31 results on '"Zeuss, Dirk"'
Search Results
2. Multispectral analysis-ready satellite data for three East African mountain ecosystems
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Bhandari, Netra, Bald, Lisa, Wraase, Luise, and Zeuss, Dirk
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- 2024
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3. Investigation of the spatiotemporal patterns of air quality over the metropolitan area of Tehran, using TROPOMI and OMI data
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Moradi, Ayoub and Zeuss, Dirk
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- 2024
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4. Seasonal variation in dragonfly assemblage colouration suggests a link between thermal melanism and phenology
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Novella-Fernandez, Roberto, Brandl, Roland, Pinkert, Stefan, Zeuss, Dirk, and Hof, Christian
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- 2023
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5. Mobility costs and energy uptake mediate the effects of morphological traits on species’ distribution and abundance
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Pinkert, Stefan, Friess, Nicolas, Zeuss, Dirk, Gossner, Martin M., Brandl, Roland, and Brunzel, Stefan
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- 2020
6. Climate–diversity relationships underlying cross-taxon diversity of the African fauna and their implications for conservation
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Pinkert, Stefan, Zeuss, Dirk, Dijkstra, Klaas-Douwe B., Kipping, Jens, Clausnitzer, Viola, Brunzel, Stefan, and Brandl, Roland
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- 2020
7. TubeDB: An on-demand processing database system for climate station data
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Wöllauer, Stephan, Zeuss, Dirk, Hänsel, Falk, and Nauss, Thomas
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- 2021
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8. The devil is in the detail: Environmental variables frequently used for habitat suitability modeling lack information for forest‐dwelling bats in Germany.
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Bald, Lisa, Gottwald, Jannis, Hillen, Jessica, Adorf, Frank, and Zeuss, Dirk
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ENDANGERED species ,LAND cover ,WILDLIFE conservation ,HABITATS ,BATS ,BIODIVERSITY monitoring - Abstract
In response to the pressing challenges of the ongoing biodiversity crisis, the protection of endangered species and their habitats, as well as the monitoring of invasive species are crucial. Habitat suitability modeling (HSM) is often treated as the silver bullet to address these challenges, commonly relying on generic variables sourced from widely available datasets. However, for species with high habitat requirements, or for modeling the suitability of habitats within the geographic range of a species, variables at a coarse level of detail may fall short. Consequently, there is potential value in considering the incorporation of more targeted data, which may extend beyond readily available land cover and climate datasets. In this study, we investigate the impact of incorporating targeted land cover variables (specifically tree species composition) and vertical structure information (derived from LiDAR data) on HSM outcomes for three forest specialist bat species (Barbastella barbastellus, Myotis bechsteinii, and Plecotus auritus) in Rhineland‐Palatinate, Germany, compared to commonly utilized environmental variables, such as generic land‐cover classifications (e.g., Corine Land Cover) and climate variables (e.g., Bioclim). The integration of targeted variables enhanced the performance of habitat suitability models for all three bat species. Furthermore, our results showed a high difference in the distribution maps that resulted from using different levels of detail in environmental variables. This underscores the importance of making the effort to generate the appropriate variables, rather than simply relying on commonly used ones, and the necessity of exercising caution when using habitat models as a tool to inform conservation strategies and spatial planning efforts. [ABSTRACT FROM AUTHOR]
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- 2024
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9. Trait overdispersion in dragonflies reveals the role and drivers of competition in community assembly across space and season.
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Novella‐Fernandez, Roberto, Chalmandrier, Loïc, Brandl, Roland, Pinkert, Stefan, Zeuss, Dirk, and Hof, Christian
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ODONATA ,DRAGONFLIES ,ANIMAL communities ,THERMAL stresses ,DAMSELFLIES ,COMPETITION (Biology) ,SOCIAL influence ,SEASONS - Abstract
Our understanding of how biotic interactions influence animal community assembly is largely restricted to local systems due to the difficulty of obtaining ecologically meaningful assemblage data across large spatial extents. Here, we used thousands of spatio‐phenologically high‐resolution assemblages across three distinct European regions together with a functional diversity approach to understand community assembly of dragonflies and damselflies (Odonata), an insect group characterized by a pronounced competitive reproductive biology. We found that adult dragonfly, but not damselfly, assemblages were consistently composed of species morphologically more different than expected by chance based on the traits that enhance their interspecific reproductive encounters. These results provide consistent evidence for the role of competition in the assembly of animal communities, which we interpret is most likely caused by the territorial reproductive biology of dragonflies. Support for competition varied both spatially and seasonally following theoretical expectations, as it was strongest in locations and seasonal moments with low thermal stress (i.e. warm conditions) and high niche packing. Our study illustrates how spatio‐temporal diversity patterns arise from variation in assembly processes. [ABSTRACT FROM AUTHOR]
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- 2024
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10. Long-Term Volumetric Change Estimation of Red Ash Quarry Sites in the Afro-Alpine Ecosystem of Bale Mountains National Park in Ethiopia.
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Muhammed, Mohammed Ahmed, Hassen, Abubeker Mohammed, Abera, Temesgen Alemayehu, Wraase, Luise, Ejigu, Behailu Legese, Hailu, Binyam Tesfaw, Miehe, Georg, and Zeuss, Dirk
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MOUNTAIN ecology ,NATIONAL parks & reserves ,ECOSYSTEMS ,QUARRIES & quarrying ,DIGITAL elevation models ,AERIAL photographs ,ROAD construction - Abstract
The Bale Mountains National Park (BMNP) in Ethiopia comprises the largest fraction of the Afro-Alpine ecosystem in Africa, which provides vital mountain ecosystem services at local, regional, and global levels. However, the BMNP has been severely threatened by natural and anthropogenic disturbances in recent decades. In particular, landscape alteration due to human activities such as red ash quarrying has become a common practice in the BMNP, which poses a major environmental challenge by severely degrading the Afro-Alpine ecosystem. This study aims to quantify the long-term volumetric changes of two red ash quarry sites in the BMNP using historical aerial photographs and in situ data, and to assess their impact on the Afro-Alpine ecosystem. The Structure-from-Motion multi-view stereo photogrammetry algorithm was used to reconstruct the three-dimensional landscape for the year 1967 and 1984 while spatial interpolation techniques were applied to generate the current digital elevation models for 2023. To quantify the volumetric changes and landscape alteration of the quarry sites, differences in digital elevation models were computed. The result showed that the volume of resources extracted from the BMNP quarry sites increased significantly over the study period from 1984 to 2023 compared with the period from 1967 to 1984. In general, between 1967 and 2023, the total net surface volume of the quarry sites decreased by 503,721 ± 27,970 m
3 and 368,523 ± 30,003 m3 , respectively. The extent of the excavated area increased by 53,147 m2 and 45,297 m2 for Site 1 and 2, respectively. In terms of habitat loss, major gravel road construction inside the BMNP resulted in the reduction of Afro-Alpine vegetation by 476,860 m2 , ericaceous vegetation by 403,806 m2 and Afromontane forest by 493,222 m2 with associated decline in species diversity and density. The excavation and gravel road construction have contributed to the degradation of the Afro-Alpine ecosystem, especially the endemic Lobelia rhynchopetalum on the quarry sites and roads. If excavation continues at the same rate as in the last half century, it can threaten the whole mountain ecosystem of the National Park and beyond, highlighting the importance of preventing these anthropogenic changes and conserving the remaining Afro-Alpine ecosystem. [ABSTRACT FROM AUTHOR]- Published
- 2024
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11. Nature 4.0: A networked sensor system for integrated biodiversity monitoring.
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Zeuss, Dirk, Bald, Lisa, Gottwald, Jannis, Becker, Marcel, Bellafkir, Hicham, Bendix, Jörg, Bengel, Phillip, Beumer, Larissa T., Brandl, Roland, Brändle, Martin, Dahlke, Stephan, Farwig, Nina, Freisleben, Bernd, Friess, Nicolas, Heidrich, Lea, Heuer, Sven, Höchst, Jonas, Holzmann, Hajo, Lampe, Patrick, and Leberecht, Martin
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BIODIVERSITY monitoring , *ECOSYSTEM management , *DETECTORS , *MODULAR construction , *ENVIRONMENTAL degradation , *SENSOR networks , *WIRELESS sensor networks , *DATA warehousing - Abstract
Ecosystem functions and services are severely threatened by unprecedented global loss in biodiversity. To counteract these trends, it is essential to develop systems to monitor changes in biodiversity for planning, evaluating, and implementing conservation and mitigation actions. However, the implementation of monitoring systems suffers from a trade‐off between grain (i.e., the level of detail), extent (i.e., the number of study sites), and temporal repetition. Here, we present an applied and realized networked sensor system for integrated biodiversity monitoring in the Nature 4.0 project as a solution to these challenges, which considers plants and animals not only as targets of investigation, but also as parts of the modular sensor network by carrying sensors. Our networked sensor system consists of three main closely interlinked components with a modular structure: sensors, data transmission, and data storage, which are integrated into pipelines for automated biodiversity monitoring. We present our own real‐world examples of applications, share our experiences in operating them, and provide our collected open data. Our flexible, low‐cost, and open‐source solutions can be applied for monitoring individual and multiple terrestrial plants and animals as well as their interactions. Ultimately, our system can also be applied to area‐wide ecosystem mapping tasks, thereby providing an exemplary cost‐efficient and powerful solution for biodiversity monitoring. Building upon our experiences in the Nature 4.0 project, we identified ten key challenges that need to be addressed to better understand and counteract the ongoing loss of biodiversity using networked sensor systems. To tackle these challenges, interdisciplinary collaboration, additional research, and practical solutions are necessary to enhance the capability and applicability of networked sensor systems for researchers and practitioners, ultimately further helping to ensure the sustainable management of ecosystems and the provision of ecosystem services. [ABSTRACT FROM AUTHOR]
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- 2024
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12. Biotic interactions in species distribution modelling: 10 questions to guide interpretation and avoid false conclusions
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Dormann, Carsten F., Bobrowski, Maria, Dehling, D. Matthias, Harris, David J., Hartig, Florian, Lischke, Heike, Moretti, Marco D., Pagel, Jörn, Pinkert, Stefan, Schleuning, Matthias, Schmidt, Susanne I., Sheppard, Christine S., Steinbauer, Manuel J., Zeuss, Dirk, and Kraan, Casper
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- 2018
13. The dark side of Lepidoptera: Colour lightness of geometrid moths decreases with increasing latitude
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Heidrich, Lea, Friess, Nicolas, Fiedler, Konrad, Brändle, Martin, Hausmann, Axel, Brandl, Roland, and Zeuss, Dirk
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- 2018
14. Environmental drivers of voltinism and body size in insect assemblages across Europe
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Zeuss, Dirk, Brunzel, Stefan, and Brandl, Roland
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- 2017
15. High-resolution digital elevation models and orthomosaics generated from historical aerial photographs (since the 1960s) of the Bale Mountains in Ethiopia.
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Muhammed, Mohammed Ahmed, Hailu, Binyam Tesfaw, Miehe, Georg, Wraase, Luise, Nauss, Thomas, and Zeuss, Dirk
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AERIAL photographs ,DIGITAL elevation models ,WATERSHED management ,ECOSYSTEMS ,STANDARD deviations ,MOUNTAIN ecology ,SPATIAL resolution ,COMPUTER vision - Abstract
The natural resources of Ethiopian high-altitude ecosystems are commonly perceived as increasingly threatened by devastating land-use practices owing to decreasing lowland resources. Quantified time-series data of the course of land-use cover changes are still needed. Very-high-resolution digital data on the historical landscape over recent decades are needed to determine the impacts of changes in afro-alpine ecosystems. However, digital elevation models (DEMs) and orthomosaics do not exist for most afro-alpine ecosystems of Africa. We processed the only available and oldest historical aerial photographs for Ethiopia and any afro-alpine ecosystem. Here, we provide a DEM and an orthomosaic image for the years 1967 and 1984 for the Bale Mountains in Ethiopia, which comprise the largest afro-alpine ecosystem in Africa. We used 298 historical aerial photographs captured in 1967 and 1984 for generating DEMs and orthomosaics with a structure-from-motion multi-view stereo photogrammetry workflow along an elevation gradient from 977 to 4377 m above sea level (a.s.l.) at very high spatial resolutions of 0.84 m and 0.98 m for the years 1967 and 1984, respectively. The structure-from-motion multi-view stereo photogrammetry workflow, employed with Agisoft Metashape, represents a modern approach that combines computer vision and photogrammetry. This method proves useful for reconstructing DEMs and orthomosaics from historical aerial photographs, with a focus on high spatial resolution. To validate the accuracy of the reconstructed DEMs, ground control points gathered through GPS measurements were used, resulting in root mean square error (RMSE) values of 3.55 m for the year 1967 and 3.44 m for the year 1984. Our datasets can be used by researchers and policymakers for watershed management, as the area provides water for more than 30 million people, landscape management, detailed mapping, and analysis of geological and archaeological features as well as natural resources, analyses of geomorphological processes, and biodiversity research. All the datasets are available online at 10.5281/zenodo.7271617 (Muhammed et al., 2022a) for all the inputs used and at 10.5281/zenodo.7269999 (Muhammed et al., 2022b) for the results obtained (very-high-resolution DEMs and orthomosaics) for both the years 1967 and 1984. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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16. spatialMaxent: Adapting species distribution modeling to spatial data.
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Bald, Lisa, Gottwald, Jannis, and Zeuss, Dirk
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SPECIES distribution ,SPATIAL data structures ,BIODIVERSITY conservation ,DATA modeling ,RESEARCH personnel - Abstract
Conventional practices in species distribution modeling lack predictive power when the spatial structure of data is not taken into account. However, choosing a modeling approach that accounts for overfitting during model training can improve predictive performance on spatially separated test data, leading to more reliable models. This study introduces spatialMaxent (https://github.com/envima/spatialMaxent), a software that combines state‐of‐the‐art spatial modeling techniques with the popular species distribution modeling software Maxent. It includes forward‐variable‐selection, forward‐feature‐selection, and regularization‐multiplier tuning based on spatial cross‐validation, which enables addressing overfitting during model training by considering the impact of spatial dependency in the training data. We assessed the performance of spatialMaxent using the National Center for Ecological Analysis and Synthesis dataset, which contains over 200 anonymized species across six regions worldwide. Our results show that spatialMaxent outperforms both conventional Maxent and models optimized according to literature recommendations without using a spatial tuning strategy in 80 percent of the cases. spatialMaxent is user‐friendly and easily accessible to researchers, government authorities, and conservation practitioners. Therefore, it has the potential to play an important role in addressing pressing challenges of biodiversity conservation. [ABSTRACT FROM AUTHOR]
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- 2023
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17. Colour lightness of butterfly assemblages across North America and Europe
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Stelbrink, Pablo, Pinkert, Stefan, Brunzel, Stefan, Kerr, Jeremy, Wheat, Christopher W., Brandl, Roland, and Zeuss, Dirk
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- 2019
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18. Remote sensing‐supported mapping of the activity of a subterranean landscape engineer across an afro‐alpine ecosystem.
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Wraase, Luise, Reuber, Victoria M., Kurth, Philipp, Fekadu, Mekbib, Demissew, Sebsebe, Miehe, Georg, Opgenoorth, Lars, Selig, Ulrike, Woldu, Zerihun, Zeuss, Dirk, Schabo, Dana G., Farwig, Nina, Nauss, Thomas, Sankey, Temuulen, and Wu, Jin
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ENGINEERS ,SATELLITE-based remote sensing ,SPECIES distribution ,ENDANGERED species ,ECOSYSTEMS ,MOUNTAIN ecology ,PLANT species - Abstract
Subterranean animals act as ecosystem engineers, for example, through soil perturbation and herbivory, shaping their environments worldwide. As the occurrence of animals is often linked to above‐ground features such as plant species composition or landscape textures, satellite‐based remote sensing approaches can be used to predict the distribution of subterranean species. Here, we combine in‐situ collected vegetation composition data with remotely sensed data to improve the prediction of a subterranean species across a large spatial scale. We compared three machine learning‐based modeling strategies, including field and satellite‐based remote sensing data to different extents, in order to predict the distribution of the subterranean giant root‐rat GRR, Tachyoryctes macrocephalus, an endangered rodent species endemic to the Bale Mountains in southeast Ethiopia. We included no, some and extensive fieldwork data in the modeling to test how these data improved prediction quality. We found prediction quality to be particularly dependent on the spatial coverage of the training data. Species distributions were best predicted by using texture metrics and eyeball‐selected data points of landscape marks created by the GRR. Vegetation composition as a predictor showed the lowest contribution to model performance and lacked spatial accuracy. Our results suggest that the time‐consuming collection of vegetation data in the field is not necessarily required for the prediction of subterranean species that leave traceable above‐ground landscape marks like the GRR. Instead, remotely sensed and spatially eyeball‐selected presence data of subterranean species could profoundly enhance predictions. The usage of remote sensing‐derived texture metrics has great potential for improving the distribution modeling of subterranean species, especially in arid ecosystems. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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19. Colour lightness of dragonfly assemblages across North America and Europe
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Pinkert, Stefan, Brandl, Roland, and Zeuss, Dirk
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- 2017
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20. The South Asian monsoon maintains the disjunction of Rumex hastatus between the western Himalayas and the Hengduan Mountains, southwest China.
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Martiné, Eric, Zeuss, Dirk, Lampei, Christian, Sun, Hang, Miehe, Georg, and Opgenoorth, Lars
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LAST Glacial Maximum , *RUMEX , *ECOLOGICAL niche , *VALLEYS , *ECOLOGICAL models , *RANDOM forest algorithms , *MONSOONS - Abstract
The Himalayas and the Hengduan Mountains of southwest China are hotspots of both climatic and species diversity. Yet, the distribution patterns of semi‐arid plant communities that have arisen throughout the region's complex uplift history remain insufficiently understood. In particular, the striking disjunctions of plants associated with dry river valleys that solely occur on the eastern and western ends of the Himalayan arc, but are absent in between, lack a sound explanation. Here we aim to disentangle the more recent environmental drivers behind the disjunction of the semi‐woody shrub Rumex hastatus found in dry river valleys of the western Himalayas and the Hengduan Mountains. We used ecological niche modeling and enhanced random forest parameterizations (down‐sampling) to infer suitable and unsuitable habitats within the study area during the last glacial maximum, under present climate conditions, and under four future climate scenarios. Annual and seasonal precipitation contributed the strongest to the discrimination between occurrences and the distribution gap, with the latter showing much higher rainfall amounts. The gap was also characterized by low overall habitat suitability, whereas occurrence probabilities in dry river valleys inhabited by R. hastatus were very high. However, some suitable but isolated habitats within the gap were detected in Bhutan and the southeastern Tibetan Plateau. The identified distribution gap was consistent in all simulated scenarios from the last glacial maximum to the near future. Our results suggest that the South Asian summer monsoon system acts as a persistent ecological barrier maintaining the disjunct distribution of dry river valley‐dwelling plants in the western Himalayas and the Hengduan Mountains. [ABSTRACT FROM AUTHOR]
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- 2022
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21. Consistent signals of a warming climate in occupancy changes of three insect taxa over 40 years in central Europe.
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Engelhardt, Eva Katharina, Biber, Matthias F., Dolek, Matthias, Fartmann, Thomas, Hochkirch, Axel, Leidinger, Jan, Löffler, Franz, Pinkert, Stefan, Poniatowski, Dominik, Voith, Johannes, Winterholler, Michael, Zeuss, Dirk, Bowler, Diana E., and Hof, Christian
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CLIMATE change ,INSECTS ,BUTTERFLIES ,TIME series analysis ,GRASSHOPPERS ,DRAGONFLIES ,HABITATS ,HABITAT selection - Abstract
Copyright of Global Change Biology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2022
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22. Chromosome numbers in three species groups of freshwater flatworms increase with increasing latitude
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Lorch, Sven, Zeuss, Dirk, Brandl, Roland, and Brändle, Martin
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reproduction ,Geographical range ,Platyhelminthes ,parthenogenesis ,polyploidy ,Original Research - Abstract
Polyploidy in combination with parthenogenesis offers advantages for plasticity and the evolution of a broad ecological tolerance of species. Therefore, a positive correlation between the level of ploidy and increasing latitude as a surrogate for environmental harshness has been suggested. Such a positive correlation is well documented for plants, but examples for animals are still rare. Species of flatworms (Platyhelminthes) are widely distributed, show a remarkably wide range of chromosome numbers, and offer therefore good model systems to study the geographical distribution of chromosome numbers. We analyzed published data on counts of chromosome numbers and geographical information of three flatworm “species” (Phagocata vitta, Polycelis felina and Crenobia alpina) sampled across Europe (220 populations). We used the mean chromosome number across individuals of a population as a proxy for the level of ploidy within populations, and we tested for relationships of this variable with latitude, mode of reproduction (sexual, asexual or both) and environmental variables (annual mean temperature, mean diurnal temperature range, mean precipitation and net primary production). The mean chromosome numbers of all three species increased with latitude and decreased with mean annual temperature. For two species, chromosome number also decreased with mean precipitation and net primary production. Furthermore, high chromosome numbers within species were accompanied with a loss of sexual reproduction. The variation of chromosome numbers within individuals of two of the three species increased with latitude. Our results support the hypothesis that polyploid lineages are able to cope with harsh climatic conditions at high latitudes. Furthermore, we propose that asexual reproduction in populations with high levels of polyploidization stabilizes hybridization events. Chromosomal irregularities within individuals tend to become more frequent at the extreme environments of high latitudes, presumably because of mitotic errors and downsizing of the genome.
- Published
- 2016
23. Butterfly dichromatism primarily evolved via Darwin's, not Wallace's, model.
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Bijl, Wouter, Zeuss, Dirk, Chazot, Nicolas, Tunström, Kalle, Wahlberg, Niklas, Wiklund, Christer, Fitzpatrick, John L., and Wheat, Christopher W.
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SEXUAL selection , *SEXUAL dimorphism , *BUTTERFLIES , *PHYLOGENETIC models , *NATURAL selection , *SPERMATOPHORES , *EVOLUTIONARY models - Abstract
Sexual dimorphism is typically thought to result from sexual selection for elaborated male traits, as proposed by Darwin. However, natural selection could reduce expression of elaborated traits in females, as proposed by Wallace. Darwin and Wallace debated the origins of dichromatism in birds and butterflies, and although evidence in birds is roughly equal, if not in favor of Wallace's model, butterflies lack a similar scale of study. Here, we present a large‐scale comparative phylogenetic analysis of the evolution of butterfly coloration, using all European non‐hesperiid butterfly species (n = 369). We modeled evolutionary changes in coloration for each species and sex along their phylogeny, thereby estimating the rate and direction of evolution in three‐dimensional color space using a novel implementation of phylogenetic ridge regression. We show that male coloration evolved faster than female coloration, especially in strongly dichromatic clades, with male contribution to changes in dichromatism roughly twice that of females. These patterns are consistent with a classic Darwinian model of dichromatism via sexual selection on male coloration, suggesting this model was the dominant driver of dichromatism in European butterflies. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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24. Environmental drivers of colour and size in insects: A macroecological perspective
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Zeuss, Dirk and Brandl, Roland (Prof. Dr.)
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Insekten ,colour ,Biowissenschaften, Biologie ,Farbe ,Schmetterlinge , Körpergröße ,Ökologie ,Geografie ,Melanismus ,Macroecology, insects ,size ,lepidoptera ,Life sciences ,ddc:570 - Abstract
Climatic conditions have profound effects on the geographical distribution of species across diverse taxa and regions. However, the role of traits of species that underpin the relationship between distribution and climate is poorly understood, especially in animals. Although many physiological and local-scale studies on animals have demonstrated associations between traits and climate, to what extent such mechanistic links may impact distribution patterns of species at macroecological scales remains largely unknown. In insects, colour and size are two very important and highly multifunctional traits, which play pivotal roles in natural and sexual selection, and may hence be related to climate. The colour of insects comprises several functions, namely crypsis, aposematism, sexual selection, species recognition, UV resistance, pathogen resistance and thermoregulation. However, the relative importance of single functions is often unclear because several functions of colouration can act simultaneously. Hitherto, thermoregulation through thermal melanism is supposed to be the dominant function of colouration in insects. Dark-coloured individuals heat up faster and attain higher steady-state body temperatures compared to light-coloured individuals of similar size under equal environmetal conditions and light-coloured individuals are supposed to have advantages in warmer climates because of a reduced risk of overheating. However, it is unknown to which extent this physical mechanism influences the colour lightness of species in response to different thermal environments at macroecological scales and across continents. Moreover, thermoregulation is not the only function of colouration of insects and it is unknown to which extent other functions of colouration dominate in particular geographical areas and taxa and thereby form macroecological patterns. The size of insects affects almost all physiological rates (e.g. rate of oxygen consumption), which subsequently determine or constrain fertility, mortality and ecological processes such as competitive interactions between individuals or species. In this way, body size is ultimately linked to the spatiotemporal distribution and abundance of animals and has important implications for the impact of climate warming – from biomass production by single species to the structure and dynamics of communities.However, a synthesis and analysis of the major environmental driver for the large-scale geographical variation of insect body size is missing so far. In this thesis, I use lepidopteran and odonate species to address the following questions: i) Are assemblages of diurnal insects darker coloured in colder regions and lighter coloured in warmer regions? ii) Is crypsis, pathogen resistance or protection from UV radiation associated with large-scale geographical variation in the colouration of insects? iii) What are the major environmental drivers for the large-scale geographical variation of body size in insects? In conclusion, colour and size of insects are related to their geographical distribution even at macroecological scales. The underlying mechanisms are especially driven by environmental temperatures: for colour because of its effect on thermoregulation and immune function, and for size because of the temperature dependency of metabolic rates and voltinism. With global warming, I would thus expect that especially dark-coloured and/or large aquatic insects might shift their distribution and retreat from warmer areas. Furthermore, insect species with the ability to increase their annual number of generations should benefit and extend their distribution to higher latitudes., Das Klima hat grundlegende Auswirkungen auf die Verbreitung von Arten. Ein mechanistisches Verständnis des Zusammenhangs zwischen Merkmalen von Arten, der räumlichen Verbreitung von Arten und klimatischen Bedingungen fehlt jedoch weitestgehend, vor allem bei Tieren. Obwohl viele physiologische und kleinräumige Studien Zusammenhänge zwischen Merkmalen von Arten und klimatischen Bedingungen gezeigt haben, ist weitgehend unbekannt, inwieweit solche mechanistischen Zusammenhänge die Verbreitung von Arten auf makroökologischer Skala beeinflussen. Bei Insekten sind Farbe und Körpergröße zwei wichtige multifunktionale Merkmale, die zentrale Rollen bei natürlicher und sexueller Selektion einnehmen und deswegen mit klimatischen Bedingungen in Beziehung stehen könnten. Die Farbe von Insekten wird mit Tarnung, Aposematismus, sexueller Selektion, Arterkennung, Resistenz gegen UV-Strahlung und Pathogene sowie Thermoregulation assoziiert. Die relative Wichtigkeit einzelner Funktionen ist jedoch oft unklar, weil mehrere Funktionen von Farbe simultan wirken können. Bisher wird davon ausgegangen, dass Thermoregulation durch thermalen Melanismus die dominante Funktion der Farbe bei Insekten ist. Dunkle Individuen erwärmen sich schneller und erreichen höhere Körpertemperaturen verglichen mit hellen Individuen unter gleichen Umweltbedingungen. Helle Individuen hingegen sollten durch ein geringeres Risiko zu Überhitzen einen Vorteil in warmen Klimaten besitzen. Es ist jedoch unbekannt, inwiefern dieser physikalische Mechanismus die Helligkeit von Arten in Abhängigkeit der thermalen Umgebung auf makroökologischer Skala und über Kontinente hinweg beeinflusst. Darüber hinaus ist Thermoregulation nicht die einzige Funktion von Farbe und es ist unbekannt, inwiefern andere Funktionen von Farbe in bestimmten Gebieten und Taxa dominieren und dadurch makroökologische Muster generieren. Die Körpergröße von Insekten beeinflusst fast alle physiologischen Prozesse (z.B. den Sauerstoffverbrauch), die wiederum Fertilität, Mortalität und ökologische Prozesse wie z.B. die Konkurrenz zwischen Individuen oder Arten bestimmen. Somit ist die Körpergröße letztendlich mit der raumzeitlichen Verbreitung und Abundanz von Arten verbunden, was wichtige Implikationen für Auswirkungen des Klimawandels hat – von der Biomasseproduktion einzelner Arten hin zur Struktur und Dynamik von Artgemeinschaften. Bisher gibt es jedoch noch keine Synthese und Analyse der wichtigsten Umwelteinflüsse auf die großräumige Verbreitung der Körpergröße von Insekten. In dieser Arbeit verwendete ich Lepidopteren (Tag- und Nachtfalter) und Odonaten (Groß- und Kleinlibellen), um die folgenden Fragen zu bearbeiten: i) Sind Gemeinschaften tagaktiver Insekten im Mittel dunkler in kälteren Regionen und heller in wärmeren Regionen? ii) Ist Tarnung, Resistenz gegen Pathogene oder Schutz vor UV-Strahlung assoziiert mit großräumiger Variation in der Farbe von Insekten? iii) Was sind die wichtigsten Umwelteinflüsse auf die großräumige Variation der Körpergröße von Insekten? Diese Arbeit demonstriert, dass Farbe und Körpergröße selbst auf makroökologischer Skala in Beziehung zur geographischen Verbreitung von Insekten stehen. Die zugrunde liegenden Mechanismen sind vor allem durch die Umgebungstemperatur gesteuert: Bei der Farbe durch deren Effekt auf Thermoregulation sowie Immunfunktion und bei der Körpergröße durch die Temperaturabhängigkeit metabolischer Raten und des Voltinismus. Mit der Klimaerwärmung erwarte ich von daher, dass vor allem dunkle und/oder große aquatische Insekten ihre Verbreitungsgebiete verändern und sich von wärmeren Regionen zurückziehen. Insektenarten mit der Fähigkeit, ihre jährliche Anzahl von Generationen zu erhöhen, sollten hingegen von steigenden Umgebungstemperaturen profitieren und ihre Verbreitungsgebiete in höhere Breiten ausdehnen.
- Published
- 2017
25. Moth body size increases with elevation along a complete tropical elevational gradient for two hyperdiverse clades.
- Author
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Brehm, Gunnar, Zeuss, Dirk, and Colwell, Robert K.
- Subjects
- *
LEPIDOPTERA , *BODY size , *MOTHS , *GEOMETRIDAE , *REGRESSION analysis - Abstract
The body size of an animal is probably its most important functional trait. For arthropods, environmental drivers of body size variation are still poorly documented and understood, especially in tropical regions. We use a unique dataset for two species‐rich, phylogenetically independent moth taxa (Lepidoptera: Geometridae; Arctiinae), collected along an extensive tropical elevational gradient in Costa Rica, to investigate the correlates and possible causes of body‐size variation. We studied 15 047 specimens (794 species) of Geometridae and 4167 specimens (308 species) of Arctiinae to test the following hypotheses: 1) body size increases with decreasing ambient temperature, as predicted by the temperature–size rule; 2) body size increases with increasing rainfall and primary productivity, as predicted from considerations of starvation resistance; and 3) body size scales allometrically with wing area, as elevation increases, such that wing loading (the ratio of body size to wing area) decreases with increasing elevation to compensate for lower air density. To test these hypotheses, we examined forewing length as a proxy for body size in relation to ambient temperature, rainfall, vegetation index and elevation as explanatory variables in linear and polynomial spatial regression models. We analysed our data separately for males and females using two principal approaches: mean forewing length of species at each site, and mean forewing length of complete local assemblages, weighted by abundance. Body size consistently increased with elevation in both taxa, both approaches, both sexes, and also within species. Temperature was the best predictor for this pattern (–0.98 < r < –0.74), whereas body size was uncorrelated or weakly correlated with rainfall and enhanced vegetation index. Wing loading increased with elevation. Our results support the temperature–size rule as an important mechanism for body size variation in arthropods along tropical elevational gradients, whereas starvation resistance and optimization of flight mechanics seem to be of minor importance. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
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26. Evolutionary processes, dispersal limitation and climatic history shape current diversity patterns of European dragonflies.
- Author
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Pinkert, Stefan, Dijkstra, Klaas‐Douwe B., Zeuss, Dirk, Reudenbach, Christoph, Brandl, Roland, and Hof, Christian
- Subjects
DRAGONFLIES ,CLASSIFICATION of insects ,SPECIES diversity ,CLIMATE change ,REGRESSION analysis - Abstract
We investigated the effects of contemporary and historical factors on the spatial variation of European dragonfly diversity. Specifically, we tested to what extent patterns of endemism and phylogenetic diversity of European dragonfly assemblages are structured by 1) phylogenetic conservatism of thermal adaptations and 2) differences in the ability of post‐glacial recolonization by species adapted to running waters (lotic) and still waters (lentic). We investigated patterns of dragonfly diversity using digital distribution maps and a phylogeny of 122 European dragonfly species, which we constructed by combining taxonomic and molecular data. We calculated total taxonomic distinctiveness and mean pairwise distances across 4192 50 × 50 km equal‐area grid cells as measures of phylogenetic diversity. We compared species richness with corrected weighted endemism and standardized effect sizes of mean pairwise distances or residuals of total taxonomic distinctiveness to identify areas with higher or lower phylogenetic diversity than expected by chance. Broken‐line regression was used to detect breakpoints in diversity–latitude relationships. Dragonfly species richness peaked in central Europe, whereas endemism and phylogenetic diversity decreased from warm areas in the south‐west to cold areas in the north‐east and with an increasing proportion of lentic species. Except for species richness, all measures of diversity were consistently higher in formerly unglaciated areas south of the 0°C isotherm during the Last Glacial Maximum than in formerly glaciated areas. These results indicate that the distributions of dragonfly species in Europe were shaped by both phylogenetic conservatism of thermal adaptations and differences between lentic and lotic species in the ability of post‐glacial recolonization/dispersal in concert with the climatic history of the continent. The complex diversity patterns of European dragonflies provide an example of how integrating climatic and evolutionary history with contemporary ecological data can improve our understanding of the processes driving the geographical variation of biological diversity. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
27. Front Cover.
- Author
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Heidrich, Lea, Friess, Nicolas, Fiedler, Konrad, Brändle, Martin, Hausmann, Axel, Brandl, Roland, and Zeuss, Dirk
- Subjects
BUTTERFLIES ,MACROECOLOGY ,BIOGEOGRAPHY - Published
- 2018
- Full Text
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28. Global warming favours light-coloured insects in Europe.
- Author
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Zeuss, Dirk, Brandl, Roland, Brändle, Martin, Rahbek, Carsten, and Brunzel, Stefan
- Published
- 2014
- Full Text
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29. Front Cover.
- Author
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Pinkert, Stefan, Zeuss, Dirk, Dijkstra, Klaas‐Douwe B., Kipping, Jens, Clausnitzer, Viola, Brunzel, Stefan, Brandl, Roland, and Leroy, Boris
- Subjects
- *
FISHERIES , *FISHERY sciences , *MARINE mammals , *AERIAL surveys - Published
- 2020
- Full Text
- View/download PDF
30. Butterfly dichromatism primarily evolved via Darwin's, not Wallace's, model.
- Author
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van der Bijl W, Zeuss D, Chazot N, Tunström K, Wahlberg N, Wiklund C, Fitzpatrick JL, and Wheat CW
- Abstract
Sexual dimorphism is typically thought to result from sexual selection for elaborated male traits, as proposed by Darwin. However, natural selection could reduce expression of elaborated traits in females, as proposed by Wallace. Darwin and Wallace debated the origins of dichromatism in birds and butterflies, and although evidence in birds is roughly equal, if not in favor of Wallace's model, butterflies lack a similar scale of study. Here, we present a large-scale comparative phylogenetic analysis of the evolution of butterfly coloration, using all European non-hesperiid butterfly species ( n = 369). We modeled evolutionary changes in coloration for each species and sex along their phylogeny, thereby estimating the rate and direction of evolution in three-dimensional color space using a novel implementation of phylogenetic ridge regression. We show that male coloration evolved faster than female coloration, especially in strongly dichromatic clades, with male contribution to changes in dichromatism roughly twice that of females. These patterns are consistent with a classic Darwinian model of dichromatism via sexual selection on male coloration, suggesting this model was the dominant driver of dichromatism in European butterflies., (© 2020 The Authors. Evolution Letters published by Wiley Periodicals, LLC on behalf of Society for the Study of Evolution (SSE) and European Society for Evolutionary Biology (ESEB).)
- Published
- 2020
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31. Thermal Biology: Melanin-Based Energy Harvesting across the Tree of Life.
- Author
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Pinkert S and Zeuss D
- Subjects
- Models, Biological, Pigmentation, Saccharomyces cerevisiae, Hot Temperature, Melanins
- Abstract
Recent results on the thermal biology of unicellular fungi provide evidence that pigmentation is an ancient adaptation for harvesting solar radiation. A new model system promises novel opportunities for quantifying radiative heat transfer and improving biophysical models., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
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