Experiments have shown that biodiversity may increase or decrease ecosystem stability. As part of a collaboration between Owen Petchey’s lab at University of Zurich and Florian Altermatt’s lab at Eawag, we performed a large experiment that showed that species richness can simultaneously increase and decrease ecological stability. This highlighed that one should consider multiple stability components and that this could provide new insights. The study was recently published in Nature (read article here) and I am proud to be part of this fruitful project. The story behind the paper can be read in this blog post by Frank Pennekamp.
Category: Publication
Two new Niphargus species
With our new publication in ZooKeys, the number of amphipod species from Switzerland has risen again. The paper contains two new species (Niphargus luchoffmanni sp. n. and Niphargus tonywhitteni sp. n.), with drawings and descriptions. Additionally, the paper provides a DELTA (DEscription Language for TAxonomy) file and BOLD barcodes, allowing everyone the identification of niphargids based on various morphological and molecular characters.
Both species are geographically restricted (Austria, Germany, Switzerland), with one (N. luchoffmanni) being endemic to the Swiss alps. The species were named after Hans Lukas “Luc” Hoffmann (1923–2016), naturalist and ecologists, founder of the MAVA foundation and co-founder of the World Wild Fund for NAture (WWF), and after Tony Whitten (1953–2017), who devoted his life to nature conservation including conserving life in caves, also being a co-chair of the Cave Invertebrate Specialist Group at IUCN.
With this publication, the next step towards the monography about Swiss amphipods is done. The book should be available by the end of the year via CSCF. This homepage will keep you updated. Or contact me if you want to be informed about the release of the Fauna Helvetica monograph.
Amphipod diversity in fluvial networks
along the fluvial network is depicted as a heatmap, with streams and underlying catchments colorized with
respect to the observed catchment-level species richness (Figure from Ecosphere 9(2): e02102)
In the recently published open-access article in Ecosphere we studied the influence of fluvial network topology on different measures of amphipod diversity. The scientific novelty is the distinction between native and non-native species within a single taxonomic group in a large and natural system. The study covers the 27,882-km2 drainage basin of the river Rhine in Switzerland and is based on a graph theory approach.
Patterns of native and non-native species in fluvial networks
As hypothesized, species richness increased along the network from headwaters to the outlet nodes. But native and non-native amphipod showed different patterns, with headwaters being refugia for native species and more downstream nodes being hotspots of biological invasions. Additionally, results from species turnover indicated a much lower dispersal limitation for non-native species. The amphipod community structure closely mirrored the topological modularity of the network.
Implications for conservation ecology
Our results highlight that connectivity plays an important role in community formation, also on a larger scale. Rivers and streams are essential in explaining biological invasions.