Roman Alther

Roman Alther
University of Zurich & Eawag: Das Wasserforschungs-Institut des ETH-Bereichs · Department of Evolutionary Biology and Environmental Studies & Department of Aquatic Ecology

PhD
Senior Research Assistant

About

36
Publications
9,912
Reads
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412
Citations
Citations since 2016
34 Research Items
406 Citations
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2016201720182019202020212022020406080100
Introduction
When growing up in the city, going out into nature was always an astonishing experience to me, because of the richness in biological forms I could observe. Consequently, when I first started my studies in biology I was driven by the very same questions which many other ecologists and evolutionary biologists have pondered for a long time, and which are still not fully resolved: Why are there so many species, and how do they continue to coexist and persist? And what are the main mechanisms that shape communities and determine the distribution of life in space and time? Dendritic aquatic systems represent a suitable study system wherein different ecological and evolutionary mechanics, such as dispersal, invasion and speciation, can be studied in a spatially explicit context.
Additional affiliations
May 2013 - December 2013
Swiss Federal Institute for Forest, Snow and Landscape Research WSL
Position
  • Scientific Internship
September 2012 - May 2013
Eawag: Das Wasserforschungs-Institut des ETH-Bereichs
Position
  • Scientific Assistant

Publications

Publications (36)
Article
Full-text available
Amphipods are among the most abundant macroinvertebrates in freshwater ecosystems of the Palaearctic and crucial for ecosystem functioning. Furthermore, their high sensitivity to environmental change and pollutants makes them widely used model organisms in environmental sciences and ecotoxicology. In field studies and surveys across Eurasia, specie...
Article
Full-text available
Quaternary climate fluctuations can affect speciation in regional biodiversity assembly in two non-mutually exclusive ways: a glacial species pump, where isolation in glacial refugia accelerates allopatric speciation, and adaptive radiation in underused adaptive zones during ice-free periods. We detected biogeographic and genetic signatures associa...
Article
Erstmals wurde die Verbreitung und Artenvielfalt der Grundwasserflohkrebse im Einzugsgebiet der Töss, unter Einbezug von Bürgerwissenschaft, räumlich hoch aufgelöst untersucht. Bei der durch die Eawag und die Universität Zürich durchgeführten Studie wurden vier in dieser Region bisher noch nicht nachgewiesene Arten gefunden. Auch konnte gezeigt wer...
Preprint
Full-text available
Quaternary climate fluctuations can affect biodiversity assembly through speciation in two non-mutually-exclusive ways: a glacial species pump, where isolation in glacial refugia accelerates allopatric speciation, and adaptive radiation during ice-free periods. Here we detected biogeographic and genetic signatures associated with both mechanisms in...
Article
Full-text available
Theory predicts that the distribution of genetic diversity in a landscape is strongly dependent on the connectivity of the metapopulation and the dispersal of individuals between patches. However, the influence of explicit spatial configurations such as dendritic landscapes on the genetic diversity of metapopulations is still understudied, and theo...
Article
Full-text available
Knowledge on the diversity and distribution of subterranean organisms is still scattered, even in faunistically relatively well-researched countries such as Switzerland. This is mostly due to the restricted access to these subterranean habitats. Better knowledge on these organisms is needed, because they contribute substantially to overall biodiver...
Preprint
Full-text available
Theory predicts that the distribution of genetic diversity in a landscape is strongly dependent on the connectivity of the metapopulation and the dispersal of individuals between patches. However, the influence of explicit spatial configurations such as dendritic landscapes on the genetic diversity and structure of metapopulations is still understu...
Article
Full-text available
Environmental change can alter species’ abundances within communities consistently; for example, increasing all abundances by the same percentage, or more idiosyncratically. Here, we show how comparing effects of temperature on species grown in isolation and when grown together helps our understanding of how ecological communities more generally re...
Article
Full-text available
Eine Pilotstudie der Eawag hat an über 300 Standorten im Schweizer Mittelland die Grundwasserfauna untersucht, wobei die Rohwässer in Brunnenstuben durch die Wasserversorgungen selbst beprobt wurden. Anschliessend wurden die gefundenen Organismen morphologisch und teils genetisch bestimmt. An über 60% der Stellen wurden Organismen aus 18 biologisch...
Article
Full-text available
Assessing individual components of biodiversity, such as local or regional taxon richness, and differences in community composition is a long‐standing challenge in ecology. It is especially relevant in spatially structured and diverse ecosystems. Environmental DNA (eDNA) has been suggested as a novel technique to detect taxa and therefore may allow...
Book
Gewässer gehören zu den artenreichsten, gleichzeitig aber auch zu den am stärksten gefährdeten Lebensräumen der Schweiz (Fischer et al., 2015). Im 20. Jahrhundert wurden Gewässer vor allem durch organische Verschmutzung und Kanalisierung beeinträchtigt. Heute stellen Habitatveränderungen, Mikroverunreinigungen, Veränderungen des Abflussregimes, die...
Article
Full-text available
Alpine landscapes are being transformed through the rapid recession of glaciers, resulting in the development of numerous non-glacial headwater streams inhabited by a diverse assemblage of macroinvertebrates. We examined spatial patterns in biodiversity and rarity of macroinvertebrates in 41 non-glacial streams from five glacierized catchments in t...
Article
Full-text available
The family Moitessieriidae is poorly known, as its members, inhabiting exclusively subterranean waters, are often known only from few minute, empty shells. Molecular studies on their relationships confirmed the distinctness of this family. Their monophyly, however, remained doubtful, since the Moitessieriidae did not form a distinct clade in the ph...
Preprint
Full-text available
Assessing individual components of biodiversity, such as local or regional taxon richness, and differences in community composition is a long-standing challenge in ecology. It is especially relevant in spatially structured and diverse ecosystems. Environmental DNA (eDNA) has been suggested as a novel technique to accurately measure biodiversity. Ho...
Article
Full-text available
Losses and gains in species diversity affect ecological stability1–7 and the sustainability of ecosystem functions and services8–13. Experiments and models have revealed positive, negative and no effects of diversity on individual components of stability, such as temporal variability, resistance and resilience2,3,6,11,12,14. How these stability com...
Article
Full-text available
The amphipod genus Niphargus (Amphipoda: Niphargidae Bousfield, 1977) is the most species-rich genus of freshwater amphipods in the World. Species of this genus, which live almost exclusively in subterranean water, offer an interesting model system for basic and applied biodiversity science. Their use, however, is often limited due to the hitherto...
Data
Table S2. List of samples used in a detailed network analyses along with GenBank Accessions
Data
Table S1. List of samples used in phylogenetic analyses along with GenBank Accessions
Data
Table S3. List of new records of Niphargus from Switzerland
Article
Full-text available
Habitat connectivity crucially influences dispersal of organisms. It is especially seen as an important driver of the spatial structuring of biological communities in ecosystems that have intrinsic and general connectivity patterns, such as the universal dendritic structure of fluvial networks. These networks not only define dispersal of native spe...
Thesis
Full-text available
The present thesis investigated the diversity and distribution of amphipods (Crustacea, Amphipoda) in Switzerland, based on an extensive collection and analysis of faunistic and ecological data. The thesis aimed to provide an updated and substantiated foundation for future ecological, faunistic and taxonomic research on these important crustaceans,...
Conference Paper
Full-text available
We show that both native and non-native amphipod community assembly in river networks are influenced by the connectivity of habitats.
Conference Paper
Full-text available
We present the first conclusive overview on amphipods of Switzerland, with distribution maps of all 43 species recorded so far.
Article
Amphipods are keystone species in many freshwater ecosystems. Understanding their distribution and diversity is crucial to ensure and preserve freshwater ecosystem functioning, particularly in the northern hemisphere. For the European Alps information on amphipods has been relatively limited until recently. We describe a new, widely distributed amp...
Article
Groundwater belongs to the spatially most extensive, but least explored freshwater systems. On a global scale, the species richness of several subterranean invertebrate taxa parallels species richness found in surface waters, while on a local scale species richness hardly exceeds 20 species. This results in a high contribution of groundwater ecosys...
Article
Full-text available
Chironomids generally dominate macroinvertebrate assemblages in alpine streams. This study compared chironomid assemblages inhabiting 51 non-glacial streams in six alpine catchments in the Swiss Alps in 2012. Total abundances ranged from 3 to ca. 1900 individuals per sample with 42 taxa identified overall. Common taxa differed among catchments and...
Article
Full-text available
Background Worldwide, natural communities are invaded by non-native species, with potentially devastating effects on the native communities. A large part of past research aimed at finding traits and characteristics of the invading species or the invaded community explaining observed invasions. Only recently, the focus shifted on the spatial pattern...
Article
We investigated environmental characteristics and macroinvertebrate trophic structures of alpine streams in the glaciated Dinwoody catchment of the Wind River Range, Wyoming, USA. Study sites were above 3100 m a.s.l. and all above treeline except for one site representing a forested headwater stream. Physico-chemistry grouped sites by sub-basin and...
Article
Full-text available
Amphipods are key organisms in many freshwater systems and contribute substantially to the diversity and functioning of macroinvertebrate communities. Furthermore, they are commonly used as bioindicators and for ecotoxicological tests. For many areas, however, diversity and distribution of amphipods is inadequately known, which limits their use in...

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