Taxonomic differences between Pinus sylvestris and P. uncinata revealed in the stomata and cuticle characters for use in the study of fossil material

Taxonomic differences in the needle epidermis characteristics of Pinus sylvestris L. and Pinus uncinata Ramond ex DC. from two Iberian populations were sought; such information could help identify these species when pollen analysis and the inspection of wood anatomy fails. The features of the cuticle are commonly well preserved in the fossil record. Although the epidermal patterns of the examined taxa were similar, qualitative differences were seen in the subsidiary and guard cells. P. sylvestris showed small subsidiary cells homogenously arranged around the opening of the epistomatal chamber, while P. uncinata showed small, lateral subsidiary cells and non-differentiated subsidiary cells in the polar position. The aperture of the epistomatic chamber of P. uncinata was also larger in diameter (15.1 ± 1.8 µm P. sylvestris; 21.1 ± 2.8 µm P. uncinata). Principal components analysis and discriminant analysis was performed on the features of the guard cells characterising the size and shape of the cuticular thickenings — all the variables analysed can be measured in disperse stomata in microscope preparations for pollen analysis. Significant differences were found in the upper woody lamellae width and the coefficient associated with the shape of the medial lamellae borders (discriminant analysis weighting 0.739 and 0.826 respectively). Other significant parameters included the coefficient associated with the relative size of the medial lamellae border width of the guard cells with respect to the distance between the external limits of the medial lamellae borders, and the length of the upper woody lamella. Different light regimens appeared not to significantly affect the variability of the studied features

The value of leaf cuticle characteristics in the identification and classification of Iberian Mediterranean members of the genus Pinus

This study reports the value of leaf cuticle characteristics in the identification and classification of Iberian Mediterranean species of the genus Pinus (P. nigra subsp. salzmannii, P. pinaster, P. pinea and P. halepensis), with the aim of using these characters to identify isolated cuticles and stomata in palynology slides. Preparations were made of the cuticles of pine needles belonging to one natural Iberian population of each of the above species. A number of epidermal morphological characteristics were then recorded with the aim of distinguishing these species from one another. The structure of the stomatal complex (the shape and arrangement of the subsidiary cells) was different in each species. The aperture of the epistomatal chamber was significantly smaller in P. pinea than in the other species examined, and the variables recorded for the thickening of the guard cells provided relationships that clearly distinguished all four taxa. The width and length of the stomata and the upper woody lamellae, the central distance between the external limits of the medial lamellae borders and the length of the stem were the most useful variables in this respect. The present results contribute to the ongoing discussion regarding the taxonomic classification of the members of Pinus, and provide valuable clues for the identification of Iberian Mediterranean pine species from small pine needle fragments or isolated stomata. After validation of the present results for multiple populations, these results could also be used to help identify fossil leaf macroremains and the scattered/ isolated stomata commonly observed in palaeopalynological samples

La opinión de profesionales sobre la incorporación de soportes tecnológicos portátiles en las aulas

In this paper, the feasibility of incorporating portable technological devices in educational practice is investigated by studying the level of acceptance of this innovative measure. To do this, we have made an inquiry to technology working professionals. The sample population includes students and teachers of the Master in Teacher Training (Secondary, Vocational, Bachelor and Languages Education) and other university graduates. The results reveal a wide acceptance of the incorporation of portable devices in addition to a high degree of awareness of some of its effects. Different levels of previous training needs of teachers, relatively homogeneous preferences among media types, and an estimate modest increase in disruption were also identified.En este artículo se investiga la viabilidad de la incorporación de soportes tecnológicos portátiles en la práctica educativa, estudiando el nivel de aceptación de esta medida innovadora. Para ello, se ha realizado una consulta a un grupo de profesionales relacionados con la tecnología. La muestra poblacional incluye alumnado y profesorado universitario de un Máster para la formación del profesorado de enseñanzas secundarias, así como titulados universitarios ajenos a dicho Máster. Los resultados revelan una amplia aceptación de la incorporación de dispositivos portátiles, además de un alto grado de concienciación sobre algunos de sus efectos. También se han detectado distintos niveles de necesidades formativas previas del profesorado, preferencias relativamente homogéneas entre tipos de soporte, y previsión de un aumento moderado de la disrupción

The long-term evolution of the Cantabrian landscapes and its possible role in the cappercaillie drama

Within the Iberian Peninsula, at the south-western boundary of its distribution area, the capercaillie is restricted to the Cantabrian and the Pyrenean Mountains. Cantabrian capercaillie Tetrao urogallus cantabricus has undergone a dramatic decline during the last three decades, as reported in the last Iberian Survey (Robles et al. 2006) and in previous issues of Grouse News (Bafiuelos et al., 2004, 2008). As a consequence, it is currently the only subspecies of capercaillie critically threatened worldwide. Although considerable efforts have been made to understand the reasons of this decline, the long-term ecology of this subspecies has received little attention, due probably to the absence of data in the palaeozoological records. Nevertheless, palaeoecological information based on their habitats can provide a useful insight that in the case of the Cantabrian Mountains offers a large body of data that covers the forest history of the last thousands of years

Interactive comment on CO2 radiative forcing during the Holocene Thermal Maximum revealed by stomatal frequency of Iberian oak leaves (2)

Here we analyse radiocarbon-dated Quercus leaf assemblages from northern Spain to obtain past atmospheric CO2 mixing ratios for the time period 9000–1100 cal BP by means of stomatal frequency analysis. Normalized, stomata based CO2 records show fluctuations of 20 ppmv during the Holocene that parallel Northern 5 Hemisphere palaeotemperature reconstructions. The calculated radiative forcing of CO2 indicates a CO2 contribution of +0.1_C to the Holocene Thermal Maximum from 7 to 5 kyr BP, and −0.05_C to the Neoglacial cooling around 4 kyr BP. Derived northern hemispheric air-temperature anomalies forced by atmospheric CO2 variation suggest an active role 10 of this trace gas as an amplifier of initial orbital forcing of Holocene climate

Cantabrian capercaillie through time: a further comment

In a recent note published in this journal (Rubiales et al. 2009) we discuss the role the long-term environmental history of the Cantabrian Mountains may have played in the dynamics of the Cantabrian capercaillie Tetrao urogallus cantabricus, the only subspecies of capercaillie at risk of extinction worldwide. Three key conclusions, in the light of the available palaeoecological data were that: 1) the vegetation occurring within the range of the Cantabrian capercaillie has heavily changed during the last three millennia, due primarily to anthropogenic activity; 2) the extensive distribution of pinewoods until the historical period is coherent with the pattern of association of capercaillie and conifers occurring in the rest of its range; and 3) in the light of the distinct current patterns of decline and persistence of the capercaillie, it could be expected that the demise of pinewoods (becoming locally extinct at the western part of the Cantabrian mountains) would have had implications in the capercaillie persistence in the long ter

Palaeobiogeographical perspectives on pinus pinea, a controversial and enigmatic mediterranean pine

The origins of some species of economic importance occurring over the Mediterranean Basin have been a traditional matter of debate that has important implications for land management. The case of Pinus pinea L. (Stone pine) is probably one of the most controversial, due to its documented long-term interaction with humans and its presence as a symbolic tree in certain areas of the Mediterranean (e.g., southwestern Iberia and Tuscany). Among the rest of the Mediterranean pines, several features make this pine unique (it has a characteristic crown shape, an edible kernel, cones that require three years to mature, and a very depauperate genetic diversity across its range). In addition, its palaeoecological information is rather limited, as the taxonomic precision attained by pollen analysts is insufficient for this tree and macroremains (such as kernels or anatomically well preserved wood) are needed to unequivocally detect the species in the fossil record. Recent findings of macrofossils of Pinus pinea in inland Iberia (Duero Basin) extend the late- Holocene range of the species, but the palaeobiogeographical information and the exhaustive genetic data available still suggest a very limited natural area (but still not sufficiently well defined) and a long and intense history of linkage to humans

Paleofitogeografía de los pinares en las montañas periféricas de la cuenca del Duero

En las dos últimas décadas se han obtenido numerosos resultados procedentes de diferentes trabajos paleobotánicos (Cuaternario final) realizados en los territorios montanos periféricos de la depresión del Duero. Las metodologías empleadas han sido diversas y tienen que ver con los diferentes tipos de yacimientos y de muestras biológicas seleccionadas para su estudio; entre ellas destacan las técnicas de microscopía óptica para la identificación de maderas subfósiles, la morfología comparada de macrorrestos y los estudios dendrocronológicos en árboles longevos y maderas subfósiles. En esta comunicación se reúnen y resumen los trabajos más importantes, haciéndose una síntesis de las conclusiones obtenidas en los trabajos paleofitogeográficos realizados hasta el momento; se hace hincapié en la información proporcionada por los macrorrestos (maderas, estróbilos) así como por la recogida en los registros dendrocronológicos (con extensión a la dendroecología). Otro de los objetivos de la comunicación es la síntesis de las conclusiones obtenidas en los trabajos paleofitogeográficos realizados hasta el momento. Uno de esos resultados es que el comportamiento de los pinares a lo largo del Holoceno presenta diferentes modalidades en cada una de las cordilleras que bordean la cuenca del Duero; desde casos con marcada estabilidad a otros en que se muestran variaciones temporales apreciables (con patrones de heterogeneidad en función de un eje N-S y/o O-E

Aprendizaje botánico mediante el mapeo e identificación de observaciones de plantas con iNaturalist, una plataforma en línea de ciencia ciudadana

La obligada adaptación del proceso enseñanza/aprendizaje incorporando herramientas tecnológicas apoyadas en inteligencia artificial y entornos colaborativos ha motivado la incorporación de la plataforma iNaturalist en asignaturas relacionadas con la botánica en enseñanzas universitarias forestales. Mediante la implementación de la iNaturalist se han diseñado unas clases prácticas de las asignaturas de Botánica de primer curso en los grados de Ingeniería Forestal y del Medio Natural (Universidad Politécnica de Madrid). Se ha utilizado un espacio del campus universitario (Arboreto de Montes), realizando una presentación y puesta en común de la actividad en aula, un recurso web, un guion de buenas prácticas, y un seguimiento progresivo de los estudiantes. En la primera evaluación de su eficacia se han registrado resultados positivos en la aceptación por el alumnado. La actividad, además, permite una transición a la docencia a distancia, y muestra su capacidad de transferibilidad a otros contextos educativos universitarios

Anthracological evidence suggests naturalness of Pinus pinaster in inland southwestern Iberia

The study of well-preserved archaeological charcoals in the pre-Roman Iron Age settlement of Castillejos II (Badajoz, Spain) is used to reconstruct environmental conditions and land-use practices in vegetation landscapes in the southwest of the Iberian Peninsula before the arrival of Roman civilization. The results support that, while evergreen Quercus forests dominated during the Holocene, Pinus pinaster existed as a natural element of southwestern Iberian Peninsula vegetation. Although its presence could be linked to anthropogenic disturbance or fire history, it is suggested that P. pinaster populations survived during the Holocene in the region, mixed with oaks or in monospecific stands in mountain enclaves. This hypothesis contrasts with previous assumptions that P. pinaster was not autochthonous in the area