Contribución al conocimiento de los Insectos Miridos de Navarra (Heteroptera, Miridae, Hahn 1831)

Se han identificado un total de 795 ejemplares de Míridos (Insecta, Heteroptera, Miridae), que corresponden a 35 géneros de 58 especies, de 64 localidades de Navarra. Dos especies son nuevas citas para la fauna de España: Trigonotylus ruficornis y Lyqus punctatus. Se aportan datos sobre el regimen alimenticio y la distribución geográfica de los Míridos

The challenge of abandonment for the sustainable management of Palaearctic natural and semi-natural grasslands

Disturbance by biomass removal is a crucial mechanism maintaining the diversity of Palaearctic grasslands, which are unique biodiversity hotspots. The century-long traditional land use of mowing, grazing and burning, has been fundamentally changed in many parts of the Palaearctic. Due to socio-economic changes, large areas of former pastures and meadows have been abandoned, leading to a succession towards secondary scrublands or forest and the encroachment of competitor grass species, all leading to a decrease in biodiversity. Here we report the causes and consequences of the cessation of traditional grassland management regimes, provide strategies for reducing the impact of abandonment and consider these from the perspective of sustainability. We consider the possibilities for initiating sustainable management regimes in the contemporary socio-economic environment, and discuss the prospects and limitation of alternative management regimes in the conservation of grassland biodiversity. These themes are also the core topics of this Special Feature, edited by the EDGG. We hope that this Special Feature will encourage steps towards more sustainable strategies for the conservation of Palaearctic grasslands and the integration of the sustainability perspective into their conservation. © by Orsolya Valkó 2018.Peer reviewe

Densification of WC-Fe-Ni-Co-Cr cemented carbides processed by HIP after sintering: effect of WC powder particle size

Shrinkage, liquid formation and mass losses of WC-19 vol% FeNiCoCr alloys during sintering have been inves- tigated in compositions either with coarse or submicron WC powders. Mass losses detected by thermogravimetry are compatible with carbothermal reduction of the different oxides present in the powder mixtures. Hardness and fracture toughness of materials based on submicron WC powders are within tolerances of those reported for WC- Co materials with similar microstructures. However, fracture strength is approx. 25% lower

Efecto del rolado y siembra de buffel sobre la evolución del estrato graminoso en un arbustal degradado del Chaco árido

In Argentinean Chaco Arid region, rolling and buffelgrass seeding is widespread. In this region, information related to its short and medium time effects on vegetation attributes is available. The purpose of this study was to evaluate the long time impacts (10 years) of roller chopping and buffelgrass seeding on grass yield, precipitation use efficiency and cover in a degraded site of the mentioned region. The treatments were: T0 = No roller chopping-seeding (Control) and T1= Roller chopping+buffelgrass seeding. Forage grass yield and precipitation use efficiency tended to be higher in T1 than in T0 during the evaluation period. Forage grass yield increment in T1 was highly associated to increment in total perennial grass cover (R2=91%), mainly due to buffelgrass cover (R2=76%). In T1, native perennial grass cover showed a negative lineal tendency in relation to years. Annual native grass, perennial native grass, total perennial grass and buffelgras covers followed a quadratic tendency related to years. Results of this study suggest that roller chopping and simultaneous buffelgrass seeding is, from a point of view of animal production, an efficient strategy for rapid restoration of grass cover and grazing capacity of degraded areas and that its effects maintains in the long time.En el Chaco Árido, el rolado y siembra de buffel (Cenchrus ciliaris var. Texas 4464) está ampliamente difundido, contándose solo con información de los efectos a corto y mediano plazo de la aplicación de esta técnica sobre atributos de vegetación. El objetivo fue evaluar el impacto a largo plazo (10 años) del rolado y siembra de buffel sobre la producción de materia seca acumulada, eficiencia del uso de la precipitación y cobertura de gramíneas en un ambiente degradado de la región. Los tratamientos fueron: T0 = Sin rolado ni siembra (Testigo) y T1= Rolado + siembra simultanea de buffel. La producción de forraje y la eficiencia de uso de la precipitación tendieron a ser mayores en T1 respecto a T0, en todo el período evaluado. El incremento de la producción en T1 estuvo altamente relacionado al incremento en la cobertura de pastos perennes totales (R2=91%), principalmente a la cobertura de buffel (R2=76%). En T1, la cobertura de pastos nativos perennes tendió a disminuir en el tiempo, mientras que la cobertura de pastos nativos anuales, la de pastos perennes totales y la de buffel, presentaron una tendencia cuadrática. Estos resultados sugieren que el rolado y siembra de buffel, desde un punto de vista de la producción animal, es una eficiente estrategia para recuperar la capacidad de forrajera de sitios degradados del Chaco Árido

Acariosis del maíz en Navarra. Ecología de Tetranychus turkestani Ugarov y Nikolski

Se ha estudiado el comportamiento ecológico de las poblaciones de Tetranychus turkestani Ugarov y Nikolski, tetraniquido fitófago que ataca al maíz en Navarra. Esta especie, que puede pasar el invierno en forma de hembra diapausica, comienza su actividad sobre la vegetación espontánea del borde de las parcelas de maíz a partir del mes de Marzo (temperatura media 13 °C). Desde esta vegetación, se desplaza a las hojas inferiores de las plantas de maíz del borde de la parcela a partir del mes de Junio, dependiendo del clima y de la existencia o no de vegetación de ribazo. A partir de ese momento, los ácaros siguen una doble dirección: hacia arriba, colonizando la planta y hacia los lados, colonizando las plantas vecinas. El estado fisiológico de la planta de maíz incide acusadamente en esta colonización. La semana previa y durante el estado de floración masculina, el crecimiento de T. turkestani se ve favorecido, produciéndose la colonización total de la planta por un lado, y de la parcela por otro. Las poblaciones de tetraníquidos se ven afectadas por: el estado fisiológico del maíz, el clima (temperaturas elevadas y humedad relativa baja les favorecen) y los enemigos naturales (especialmente los ácaros fitoseidos) que controlan sus poblaciones.Ecological populations behavior of Tetranychus turkestani UGAROV Y NIKOLSKI, phytophagous spider mite, infesting corn in Navarra has been studied. This species, which can spend winter time as diapausic female, starts its activity on spontaneous vegetation of the corn plots borders at the beginning of March (mean temperature 13 °C). From here on, and beginning with June, mites move to corn basal leaves of the plots border depending of weather and existence of slope vegetation. Beginning with this moment, mites follow a double direction: upward colonizing corn plants and toward every direction colonizing neighboring corn plants. Corn plants physiological state falls this colonization. During the masculine flowering state and previous week to this time, T. turkestani population increase is favored and total plant and total plot colonization occur. Spider mite populations are affected by: corn physiological state, clime (high temperatures and relative low humidity favour the mite) and natural enemies (predaceous phytoseiid mites over all) which control spider mite populations

Fitoseidos (Acari: Phytoseiidae) en maíz y en vegetación de ribazo en Navarra. Densidades y composición de especies

En el presente trabajo se da cuenta de las especies de fitoseidos encontradas sobre Tetranychus turkestani en el cultivo de maíz y en la vegetación de ribazo durante los años 1992 a 1994 en Navarra. En total se han encontrado quince especies de fitoseidos, siendo la más abundante y frecuente en maíz Amblyseius californicus (McGregor) siendo también muy frecuente en plantas espontaneas. Del resto de las especies destacan Euseius stipulates (A.-H.) en maíz y Amblyseius cucumeris (Oudemans) en maíz y en ribazo. Se ha determinado la presencia a lo largo del período del cultivo de las diversas especies y las densidades de fitoseidos por especie vegetal, destacando en este caso el alto valor que alcanza el maíz. Asimismo se ha observado la diferente composición de la fauna de fitoseidos en los cuatro habitats implicados: planta de maíz, restos de la cosecha anterior, gramíneas y otras especies de ribazo.The present work identifies the predaceous phytoseid mites on Tetranychus turkestani on corn from Navarra, in the years 1992-1994. A total of 15 species have been found. Amblyseius californicus (McGregor) is the most abundant mite on corn and on the border vegetation, Euseius stipulatus (A.-H.) on corn and Amblyseius cucumeris (Oudemans) on Gramineae and on remains of the anterior corn crop. The phytoseid presence through corn life cycle has been determinated and the phytoseid density by vegetal species (the highest density is the corn too). Finally, the different composition of the phytoseid community it has been observed in the four implicated habitats: corn, remains of the anterior corn crop, gramineas and other border plants

Depredadores de la familia Phytoseiidae sobre ácaro rojo Panonychus ulmi (Koch) en frutales de Navarra

Mites population dinamic of the family Phytoseiidae have been studied for several varieties of apple, pear and peach orchards through the year 1992 in Navarra (Northern Spain). For all the studied varieties, Amblyseius californicus (McGregor) and Euseius stipulatus (Athias-Henriot) are the dominant species. In apple orchards A. californicus is the most frecuent and abundant species (87 %) and in pear and peach orchards both population compositions are quite similar. A. californicus appears first in June and E. stipulatus appears later in the season.Se ha estudiado a lo largo del año 1992 los fitoseidos de dieciocho parcelas de frutales en el sur de Navarra, correspondientes a tres especies (peral, melocotonero y manzano). Este estudio se integra dentro de una campaña de control integrado en frutales. Se presentan las especies de fitoseidos recogidas así como su porcentaje y evolución a lo largo de la campaña. También se han estudiado en relación con las variedades de cada especie de frutal. Se ha encontrado que en los tres frutales las especies dominantes son Amblyseius californicus (McGregor) y Euseius stipulatus (Athias-Henriot), siendo la proporción total entre ellas casi igual en peral y melocotonero, sin embargo en manzano A. californicus es la especie dominante, alcanzando un 87 %. También se ha observado que es la especie que aparece en primer lugar, desde principios de junio, mientras que E. stipulatus aparece más tardíamente. Los niveles de población de fitoseidos están en relación directa con los tratamientos fitosanitarios, así en peral el número de fitoseidos es menor que en el resto por la frecuente utilización de insecticidas contra Cacopsylla pyri. Este es un estudio preliminar sobre esta familia de ácaros depredadores con vistas a unos futuros planes de control integrado más respetuosos con el medio ambiente

Investment in the long-tail of biodiversity data: from local research to global knowledge

In business, the "long-tail economy" refers to a market strategy where the gravity center shifts from a few high-demand products to many, varied products focused on small niches. Commercialization of individually low-demand products can be profitable as long as their production cost is low and, all taken together, they aggregate into a big chunk of the market. Similarly, in the "business" of biodiversity data acquisition, we can find several mainstream products that produce zillions of bits of information every year and account for most of the budget allocated to increase our primary data-based knowledge about Earth's biological diversity. These products play a crucial role in biodiversity research. However, along with these large global projects, there is a constellation of small-scale institutions that work locally, but whose contribution to our understanding of natural processes should not be dismissed. These information datasets can be collectively referred to as the "long-tail biodiversity data"

Scale-dependent plant diversity in Palaearctic grasslands: a comparative overview

Here we present an extensive overview of plant diversity values in Palaearctic grasslands for seven standard grain sizes from 0.0001 to 100 m². The data originate from 20 studies, including the Field Workshops of the Eurasian Dry Grassland Group (EDGG), ranging geographically from Spain in the west to Siberia in the east, from Sicily in the south to Estonia in the north and from the sea coast up to 3100 m a.s.l. The majority of data is from dry grasslands (Festuco-Brometea, Koelerio-Corynephoretea, Cleistogenetea squarrosae), but there are also some mesic, wet, saline, acidic, alpine and Mediterranean grasslands included. Among others, we compiled data from 1795 1-m², 1109 10-m² and 338 100-m² plots. In all cases we present mean, minimum and maximum richness for the seven grain sizes, plus, in cases where also terricolous bryophytes and lichens had been recorded, the same values for total “plant” species richness, non-vascular plant species richness and fraction of non-vascular plants. The maximum richness values were 82, 101 and 134 for all “plants”, and 79, 98 and 127 vascular plants at grain sizes of 1 m², 10 m² and 100 m², respectively (all in Transylvania, Romania). Our overview comprises new, hitherto unpublished world records of vascular plant species richness at the scales of 0.0001 m² (9) and 0.001 m² (19, both shoot presence), from meso-xeric, basiphilous grasslands in Navarre, Spain, which is much higher than the previously known maxima. The highest values of non-vascular plant richness at 1 m², 10 m² and 100 m², respectively, were 49, 64 and 64, respectively (all in Sedo-Scleranthenea communities of Öland, Sweden, and Saaremaa, Estonia). In general, the dry, alpine and Mediterranean grasslands were much richer than the studied mesic, wet or saline grasslands at any spatial scale. The presented set of mean, minimum and maximum values and their metadata is publically available and will be continuously updated. These data can serve as a reference of “normal” richness, both in fundamental and applied research. To facilitate the application, we provide an easy formula based on the power-law species-area relationship that allows the estimation of richness values at intermediate grain sizes not included in our dataset. In conclusion, our data emphasise the role of Palaearctic grasslands as global hotspot of small-scale vascular plant diversity, while at the same time highlighting that in some grassland types also the bryophyte and lichen diversity can be extraordinarily high

Disturbance indicator values for European plants

Motivation Indicator values are numerical values used to characterize the ecological niches of species and to estimate their occurrence along gradients. Indicator values on climatic and edaphic niches of plant species have received considerable attention in ecological research, whereas data on the optimal positioning of species along disturbance gradients are less developed. Here, we present a new data set of disturbance indicator values identifying optima along gradients of natural and anthropogenic disturbance for 6382 vascular plant species based on the analysis of 736,366 European vegetation plots and using expert-based characterization of disturbance regimes in 236 habitat types. The indicator values presented here are crucial for integrating disturbance niche optima into large-scale vegetation analyses and macroecological studies. Main types of variables contained We set up five main continuous indicator values for European vascular plants: disturbance severity, disturbance frequency, mowing frequency, grazing pressure and soil disturbance. The first two indicators are provided separately for the whole community and for the herb layer. We calculated the values as the average of expert-based estimates of disturbance values in all habitat types where a species occurs, weighted by the number of plots in which the species occurs within a given habitat type. Spatial location and grain Europe. Vegetation plots ranging in size from 1 to 1000 m(2). Time period and grain Vegetation plots mostly sampled between 1956 and 2013 (= 5th and 95th quantiles of the sampling year, respectively). Major taxa and level of measurement Species-level indicator values for vascular plants. Software format csv file