325 resultados para swd: Zahlungsbereitschaft


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Vegetation changes, such as shrub encroachment and wetland expansion, have been observed in many Arctic tundra regions. These changes feed back to permafrost and climate. Permafrost can be protected by soil shading through vegetation as it reduces the amount of solar energy available for thawing. Regional climate can be affected by a reduction in surface albedo as more energy is available for atmospheric and soil heating. Here, we compared the shortwave radiation budget of two common Arctic tundra vegetation types dominated by dwarf shrubs (Betula nana) and wet sedges (Eriophorum angustifolium) in North-East Siberia. We measured time series of the shortwave and longwave radiation budget above the canopy and transmitted radiation below the canopy. Additionally, we quantified soil temperature and heat flux as well as active layer thickness. The mean growing season albedo of dwarf shrubs was 0.15 ± 0.01, for sedges it was higher (0.17 ± 0.02). Dwarf shrub transmittance was 0.36 ± 0.07 on average, and sedge transmittance was 0.28 ± 0.08. The standing dead leaves contributed strongly to the soil shading of wet sedges. Despite a lower albedo and less soil shading, the soil below dwarf shrubs conducted less heat resulting in a 17 cm shallower active layer as compared to sedges. This result was supported by additional, spatially distributed measurements of both vegetation types. Clouds were a major influencing factor for albedo and transmittance, particularly in sedge vegetation. Cloud cover reduced the albedo by 0.01 in dwarf shrubs and by 0.03 in sedges, while transmittance was increased by 0.08 and 0.10 in dwarf shrubs and sedges, respectively. Our results suggest that the observed deeper active layer below wet sedges is not primarily a result of the summer canopy radiation budget. Soil properties, such as soil albedo, moisture, and thermal conductivity, may be more influential, at least in our comparison between dwarf shrub vegetation on relatively dry patches and sedge vegetation with higher soil moisture.

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In 2001, a weather and climate monitoring network was established along the temperature and aridity gradient between the sub-humid Moroccan High Atlas Mountains and the former end lake of the Middle Drâa in a pre-Saharan environment. The highest Automated Weather Stations (AWS) was installed just below the M'Goun summit at 3850 m, the lowest station Lac Iriki was at 450 m. This network of 13 AWS stations was funded and maintained by the German IMPETUS (BMBF Grant 01LW06001A, North Rhine-Westphalia Grant 313-21200200) project and since 2011 five stations were further maintained by the GERMAN DFG Fennec project (FI 786/3-1), this way some stations of the AWS network provided data for almost 12 years from 2001-2012. Standard meteorological variables such as temperature, humidity, and wind were measured at an altitude of 2 m above ground. Other meteorological variables comprise precipitation, station pressure, solar irradiance, soil temperature at different depths and for high mountain station snow water equivalent. The stations produced data summaries for 5-minute-precipitation-data, 10- or 15-minute-data and a daily summary of all other variables. This network is a unique resource of multi-year weather data in the remote semi-arid to arid mountain region of the Saharan flank of the Atlas Mountains. The network is described in Schulz et al. (2010) and its further continuation until 2012 is briefly discussed in Redl et al. (2015, doi:10.1175/MWR-D-15-0223.1) and Redl et al. (2016, doi:10.1002/2015JD024443).

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Observations of snow properties, superimposed ice, and atmospheric heat fluxes have been performed on first-year and second-year sea ice in the western Weddell Sea, Antarctica. Snow in this region is particular as it does usually survive summer ablation. Measurements were performed during Ice Station Polarstern (ISPOL), a 5-week drift station of the German icebreaker RV Polarstern. Net heat flux to the snowpack was 8 W/m**2, causing only 0.1 to 0.2 m of thinning of both snow cover types, thinner first-year and thicker second-year snow. Snow thinning was dominated by compaction and evaporation, whereas melt was of minor importance and occurred only internally at or close to the surface. Characteristic differences between snow on first-year and second-year ice were found in snow thickness, temperature, and stratigraphy. Snow on second-year ice was thicker, colder, denser, and more layered than on first-year ice. Metamorphism and ablation, and thus mass balance, were similar between both regimes, because they depend more on surface heat fluxes and less on underground properties. Ice freeboard was mostly negative, but flooding occurred mainly on first-year ice. Snow and ice interface temperature did not reach the melting point during the observation period. Nevertheless, formation of discontinuous superimposed ice was observed. Color tracer experiments suggest considerable meltwater percolation within the snow, despite below-melting temperatures of lower layers. Strong meridional gradients of snow and sea-ice properties were found in this region. They suggest similar gradients in atmospheric and oceanographic conditions and implicate their importance for melt processes and the location of the summer ice edge.

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Samoylov Island is centrally located within the Lena River Delta at 72° N, 126° E and lies within the Siberian zone of continuous permafrost. The landscape on Samoylov Island consists mainly of late Holocene river terraces with polygonal tundra, ponds and lakes, and an active floodplain. The island has been the focus of numerous multidisciplinary studies since 1993, which have focused on climate, land cover, ecology, hydrology, permafrost and limnology. This paper aims to provide a framework for future studies by describing the characteristics of the island's meteorological parameters (temperature, radiation and snow cover), soil temperature, and soil moisture. The land surface characteristics have been described using high resolution aerial images in combination with data from ground-based observations. Of note is that deeper permafrost temperatures have increased between 0.3 to 1.3 °C over the last five years. However, no clear warming of air and active layer temperatures is detected since 1998, though winter air temperatures during recent years have not been as cold as in earlier years.

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We present the first ecosystem-scale methane flux data from a northern Siberian tundra ecosystem covering the entire snow-free period from spring thaw until initial freeze-back. Eddy covariance measurements of methane emission were carried out from the beginning of June until the end of September in the southern central part of the Lena River Delta (72°22' N, 126°30' E). The study site is located in the zone of continuous permafrost and is characterized by Arctic continental climate with very low precipitation and a mean annual temperature of -14.7°C. We found relatively low fluxes of on average 18.7 mg/m**2/d, which we consider to be because of (1) extremely cold permafrost, (2) substrate limitation of the methanogenic archaea, and (3) a relatively high surface coverage of noninundated, moderately moist areas. Near-surface turbulence as measured by the eddy covariance system in 4 m above the ground surface was identified as the most important control on ecosystem-scale methane emission and explained about 60% of the variance in emissions, while soil temperature explained only 8%. In addition, atmospheric pressure was found to significantly improve an exponential model based on turbulence and soil temperature. Ebullition from waterlogged areas triggered by decreasing atmospheric pressure and near-surface turbulence is thought to be an important pathway that warrants more attention in future studies. The close coupling of methane fluxes and atmospheric parameters demonstrated here raises questions regarding the reliability of enclosure-based measurements, which inherently exclude these parameters.

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Currently, there is increasing use of nanomaterials in the food industry thanks to the many advantages offered and make the products that contain them more competitive in the market. Their physicochemical properties often differ from those of bulk materials, which require specialized risk assessment. This should cover the risks to the health of workers and consumers as well as possible environmental risks. The risk assessment methods must go updating due to more widespread use of nanomaterials, especially now that are making their way down to consumer products. Today there is no specific legislation for nanomaterials, but there are several european dispositions and regulations that include them. This review gives an overview of the risk assessment and the existing current legislation regarding the use of nanotechnology in the food industry.

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In recent years, depth cameras have been widely utilized in camera tracking for augmented and mixed reality. Many of the studies focus on the methods that generate the reference model simultaneously with the tracking and allow operation in unprepared environments. However, methods that rely on predefined CAD models have their advantages. In such methods, the measurement errors are not accumulated to the model, they are tolerant to inaccurate initialization, and the tracking is always performed directly in reference model's coordinate system. In this paper, we present a method for tracking a depth camera with existing CAD models and the Iterative Closest Point (ICP) algorithm. In our approach, we render the CAD model using the latest pose estimate and construct a point cloud from the corresponding depth map. We construct another point cloud from currently captured depth frame, and find the incremental change in the camera pose by aligning the point clouds. We utilize a GPGPU-based implementation of the ICP which efficiently uses all the depth data in the process. The method runs in real-time, it is robust for outliers, and it does not require any preprocessing of the CAD models. We evaluated the approach using the Kinect depth sensor, and compared the results to a 2D edge-based method, to a depth-based SLAM method, and to the ground truth. The results show that the approach is more stable compared to the edge-based method and it suffers less from drift compared to the depth-based SLAM.

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Forschungsgegenstand der Arbeit sind Marketingstrategien zur In-Wert-Setzung von Naturschutzmaßnahmen in der ökologischen Direktvermarktung. Vor diesem Hintergrund wurden anhand konkreter Beispiele unterschiedliche Marketingstrategien und Kommunikationskonzepte verglichen und untersucht, wodurch die Aufpreisbereitschaft der KundInnen für den Zusatznutzen „Naturschutz“ beeinflusst wird. Die Untersuchungen fanden zwischen November 2015 und Januar 2016 auf drei Höfen, die Naturschutzmaßnahmen in die ökologische Direktvermarktung integriert haben, statt. Zunächst wurden leitfadengestützte Experteninterviews mit den Betriebsleitern, bzw. den Verantwortlichen für den Naturschutz, durchgeführt. Schwerpunkt der Interviews war das Naturschutzengagement der Betriebe und die Verwendung der Marketinginstrumente. Die Auswertung erfolgte anhand der inhaltlich strukturierenden qualitativen Inhaltsanalyse. Anschließend fanden in den drei Hofläden persönlich-schriftliche Kundenbefragungen mit Hilfe standardisierter Fragebögen statt. Zur Auswertung wurden statistische Tests im Rahmen der deskriptiven und explorativen Datenanalyse mit der Statistiksoftware SPSS 22.0 vorgenommen. Ergänzt wurden die Daten durch eine Internetrecherche zu weiteren Kommunikations- und Vermarktungskonzepten. Die Ergebnisse zeigten, dass es insgesamt in Deutschland nur wenige Marketingstrategien zur In- Wert-Setzung von Naturschutzmaßnahmen in der Direktvermarktung zu geben scheint. Auf den Höfen wurden zur In-Wert-Setzung des Naturschutzes insbesondere Öko-Marketingstrategien und Zusatznutzenstrategien verfolgt. Dabei stand die Kommunikationspolitik im Vordergrund. Die Intensität, mit der der Naturschutz marketingtechnisch eingesetzt wurde, reichte von sehr gering (Vorwerk Podemus) bis zu sehr ausgeprägt (Lämmerhof). Ob die KundInnen bereit sind, einen Aufpreis für den Naturschutz zu zahlen und ob es ihnen wichtig ist, dass sich der Betrieb für den Naturschutz einsetzt, stand in einem signifikanten Zusammenhang. Auch ob die KundInnen sich über das Engagement der Betriebe in den Bereichen Arten- und Biotopschutz gut informiert fühlten, beeinflusste die Aufpreisbereitschaft. Andere Studien bestätigen eine Aufpreisbereitschaft für einen Zusatznutzen wie den Naturschutz. Die Zahlungsbereitschaft kann durch persönliche Betroffenheit erhöht werden. Die Ergebnisse legen nahe, dass die Sensibilisierung der KundInnen mit Hilfe eines systematisch geplanten und umgesetzten Kommunikationskonzeptes für die In-Wert-Setzung von Naturschutzmaßnahmen von großer Bedeutung ist. Transparenz und Glaubwürdigkeit spielen bei dem Transport des Konzeptes eine ausschlaggebende Rolle. Abschließend wurden Handlungsempfehlungen für LandwirtInnen und DirektvermarkterInnen formuliert.

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Drosophila suzukii (Diptera: Drosophilidae), conhecida como drosófila da asa manchada (SWD) ou suzuki, é uma praga quarentenária nativa da Ásia em expansão mundial na atualidade. Em 2008, SWD foi coletada nos EUA (Califórnia) e, desde então, registrada em outros estados americanos (WALSH et al. 2011) e também na Europa (CINI et al. 2012). No Brasil, a praga foi detectada no ano de 2014 ocasionando danos na ordem de 30% em cultivos de morango no Estado do Rio Grande do Sul (SANTOS, 2014a). Os danos são causados pela alimentação das larvas em frutos ainda fixos às plantas, e pela introdução de patógenos no local da oviposição. O fruto atacado entra em colapso exibindo intensa perda de líquidos. Entre os hospedeiros da SWD estão as fruteiras que produzem frutos de epiderme fina como, por exemplo, os pequenos frutos: morango, framboesa, amora-preta e o mirtilo. Em se tratando de uma espécie recentemente introduzida no Brasil, poucas são as informações sobre a eficiência de atrativos para monitoramento das populações. O vinagre de maçã tem sido usado em vários estudos científicos, sendo até sugerido como atrativo para o monitoramento da espécie no Brasil (SANTOS, 2014b). Apesar disto, a atratividade é apontada como de curta duração e de baixa seletividade. Assim, Santos (2016) recomenda, em substituição ao vinagre de maçã, o uso de um atrativo à base de fermento biológico, açúcar e água, o qual tem se mostrado promissor e seletivo para monitoramento de SWD. Nos 24 EUA, após extensa avaliação laboratorial e de campo, foram isolados componentes químicos essenciais da atratividade de D. Suzukii, os quais estão sendo produzidos e comercializados em forma de dispenser, com os nomes comerciais de Pherocon® SWD e Scentry® SWD. Como inexistem informações sobre a eficiência e a seletividade de tais produtos para o monitoramento da suzuki no Brasil, foi planejado o presente estudo, cujo objetivo foi o de avaliar a captura e a seletividade de atrativos e de misturas no monitoramento de D. suzukii em pomar de framboesa no município de Vacaria, RS.