Aliens in caves: the global dimension of biological invasions in subterranean ecosystems

Four years monitoring of the endangered European plethodontid salamanders

The ongoing biodiversity crisis is strongly threatening amphibians, mostly because of their peculiar physiology, their sensitivity to climate change and the spread of diseases. Effective monitoring involving assessments of pressure effects across time and estimation of population trends play a key role in mitigating amphibian decline. To improve implementation of standardized protocols and conservation efforts, we present here a dataset related to one of the amphibian genera whose onservation status is considered the most declining according to the IUCN. We report information on 66 populations of the endangered European cave salamanders, genus Speleomantes, that was collected through a standardized monitoring along a four-year period (2021-2024). Demographics data of the populations and fitness-related data of single individuals are reported. Furthermore, we include 3,836 high quality images of individuals that can allow to perform studies aiming to assess the phenotypic variability within the genus, and to perform long-term capture-mark-recaptured studies.

Groundwater is a hidden global keystone ecosystem

Groundwater is a vital ecosystem of the global water cycle, hosting unique biodiversity and providing essential services to societies. Despite being the largest unfrozen freshwater resource, in a period of depletion by extraction and pollution, groundwater environments have been repeatedly overlooked in global biodiversity conservation agendas. Disregarding the importance of groundwater as an ecosystem ignores its critical role in preserving surface biomes. To foster timely global conservation of groundwater, we propose elevating the concept of keystone species into the realm of ecosystems, claiming groundwater as a keystone ecosystem that influences the integrity of many dependent ecosystems. Our global analysis shows that over half of land surface areas (52.6%) has a medium-to-high interaction with groundwater, reaching up to 74.9% when deserts and high mountains are excluded. We postulate that the intrinsic transboundary features of groundwater are critical for shifting perspectives towards more holistic approaches in aquatic ecology and beyond. Furthermore, we propose eight key themes to develop a science-policy integrated groundwater conservation agenda. Given ecosystems above and below the ground intersect at many levels, considering groundwater as an essential component of planetary health is pivotal to reduce biodiversity loss and buffer against climate change.

A comprehensive update on the morphology and distribution of the invasive scaffold-web spider Eidmannella pallida (Araneae, Nesticidae) with a focus on new records from Italy

Updated non-native distributional data of the invasive spider Eidmannella pallida (Emerton, 1875), Nesticidae, are herein summarized together with the morphological characters of the species. We report all the known localities from the literature. Furthermore, we present and discuss recent findings for the Italian peninsula. In particular, the species has been consistently found in vineyards and annual crop fields in North Italy and in olive groves in South Italy. We include a redescription of the species, and detailed illustrations of the diagnostic characters of both males and females, based on stereomicroscope and SEM images. The spreading potential of the species and its possible impacts on local communities are discussed. Our data suggest that E. pallida has high invasiveness potential and several new findings in non-native areas were recorded in the last years. We found that E. pallida can establish permanent populations in crop-dominated landscapes and has a tendency to exploit vulnerable ecosystems such as the subterranean environment. We thus recommend new and more comprehensive studies on this species to investigate in deeper detail its phylogeny, ecology, and micro-habitat preferences. A high effort should be placed to assess the potential negative effects of E. pallida on the endemic fauna in invaded areas, especially in caves.