Human activities are significantly affecting biodiversity on a global scale. Beyond the decline in species numbers, the composition of entire species communities is undergoing profound changes. In our study, published in Nature, we highlight these shifts. Our research stands among the most extensive studies ever conducted on the subject.
Cryptic freshwater species contribute to biodiversity, but their community integration remains unclear. In a recent study published in Freshwater Biology, we examined local and regional co-occurrences of cryptic amphipod species to understand the role of phylogenetic relationships in shaping biodiversity patterns. Our findings suggest that regional overlap results from dispersal rather than phylogenetic relatedness, with sympatries occurring more frequently among species from different clades. Ultimately, spatial patterns reflect historical events like mountain formation and climatic shifts, influencing biodiversity at local and regional scales.
In an international collaboration published in Global Change Biology, we investigated the importance of groundwater as a key global ecosystem. Groundwater plays a central role in the global water cycle, harbors a unique biodiversity and provides important ecosystem services such as clean drinking water. However, it is under increasing pressure and is often neglected in nature conservation. Our assessments show that groundwater interacts with more than half of the land surface. It is therefore essential to recognize its interconnected nature and pursue holistic approaches to groundwater protection. We propose eight concrete steps for a scientific and political agenda to protect groundwater and combat the loss of its biodiversity.
The Conversation published an article on the publication: https://theconversation.com/we-rely-heavily-on-groundwater-but-pumping-too-much-threatens-thousands-of-underground-species-218919
The latest two publications from our work on groundwater treat taxonomic questions on Niphargus and Haplotaxis. In a first study published in Zoologischer Anzeiger, we used molecular methods to review the taxonomic status of the Niphargus ruffoi clade, including the species N. ruffoi and Niphargus arolaensis, across the Alpine arc. In another study published in Zoosymposia, we questioned the supposedly sub-cosmopolitan species status of Haplotaxis gordioides, with our results suggesting that the species is a complex of at least 6 cryptic species in Switzerland.
Through close cooperation with local waterproviders in the Töss catchment area, we were able to detect a diverse groundwater fauna. The corresponding publication has just been published in Molecular Ecology (https://doi.org/10.1111/mec.16955). In contrast to earlier studies, we did not have to use nets and actually catch the organisms, but were able to detect them on the basis of DNA traces in water samples. We were able to show that the diversity of groundwater fauna differs depending on whether the samples were taken from agricultural or forested sites. However, it is not yet possible to make a statement about the cause or to do a water quality assessment. Eawag has published a news article on the publication. Many thanks also to the FOEN, the SVGW and Eawag for their financial support of the research project.
