u3c4 μs) Neutral and Ion Spectroscopic Signatures in Lightning-Like Discharges

This study presents experimental results for the radial and temporal variation of neutral and ion spectroscopic signatures emerging from the heated channel of lightning-like discharges diagnosed with a high speed (900,000 fps) imaging spectrograph. Light emissions emanate from three regions: an inner core (up to ∼2 mm), an external sheath (up to ∼4 mm) featuring a sudden temperature increase, and further optical emissions forming a dim glow from 4 mm up to 16 mm. The optical emissions are initially

Aportación al conocimiento de la flora briológica española. Nótula IV: las Sierras de Jabalambre y Gúdar (Teruel)

La VII Reunión de Briología tuvo lugar los días 5 al 9 de abril de 1976 en Mora de Rubielos, con objeto de continuar el estudio del Sistema Ibérico iniciado con la Sierra de Albarracín. Durante las jornadas de trabajo se exploraron las sierras de Jabalambre y Gúdar. En esta comunicación damos a conocer el resultado de nuestras recolecciones en ambas Sierras. Después de un somero estudio de la vegetación de la zona objeto de nuestro trabajo, se da a conocer la presencia de 17 especies de Hepáticas y 125 de Musgos. Este resultado representa la primera aportación para esta parte del Sistema Ibérico y una notable contribución al conocimiento de la brioflora turolense.The VII Bryological Meeting took place on the 5th to the 9th of April, 1976 in Mora de Rubielos, its aim being to continue the study of the Iberian System which began in the Sierra de Albarracín. Work done during the Meeting consisted in exploring the sierras ofJabaIambre and Gúdar. The result of our gatherings in both these sierras is made known in this article. After a summary study ofthe vegetation of the area which was the subject of our investigation, the presence of 17 species of Hepaticae and 125 of Mosses is discovered. These results form the first contribution for this part of the Iberian System and an important contribution to the knowledge of the Teruel bryoflora

EL ORDEN RACOMlTRl ETALlA HETEROSTICH I PH ILlPPl 1956 EN LA PENíNSULAIB ERICA. NOTA PRELIMINAR

Briophitic communities belonging to Grimmio-Racomitrion heterostichi Marstaller 1982 and Racomitrion lanuginosi (Gams 1927) Preis 1937 are dealt with. Associations described in the european literature are recorded. Some other communities will be published after completing their study.Se contemplan comunidades briofíticas de Grimmio-Racomitrion heterostichi Marstaller 1982 y Racomitrion lanuginosi (Gams 1927) Preis 1937, se citan asociaciones descritas en la bibliografía europea y se comentan otras comunidades que serán publicadas cuando se complete su estudio

Macroeconomics in practice: using WIKIS for collaborative learning

This project is based on the creation of collaborative wikis for students of Macroeconomics to elaborate a final work in which they apply the theoretical knowledge learnt in the subject to the real world. The initiative was implemented during the course 2015-2016 and aimed at 140 students enrolled in the subject at the Degree of Finance and Accountancy of the University of Cadiz. To emphasize the link between the theories explained in class and the real world, in previous courses we have already used news and other resources. With this project, we now introduce the use of wikis, which consist on the creation of a website to allow collaborative creation and modification of contents and structure from the web browser. Students were organized in 44 teams, of about 3 members, to examine data on a certain macroeconomic variable (i.e. inflation or GDP), in a particular geographical context (i.e. G20 or EU countries). The objectives of the project include: i) to enhance learning and comprehension of theoretical knowledge and ii) to contribute to the development of skills related to the subject, such as the skill to apply the acquired knowledge, the skill to analyze and search information and teamwork. Students’ opinions gathered from a survey at the end of the course suggest that these objectives have been achieved

Autoaprendizaje tutorizado de los estados de la materia. Empleando un software interactivo

During this academical year, we are testing the new ECTS educational system in some of the Cordoba universitary studies. With this new credit concept, all the work of the students tend to be evaluated. This report presents an interactive software about the states of the matter we have developed so that it could be used for the new educational systme. Firstly, we describe the application as an useful work tool and describe the methodology based on it. Finally, we evaluate the students' knowledge and compare the results obtained with this new tool and with the traditional one. As a consequence of that comparative study, we can conclude that the software described is useful for the ECTS system.El sistema de créditos europeos (ECTS) se está aplicando de forma experimental en algunas de las Titulaciones de la Universidad de Córdoba. Con este nuevo concepto de crédito se pretende valorar todo el trabajo del alumno. En este artículo se presenta un software para el estudio interactivo de los estados de la materia, con el objetivo de la adaptación de la enseñanza al nuevo sistema educativo. En la primera parte, se presenta el programa como herramienta útil de trabajo. A continuación, se hace un estudio de esta nueva forma de aprendizaje, utilizando el software como medio visual de los procesos que el alumno debe aprender. Finalmente, se valora el conocimiento que el alumno ha adquirido utilizando esta herramienta didáctica, y se compara con los resultados obtenidos aplicando los métodos de enseñanza tradicional, basada en clases magistrales y toma de apuntes del alumno. Con este estudio hemos podido comprobar la eficacia de esta metodología, así como su aplicabilidad en los sistemas de créditos europeos

Frugivoría y dispersión de semillas por mamíferos carnívoros: rasgos funcionales

Muchas especies de mamíferos carnívoros (Orden Carnivora) consumen frutos carnosos, transportan semillas en sus tractos digestivos y las defecan sin dañarlas en condiciones apropiadas para la germinación. En este artículo, revisamos el conocimiento adquirido sobre este mutualismo en las últimas tres décadas, desde que tres trabajos pioneros revelaron la importancia de los carnívoros como dispersores de semillas en ecosistemas templados. Nos centramos en los rasgos funcionales de los carnívoros consumiendo frutos y diseminando semillas, haciendo especial énfasis en sus diferencias con las aves, el principal grupo de vertebrados frugívoros en ecosistemas templados. Los carnívoros no están sujetos a las restricciones fenológicas o morfológicas que típicamente limitan el consumo de determinados frutos en muchas especies de aves. Consumen preferentemente frutos cuyos atributos son compartidos con muchas especies de frutos cultivados por el hombre, lo que explica el consumo frecuente de éstos en paisajes antrópicos. Sus amplios requerimientos espaciales favorecen la dispersión de semillas a larga distancia, mientras que su generalismo en relación al hábitat favorece el flujo de semillas entre hábitats contrastados. De este modo, los carnívoros promueven la conectividad entre poblaciones vegetales y la colonización. Estas funciones ecológicas son clave para las comunidades vegetales nativas, especialmente en escenarios de cambios de uso de suelo. Sin embargo, estos patrones de dispersión de semillas pueden contribuir a la invasión de plantas exóticas. Aún ignoramos en gran medida el papel de los carnívoros en términos cuantitativos de la dispersión de semillas y las diferencias funcionales entre especies dentro del gremio. La integración de muestreos clásicos e innovadoras técnicas moleculares y de análisis espacial promete aportar conocimiento inédito en estas cuestiones[EN ] Many species of carnivorous mammals (Order Carnivora) consume fleshy fruits, transport seeds in their digestive tracts, and defecate them without damage in conditions that are suitable for germination. In this article, we review the state of the art on this mutualism in the past three decades, since three pioneering studies revealed the importance of carnivores as seed dispersers in temperate ecosystems. We focus on the functional traits of carnivores consuming fruits and disseminating seeds, with particular emphasis on their differences with birds, the main group of vertebrate frugivores in temperate ecosystems. Carnivores are not subject to the phenological or morphological constraints that typically limit the consumption of certain fruit species in many bird species. They preferably consume fruits whose traits are shared with many fruit species cultivated by man, which explains the frequent consumption of cultivated fruits in anthropogenic landscapes. The large spatial requirements of carnivores promote long-distance seed dispersal, while their habitat generalism promotes seed flows between contrasting habitats. Thus, carnivores promote connectivity between plant populations and colonization. These are key ecological functions for native plant communities, especially in scenarios of land-use changes. However, these seed dispersal patterns can contribute to the invasion of exotic plants. We still largely ignore the role of carnivores in quantitative terms of seed dispersal and the functional differences between species within the guild. Integrating traditional fieldwork and innovative molecular techniques and spatial analysis promises to provide unprecedented knowledge on these issuesPeer reviewe

Stand Characterization of Eucalyptus spp. Plantations in Uruguay Using Airborne Lidar Scanner Technology

Airborne lidar scanner (ALS) technology is used in a variety of applications, including forestry. ALS has enormous potential for the estimation of relevant biometric parameters in forest plantations. This study investigates the use of an object-oriented semi-automated segmentation algorithm for stands delineation, based on modeling ALS data, in plantations of Eucalyptus grandis and E. dunnii in Uruguay. The results show that non-parametric methods delivered more accurate and less biased results for total volume (TV) with R2 0.93, RMSE 20.04 m3 h−1 for E. grandis and R2 0.93, RMSE 18.43 m3 h−1 for E.dunnii; and above ground biomass (AGB) with R2 0.95, RMSE 70.2 kg h−1 for E. grandis and R2 0.96, RMSE: 71.2 Kg h−1 for E. dunnii. Parametric methods performed better for dominant height (Ho) with R2 0.98, RMSE 0.67 m and R2: 0.96, RMSE: 0.8 m for E. grandis and E. dunnii, respectively. The most informative ALS metrics for the estimation of AGB and TV were metrics related to the elevation in parametric models (Elev.70 and Elev.75), while for the non-parametric models (k-NN) they were Elev.75 and canopy density. For Ho, the ALS metrics selected were also related to elevation both in the parametric (Elev.90 and Elev.99) and random forest models (Elev.max and Elev.75). The segmentation methodology proposed here matched closely the segments delineated by human operators, and provides a low-cost, cost-effective, easy to apply and update model aimed at generating AGB or TV maps for harvest tasks, based on rasters derived from ALS metrics. The present research shows the capacity of ALS metrics to improve extensive strategic inventories; validating and promoting the adoption of ALS technology for inventory forest stands of Eucalyptus spp. in Uruguay