Pathways to polyploidy : indications of a female triploid bridge in the alpine species Ranunculus kuepferi (Ranunculaceae)

Polyploidy is one of the most important evolutionary processes in plants. In natural populations, polyploids usually emerge from unreduced gametes which either fuse with reduced ones, resulting in triploid offspring (triploid bridge), or with other unreduced gametes, resulting in tetraploid embryos. The frequencies of these two pathways, and male versus female gamete contributions, however, are largely unexplored. Ranunculus kuepferi occurs with diploid, triploid and autotetraploid cytotypes in the Alps, whereby diploids are mostly sexual, while tetraploids are facultative apomicts. To test for the occurrence of polyploidization events by triploid bridge, we investigated 551 plants of natural populations via flow cytometric seed screening. We assessed ploidy shifts in the embryo to reconstruct female versus male gamete contributions to polyploid embryo and/or endosperm formation. Seed formation via unreduced egg cells (B-III hybrids) occurred in all three cytotypes, while only in one case both gametes were unreduced. Polyploids further formed seeds with reduced, unfertilized egg cells (polyhaploids and aneuploids). Pollen was highly variable in diameter, but only pollen > 27 mu m was viable, whereby diploids produced higher proportions of well-developed pollen. Pollen size was not informative for the formation of unreduced pollen. These results suggest that a female triploid bridge via unreduced egg cells is the major pathway toward polyploidization in R. kuepferi, maybe as a consequence of constraints of endosperm development. Triploids resulting from unreduced male gametes were not observed, which explains the lack of obligate sexual tetraploid individuals and populations. Unreduced egg cell formation in diploids represents the first step toward apomixis

Long-Term Socio-Ecological Research in Practice: Lessons from Inter- and Transdisciplinary Research in the Austrian Eisenwurzen

Long-Term Socio-Ecological Research (LTSER) is an inter- and transdisciplinary research field addressing socio-ecological change over time at various spatial and temporal scales. In the Austrian Eisenwurzen region, an LTSER platform was founded in 2004. It has fostered and documented research projects aiming at advancing LTSER scientifically and at providing regional stakeholders with relevant information for sustainable regional development. Since its establishment, a broad range of research activities has been pursued in the region, integrating information from long-term ecological monitoring sites with approaches from social sciences and the humanities, and in cooperation with regional stakeholders. Based on the experiences gained in the Eisenwurzen LTSER platform, this article presents current activities in the heterogeneous field of LTSER, identifying specific (inter-)disciplinary contributions of three research strands of LTSER: long-term ecological research, socio-ecological basic research, and transdisciplinary research. Given the broad array of diverse contributions to LTSER, we argue that the platform has become a relevant "boundary organization", linking research to its regional non-academic context, and ensuring interdisciplinary exchange among the variety of disciplines. We consider the diversity of LTSER approaches an important resource for future research. Major success criteria of LTSER face specific challenges: (1) existing loose, yet stable networks need to be maintained and extended; (2) continuous generation of and access to relevant data needs to be secured and more data need to be included; and (3) consecutive research projects that have allowed for capacity building in the past may be threatened in the future if national Austrian research funders cease to provide resources

Scientific and normative foundations for the valuation of alien-species impacts: thirteen core principles

Biological invasions cause many impacts that differ widely in how they are perceived. We argue that many conflicts in the valuation of the impacts of alien species are attributable to differences in the framing of the issue and implicit assumptions—such conflicts are often not acknowledged. We present 13 principles that can help guide valuation and therefore inform the management of alien species. Seven of these relate to the science domain, representing aspects of change caused by alien species that can be measured or otherwise assessed using scientific methods. The remaining six principles invoke values, risk perception, and environmental ethics, but also cognitive and motivational decision biases. We illustrate the consequences of insufficient appreciation of these principles. Finally, we provide guidance rooted in political agreements and environmental ethics for improving the consideration of the consequences of these principles and present appropriate tools for management decisions relating to alien species

Reconsidering endemism in the Northeastern Limestone Alps

The restricted distribution of endemic plant species in the Northern Limestone Alps is commonly explained by a severe loss of biotypes and genetic plasticity during Pleistocene glaciation. In the present paper we examine the ecological features of the regional endemic species and plant communities to see if they actually support this interpretation. In particular, we focus on (1) species composition and habitat characteristics of endemic plant communities, (2) the frequency of endemic species in different plant communities and habitat types, (3) the correlation between the frequency of endemic species and the density of the vegetation cover and (4) the altitudinal distribution of endemic species. Concerning endemic plant communities, there is considerable variation in species composition as well as in habitat requirements. Communities of rock, scree and snowbed habitats are characterised by the predominance of endemic or subendemic species, whereas endemic alpine grassland types contain mainly non-endemic plants. Regarding the distribution of endemic plants, no uniform trend could be detected. The endemic species pool contains plants restricted to azonal stands as well as typical species of climax grasslands and widespread generalists. Some endemics distinctly prefer open vegetation types, others predominantly occur in dense grasslands. The bulk of the species considered performs best in the lower alpine zone, some others are especially common in the subalpine zone, whereas only one species showed an occurrence peak in the upper alpine belt. In summary, it may be said that the habitat requirements of endemic plants are rather species-specific and that there are only a few general trends. This fact seems to indicate the complex nature of the phenomenon of regional endemism, which is influenced by a range of factors. The prevailing historical explanation may not be appropriate for every species. Hence, the consideration of current ecological conditions in addition to historical factors may provide a more comprehensive explanation of regional endemism

Dispersal and extrapolation on the accuracy of temporal predictions from distribution models for the Darwin's frog

Indexación: Web of Science; Scopus.Climate change is a major threat to biodiversity; the development of models that reliably predict its effects on species distributions is a priority for conservation biogeography. Two of the main issues for accurate temporal predictions from Species Distribution Models (SDM) are model extrapolation and unrealistic dispersal scenarios. We assessed the consequences of these issues on the accuracy of climate-driven SDM predictions for the dispersal-limited Darwin's frog Rhinoderma darwinii in South America. We calibrated models using historical data (1950-1975) and projected them across 40 yr to predict distribution under current climatic conditions, assessing predictive accuracy through the area under the ROC curve (AUC) and True Skill Statistics (TSS), contrasting binary model predictions against temporal-independent validation data set (i.e., current presences/absences). To assess the effects of incorporating dispersal processes we compared the predictive accuracy of dispersal constrained models with no dispersal limited SDMs; and to assess the effects of model extrapolation on the predictive accuracy of SDMs, we compared this between extrapolated and no extrapolated areas. The incorporation of dispersal processes enhanced predictive accuracy, mainly due to a decrease in the false presence rate of model predictions, which is consistent with discrimination of suitable but inaccessible habitat. This also had consequences on range size changes over time, which is the most used proxy for extinction risk from climate change. The area of current climatic conditions that was absent in the baseline conditions (i.e., extrapolated areas) represents 39% of the study area, leading to a significant decrease in predictive accuracy of model predictions for those areas. Our results highlight (1) incorporating dispersal processes can improve predictive accuracy of temporal transference of SDMs and reduce uncertainties of extinction risk assessments from global change; (2) as geographical areas subjected to novel climates are expected to arise, they must be reported as they show less accurate predictions under future climate scenarios. Consequently, environmental extrapolation and dispersal processes should be explicitly incorporated to report and reduce uncertainties in temporal predictions of SDMs, respectively. Doing so, we expect to improve the reliability of the information we provide for conservation decision makers under future climate change scenarios.http://onlinelibrary.wiley.com/doi/10.1002/eap.1556/abstract;jsessionid=1E2084FF99600D0EEC9FA358A3DBC2A3.f02t0

Unexpected biodiversity loss under global warming in the neotropical Guayana Highlands: a preliminary appraisal

The fully vegetated summits of the table mountains that form the Guayana Highlands (GH), in northern South America, hold amazing biodiversity and endemism levels, and unique vegetation types. In spite of their present-day healthy appearance, their biota is seriously threatened of habitat loss by upward displacement, because of the projected warming for the end of this century. Available data are still insufficient for a definite assessment, but preliminary estimations based on representative endemic vascular plant species show that roughly one-tenth to one-third of them would loss their habitat with the 2-4°C temperature increase predicted for the region by AD 2100. Given the underlying endemism, the eventual loss of biodiversity will be of global nature. Other mountain ranges around the world with similar characteristics of the GH, namely topographical isolation, high endemism and absence of nival stage because of the lower altitude, would be under similar unexpected risk, and should be urgently considered for conservation purposes

TRY plant trait database - enhanced coverage and open access

Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Small but nice – Insights into working in a One Person Library

Dieser Report gibt anhand eines Beispiels – der Bibliothek des Campus Rudolfinerhaus – einen Einblick in den vielfältigen Arbeitsalltag in einer One Person Library (OPL). Dazu wird zuerst der Begriff One Person Library definiert. Im Anschluss daran widmet sich der vorliegende Report der Beispiel-OPL: Die Trägerorganisation, die Bibliothek selbst sowie die Tätigkeitsbereiche der dort beschäftigten Informationsmanagerin werden vorgestellt. Diese Tätigkeitsbereiche lassen sich grob in sechs Gruppen gliedern: Verwaltung der Bibliothek, Bestandsmanagement, Literaturvermittlung, Vernetzung, Fort- und Weiterbildung sowie zusätzliche nicht-bibliothekarische Tätigkeiten. Zusammenfassend lässt sich sagen, dass die Arbeit in einer OPL durch das breite Spektrum an Tätigkeiten herausfordernd (im besten Sinne) und vielseitig ist – wie dieses Beispiel anschaulich zeigt.This report gives an insight into the diverse everyday work in a One Person Library (OPL) by using the library of the Rudolfinerhaus campus as an example. First, the term One Person Library is defined. Following this, the report is devoted to the concrete OPL example: The supporting organization of the OPL, the library itself, and the areas of activity of the information manager employed there are presented in brief. These areas of activity can be roughly divided into six groups: library administration, stock management, information dissemination, networking, further education, and additional non-library activities. In summary, the work in an OPL is challenging (in the best sense), exciting and varied because of the wide range of activities it encompasses – as this example clearly shows

Niche expansion and temperature sensitivity of tropical African montane forests

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Abstract Aim Climate and land-use change will have a dramatic impact on future ecosystems through alterations to species ranges and community composition. When forming conservation strategies, correlative species distribution models are often created to assess risks for individual species. These models are based on the assumption of climatic equilibrium, such that the modern range is representative of the full range of conditions under which species could thrive. However, the palaeo-ecological record illustrates examples of disequilibrium in species today, and recent studies suggest that many species could occur in much broader climatic settings than previously thought. Montane ecosystems are thought to be at disproportionate risk due to temperature sensitivity and restricted geographical ranges. However, in the Afrotropics the palaeo-ecological record shows that montane forest taxa expanded into the lowlands numerous times, suggesting a possible tolerance to warm temperatures. Location Africa. Methods We integrate palaeo-ecological and palaeo-climatic data in order to compare climate conditions in which species are currently found with those in the past. We use species distribution models to construct potential modern ranges for Afromontane species based on modern distributions and distributions in the palaeo-ecological record in order to evaluate the equilibrium of species ranges. Results We show that many Afromontane trees have occupied warmer climates in the past, which suggests that the current low-elevation boundaries are not set by climate. Interestingly, the species with the largest disequilibrium between palaeo- and modern distributions are those whose modern distributions show the least temperature sensitivity. Mapping of species potential ranges based on modern and palaeo- distributions clearly shows that suitable climate conditions exist today in the lowlands for less temperature-sensitive species. Main conclusions These results imply that the current range of these forest trees does not necessarily inform risk from climatic change, and that human land use may be the major pressure for many species in the future.Thanks to Maria Orbay-Cerrato for pollen processing in the lab and funding from the Voss Postdoctoral Fellowship Program at Brown University. We would also like to thank two anonymous referees for their kind comments and insights. This research was funded by the ERA-Net BiodivERsA, with the national funders Portugal, Germany, Sweden and France, part of the 2012 BiodivERsA call for research proposals