24 research outputs found

    High functional diversity is related to high nitrogen availability in a deciduous forest - evidence from a functional trait approach

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    The current study tested the assumption that floristic and functional diversity patterns are negatively related to soil nitrogen content. We analyzed 20 plots with soil N-contents ranging from 0.63% to 1.06% in a deciduous forest near Munich (Germany). To describe species adaptation strategies to different nitrogen availabilities, we used a plant functional type (PFT) approach. Each identified PFT represents one realized adaptation strategy to the current environment. These were correlated, next to plant species richness and evenness, to soil nitrogen contents. We found that N-efficient species were typical for low soil nitrogen contents, while N-requiring species occur at high N-contents. In contrast to our initial hypotheses, floristic and functional diversity measures (number of PFTs) were positively related to nitrogen content in the soil. Every functional group has its own adaptation to the prevailing environmental conditions; in consequence, these functional groups can co-exist but do not out-compete one another. The increased number of functional groups at high N-contents leads to increased species richness. Hence, for explaining diversity patterns we need to consider species groups representing different adaptations to the current environmental conditions. Such co-existing ecological strategies may even overcome the importance of competition in their effect on biodiversity

    ReSurveyGermany: Vegetation-plot time-series over the past hundred years in Germany

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    Vegetation-plot resurvey data are a main source of information on terrestrial biodiversity change, with records reaching back more than one century. Although more and more data from re-sampled plots have been published, there is not yet a comprehensive open-access dataset available for analysis. Here, we compiled and harmonised vegetation-plot resurvey data from Germany covering almost 100 years. We show the distribution of the plot data in space, time and across habitat types of the European Nature Information System (EUNIS). In addition, we include metadata on geographic location, plot size and vegetation structure. The data allow temporal biodiversity change to be assessed at the community scale, reaching back further into the past than most comparable data yet available. They also enable tracking changes in the incidence and distribution of individual species across Germany. In summary, the data come at a level of detail that holds promise for broadening our understanding of the mechanisms and drivers behind plant diversity change over the last century

    Directional turnover towards larger-ranged plants over time and across habitats

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    Species turnover is ubiquitous. However, it remains unknown whether certain types of species are consistently gained or lost across different habitats. Here, we analysed the trajectories of 1827 plant species over time intervals of up to 78 years at 141 sites across mountain summits, forests, and lowland grasslands in Europe. We found, albeit with relatively small effect sizes, displacements of smaller- by larger-ranged species across habitats. Communities shifted in parallel towards more nutrient-demanding species, with species from nutrient-rich habitats having larger ranges. Because these species are typically strong competitors, declines of smaller-ranged species could reflect not only abiotic drivers of global change, but also biotic pressure from increased competition. The ubiquitous component of turnover based on species range size we found here may partially reconcile findings of no net loss in local diversity with global species loss, and link community-scale turnover to macroecological processes such as biotic homogenisation

    Neurologic phenotypes associated with COL4A1/2 mutations

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    Objective: To characterize the neurologic phenotypes associated with COL4A1/2 mutations and to seek genotype–phenotype correlation. Methods: We analyzed clinical, EEG, and neuroimaging data of 44 new and 55 previously reported patients with COL4A1/COL4A2 mutations. Results: Childhood-onset focal seizures, frequently complicated by status epilepticus and resistance to antiepileptic drugs, was the most common phenotype. EEG typically showed focal epileptiform discharges in the context of other abnormalities, including generalized sharp waves or slowing. In 46.4% of new patients with focal seizures, porencephalic cysts on brain MRI colocalized with the area of the focal epileptiform discharges. In patients with porencephalic cysts, brain MRI frequently also showed extensive white matter abnormalities, consistent with the finding of diffuse cerebral disturbance on EEG. Notably, we also identified a subgroup of patients with epilepsy as their main clinical feature, in which brain MRI showed nonspecific findings, in particular periventricular leukoencephalopathy and ventricular asymmetry. Analysis of 15 pedigrees suggested a worsening of the severity of clinical phenotype in succeeding generations, particularly when maternally inherited. Mutations associated with epilepsy were spread across COL4A1 and a clear genotype–phenotype correlation did not emerge. Conclusion: COL4A1/COL4A2 mutations typically cause a severe neurologic condition and a broader spectrum of milder phenotypes, in which epilepsy is the predominant feature. Early identification of patients carrying COL4A1/COL4A2 mutations may have important clinical consequences, while for research efforts, omission from large-scale epilepsy sequencing studies of individuals with abnormalities on brain MRI may generate misleading estimates of the genetic contribution to the epilepsies overall

    Strict forest nature reserves research in Bavaria : analysis of vegetation data for ecological long-term observation

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    Ein im Jahr 2012 in Bayern verabschiedetes Naturwaldreservats-Forschungskonzept weist 26 der insgesamt 159 Reservate als Schwerpunktreservate für die künftige Dauerbeobachtung aus. 2013 wurden in vier der 26 Schwerpunktreservate erste Dauerbeobachtungsflächen eingerichtet. Alle Probeflächen liegen innerhalb von 1 ha großen Repräsentationsflächen der Schwerpunktreservate und umfassen jeweils 6 Probekreise mit einem Radius von 10 m (314 m2). Der Kreismittelpunkt wurde fest vermarkt; auf jedem der Probekreise wurde eine pflanzensoziologische Aufnahme nach Braun-Blanquet (1964) angefertigt. Das Konzept des geplanten Langzeit-Monitorings der Waldbestände wird vorgestellt, Auswertungswege werden skizziert und an Hand der ersten in 2013 erhobenen Daten erläutert. Da die erhobenen Daten räumlich stark autokorreliert sind, wurden sie in einen für die Waldfläche Bayerns repräsentativen Referenzdatensatz eingehängt. Dieser besteht aus von Ewald (2009) für die pnV-Einstufung an 313 Probepunkten der nationalen Bodenzustandserhebung (BZE II) im 8 x 8 km Grundraster definierten Partneraufnahmen in den jeweils nächstgelegenen Naturwaldreservaten. Mittels Entzerrter Korrespondenzanalyse (DCA) wurden Aufnahme-Verteilungsmuster ermittelt. Der Referenzdatensatz ermöglichte eine objektive Waldgesellschafts-Zuordnung jeder Vegetationsaufnahme, indem die größte floristische Übereinstimmung zu einer Referenzaufnahme errechnet wurde. Die weitere Charakterisierung erfolgte anschließend über pflanzensoziologische Tabellenarbeit. Die in je zwei Naturwaldreservaten im Hügelland Nord- und Südbayerns neu erhobenen Daten beinhalten Buchenwälder auf Kalk (Hordelymo-Fagetum) und Silikatstandorten (Galio- und Luzulo-Fagetum), Hangmischwälder (Adoxo-Aceretum) und Auwälder (Pruno-Fraxinetum, Querco-Ulmetum). Der vorherrschende Nährstoff- und Basengradient entspricht dem floristischen Hauptgefälle im gesamtbayerischen Referenzdatensatz. Ebenso wurde ein Gefälle von Wärmezeigern auf der 2. Achse in beiden Datensätzen (Referenzdatensatz und neu erhobene Daten) abgebildet. Im Falle der neu erhobenen Daten erscheint das Temperaturgefälle allerdings als Pseudo-Effekt, der durch Nadelholzanbau (mit-)verursacht ist. Die Möglichkeiten der Datenauswertung werden in den nächsten zwei Jahrzehnten sukzessive ansteigen. In dem bis 2022 vollständig erstinventarisierten Gesamtset der 26 Schwerpunkt-reservate wird künftig die Beobachtung der Dynamik innerhalb der Buchenwälder ebenso möglich sein wie im Randbereich sowie jenseits der Höhen-, Trocken- oder Nässegrenze der Buche.A recent research concept prioritises 26 out of Bavaria's 159 strict forest nature reserves for longterm observation. In 2013 the first permanent plot sample for ecological studies was established in four of the priority reserves. A total of 24 circular 314 m2 vegetation plots were located within the large (1 ha) permanent core areas of six priority reserves. The concept for longterm observation of natural forests is presented, pathways of analysis are outlined and exemplified on the basis of the 2013 vegetation data. Because plots are inevitably spatially autocorrelated, they were coupled with a representative reference from the whole of Bavaria. The latter data set comprises 313 plots in strict forest nature reserves which were selected to represent the potential natural vegetation of plots in the 8 x 8 km grid of the “Forest Soil Condition Survey” (BZE II; Ewald 2009). Detrended Correspondence Analysis (DCA) was used to detect gradients of species composition and corresponding plot groupings. Thus, the newly collected plots were classified inde-pendently and impartially on the base of their floristic similarity to reference vegetation types. The subsequent characterisation of vegetation types was performed by ordering phytosociological tables. The newly collected data comprise beech forests on limestone (Hordelymo-Fagetum) and on siliceous substrates (Galio- and Luzulo-Fagetum), as well as mixed forests of unstable hillsides (Adoxo-Aceretum) and riverine forests (Pruno-Fraxinetum, QuercoUlmetum). Posthoc correlation with Ellenberg indicator values suggested soil reaction and nutrient availability as putative drivers of species turnover along the first axis; species turnover along the second axis was apparently caused by a temperature gradient. While these correlations are congruent between ordinations of the newly collected and the reference data set, the temperature gradient (featuring low Ellenberg temperature values) in the new plots appears as a pseudo-effect due to cultivated conifers. Opportunities for data analysis will gradually increase within the next two decades, and, with the data set of the 26 priority reserves completed, the longterm observation of vegetation dynamics in beech forests as well as at the temperature- and moistureinduced margins of beech distribution will become pivotal

    The Galio-Carpinetum in the vicinity of Munich (Germany) - a result of former woodland management practices?

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    In der vorliegenden Studie wird die Gehölzentwicklung eines Eichen-Hainbuchenwald-Gebietes bei München während der letzten zwei Jahrzehnte untersucht. Eine Vorhersage der künftigen Gehölzartenzusammensetzung kann aus der Entwicklung der Verjüngung abgeleitet werden. Für die Zukunft wird ein Wechsel in der Baumartenzusammensetzung prognostiziert. So wird insbesondere der Berg-Ahorn an Bedeutung gewinnen, als Nebenbaumarten werden Esche, Ulme und Hainbuche vorhanden sein. Die für das Galio-Carpinetum charakteristische Stiel-Eiche kann sich nicht mehr erfolgreich verjüngen. Diese Arbeit gibt für den Münchener Großraum Hinweise, dass das Galio-Carpinetum seine Verbreitung der Nieder- bzw. Mittelwaldwirtschaft verdankt, also nicht in erster Linie Ausdruck der abiotischen Umweltbedingungen im Sinne des PNV-Konzepts ist. Eine syntaxonomische Neubeurteilung (insbesondere zur Abgrenzung vom Adoxo-Aceretum) dieser Pflanzengesellschaft scheint notwendig zu sein.The aim of the current study is to investigate the development of the tree species composition of the Galio-Carpinetum in the vicinity of Munich (Germany) during the last two decades. Future tree species composition can be predicted based on an examination of patterns in the present tree regeneration. A shift in species composition can be expected, with Acer pseudoplatanus becoming more important together with associated tree species such as Fraxinus excelsior, Ulmus glabra and Carpinus betulus. Quercus robur, a typical species for the Galio-Carpinetum, is not able to regenerate and will decline. We conclude that the Galio-Carpinetum in the vicinity of Munich can be mainly seen as a result from former woodland management practices such as coppicing and coppice-with-standards, and not first and foremost as an outcome of the abiotic parameters. A re-evaluation of the syntaxonomy of this plant community (especially its differentiation from the Adoxo-Aceretum) seems to be necessary

    Sexual segregation results in pronounced sex-specific density gradients in the mountain ungulate, Rupicapra rupicapra

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    Abstract Sex-specific differences in habitat selection and space use are common in ungulates. Yet, it is largely unknown how this behavioral dimorphism, ultimately leading to sexual segregation, translates to population-level patterns and density gradients across landscapes. Alpine chamois (Rupicapra rupicapra r.) predominantly occupy habitat above tree line, yet especially males may also take advantage of forested habitats. To estimate male and female chamois density and determinants thereof, we applied Bayesian spatial capture-recapture (SCR) models in two contrasting study areas in the Alps, Germany, during autumn. We fitted SCR models to non-invasive individual encounter data derived from genotyped feces. Sex-specific densities were modeled as a function of terrain ruggedness, forest canopy cover, proportion of barren ground, and site severity. We detected pronounced differences in male and female density patterns, driven primarily by terrain ruggedness, rather than by sex-specific effects of canopy cover. The positive effect of ruggedness on density was weaker for males which translated into a higher proportion of males occupying less variable terrain, frequently located in forests, compared to females. By estimating sex-specific variation in both detection probabilities and density, we were able to quantify and map how individual behavioral differences scale up and shape spatial patterns in population density

    Genomic DNA methylation distinguishes subtypes of human focal cortical dysplasia

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    OBJECTIVES: Focal cortical dysplasia (FCD) is a major cause of drug-resistant focal epilepsy in children, and the clinicopathological classification remains a challenging issue in daily practice. With the recent progress in DNA methylation-based classification of human brain tumors we examined whether genomic DNA methylation and gene expression analysis can be used to also distinguish human FCD subtypes. METHODS: DNA methylomes and transcriptomes were generated from massive parallel sequencing in 15 surgical FCD specimens, matched with 5 epilepsy and 6 nonepilepsy controls. RESULTS: Differential hierarchical cluster analysis of DNA methylation distinguished major FCD subtypes (ie, Ia, IIa, and IIb) from patients with temporal lobe epilepsy patients and nonepileptic controls. Targeted panel sequencing identified a novel likely pathogenic variant in DEPDC5 in a patient with FCD type IIa. However, no enrichment of differential DNA methylation or gene expression was observed in mechanistic target of rapamycin (mTOR) pathway-related genes. SIGNIFICANCE: Our studies extend the evidence for disease-specific methylation signatures toward focal epilepsies in favor of an integrated clinicopathologic and molecular classification system of FCD subtypes incorporating genomic methylation
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