Explore the vast range of titles available.

Medium-to-large mammals within tropical forests represent a rich and functionally diversified component of this biome; however, they continue to be threatened by hunting and habitat loss. Assessing these communities implies studying species' richness and composition, and determining a state variable of species abundance in order to infer changes in species distribution and habitat associations. The Tropical Ecology, Assessment and Monitoring (TEAM) network fills a chronic gap in standardized data collection by implementing a systematic monitoring framework of biodiversity, including mammal communities, across several sites. In this study, we used TEAM camera trap data collected in the Udzungwa Mountains of Tanzania, an area of exceptional importance for mammal diversity, to propose an example of a baseline assessment of species' occupancy. We used 60 camera trap locations and cumulated 1,818 camera days in 2009. Sampling yielded 10,647 images of 26 species of mammals. We estimated that a minimum of 32 species are in fact present, matching available knowledge from other sources. Estimated species richness at camera sites did not vary with a suite of habitat covariates derived from remote sensing, however the detection probability varied with functional guilds, with herbivores being more detectable than other guilds. Species-specific occupancy modelling revealed novel ecological knowledge for the 11 most detected species, highlighting patterns such as 'montane forest dwellers', e.g. the endemic Sanje mangabey (Cercocebus sanjei), and 'lowland forest dwellers', e.g. suni antelope (Neotragus moschatus). Our results show that the analysis of camera trap data with account for imperfect detection can provide a solid ecological assessment of mammal communities that can be systematically replicated across sites.

To understand how diversity is distributed in space is a fundamental aim for optimizing future species and community conservation. We examined in parallel species richness and beta diversity components of nine taxonomic groups along a finite space, represented by pastured grasslands along an elevational gradient. Beta diversity, which is assumed to bridge local alpha diversity to regional gamma diversity was partitioned into the two components turnover and nestedness and analyzed at two levels: from the lowest elevation to all other elevations, and between neighboring elevations. Species richness of vascular plants, butterflies, beetles, spiders and earthworms showed a hump-shaped relationship with increasing elevation, while it decreased linearly for grasshoppers and ants, but increased for lichens and bryophytes. For most of the groups, turnover increased with increasing elevational distance along the gradient while nestedness decreased. With regard to step-wise beta diversity, rates of turnover or nestedness did not change notably between neighboring steps for the majority of groups. Our results support the assumption that species communities occupying the same habitat significantly change along elevation, however transition seems to happen continuously and is not detectable between neighboring steps. Our findings, rather than delineating levels of major diversity losses, indicate that conservation actions targeting at a preventive protection for species and their environment in mountainous regions require the consideration of entire spatial settings.

Although biomonitoring is the core approach adopted by the European Union's Water Framework Directive (WFD), many biotic indices still lack a thorough analysis of their performance and uncertainty. The multihabitat sampling and the application of STAR_ICMi index on macroinvertebrates are the standard methods to assess the ecological status of rivers in Italy. Ever since the Italians' implementation, dates back to 2010, few studies have tested the index performance with different sampling efforts, and even rarer are those assessing index uncertainty. However, these are worthwhile topics to investigate because all the Environmental Agencies are applying this index with both ecological and economic consequences. Aims of this study were (i) to assess the effect of subsampling on the STAR_ICMi index, (ii) to propose a standard method to calculate the index precision, and (iii) to test several less time-consuming alternatives to census all the individuals in the sample. I showed that the index is strongly affected by subsampling, and unbiased comparisons of ecological status can only be done at the same sampling effort. The index precision, calculated by bootstrapping the observed abundance of taxa, was so low in some circumstances, to increase the risk of misclassification. Finally, I showed that to avoid counting all the individuals in a sample, it is possible to estimate the most abundant taxa using a rank-abundance model. With this less time-consuming method, the STAR_ICMi index is predicted with sufficient precision. Bien que le biomonitoring soit l'approche de base adoptée par la directive-cadre sur l'eau de l'Union européenne, de nombreux indices biotiques manquent encore d'une analyse approfondie de leur performance et de leur incertitude. L'échantillonnage multihabitat et l'application de l'indice STAR_ICMi sur les macroinvertebrés sont les méthodes standard pour évaluer l'état écologique des rivières en Italie. Depuis leur mise en œuvre qui remonte à 2010, peu d'études ont testé la performance de l'indice avec différents efforts d'échantillonnage, et encore plus rares sont ceux qui évaluent l'incertitude de l'indice. Cependant, ce sont des sujets intéressants à étudier parce que toutes les agences environnementales appliquent cet indice avec des conséquences écologiques et économiques. Les objectifs de cette étude étaient les suivants : (i) évaluer l'effet du sous-échantillonnage sur l'indice STAR_ICMi, (ii) proposer une méthode standard pour calculer la précision de l'indice et (iii) tester plusieurs alternatives moins coûteuses au recensement de tous les individus dans l'échantillon. L'indice est fortement influencé par le sous-échantillonnage et des comparaisons impartiales de l'état écologique ne peuvent être faites qu'au même effort d'échantillonnage. La précision de l'indice, calculée par la méthode de bootsrapping sur l'abondance observée de taxons, était très faible dans certaines circonstances, augmentant le risque de classification erronée. Finalement, pour éviter de compter tous les individus d'un échantillon, il est possible d'estimer les taxons les plus abondants en utilisant un modèle de rang-abondance. Avec cette méthode moins longue, l'indice STAR_ICMi est estimé avec une précision suffisante.

Although processes involved in the relationship between hyporheic and benthic zone have been elucidated in recent years, the spatial and temporal dynamics of the invertebrate assemblages is unclear in alpine streams. A field study was carried out in a glacier-fed stream and in its main spring-fed tributary, in the Italian Alps. Benthic hyporheic connectivity was investigated by means of a pond net, a pump, and artificial substrates. The main determinant in structuring the community was the habitat (=benthic, hyporheic), accounting for 22% of the total faunal variation. A strong similarity was detected between the two streams in structure, function, and species seasonal variations of the hyporheos, that was, in both, more species rich than the benthos. In contrast, benthos was generally very different between the two streams, with a more pronounced turnover in the glacier-fed than in the spring-fed stream. Overall, the highly disturbed glacial system hosted a simplified benthos and hyporheos compared to the stable spring system, in agreement with the intermediate disturbance hypothesis. Our findings provided also evidences about the trophic-sink effect between benthos and hyporheos. Spatial connectivity that we highlighted might have a key role in the dispersal of invertebrates facing changes in habitats features due to climate change.

We explored the influence of climatic factors on diversity patterns of multiple taxa (lichens, bryophytes, and vascular plants) along a steep elevational gradient to predict communities’ dynamics under future climate change scenarios in Mediterranean regions. We analysed (1) species richness patterns in terms of heat-adapted, intermediate, and cold-adapted species; (2) pairwise beta-diversity patterns, also accounting for its two different components, species replacement and richness difference; (3) the influence of climatic variables on species functional traits. Species richness is influenced by different factors between three taxonomic groups, while beta diversity differs mainly between plants and cryptogams. Functional traits are influenced by different factors in each taxonomic group. On the basis of our observations, poikilohydric cryptogams could be more impacted by climate change than vascular plants. However, contrasting species-climate and traits-climate relationships were also found between lichens and bryophytes suggesting that each group may be sensitive to different components of climate change. Our study supports the usefulness of a multi-taxon approach coupled with a species traits analysis to better unravel the response of terrestrial communities to climate change. This would be especially relevant for lichens and bryophytes, whose response to climate change is still poorly explored.

Understanding the drivers of species richness gradients is a central challenge of ecological and biodiversity research in freshwater science. Species richness along elevational gradients reveals a great variety of patterns. Here, we investigate elevational changes in species richness and turnover between microhabitats in near-natural spring habitats across Switzerland. Species richness was determined for 175 subsamples from 71 near-natural springs, and Poisson regression was applied between species richness and environmental predictors. Compositional turnover was calculated between the different microhabitats within single springs using the Jaccard index based on observed species and the Chao index based on estimated species numbers. In total, 539 diatom species were identified. Species richness increased monotonically with elevation. Habitat diversity and elevation explaining some of the species richness per site. The Jaccard index for the measured compositional turnover showed a mean similarity of 70% between microhabitats within springs, whereas the Chao index which accounts for sampling artefacts estimated a turnover of only 37%. Thus, the commonly applied method of counting 500 valves led to an undersampling of the rare species and might need to be reconsidered when assessing diatom biodiversity.

Given the limited understanding of species diversity and ecological preferences of diatoms of the genus Navicula in spring ecosystems, herein we present and describe as species new to science, Navicula aquaesuavis Lange-Bert., Levkov, Cid-Rodríguez, A.A.Saber and Cantonati sp. nov. This species was collected from a mountain spring located above the tree line at 1613 m a.s.l. in the Northern Apennines. The Fontana del Vescovo (Bishop’s spring), which is the locus classicus of the new species, has a low conductivity (60–70 µS cm−1), temperature of ca. 5 °C, circumneutral pH (7.3–7.5), relatively low nitrate (ca. 1 mg L−1), and also suffered from a discharge reduction from 1 to 0.1 L s−1 from 2011 to 2023. The putative new species was confirmed by a second finding in Northern Macedonia, and we thoroughly document this second population as well. We seized the opportunity to describe this new Navicula and review the global literature on the diatom genus Navicula in spring ecosystems. Using the results of this review and our own databases on springs and wells in central Europe and Egypt, we discuss the main Navicula species and their environmental preferences in spring habitats.

As a follow-up to the project “Springs in the Bavarian National Parks as Indicators of Climate Change (SpringNPB)”, a standard methodology for using springs as sentinel environments of climate change was transferred to the UNESCO Rhön Biosphere Reserve and other Bavarian middle-elevation mountain ranges. We studied diatoms from fifteen springs selected in the UNESCO Biosphere Reserve (9) and Steigerwald Nature Park (6). A total of 127 species belonging to 40 genera were found sampling 3 microhabitat types (lithic materials, hygrophilous or aquatic vegetation, and surface sediments). The cumulative percentage of endangered species according to the Red List was 41.5%. These very shaded, low–medium conductivity, low-discharge forest springs are fed by small surficial aquifers. As a consequence, the discharge fluctuates widely, and some springs even occasionally fall dry. Our results could contribute to the use of diatoms as indicators of discharge variability/desiccation in springs: springs affected by discharge variability have lower diatom species richness and distinct diatom communities; diatom indicators and metrics can be validated using invertebrates; larger databases will be necessary to identify the most suitable diatom indicators.

In this study, we focused on the bedrock-dependent effects of climate change on terricolous lichen communities along elevational gradients in the Alps. In particular, we contrasted between carbonatic and siliceous bedrock, hypothesizing more favourable conditions on siliceous than on carbonatic bedrock, where dryer conditions may exacerbate the effects of climate change. To test this hypothesis, we compared terricolous lichen diversity patterns between the two bedrock types in terms of (1) species richness, (2) beta-diversity, (3) proportion of cryophilous species, and (4) functional diversity, also testing the effect of the elevational gradient as a proxy for expected climate warming. Our results indicate that the most cold-adapted part of the terricolus lichen biota of the Alps could be especially threatened in the near future, mainly on carbonatic bedrock. Actually, contrasting diversity patterns were found between carbonatic and siliceous bedrock, clearly revealing a bedrock-dependent effect of climate change on terricolous lichens of the Alps. As hypothesized, siliceous bedrock hosts a richer lichen biota than carbonatic bedrock, reflecting a general richness pattern at the national level. In general, siliceous bedrock seems to be less prone to rapid pauperization of its lichen biota, providing more suitable climatic refugia that can mitigate the effects of climate warming on terricolous lichens.