39 research outputs found

    Buchweizenanbau in der Schweiz: neue Sorten fĂŒr eine alte Nischenkultur

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    Die Geschichte des Buchweizens reicht weit in die Vergangenheit zurĂŒck. UrsprĂŒnglich stammt Buchweizen aus China wo Buchweizenarten gemĂ€ss Pollenuntersuchungen bereits 2500 v. Chr. wuchsen (Zeller und Hsam 2004). Von dort breitete sich der Buchweizen vermutlich im Mittelalter ĂŒber Kirgistan, Tadschikistan und Usbekistan in Richtung Europa aus (Zeller 2001). Mit der Intensivierung des Ackerbaus verlor er aber nach und nach an Bedeutung. Aktuell (Datengrundlage 2017) gilt Russland mit 1,52 Millionen Tonnen (von weltweit ca. 4 Millionen Tonnen) als fĂŒhrender Buchweizenproduzent (FAO 2019). In der russischen KĂŒche ist Buchweizen – als Beilage oder Hauptgericht – auch heute noch ein wichtiger Nahrungsbestandteil (Miedaner und Longin 2012). Ab 1400 n. Chr. hat sich der Buchweizenanbau auch in der Schweiz etabliert. Bereits um 1800 n. Chr. beschrĂ€nkten sich die Anbaugebiete aber nur noch auf einige TĂ€ler in GraubĂŒnden und im Tessin. (Schilperoord 2017). Hauptgrund war die verstĂ€rkte Verbreitung und Förderung des Kartoffelanbaus, was die gesamtschweizerische AnbauflĂ€che von Buchweizen bis ins Jahr 1972 auf unter eine Hektare schrumpfen liess (Lustenberger et al. 1977). Seither taucht Buchweizen nicht mehr einzeln in der Anbaustatistik auf und bis auf die Sorte Brusio ist keine Schweizer Buchweizensorte in der Genbank eingelagert worden (BLW 2019). Seit einigen Jahren nimmt die Bedeutung von Buchweizen in der menschlichen ErnĂ€hrung aber wieder zu. Gerade fĂŒr Menschen mit einer GlutenunvertrĂ€glichkeit (Zöliakie) bietet der glutenfreie Buchweizen eine Alternative zu herkömmlichen Getreideprodukten. Daneben ist Buchweizen auch reich an Spurenelementen wie Zink oder Mangan und wirkt Erkrankungen wie Bluthochdruck oder hohen Cholesterinwerten entgegen (Skrabanja et al. 2004). Aufgrund der geringen AnsprĂŒche an Klima und Boden (Lustenberger et al. 1977) und der eher kurzen Vegetationsdauer von ca. 115 Tagen (Aufhammer et al. 1995) kann Buchweizen als Fruchtfolgeglied interessant sein. Da Buchweizen botanisch gesehen mit keiner anderen hĂ€ufig in der Schweiz angebauten Kulturpflanze verwandt ist, kann er zur Auflockerung der Fruchtfolge und Aufwertung des Bodens genutzt werden. Durch die kurze Vegetationsdauer besteht zudem die Möglichkeit, Buchweizen als Zweitkultur z. B. nach Wintergerste anzubauen. Als GrĂŒndĂŒngungs- und Untersaatenkomponente wird Buchweizen seit vielen Jahren eingesetzt. Unter guten Wachstumsbedingungen ist Buchweizen aufgrund der schnellen Jugendentwicklung ein guter UnkrautunterdrĂŒcker. Auch fĂŒr Insekten ist die Ackerfrucht von Bedeutung, denn sie blĂŒht – je nach Saatzeitpunkt und Sorte – ĂŒber eine lĂ€ngere Zeit und v. a. wĂ€hrend der tendenziell eher trachtarmen Sommermonate. Beim Anbau von Buchweizen als Reinkultur zur Körnernutzung stellen sich zahlreiche Herausforderungen. So ist z. B. die Bestimmung des richtigen Erntezeitpunkts aufgrund des unbegrenzten Wuchses der aktuell verfĂŒgbaren Sorten und deshalb auch die Ernte mit dem MĂ€hdrescher schwierig. Neue ZĂŒchtungen aus Russland versprechen jedoch eine gleichmĂ€ssige Abreife bei gleichzeitig hohen KornertrĂ€gen und tieferen Erntefeuchtigkeiten. Um LösungsansĂ€tze fĂŒr den Buchweizenanbau in der Schweiz zu entwickeln, wurden in einem gemeinsamen Projekt von Agroscope und der Hochschule fĂŒr Agrar-, Forst- und Lebensmittelwissenschaften HAFL Versuche mit verschiedenen Buchweizensorten und Saatdichten durchgefĂŒhrt. In den Sortenversuchen wurde zudem der Wert fĂŒr BestĂ€uber quantifiziert

    Diurnal timing of nonmigratory movement by birds: the importance of foraging spatial scales

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    Timing of activity can reveal an organism's efforts to optimize foraging either by minimizing energy loss through passive movement or by maximizing energetic gain through foraging. Here, we assess whether signals of either of these strategies are detectable in the timing of activity of daily, local movements by birds. We compare the similarities of timing of movement activity among species using six temporal variables: start of activity relative to sunrise, end of activity relative to sunset, relative speed at midday, number of movement bouts, bout duration and proportion of active daytime hours. We test for the influence of flight mode and foraging habitat on the timing of movement activity across avian guilds. We used 64 570 days of GPS movement data collected between 2002 and 2019 for local (non‐migratory) movements of 991 birds from 49 species, representing 14 orders. Dissimilarity among daily activity patterns was best explained by flight mode. Terrestrial soaring birds began activity later and stopped activity earlier than pelagic soaring or flapping birds. Broad‐scale foraging habitat explained less of the clustering patterns because of divergent timing of active periods of pelagic surface and diving foragers. Among pelagic birds, surface foragers were active throughout all 24 hrs of the day while diving foragers matched their active hours more closely to daylight hours. Pelagic surface foragers also had the greatest daily foraging distances, which was consistent with their daytime activity patterns. This study demonstrates that flight mode and foraging habitat influence temporal patterns of daily movement activity of birds.We thank the Nature Conservancy, the Bailey Wildlife Foundation, the Bluestone Foundation, the Ocean View Foundation, Biodiversity Research Institute, the Maine Outdoor Heritage Fund, the Davis Conservation Foundation and The U.S. Department of Energy (DE‐EE0005362), and the Darwin Initiative (19-026), EDP S.A. ‘Fundação para a Biodiversidade’ and the Portuguese Foundation for Science and Technology (FCT) (DL57/2019/CP 1440/CT 0021), Enterprise St Helena (ESH), Friends of National Zoo Conservation Research Grant Program and Conservation Nation, ConocoPhillips Global Signature Program, Maryland Department of Natural Resources, Cellular Tracking Technologies and Hawk Mountain Sanctuary for providing funding and in-kind support for the GPS data used in our analyses

    Post-orogenic shoshonitic magmas of the Yzerfontein pluton, South Africa: the 'smoking gun' of mantle melting and crustal growth during Cape granite genesis?

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    The post-orogenic Yzerfontein pluton, in the Saldania Belt of South Africa was constructed through numerous injections of shoshonitic magmas. Most magma compositions are adequately modelled as products of fractionation, but the monzogranites and syenogranites may have a separate origin. A separate high-Mg mafic series has a less radiogenic mantle source. Fine-grained magmatic enclaves in the intermediate shoshonitic rocks are autoliths. The pluton was emplaced between 533 ± 3 and 537 ± 3 Ma (LASF-ICP-MS U–Pb zircon), essentially synchronously with many granitic magmas of the Cape Granite Suite (CGS). Yzerfontein may represent a high-level expression of the mantle heat source that initiated partial melting of the local crust and produced the CGS granitic magmas, late in the Saldanian Orogeny. However, magma mixing is not evident at emplacement level and there are no magmatic kinships with the I-type granitic rocks of the CGS. The mantle wedge is inferred to have been enriched during subduction along the active continental margin. In the late- to post-orogenic phase, the enriched mantle partially melted to produce heterogeneous magma batches, exemplified by those that formed the Yzerfontein pluton, which was further hybridized through minor assimilation of crustal materials. Like Yzerfontein, the small volumes of mafic rocks associated with many batholiths, worldwide, are probably also lowvolume, high-level expressions of crustal growth through the emplacement of major amounts of mafic magma into the deep crust.IS

    Diurnal timing of nonmigratory movement by birds: the importance of foraging spatial scales

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    This is the author accepted manuscript. The final version is available from Wiley via the DOI in this recordData Availability statement: R code used in analyses can be accessed at datadryad.com. Most of the data used are publicly available at www.movebank.orgTiming of activity can reveal an organism's efforts to optimize foraging either by minimizing energy loss through passive movement or by maximizing energetic gain through foraging. Here, we assess whether signals of either of these strategies are detectable in the timing of activity of daily, local movements by birds. We compare the similarities of timing of movement activity among species using six temporal variables: start of activity relative to sunrise, end of activity relative to sunset, relative speed at midday, number of movement bouts, bout duration, and proportion of active daytime hours. We test for the influence of flight mode and foraging habitat on the timing of movement activity across avian guilds. We used 64570 days of GPS movement data collected between 2002 and 2019 for local (non‐migratory) movements of 991 birds from 49 species, representing 14 orders. Dissimilarity among daily activity patterns was best explained by flight mode. Terrestrial soaring birds began activity later and stopped activity earlier than pelagic soaring or flapping birds. Broad‐scale foraging habitat explained less of the clustering patterns because of divergent timing of active periods of pelagic surface and diving foragers. Among pelagic birds, surface foragers were active throughout the day while diving foragers matched their active hours more closely to daylight hours. Pelagic surface foragers also had the greatest daily foraging distances, which was consistent with their daytime activity patterns. This study demonstrates that flight mode and foraging habitat influence temporal patterns of daily movement activity of birds.Nature ConservancyBailey Wildlife FoundationBluestone FoundationOcean View FoundationBiodiversity Research InstituteMaine Outdoor Heritage FundDavis Conservation FoundationUS Department of EnergyDarwin InitiativePortuguese Foundation for Science and Technology (FCT)Enterprise St Helena (ESH)Hawk Mountain Sanctuar

    Osseointegration: the slow delivery of BMP-2 enhances osteoinductivity

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    Although the placement of dental and orthopedic implants is now generally a safe, reliable and successful undertaking, the functional outcome is less assured in patients whose bone-healing capacity is compromised. To enhance peri-implant osteogenesis in these individuals, BMP-2 could be locally administered. However, neither a free suspension nor an implant-adsorbed depot of the agent is capable of triggering sustained bone formation. We hypothesize that this end could be achieved by incorporating BMP-2 into the three-dimensional crystalline latticework of a bone-mineral like, calcium-phosphate implant coating, where from it would be liberated gradually - as the inorganic layer undergoes osteoclast-mediated degradation - not rapidly, as from an implant-adsorbed (two-dimensional) depot. To test this postulate, we compared the osteoinductive efficacies of implant coatings bearing either an incorporated, an adorbed, or an incorporated and an adsorbed depot of BMP-2 at a maxillary site in miniature pigs. The implants were retrieved 1, 2 and 3 weeks after surgery for the histomorphometric analysis of bone formation within a defined 'osteoinductive' space. At each juncture, the volume of newly-formed bone within the osteoinductive space was greatest around implants that bore a coating-incorporated depot of BMP-2, peak osteogenic activity being attained during the first week and sustained thereafter. In the other groups, the temporal course of bone formation was variable, and the peak levels were not sustained. The findings of this study confirm our hypothesis: they demonstrate that we now have at our disposal a means of efficaciously augmenting and expediting peri-implant bone formation. Clinically, this possibility would render the process of implant placement a safer and a more reliable undertaking in patients whose bone-healing capacity is compromised, and would also permit a curtailment of the postoperative recovery period by a forestallment of the mechanical-loading phase
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