Institut für Ökologie, Evolution und Diversität
Refine
Year of publication
Document Type
- Article (341)
- Preprint (31)
- Doctoral Thesis (24)
- Part of Periodical (7)
- Book (5)
- Contribution to a Periodical (3)
- Part of a Book (2)
- Conference Proceeding (2)
- Periodical (1)
Language
- English (384)
- German (19)
- Multiple languages (7)
- French (6)
Is part of the Bibliography
- no (416)
Keywords
- Invasive species (10)
- Biodiversity (9)
- Biogeography (9)
- taxonomy (8)
- Thailand (5)
- phylogeny (5)
- Biodiversität (4)
- Community ecology (4)
- Ecological modelling (4)
- Ecology (4)
Institute
- Institut für Ökologie, Evolution und Diversität (416) (remove)
The gradual heterogeneity of climatic factors pose varying selection pressures across geographic distances that leave signatures of clinal variation in the genome. Separating signatures of clinal adaptation from signatures of other evolutionary forces, such as demographic processes, genetic drift, and adaptation to non-clinal conditions of the immediate local environment is a major challenge. Here, we examine climate adaptation in five natural populations of the harlequin fly Chironomus riparius sampled along a climatic gradient across Europe. Our study integrates experimental data, individual genome resequencing, Pool-Seq data, and population genetic modelling. Common-garden experiments revealed a positive correlation of population growth rates corresponding to the population origin along the climate gradient, suggesting thermal adaptation on the phenotypic level. Based on a population genomic analysis, we derived empirical estimates of historical demography and migration. We used an FST outlier approach to infer positive selection across the climate gradient, in combination with an environmental association analysis. In total we identified 162 candidate genes as genomic basis of climate adaptation. Enriched functions among these candidate genes involved the apoptotic process and molecular response to heat, as well as functions identified in other studies of climate adaptation in other insects. Our results show that local climate conditions impose strong selection pressures and lead to genomic adaptation despite strong gene flow. Moreover, these results imply that selection to different climatic conditions seems to converge on a functional level, at least between different insect species.
The German postgraduate degree program in ecotoxicology (SETAC GLB and GDCh) : a success story
(2016)
This article gives a comprehensive overview on the strategy, the development and the progress of the German postgraduate degree program in ecotoxicology (SETAC GLB and GDCh). The program soon prompted positive results: more than 10 years now the courses had an average enrolment rate of 90 %, and employment-seeking graduates from the first courses mostly succeeded in quickly finding employment relevant to their training. With over 450 students enrolled to date, the degree program contributes significantly to the field of Environmental Chemistry and Ecotoxicology.
It is commonly assumed that the colonization of restored river reaches by fish depends on the regional species pools; however, quantifications of the relationship between the composition of the regional species pool and restoration outcome are lacking. We analyzed data from 18 German river restoration projects and adjacent river reaches constituting the regional species pools of the restored reaches. We found that the ability of statistical models to describe the fish assemblages established in the restored reaches was greater when these models were based on ‘biotic’ variables relating to the regional species pool and the ecological traits of species rather than on ‘abiotic’ variables relating to the hydromorphological habitat structure of the restored habitats and descriptors of the restoration projects. For species presence in restored reaches, ‘biotic’ variables explained 34% of variability, with the occurrence rate of a species in the regional species pool being the most important variable, while ’abiotic’ variables explained only the negligible amount of 2% of variability. For fish density in restored reaches, about twice the amount of variability was explained by ‘biotic’ (38%) compared to ‘abiotic’ (21%) variables, with species density in the regional species pool being most important. These results indicate that the colonization of restored river reaches by fish is largely determined by the assemblages in the surrounding species pool. Knowledge of species presence and abundance in the regional species pool can be used to estimate the likelihood of fish species becoming established in restored reaches.
Southern African protected areas (PAs) harbour a great diversity of animals, which represent a large potential for wildlife tourism. In this region, global change is expected to result in vegetation changes, such as bush encroachment and increases in vegetation density. However, little is known on the influence of vegetation structure on wildlife tourists’ wildlife viewing experience and satisfaction. In this study, we collected data on vegetation structure and perceived mammal densities along 196 road transects (each 5 km long) and conducted a social survey with 651 questionnaires across four PAs in three Southern African countries. Our objectives were 1) to assess visitors’ attitude towards vegetation, 2) to test the influence of perceived mammal density and vegetation structure on the easiness to spot animals, and 3) on visitors’ satisfaction during their visit to PAs. Using a Boosted Regression Tree procedure, we found mostly negative non-linear relationships between vegetation density and wildlife tourists’ experience, and positive relationships between perceived mammal densities and wildlife tourists’ experience. In particular, wildlife tourists disliked road transects with high estimates of vegetation density. Similarly, the easiness to spot animals dropped at thresholds of high vegetation density and at perceived mammal densities lower than 46 individuals per road transect. Finally, tourists’ satisfaction declined linearly with vegetation density and dropped at mammal densities smaller than 26 individuals per transect. Our results suggest that vegetation density has important impacts on tourists’ wildlife viewing experience and satisfaction. Hence, the management of PAs in savannah landscapes should consider how tourists perceive these landscapes and their mammal diversity in order to maintain and develop a sustainable wildlife tourism.
Background: The angiosperm family Bromeliaceae comprises over 3.500 species characterized by exceptionally high morphological and ecological diversity, but a very low genetic variation. In many genera, plants are vegetatively very similar which makes determination of non flowering bromeliads difficult. This is particularly problematic with living collections where plants are often cultivated over decades without flowering. DNA barcoding is therefore a very promising approach to provide reliable and convenient assistance in species determination. However, the observed low genetic variation of canonical barcoding markers in bromeliads causes problems.
Result. In this study the low-copy nuclear gene Agt1 is identified as a novel DNA barcoding marker suitable for molecular identification of closely related bromeliad species. Combining a comparatively slowly evolving exon sequence with an adjacent, genetically highly variable intron, correctly matching MegaBLAST based species identification rate was found to be approximately double the highest rate yet reported for bromeliads using other barcode markers.
Conclusion. In the present work, we characterize Agt1 as a novel plant DNA barcoding marker to be used for barcoding of bromeliads, a plant group with low genetic variation. Moreover, we provide a comprehensive marker sequence dataset for further use in the bromeliad research community.
Despite prevailing arid conditions, the diversity of terrestrial and freshwater biota in the Middle East is amazingly high and marine biodiversity is among the highest on Earth. Th roughout the Region, threats to the environment are moderate to severe. Despite the outstanding economic and ecological importance of biological diversity, the capacity in biodiversity-related research and academic education is inadequate. The "Middle Eastern Biodiversity Network" (MEBN), founded in 2006 by six universities and research institutes in Iran, Jordan, Germany, Lebanon and Yemen was designed to fi ll this gap. An integrated approach is taken to upgrade biodiversity research and education in order to improve regional ecosystem conservation and management capacities. A wide range of activities are carried out in the framework of the Network, including capacity building in biological collection management and professional natural history curatorship, developing university curricula in biodiversity, conducting scientifi c research, organising workshops and conferences on Middle Eastern biodiversity, and translating the results of biodiversity research into conservation and sustainable development. Keywords: Middle Eastern biodiversity, nature museums, biodiversity research, biodiversity education, biodiversity conservation, biodiversity networks
Global change effects on biodiversity and human wellbeing call for improved long-term environmental data as a basis for science, policy and decision making, including increased interoperability, multifunctionality, and harmonization. Based on the example of two global initiatives, the International Long-Term Ecological Research (ILTER) network and the Group on Earth Observations Biodiversity Observation Network (GEO BON), we propose merging the frameworks behind these initiatives, namely ecosystem integrity and essential biodiversity variables, to serve as an improved guideline for future site-based long-term research and monitoring in terrestrial, freshwater and coastal ecosystems. We derive a list of specific recommendations of what and how to measure at a monitoring site and call for an integration of sites into co-located site networks across individual monitoring initiatives, and centered on ecosystems. This facilitates the generation of linked comprehensive ecosystem monitoring data, supports synergies in the use of costly infrastructures, fosters cross-initiative research and provides a template for collaboration beyond the ILTER and GEO BON communities.
Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species’ threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project – and avert – future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups – including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems – www.predicts.org.uk). We make site-level summary data available alongside this article. The full database will be publicly available in 2015.
The process of ecological speciation drives the evolution of locally adapted and reproductively isolated populations in response to divergent natural selection. In Southern Mexico, several lineages of the freshwater fish species of the genus Poecilia have independently colonized toxic, hydrogen sulfide-rich springs. Even though ecological speciation processes are increasingly well understood in this system, aligning the taxonomy of these fish with evolutionary processes has lagged behind. While some sulfide spring populations are classified as ecotypes of Poecilia mexicana, others, like P. sulphuraria, have been described as highly endemic species. Our study particularly focused on elucidating the taxonomy of the long described sulfide spring endemic, Poecilia thermalis Steindachner 1863, and investigates if similar evolutionary patterns of phenotypic trait divergence and reproductive isolation are present as observed in other sulfidic species of Poecilia. We applied a geometric morphometric approach to assess body shape similarity to other sulfidic and non-sulfidic fish of the genus Poecilia. We also conducted phylogenetic and population genetic analyses to establish the phylogenetic relationships of P. thermalis and used a population genetic approach to determine levels of gene flow among Poecilia from sulfidic and non-sulfidic sites. Our results indicate that P. thermalis' body shape has evolved in convergence with other sulfide spring populations in the genus. Phylogenetic analyses placed P. thermalis as most closely related to one population of P. sulphuraria, and population genetic analyses demonstrated that P. thermalis is genetically isolated from both P. mexicana ecotypes and P. sulphuraria. Based on these findings, we make taxonomic recommendations for P. thermalis. Overall, our study verifies the role of hydrogen sulfide as a main factor shaping convergent, phenotypic evolution and the emergence of reproductive isolation between Poecilia populations residing in adjacent sulfidic and non-sulfidic environments.
This article reports on the second Young Environmental Scientists Meeting that was hosted from 28 February to 2 March 2011 by the Institute for Environmental Research at RWTH Aachen University, Germany. This extraordinary meeting was again initiated and organized by the Student Advisory Council under the umbrella of Society of Environmental Toxicology and Chemistry Europe. A movie about the meeting and the abstracts of poster and platform presentations are freely available as supplemental material of this article.
The swine plasma metabolome chronicles "many days" biological timing and functions linked to growth
(2016)
The paradigm of chronobiology is based almost wholly upon the daily biological clock, or circadian rhythm, which has been the focus of intense molecular, cellular, pharmacological, and behavioral, research. However, the circadian rhythm does not explain biological timings related to fundamental aspects of life history such as rates of tissue/organ/body size development and control of the timing of life stages such as gestation length, age at maturity, and lifespan. This suggests that another biological timing mechanism is at work. Here we focus on a "many days" (multidien) chronobiological period first observed as enigmatic recurring growth lines in developing mammalian tooth enamel that is strongly associate with all adult tissue, organ, and body masses as well as life history attributes such as gestation length, age at maturity, weaning, and lifespan, particularly among the well studied primates. Yet, knowledge of the biological factors regulating the patterning of mammalian life, such as the development of body size and life history structure, does not exist. To identify underlying molecular mechanisms we performed metabolome and genome analyses from blood plasma in domestic pigs. We show that blood plasma metabolites and small non-coding RNA (sncRNA) drawn from 33 domestic pigs over a two-week period strongly oscillate on a 5-day multidien rhythm, as does the pig enamel rhythm. Metabolomics and genomics pathway analyses actually reveal two 5-day rhythms, one related to growth in which biological functions include cell proliferation, apoptosis, and transcription regulation/protein synthesis, and another 5-day rhythm related to degradative pathways that follows three days later. Our results provide experimental confirmation of a 5-day multidien rhythm in the domestic pig linking the periodic growth of enamel with oscillations of the metabolome and genome. This association reveals a new class of chronobiological rhythm and a snapshot of the biological bases that regulate mammalian growth, body size, and life history.
Background: Taxonomy or biological systematics is the basic scientific discipline of biology, postulating hypotheses of identity and relationships, on which all other natural sciences dealing with organisms relies. However, the scientific contributions of taxonomists have been largely neglected when using species names in scientific publications by not citing the authority on which they are based.
Discussion: Consequences of this neglect is reduced recognition of the importance of taxonomy, which in turn results in diminished funding, lower interest from journals in publishing taxonomic research, and a reduced number of young scientists entering the field. This has lead to the so-called taxonomic impediment at a time when biodiversity studies are of critical importance.
Here we emphasize a practical and obvious solution to this dilemma. We propose that whenever a species name is used, the author(s) of the species hypothesis be included and the original literature source cited, including taxonomic revisions and identification literature - nothing more than what is done for every other hypothesis or assumption included in a scientific publication. In addition, we postulate that journals primarily publishing taxonomic studies should be indexed in ISISM.
Summary: The proposal outlined above would make visible the true contribution of taxonomists within the scientific community, and would provide a more accurate assessment for funding agencies impact and importance of taxonomy, and help in the recruitment of young scientists into the field, thus helping to alleviate the taxonomic impediment. In addition, it would also make much of the biological literature more robust by reducing or alleviating taxonomic uncertainty.
Keywords: Taxonomy crisis; taxonomic impediment; impact factor; original species description; citation index; systematics
Atelopus is a species-rich group of Neotropical bufonids. Present knowledge on bioacoustics in this genus is relatively poor, as vocalisations have been described in only about one fifth of the ca. 100 species known. All studied members of the genus produce vocalisations although, with a few exceptions, most species lack a middle ear. Nonetheless, hearing has been demonstrated even in earless Atelopus making bioacoustics in these toads an inspiring research field. So far, three structural call types have been identified in the genus. As sympatry is uncommon in Atelopus, calls of the same type often vary little between species. Based on recordings from the 1980s, we describe vocalisations of three Venezuelan species (A. carbonerensis, A. mucubajiensis, A. tamaense) from the Cordillera de Mérida, commonly known as the Andes of Venezuela and the Tamá Massif, a Venezuelan spur of the Colombian Cordillera Oriental. Vocalisations correspond, in part, to the previously identified call types in Atelopus. Evaluation of the vocalisations of the three species presented in this study leads us to recognise a fourth structural call type for the genus. With this new addition, the Atelopus acoustic repertoire now includes (1) pulsed calls, (2) pure tone calls, (3) pulsed short calls and (4) pure tone short calls. The call descriptions provided here are valuable contributions to the bioacoustics of these Venezuelan Atelopus species, since all of them have experienced dramatic population declines that limit possibilities of further studies.
Although there is an increasing need for data in ecological studies, many datasets are still lost or not sufficiently visible due to a lack of appropriate data archives. With the West African Data and Metadata Repository, we present a secure long-term archive for a data-poor region allowing detailed documentation by metadata following the EML standard and giving data holders the opportunity to define levels of data access and conditions of use. This article gives an overview of structure, functions and content. The repository is online at the URL http://westafricandata.senckenberg.de.
Background: As ectothermic animals, temperature influences insects in almost every aspect. The potential disease spreading Asian bush mosquito (Aedes japonicus japonicus) is native to temperate East Asia but invasive in several parts of the world. We report on the previously poorly understood temperature-dependence of its life history under laboratory conditions to understand invasion processes and to model temperature niches.
Results: To evaluate winter survival, eggs were exposed between 1 day and 14 days to low temperatures (5 °C, 0 °C, -5 °C and -9 °C). Hatching success was drastically decreased after exposure to 0 °C and -5 °C, and the minimal hatching success of 0% was reached at -9 °C after two days. We then exposed larvae to 14 temperatures and assessed their life trait parameters. Larval survival to adulthood was only possible between 10 °C and 31 °C. Based on this, we modelled the optimal (25 °C), minimal (7 °C) and maximal (31 °C) temperature for cumulative female survival. The time to adult emergence ranges from 12 days to 58 days depending on temperature. We used an age-at-emergence-temperature model to calculate the number of potential generations per year for the Asian bush mosquito in Germany with an average of 4.72 potential generations. At lower temperatures, individuals grew larger than at higher temperatures with female R1 length ranging from 3.04 ± 0.1 mm at 31 °C to 4.26 ± 0.2 mm at 15 °C.
Conclusions: Reduced egg hatch after exposure to sub-zero temperatures prohibits the establishment of the Asian bush mosquito in large parts of Germany. Larval overwintering is not possible at temperature ≤ 5 °C. The many potential generations displayed per year may contribute to the species’ invasion success. This study on the thermal ecology of the Asian bush mosquito adds to our knowledge on the temperature dependence of the species and data could be incorporated in epidemiological and population dynamic modelling.
Three fungi associated with living leaves of plants are new records for Panama: Annellophora phoenicis causing leaf spots of Cocos nucifera (Arecaceae), Cercospora corniculatae (C. apii s. lat.) on living leaves of Oxalis barrelieri (Oxalidaceae) with and without discoloration, and Sclerotium coffeicola on zonate leaf spots of Annona montana (Annonaceae) and Dioscorea alata (Dioscoreaceae). Some records of A. phoenicis and S. coffeicola relevant for known geographical distribution and available by literature are critically revised.
The intensive foraging of insectivorous birds and bats is well known to reduce the density of arboreal herbivorous arthropods but quantification of collateral leaf damage remains limited for temperate forest canopies. We conducted exclusion experiments with nets in the crowns of young and mature oaks, Quercus robur, in south and central Germany to investigate the extent to which aerial vertebrates reduce herbivory through predation. We repeatedly estimated leaf damage throughout the vegetation period. Exclusion of birds and bats led to a distinct increase in arthropod herbivory, emphasizing the prominent role of vertebrate predators in controlling arthropods. Leaf damage (e.g., number of holes) differed strongly between sites and was 59% higher in south Germany, where species richness of vertebrate predators and relative oak density were lower compared with our other study site in central Germany. The effects of bird and bat exclusion on herbivory were 19% greater on young than on mature trees in south Germany. Our results support previous studies that have demonstrated clear effects of insectivorous vertebrates on leaf damage through the control of herbivorous arthropods. Moreover, our comparative approach on quantification of leaf damage highlights the importance of local attributes such as tree age, forest composition and species richness of vertebrate predators for control of arthropod herbivory.
Microplastics (MP) are contaminants of emerging concern in aquatic ecosystems. While the number of studies is rapidly increasing, a comparison of the toxicity of MP and natural particulate matter is largely missing. In addition, research focusses on the impacts of hydrophobic chemicals sorbed to plastics. However, the interactive effects of MP and hydrophilic, dissolved chemicals remain largely unknown. Therefore, we conducted chronic toxicity studies with larvae of the freshwater dipteran Chironomus riparius exposed to unplasticised polyvinyl chloride MP (PVC-MP) as well as kaolin and diatomite as reference materials for 28 days. In addition, we investigated the effects of particles in combination with the neonicotinoid imidacloprid in a multiple-stressor experiment. High concentrations of kaolin positively affected the chironomids. In contrast, exposure to diatomite and PVC-MP reduced the emergence and mass of C. riparius. Likewise, the toxicity of imidacloprid was enhanced in the presence of PVC-MP and slightly decreased in the co-exposure with kaolin. Overall, parallel experiments and chemical analysis indicate that the toxicity of PVC-MP was not caused by leached or sorbed chemicals. Our study demonstrates that PVC-MP induce more severe effects than both natural particulate materials. However, the latter are not benign per se, as the case of diatomite highlights. Considering the high, environmentally irrelevant concentrations needed to induce adverse effects, C. riparius is insensitive to exposures to PVC-MP.
Peronospora salviae‐officinalis, the causal agent of downy mildew on common sage, is an obligate biotrophic pathogen. It grows in the intercellular spaces of the leaf tissue of sage and forms intracellular haustoria to interface with host cells. Although P. salviae‐officinalis was described as a species of its own 10 years ago, the infection process remains obscure. To address this, a histological study of various infection events, from the adhesion of conidia on the leaf surface to de novo sporulation is presented here. As histological studies of oomycetes are challenging due to the lack of chitin in their cell wall, we also present an improved method for staining downy mildews for confocal laser scanning microscopy as well as evaluating the potential of autofluorescence of fixed nonstained samples. For staining, a 1:1 mixture of aniline blue and trypan blue was found most suitable and was used for staining of oomycete and plant structures, allowing discrimination between them as well as the visualization of plant immune responses. The method was also used to examine samples of Peronospora lamii on Lamium purpureum and Peronospora belbahrii on Ocimum basilicum, demonstrating the potential of the presented histological method for studying the infection processes of downy mildews in general.