11 research outputs found

    Influence of the vegetation structure on the nest-site selection of birds of prey in the March floodplain forests, Lower Austria

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    Zwischen Januar und Juli 2008 wurden im March-Auwald zwischen Hohenau und Drösing im niederösterreichischen Bezirk GĂ€nserndorf (19,7 km2) systematisch Greifvogelhorste kartiert, und auf Besetzung und Bruterfolg kontrolliert. Im weitgehend geschlossenen Waldgebiet sind zwei unterschiedliche Forstwirtschaftsformen vorrangig. Der nördliche Teil wird als Hochwald (960 ha) gefĂŒhrt, der sĂŒdliche Teil als Mittel- und Niederwald (1010 ha). Analysen zur Waldstruktur rund um jeden Horstplatz (Mikrohabitat, r=15 m, 706,5 m2), sowie zum Anteil verschiedener Biotoptypen im Kernbereich der Greifvogelreviere (Makrohabitat, r=250 m, 19,6 ha) geben Aufschluss, welche Faktoren die Verbreitung der Greifvögel in den March-Auen beeinflussen. Um einen reprĂ€sentativen Querschnitt des vorhandenen Strukturangebots zu erhalten, wurden die Erhebungen in gleicher Art auf 50 zufĂ€llig bestimmten FlĂ€chen wiederholt. Die erhobenen Daten zur Habitatwahl wurden in einem geographischen Informationssystem ausgewertet. Insgesamt wurden 167 Horste kartiert, davon waren 57 von Greifvögeln besetzt. Die hĂ€ufigste Art ist der MĂ€usebussard (Buteo buteo) mit 34 besetzten Horsten, gefolgt von der Rohrweihe (Circus aeroginosus) mit 5-6 Brutpaaren. Der Rotmilanbestand (Milvus milvus) von 3 Brutpaaren ist von nationaler Bedeutung. Schwarzmilan (Milvus migrans), Wespenbussard (Pernis apivorus) und Habicht (Accipiter gentilis) sind mit je 3 Brutpaaren, Turmfalke (Falco tinnunculus) und Baumfalke (Falco subbuteo) mit je 2 Brutpaaren vertreten. Seit 2002 brĂŒtet auch ein Seeadlerpaar (Haliaeetus albicilla) erfolgreich im Untersuchungsgebiet. ZusĂ€tzlich brĂŒten Sperber (Accipiter nisus), Sakerfalke (Falco cherrug) und Kaiseradler (Aquila heliaca) in den umliegenden FlĂ€chen. Die GreifvogelbestĂ€nde sind seit den 1990er Jahren weitgehend stabil. Allein beim MĂ€usebussard ist eine Bestandszunahme zu verzeichnen, die auf natĂŒrliche Schwankungen entsprechend der MĂ€usegradation und auf eine Entdynamisierung der Au zurĂŒckzufĂŒhren ist. Die vorgefundenen Siedlungsdichten der Greifvögel an der March sind auch in einem mitteleuropĂ€ischen Vergleich als hoch einzustufen. Die Habitatanalyse hat gezeigt, dass Greifvögel StieleichenĂŒberhĂ€lter und zusammenhĂ€ngende, alte Pappelkulturen als HorstbĂ€ume bevorzugen. Diese Baumarten finden sich im Mittelwald hĂ€ufiger als im Hochwald. Auch sind im Mittelwald mehr Großhorste zu finden, die wertvoll fĂŒr Seeadler und Kaiseradler, sowie den Schwarzstorch sind. DarĂŒber hinaus bevorzugen Greifvögel strukturierte AltholzbestĂ€nde mit einer ausgeprĂ€gten vertikalen Schichtung und einem hohen Totholzanteil. Diese Strukturen deuten auf einen geringen forstlichen Nutzen und dadurch eine geringe menschliche Störung der NistplĂ€tze hin. Die genannten Kriterien erfĂŒllen insbesondere eingerichtete Horstschutzgebiete, die frei von forstlicher Nutzung sind. Die Ausdehnung der AltholzbestĂ€nde, die Reduzierung von Störungen durch den Menschen sowie die Dynamisierung der Au durch Revitalisierungsprojekte sind wichtige Schritte fĂŒr einen langfristigen Erhalt der vielfĂ€ltigen Greifvogelfauna der March-Auen.Between Austria, Slovakia and the Czech Republic, were studied in 2008. The study area (19.7 km2) had not been explored by ornithologists until the 1990s due to the considerable flood dynamics and the subsequent limited accessibility. The present field study was performed between January and July 2008 between Hohenau and Drösing (Lower Austria), consisting of two reference areas of comparable size but with different cultivation techniques, i.e. the high forest cultivation in the North (960 ha) and the middle forest cultivation in the South (1010 ha). Additionally, the field study was conducted to explore the influence of the vegetation structure around the nesting site (microhabitat, r=15 m, 706.5 m2) and the landscape characteristics (macrohabitat, r=250 m, 19.6 ha) on the habitat choices of birds of prey. To get a representative sample for comparison, the same data were collected at 50 randomly selected sites. Aeries were mapped along transects between 50 m intervals, and 167 were found in total. 57 out of 167 aeries were occupied by birds of prey. In total, nine breeding raptor species were recorded. The most abundant species was the Common Buzzard (Buteo buteo), occupying 34 aeries, followed by the Marsh Harrier (Circus aeroginosus) with five or six pairs. The Red Kite (Milvus milvus) population, with a quantity of three pairs was remarkable on a national scale. The Black Kite (Milvus migrans) (three pairs), the Honey Buzzard (Pernis apivorus) (three pairs), the Goshawk (Accipiter gentilis) (three pairs), the Kestrel (Falco tinnunculus) (two pairs) and the Hobby (Falco subbuteo) (two pairs) also bred in the study area. Since 2002 the White-tailed Eagle (Haliaeetus albicilla) has bred successfully in the floodplains. The Sparrowhawk (Accipiter nisus), the Saker Falcon (Falco cherrug) and the Imperial Eagle (Aquila heliaca) were not found as breeders in the study area, but were known to breed nearby. The results indicated a population growth of the Common Buzzard, whereas the density of other predatory birds has been steady for the last 15 years. The density is high compared to other places in central Europe, including the Danube floodplains in Austria. Besides, the density seems to be independent from the type of cultivation. The data concerning the habitat structure were analyzed in a Geographic Information System (GIS) and indicate the March flood-plain forests as very attractive for raptors. The investigation area offers a varied and structured landscape with abundant waterbodies and meadows. Predatory birds prefer old growth trees, particularly oaks (Quercus sp.) and poplars (Populus sp.) for nesting. These types of trees are numerous in middle forest cultivation. Additionally, a higher number of older aeries can be found there compared to high forest cultivations. Birds of prey prefer a distinctive forest structure with plenty of deadwood, far away from paths or protected by dense shrub and undergrowth. Therefore, the conservation of mature forests, the reduction of human disturbance and the reactivation of the flood dynamics could have a positive effect on the raptor population in the long term

    The Application of DNA Barcodes for the Identification of Marine Crustaceans from the North Sea and Adjacent Regions

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    During the last years DNA barcoding has become a popular method of choice for molecular specimen identification. Here we present a comprehensive DNA barcode library of various crustacean taxa found in the North Sea, one of the most extensively studied marine regions of the world. Our data set includes 1,332 barcodes covering 205 species, including taxa of the Amphipoda, Copepoda, Decapoda, Isopoda, Thecostraca, and others. This dataset represents the most extensive DNA barcode library of the Crustacea in terms of species number to date. By using the Barcode of Life Data Systems (BOLD), unique BINs were identified for 198 (96.6%) of the analyzed species. Six species were characterized by two BINs (2.9%), and three BINs were found for the amphipod species Gammarus salinus Spooner, 1947 (0.4%). Intraspecific distances with values higher than 2.2% were revealed for 13 species (6.3%). Exceptionally high distances of up to 14.87% between two distinct but monophyletic clusters were found for the parasitic copepod Caligus elongatus Nordmann, 1832, supporting the results of previous studies that indicated the existence of an overlooked sea louse species. In contrast to these high distances, haplotype-sharing was observed for two decapod spider crab species, Macropodia parva Van Noort & Adema, 1985 and Macropodia rostrata (Linnaeus, 1761), underlining the need for a taxonomic revision of both species. Summarizing the results, our study confirms the application of DNA barcodes as highly effective identification system for the analyzed marine crustaceans of the North Sea and represents an important milestone for modern biodiversity assessment studies using barcode sequence

    Recent growth in occurrences of Acrida ungarica (Orthoptera: Acrididae) at the northern margin of the species range: Is it the result of global warming?

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    The number of records of Acrida ungarica in novel habitats and in places where the species was considered extinct, has markedly increased in recent years. We hypothesized that the newly revealed occurrences, on the northern margin of the species range, were not due to an increase in survey effort, but rather a result of the warming climate in the Carpathian Basin. We studied the occurrence data of Acrida ungarica and the intensity of Orthoptera surveys over the period of 2002-2022 in 1,840 6 × 5.5 km grid cells of the Central European Flora Mapping System. As background variables, we included macroclimatic data and the vegetation cover of the main potential habitats. The number of grid cells containing A. ungarica was significantly higher than the corresponding increase in cells surveyed for orthopterans and the presence of sand and salt steppe habitats, respectively. Furthermore, from 2012 to 2022, significant increasing trends were revealed in effective heat summation above 10°C in the summer months. That the increase in the known distribution of A. ungarica is unrelated to the rise in survey intensity indicates that the species distribution seems to be increasing, making it one of the winners from global warming. At the same time, regional rising levels of disturbance (highway networks, large fallow areas) can contribute to the successful horizontal expansion of a species related to open habitats and this species tolerance of disturbance

    The Austrian biodiversity monitoring “ÖBM Kulturlandschaft” and a unified biodiversity number for trend assessments

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    The Austrian biodiversity monitoring ÖBM-Kulturlandschaft has a focus on habitat and species diversity in Austrian cultural landscapes (including alpine pastures) and started in the year 2017. The stratified random selection of the sampling sites is based on the 1 kmÂČ grid of Statistics Austria. A minimum of 50% of agricultural area within the 1 kmÂČ was the limit for considering a grid cell; 100 nested sampling plots are arranged hierarchically (i) remote sensing based landscape survey: 3 x 3 kmÂČ - landscape plots, (ii) habitat mapping: 625 m x 625 m test areas; and (iii) per test area: 10 test circles for surveys of vascular plants, grasshoppers and butterflies. A rolling (staggered) survey is planned: in the first year of the survey, half of the 100 sampling plots have been covered, in the second survey year the remaining half of the sampling plots. The repetition of surveys should take place every three to five years. Remote sensing data will be applied within the framework of ÖBM-Kulturlandschaft at three different levels: (i) phenological characterizations of the habitat types within the 625 m x 625 m sampling plots, (ii) detection of changes in ecosystem functions (e.g. NDVI) and ecosystem structure (e.g. land cover) around the sampling plots at 3x3 kmÂČ and (iii) nation-wide analysis of land cover change with the COPERNICUS products available for the entire EU. The recording of habitat types is based on the red lists published by the Environment Agency Austria. Regarding organismic groups, the survey methods are closely aligned with those applied in the monitoring project Biodiversity-Nature-Safety (BINATS; Pascher et al. 2011) that focusses on maize and oilseed rape cultivation areas and it is planned to merge data from BINATS and ÖBM-Kulturlandschaft to provide overall results for the Austrian cultural landscapes. Vascular plants, grasshoppers and butterflies were chosen mainly for being optimal surrogates for overall biodiversity, suppliers of ecosystem services, and/or due to practical advantages in surveying. Preliminary results from 2017 are that 69 species of grasshoppers (49% of Austrian species; n = 48 test areas) and 103 species of butterflies (48%, n=49) were detected. Average species richness was 10.6±4.6 for grasshoppers and 10.5±4.7 for butterflies per test area, and 3.9±2.9 for grasshoppers and 2.8±2.2 for butterflies per test circles. A novel method for biodiversity accounting will be used to summarise the population change results of all species obtained during monitoring. With this method, measured population change results are weighted by the species’ Red List category at the national and international scale and its dependence on the monitoring area (determined by habitat requirements and total range). References: K Pascher et al (2011) Setup, efforts and practical experiences of a monitoring program for genetically modified plants - an Austrian case study for oilseed rape and maize. Env Sci Eur 23:12peerReviewe

    A multi-taxon analysis of European Red Lists reveals major threats to biodiversity.

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    Biodiversity loss is a major global challenge and minimizing extinction rates is the goal of several multilateral environmental agreements. Policy decisions require comprehensive, spatially explicit information on species’ distributions and threats. We present an analysis of the conservation status of 14,669 European terrestrial, freshwater and marine species (ca. 10% of the continental fauna and flora), including all vertebrates and selected groups of invertebrates and plants. Our results reveal that 19% of European species are threatened with extinction, with higher extinction risks for plants (27%) and invertebrates (24%) compared to vertebrates (18%). These numbers exceed recent IPBES (Intergovernmental Platform on Biodiversity and Ecosystem Services) assumptions of extinction risk. Changes in agricultural practices and associated habitat loss, overharvesting, pollution and development are major threats to biodiversity. Maintaining and restoring sustainable land and water use practices is crucial to minimize future biodiversity declines
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