-
Biodiversity in mountain groundwater: the Mercantour National Park as a European hotspot
-
Abstract Mercantour National Park (France) is recognized as a highly heterogeneous region with extremely varied geology, geomorphology and climatology, resulting in an exceptional biodiversity. From a hydrogeological point of view, it is also an area organized of small and discontinuous aquifers, their obligate groundwater fauna remaining absolutely unknown. This work explores the species richness of groundwaters in Mercantour National Park, using a sampling design at the catchment (six major valleys) and aquifer scales (aquifers in consolidated rocks and unconsolidated sediments). A major finding of this study is the discovery of 44 species restricted to groundwater, from which 43 are new to the Park and 10 are new to Science. Although a relatively small number of sites were sampled (53), the area may be considered as a new hotspot of groundwater biodiversity at the European level. The particular structure of the groundwater network, the high environmental heterogeneity of the region, and its Mediterranean position may explain such a high biodiversity. Species rarefaction curve showed that many species have yet to be discovered in groundwater of the Mercantour National Park. With more than 78% of species collected in the hyporheic zone, this study also highlights the importance of porous aquifers in sustaining groundwater biodiversity of mountainous regions. Key words: groundwater invertebrates, stygobionts, biodiversity hotspot, Mercantour National Park, hyporheic zone, spring. Résumé Biodiversité dans les eaux souterraines de montagne. Le Parc National du Mercantour: un ‘hotspot’ européen. Le Parc National du Mercantour est une région physiquement très hétérogène, avec des faciès géologiques, géomorphologiques et climatologiques extrêmement variés, à l’origine d’une biodiversité exceptionnelle. D'un point de vue hydrogéologique, son réseau souterrain est organisé en aquifères discontinus et de petite taille, dont la faune aquatique (stygobie) est aujourd’hui inconnue. Ce travail explore la richesse spécifique des eaux souterraines du Parc National du Mercantour, après la mise en œuvre d'un plan d'échantillonnage prenant en compte l'hétérogénéité environnementale à l’échelle du bassin versant (six vallées majeures) et de l'aquifère (aquifère fissuré ou poreux). Le premier fait marquant est la récolte de 44 espèces stygobies, 43 étant nouvelles pour le parc et 10 nouvelles pour la Science. Sur la base d’un nombre relativement faible de sites (53), cette zone peut être considérée comme un nouveau ‘hotspot’ de biodiversité des eaux souterraines à l'échelle européenne. La structure particulière du réseau hydrogéologique, l'hétérogénéité environnementale élevée, et la position méditerranéenne de cette région, pourraient expliquer une telle biodiversité. La courbe de raréfaction des espèces montre que nos connaissances sur le Mercantour sont néanmoins loin d'être complètes et que de nombreuses espèces restent encore à découvrir. Avec plus de 78 % des espèces récoltées dans la zone hyporhéique, ce travail souligne également le rôle des aquifères poreux, dans le maintien de la biodiversité des eaux souterraines de montagne. Mots-clés: invertébrés souterrains, stygobies, ‘hotspot’ de biodiversité, Parc National du Mercantour, zone hyporhéique, source.
Located in
Library
/
RBINS Staff Publications
-
Biodiversity of Belgian groundwater fauna in relation to environmental conditions
-
1. The Pleistocene glaciations during the Quaternary appear to have resulted in an impoverished groundwater fauna in northern Europe. Re-colonisation may have occurred either through long-distance dispersal from unglaciated southern areas or from local refugia. 2. The Belgian groundwater fauna was sampled at multiple sites, and its habitats characterised, to assess whether the composition of present-day stygobiotic assemblages can be attributed to either of these mechanisms. 3. A total of 202 sampling sites were selected in four hydrogeographic units of the Meuse River catchment. Sites were equally divided among the saturated and unsaturated zones of fractured aquifers (karst) and within the hyporheic and phreatic zones of porous aquifers. Seventeen environmental parameters were determined in parallel. 4. More than 140 species were recorded, including representatives of the Amphipoda, Cladocera, Copepoda, Hydrachnidia, Isopoda, Oligochaeta, Ostracoda, Mollusca, Syncarida and Nematoda. Thirty stygobiont specieswere identified, of which10 species were new to the Belgian fauna, raising the total number of stygobiotic species in Belgium to 41. 5. The frequency of occurrences of stygobiotic species was always low, with 37% of the sampled sites lacking stygobionts. A few species were exclusive to one hydrological zone, although no statistically significant differences were detected in species richness at any of the four hierarchial levels considered (Meuse catchment = region, hydrogeographic units, aquifer type and hydrological zone). 6. Overall, results suggest that the stygobiotic fauna of Belgium is species-poor and mostly comprises widely distributed species with broad ecological tolerances. This supports the view that eurytopic species re-colonised the area by long-distance dispersal from refugia in southern Europe. The virtual absence of endemic species further suggests that the scenario of an ancient fauna that survived in local refugia is of minor importance.
Located in
Library
/
RBINS Staff Publications
-
Biodiversity of Belgian groundwaters and characterization of their stygobiotic fauna from a historical and ecological perspective
-
Located in
Library
/
RBINS Staff Publications
-
Biodiversity of eukaryotes in large tropical trees: the Life On Trees (LOT) program
-
Introduction: Basic data on biodiversity, such as the variety of life forms coexisting on a single tree, are still lacking and prevent a full understanding of the complexity of interactions among organisms in a tropical rainforest. Filling this gap has recently become more achievable thanks to advances in canopy access methods and genetic tools. Objective: The main aims of the research program Life On Trees (LOT) are to generate baseline knowledge about the number of species a single tropical tree can support and to understand how these communities of organisms are assembled. Methods: Our first project is performed in one of the most biologically diverse regions: the Peruvian Amazon, in the Rio Abiseo National Park. We focus our sampling on a spectacular Dussia tree (Fabaceae), which is 50 m high and 45 m wide and covered with epiphytes. For safety reasons, the sampling is carried out by professional climbers, guided by experts of the different eukaryotic groups studied (plants, fungi, animals, protists). In order to better understand the contribution of different tree components (bark, leaves, fruits, flowers, dead wood) to overall tree biodiversity, we assign observations into communities based on height zone or microhabitat and examine similarities and nestedness in the composition of these communities. The complex architecture of the tree is studied using terrestrial LiDAR and the location of samples is recorded using a high precision differential GPS receiver (dGNSS). The collected specimens will be determined by classical taxonomy and genetic methods (DNA metabarcoding). An online tracking system for those specimens sent to taxonomists for identification, as well as a central database system, are already under development. Results: The first results of the LOT-Peru project from April-May 2022 and of the preliminary tests conducted in October 2021 will be presented. Implications: The scope of this program is not only scientific. Using the simple example of a large tree, we can reach out to the public and explain difficult concepts, such as what biodiversity is and how it is generated and sustained. In addition, the tree is a strong symbol that has an emotional impact. We hope that this program will build awareness about the impacts of deforestation, and conversely the value of conservation, by showing foresters, city dwellers or villagers that when a tree is cut down, a whole range of biodiversity disappears.
Located in
Library
/
RBINS Staff Publications 2022
-
Biodiversity of non-marine ostracods (Crustacea, Ostracoda) in the alluvial valley of the upper Paraná River, Brazil
-
Located in
Library
/
RBINS Staff Publications
-
Biodiversity of ostracod communities (Crustacea, Ostracoda) in a tropical floodplain
-
Neotropical floodplains harbour both floating and rooted plants and are associated with rich ostracod communities. After dry seasons, flooding causes recruitment in 2 ways: floods bring in allochthonous macrophytes with associated pleuston communities, and these rising water levels rehydrate plants and attached (ostracod) eggs that dried at the onset of the dry season. We analysed the ostracods communities in the Araguaia River floodplain (Brazil) during 2 hydrological periods (dry and rainy) and evaluated the species distribution in relation to abiotic and biotic factors. We compared the ostracod fauna of 6 lakes in the dry and rainy period and 17 lakes in the rainy period. We tested the hypothesis that the highest values of ostracod community attributes (richness, density, and evenness) occur in the rainy season owing to the influx of allochthonous individuals and the rehydration of the dried autochthonous macrophytes. We indeed observed the highest richness and diversity of ostracods in the rainy season; the homogenizing effect of the flood pulse at the onset of the rainy season caused a more homogeneous fauna (lower beta diversity) during that hydrological period. The distribution of species showed a significant effect of both abiotic factors (local) and hydrological period (regional).
Located in
Library
/
RBINS Staff Publications 2017
-
Biodiversity, Biogeography and Nature Conservation in Wallacea and New Guinea. Volume IV
-
Located in
Library
/
RBINS Staff Publications 2021
-
Biofluorescence in Morelia, Malayopython and Python: first reports for the Pythonidae
-
Ultraviolet (UV) induced biofluorescence in snakes has been underexplored compared to lizards. This study reports for the first time UV fluorescence in several Pythonidae species, including Morelia viridis, Malayopython reticulatus, and Python regius. Specimens were examined under both white and UV light, revealing that UV fluorescence in these snakes is likely skin-based, induced by chemical compounds rather than bone-based as seen in other reptiles. Notably, Morelia viridis and M. azurea exhibited a golden mustard yellow fluorescence, while Malayopython reticulatus displayed a complex pattern with intense yellow fluorescence. The study also found that UV fluorescence is absent in ethanol-preserved specimens, suggesting the degradation of fluorescent compounds during preservation. These findings contribute to the understanding of UV fluorescence in snakes and highlight the need for further research on its functional significance and the specific molecules involved.
Located in
Library
/
RBINS Staff Publications 2024
-
Biofluorescence of the Crocodile Skinks, genus Tribolonotus: first report in Scincidae
-
Biofluorescence, the phenomenon where organisms absorb short wavelengths of light and re-emit longer wavelengths, has been documented in various reptile and amphibian groups. This study reports the first observation of UV-induced biofluorescence in the genus Tribolonotus (crocodile skinks), marking the first such report for the family Scincidae. Specimens of Tribolonotus novaeguineae, T. brongersmai, and T. gracilis were examined under UV light, revealing distinct fluorescence patterns. The fluorescence is primarily bone-induced, linked to the presence of osteoderms, although some skin-based fluorescence was also observed, particularly around the eyes. The study suggests potential ecological roles for this fluorescence, such as intraspecific signaling or predator-prey interactions, and highlights the need for further research to understand the functional significance of biofluorescence in these skinks.
Located in
Library
/
RBINS Staff Publications 2024
-
BIOFRAG - a new database for analysing BIOdiversity responses to forest FRAGmentation.
-
Habitat fragmentation studies have produced complex results that are challenging to synthesize. Inconsistencies among studies may result from variation in the choice of landscape metrics and response variables, which is often compounded by a lack of key statistical or methodological information. Collating primary datasets on biodiversity responses to fragmentation in a consistent and flexible database permits simple data retrieval for subsequent analyses. We present a relational database that links such field data to taxonomic nomenclature, spatial and temporal plot attributes, and environmental characteristics. Field assessments include measurements of the response(s) (e.g., presence, abundance, ground cover) of one or more species linked to plots in fragments within a partially forested landscape. The database currently holds 9830 unique species recorded in plots of 58 unique landscapes in six of eight realms: mammals 315, birds 1286, herptiles 460, insects 4521, spiders 204, other arthropods 85, gastropods 70, annelids 8, platyhelminthes 4, Onychophora 2, vascular plants 2112, nonvascular plants and lichens 320, and fungi 449. Three landscapes were sampled as long-term time series (>10 years). Seven hundred and eleven species are found in two or more landscapes. Consolidating the substantial amount of primary data available on biodiversity responses to fragmentation in the context of land-use change and natural disturbances is an essential part of understanding the effects of increasing anthropogenic pressures on land. The consistent format of this database facilitates testing of generalizations concerning biologic responses to fragmentation across diverse systems and taxa. It also allows the re-examination of existing datasets with alternative landscape metrics and robust statistical methods, for example, helping to address pseudo-replication problems. The database can thus help researchers in producing broad syntheses of the effects of land use. The database is dynamic and inclusive, and contributions from individual and large-scale data-collection efforts are welcome.
Located in
Library
/
RBINS Staff Publications
