The Last Glacial Maximum shaped today’s subterranean diversity

The reconstructed Last Glacial Maximum ice extent and groundwater amphipod sampling sites across Switzerland. Black dots indicate sampled sites and orange dots indicate sites where groundwater amphipods were found.

As part of Mara Knüsel’s impressive PhD work, we publisehd a paper in Ecography that explores how Late Pleistocene glaciation influenced the diversity and distribution of 36 groundwater amphipod species in the Alpine and peri-Alpine regions. It is based on a massive citizen science approach in collaboration with drinking water providers. The analysis, based on data from over 1,000 systematic sampling sites across Switzerland, reveals a significant impact of the Last Glacial Maximum (LGM) ice extent on the current distribution of groundwater amphipods. The findings highlight a pronounced species turnover and distinct spatial envelopes of species occurrences in zones that were formerly ice-covered, ice-free, or transitional.

A new amphipod species from the Alps

The genus Niphargus, the most diverse subterranean amphipod genus in the western Palearctic, shows many cryptic species and homoplasy, necessitating molecular methods for understanding its evolution. In a new study, published in Contributions to Zoology, we used DNA-based taxonomy and traditional morphotaxonomy to study Niphargus bihorensis Schellenberg, 1940, from the Western Alps and Carpathians. The type material from Bihor County, Romania, revealed a cryptic species, N. absconditus n. sp., in the same area. Furthermore, we describe the Alpine populations as a new species, N. tizianoi n. sp. Our phylogenetic analyses suggest the N. bihorensis species complex is part of a well-supported clade with species ranging from Switzerland to Iran.

Deficits in the ecological state of small Swiss streams

The studied small streams across Switzerland. Figure adapted from Ilg & Alther (2024).

We published a study of 99 small Swiss streams in Aqua & Gas which reveals that most of these streams have significant ecological deficits, limiting their ability to serve as habitats for animals. In over 70% of the streams studied, pesticide-sensitive insect larvae and other small animals are partially missing. Statistical analyses show that these aquatic organisms are particularly affected when the stream bed structure and morphology have been altered or when the catchment area has a high proportion of agricultural land.

How to preserve subterranean biodiversity

Our international collaborative team in the Biodiversa funded project DarCo has published a perspective paper in npj biodiversity. Subterranean ecosystems, consisting of terrestrial, semi-aquatic, and aquatic components, face increasing threats from human activities, and existing surface-protected areas are insufficient to safeguard their biodiversity. Establishing protected areas for subterranean ecosystems is hindered by technical challenges in mapping three-dimensional systems, the rarity and endemism of subterranean organisms, and the need for collaboration among multiple stakeholders with competing interests. Despite uncertainties, our paper emphasizes the timely and critical assessment of general criteria for subterranean biodiversity protection, advocating for their implementation based on precautionary principles and proposing solutions to enhance the coverage of subterranean ecosystems within European protected areas.

Groundwater is a hidden keystone ecosystem

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: