Low Number Of Species Research Articles

Temporal and spatial variations of propagule deposition in the riparian zones of mountain rivers

AbstractAlthough dispersal is important for riparian plants, few studies have evaluated the variations of species richness and composition of propagules deposited by different dispersal mechanisms. In the present study, we evaluate the temporal and spatial variations in the diversity of propagules deposited by hydrochory and by other types of dispersal along mountain rivers. We sampled the propagules deposited in the riparian zone on a distance gradient with respect to the site of origin of the rivers in two seasons. We found no differences in the number of propagules between seasons. In the rainy season, we observed a greater number of species deposited by hydrochory, while for other types of dispersal there was a greater number of species in the dry season. Differences in composition were observed for hydrochory but not for other types of dispersal. There were no changes in the number of propagules deposited along the river by hydrochory, while for other types of dispersal an increase was observed in the dry season. A lower number of species deposited by hydrochory along the river was observed during the rainy season. Finally, we observed that turnover increases for other types of dispersal in the dry season but not for hydrochory. The results underline the importance of types of dispersal other than hydrochory in the contribution of propagules dispersed and the temporal and spatial particularities of the hydrochory in mountain rivers.

The potential role of herpetofauna species diversity on palm oil agro-ecosystems: a case study in the plantation of PT BSM South Sumatra

The palm oil industry is one of the national strategic industries that must gradually apply the concept of green economy where the use of biodiversity (to reduce the use of chemicals in increasing land fertility and controlling pests/diseases) should be optimized in various aspects of management. Therefore, the potential for species diversity and the role of biodiversity in palm oil agro-ecosystems needs to be investigated, one of which is herpetofauna diversity. Data collection on the diversity of herpetofauna species was carried out simultaneously on seven types of land cover for PT BSM’s palm oil plantations using the Visual Encounter Survey (VES) method. The results showed that the number of herpetofauna species varied according to land cover type with a total of 26 species. The highest number of species and individuals was found in shrubs (12 species and 18 individuals). While the lowest number of species and individuals was found in smallholder palm oil plantations 1 (5 species and 9 individuals). Based on the list of herpetofauna species in the study area, nine of these species have potential roles for the oil palm agro-ecosystem. These roles as biological control (predators, parasitoids, pathogens) include Takydromus sexlineatus, Eutropis multifasciata, Chalcorana chalconota, Occydoziga sumtrana, Malayopython reticulatus, Bungarus candidus, and Naja sumatrana, as well as decomposition controllers, Varanus salvator. The Shrubs land cover has a complete composisition of the roles of herpetofauna, while in the others land cover, have one individuals that play a role in the oil palm agroecosystem.

Potential and role of bird diversity in various oil palm land cover of PT Selatan Agro Makmur Lestari, South Sumatra

The change in the development paradigm to a “green economy” requires the management of oil palm plantations (as one of the national strategic industries) to make more use of biodiversity in increasing its productivity. In addition to reducing production costs (the use of chemical fertilizers, chemical pest and weed control), optimizing the use of biodiversity in oil palm agrosystems will be able to realize the management of oil palm plantations in a sustainable and environmentally sound manner. This study aims to identify the potential for species diversity and the role of birds in oil palm plantation agrosystems. Data collection on the potential for species diversity was carried out on six types of oil palm plantation land cover at PT Selatan Agro Makmur Lestari, South Sumatra with the transect line method along 1 km with a width of 50 meters. As for the role of various types of birds in the ecosystem, a literature review is carried out. The highest number of species and individuals was found in shrubs as many as 19 species and 69 individuals. On the other hand, the lowest number of species and individuals was found in smallholder oil palm plantations-II with 6 species and 16 individuals. In terms of the number of individuals, cave swiftlet (Collocalia linchi) was the largest species with 58 individuals, while cerulean kingfisher (Alcedo coerulescens), pink-necked green pigeon (Treron vernans), and white-headed munia (Lonchura maja) were the species with the fewest individual encounters. (only 1 individual). Based on the literature review, the types of birds found at the research site have four ecological roles. There are insect pest controller, seed dispersers, predator, and weed controller. Further research is needed to examine more deeply the role (quantitative ecology) of each bird species in oil palm agrosystems.

A test of the Geographic Mosaic Theory of Coevolution: investigating widespread species of Amazonian Protium (Burseraceae) trees, their chemical defenses, and their associated herbivore faunas

IntroductionPlants and their insect herbivores represent a large fraction of the species in Amazonian forests and are often directly implicated in the origin and maintenance of biodiversity at local and regional scales. How these interactions may change over geographic distance is unknown because very few studies have investigated the herbivore fauna and defense chemicals of any host plant species at multiple sites in tropical forests. One hypothesis, the Geographic Mosaic Theory of Coevolution, predicts that if herbivore assemblages turn over in different parts of a plant’s range, then plant defense chemicals should also change, reflecting local selection pressures.MethodsWe tested this theory by studying 12 species of Protium (Burseraceae) trees that occur in both Iquitos, Peru, and Manaus, Brazil, in rainforests separated by 1500 km. We surveyed all insects observed directly feeding on the plants in both locations for 48 weeks in Manaus and 64 weeks in Iquitos. We analyzed the secondary metabolites in the leaves of all species in both locations using GC/MS and HPLC.Results and DiscussionAlthough in both locations we found that Protium herbivores were dominated by insects from the orders Hemiptera, Coleoptera and Lepidoptera, we found almost complete turnover in the herbivore species composition in the two sites, and each host plant species had a different assemblage of herbivores in each location. Comparing the phylogenetic beta-diversity, we found low similarity in herbivore phylogenetic relatedness between host plant species in the two locations. However, the secondary metabolites found within a Protium species were similar across the two locations. We found no strong evidence that individuals from a host plant species in Iquitos or Manaus expressed locally-adapted defense chemicals, as individuals from geographic locations did not form clusters when looking at patterns of chemical similarity. These results are not consistent with the Geographic Mosaic Theory of Coevolution. The most intriguing pattern we found was a strong correlation between the diversity of herbivores per host plant species in both locations. We also found that plants with high chemical richness had lower numbers of herbivore species and numbers of total herbivores in both locations. We conclude that high chemical diversity is the most effective strategy for Protium trees to reduce insect herbivore attacks. We speculate that each secondary metabolite is effective at repelling only a few insect herbivores, and that different chemicals are likely effective in different parts of a plants’ geographic range. Future studies should investigate additional locations and additional natural enemies (i.e., fungal pathogens) to test the hypothesis that chemical diversity reduces attack from natural enemies and may explain the ecological and evolutionary success of rainforest trees over time and space.

Comparable ectomycorrhizal fungal species richness but low species similarity among native Abies alba and alien Abies grandis from provenance trials in Poland

Our study contributes to the understanding of the diversity of ectomycorrhizal fungal (ECMF) communities of native A. alba and alien A. grandis in provenance trials situated in lowland and montane regions in Poland (Central Europe). Ectomycorrhizal fungi were identified directly from field-collected root tips using PCR- and Sanger-sequencing-based methods. We found that the studied fir species had relatively high and comparable ECMF species richness (66 and 69 fungal taxa on A. grandis and A. alba, respectively). Twenty-six taxa were associated with both hosts and 83 taxa were found uniquely on one or the other fir species. The ECMF community composition and structure of A. alba and A. grandis differed substantially both at the species and the phylogenetic lineage levels. Soil parameters such as total nitrogen, magnesium and potassium content and C/N ratio appeared moderately but significantly correlated with the ECMF community assembly of both firs. The provenance of the host tree species did not appear to be a strong factor in structuring the ECMF communities. This was found despite the low number of common ECMF species and relatively high number of unique species among the individual provenances of both fir species. The results of the study suggest that locally based specificity in host–fungal communities is likely a contributing factor in the outcome of provenance trials. We posit that much insight into the role of tree provenances in shaping ECMF communities will be gained by further exploring this area of research. On the surveyed experimental forest sites of A. alba and A. grandis, fungal species of conservation concern – particularly those that were endangered and rare – have been reported. Our findings imply that tree species planted outside their natural range serve as ecologically important species because they may act as an excellent reservoir of ECMF diversity, a factor of importance in functioning forest ecosystems.

Fire shapes fungal guild diversity and composition through direct and indirect pathways.

Fire has shaped global ecosystems for millennia by directly killing organisms and indirectly altering habitats and resources. All terrestrial ecosystems, including fire-prone ecosystems, rely on soil-inhabiting fungi, where they play vital roles in ecological processes. Yet our understanding of how fire regimes influence soil fungi remains limited and our knowledge of these interactions in semiarid landscapes is virtually absent. We collected soil samples and vegetation measurements from sites across a gradient in time-since-fire ages (0-75 years-since-fire) and fire frequency (burnt 0-5 times during the recent 29-year period) in a semiarid heathland of south-eastern Australia. We characterized fungal communities using ITS amplicon-sequencing and assigned fungi taxonomically to trophic guilds. We used structural equation models to examine direct, indirect and total effects of time-since-fire and fire frequency on total fungal, ectomycorrhizal, saprotrophic and pathogenic richness. We used multivariate analyses to investigate how total fungal, ectomycorrhizal, saprotrophic and pathogenic species composition differed between post-fire successional stages and fire frequency classes. Time-since-fire was an important driver of saprotrophic richness; directly, saprotrophic richness increased with time-since-fire, and indirectly, saprotrophic richness declined with time-since-fire (resulting in a positive total effect), mediated through the impact of fire on substrates. Frequently burnt sites had lower numbers of saprotrophic and pathogenic species. Post-fire successional stages and fire frequency classes were characterized by distinct fungal communities, with large differences in ectomycorrhizal species composition. Understanding the complex responses of fungal communities to fire can be improved by exploring how the effects of fire flow through ecosystems. Diverse fire histories may be important for maintaining the functional diversity of fungi in semiarid regions.

Fish Species Composition of Bottom Gillnet Catches by Japanese Fishing Vessels Operated in Russian Zone of Kunashir Strait in 1998–2014

Overall, 85 fish species assigned to 56 genera, 27 families, and 13 orders were observed in the bottom net catches from the Kunashir Strait in 1998–2014. The highest number of species (18) represented the family Pleuronectidae, while the family Cottidae involved the lower number of species (14). Thus, 35 species were found in the Nemuro Strait (including the Kunashir Strait) for the first time. Considering the information in the literature, the total number of fish species in the strait separating the Southern Kuril Islands from the Hokkaido Island increased to 173.

Marine and estuarine crustacean diversity and assemblage structure in eastern Brazil three years after the Fundão mining dam failure

The present study investigates the spatial and temporal patterns of species richness and assemblage structure of decapod and stomatopod crustaceans in the area impacted by the Fundão dam collapse (Rio Doce basin, Brazil) in November 2015. From October 2018 to September 2019, monthly bottom-trawl samples were collected in estuarine and marine waters of the Rio Doce (directly impacted area) and three other localities. Forty-one crustacean species were recorded, with the overall community structure dominated by six species. The seabob shrimp Xiphopenaeus kroyeri was the most common species, with the coastal marine area near to the Rio Doce mouth being an important fishery ground. Species composition changed significantly among localities, habitats, and seasons, with marine and estuarine assemblages shaped by freshwater discharge. Distribution patterns of species were significantly influenced by the environmental variables potentially altered by tailings, such as turbidity and pH. Species richness and abundance differed among localities; as expected, they were generally higher on the inner shelf than in estuaries and higher during the dry season than the rainy season. Due to the lack of information before the disaster, the low number of species found in the Rio Doce estuary cannot be solely attributed to the disaster but also its freshwater condition. This is the first broad study of the estuarine and coastal marine decapod and stomatopod crustaceans in the region, and we suggest the need for long-term monitoring considering that the effects of this disaster are not easy to detect and probably need multi-year study to be evidenced.

Taxonomic status and distribution of Australian caddisflies (Insecta: Trichoptera)

This review of the status of Australian caddisflies focuses on publications from 1982 to 2022. Information is provided on new species described in that period, new keys, new descriptions of both adults and larvae, and the distribution of families and genera from states/regions and the Northern Territory. Australia’s caddisfly fauna now totals 27 families, 111 genera and 868 species, with 97.9% of species endemic to Australia (only 19 of the 868 species are known from outside Australia, mainly from the nearby island of New Guinea – Papua New Guinea and Papua Province, Indonesia); some species also extend into New Zealand and South-East Asia. The biogeography of the Australian fauna is discussed briefly in terms of “northern” and “southern” faunal elements, faunal provinces, distributional barriers, areas of highest biodiversity and refuge areas. Northern and southern elements in the Australian Trichoptera fauna are indicated. The highest biodiversity is recorded in the following states/regions: New South Wales with 263 species, northern Queensland (N-Qld) with 248 species and Victoria with 247 species. The highest endemicity is in southern Western Australia (S-WA), with 73% endemic species, followed by N-Qld with 58% and Tasmania with 57%. The lowest numbers of species have been recorded from South Australia and S-WA, with 42 and 49 species respectively.

Seasonal variation of phytoplankton in My Thanh River, Mekong delta, Vietnam

A study on the seasonal variation of phytoplankton composition was conducted at the upper, middle, and lower parts of the My Thanh River, which supplies an important source of water for aquaculture. Qualitative and quantitative samples of phytoplankton were collected monthly at both high and low tide. The results showed that a total of 171 phytoplankton (algae) species were recorded, belonging to 59 genera and 5 phyla. Diatoms were the most abundant group with the highest species number, followed by green algae. The other phyla possessed a lower number of species. The species composition was more diverse in the rainy season and at high tide at most of the sampling sites. The mean density of algae varied from 30,900-43,521 ind.L-1. The density of diatoms was higher in the middle and lower parts. At the same time, euglenoids displayed the highest density in the upper part, showing a difference in the dominant algae group under the influence of salinity. Salinity was found to be significantly positively correlated (p<0.01) with diatoms, whereas it was negatively correlated (p<0.05) with blue-green algae and euglenoids. The algae composition was quite diverse, with the H’ index ranging from 2.0-3.3, showing the water quality was slightly to moderately polluted.

Parasite diversity at isolated, disturbed hydrothermal vents.

Habitat isolation and disturbance are important regulators of biodiversity, yet it remains unclear how these environmental features drive differences in parasite diversity between ecosystems. We test whether the biological communities in an isolated, frequently disturbed marine ecosystem (deep-sea hydrothermal vents) have reduced parasite richness and relatively fewer parasite species with indirect life cycles (ILCs) compared to ecosystems that are less isolated and less disturbed. We surveyed the parasite fauna of the biological community at the 9°50'N hydrothermal vent field on the East Pacific Rise and compared it to similar datasets from a well-connected and moderately disturbed ecosystem (kelp forest) and an isolated and undisturbed ecosystem (atoll sandflat). Parasite richness within host species did not differ significantly between ecosystems, yet total parasite richness in the vent community was much lower due to the low number of predatory fish species. Contrary to expectation, the proportion of ILC parasite species was not lower at vents due to a high richness of trematodes, while other ILC parasite taxa were scarce (nematodes) or absent (cestodes). These results demonstrate the success of diverse parasite taxa in an extreme environment and reinforce the importance of host diversity and food web complexity in governing parasite diversity.

EDNA metabarcoding vs metagenomics: an assessment of dietary competition in two estuarine pipefishes

Understanding the dietary preferences of endangered species can be useful in implementing conservation strategies, including habitat restoration, translocation, and captive breeding. Environmental DNA (eDNA) from feces provides a non-invasive method for analysing animal diets. Currently, metabarcoding, a PCR-based approach, is the method of choice for analysing such data. However, this method has limitations, specifically PCR bias, which can result in the overestimation of the importance of certain taxa and failure to detect other taxa because they do not amplify. The present study compared metabarcoding with metagenomics, a PCR-free method, to assess the diversity of prey items in the feces of a critically endangered South African estuarine pipefish, Syngnathus watermeyeri, and its widely distributed congener S. temminckii to investigate potential dietary competition. The metabarcoding results showed a distinct difference between the diets of S. watermeyeri and S. temminckii, with the former mainly consuming calanoid copepods and the latter preferring caridean shrimp. In each case, a single species dominated the sequences generated by metabarcoding. Metagenomics produced more species identifications, and although the same trend was found regarding the preference of S. watermeyeri for copepods and that of S. temminckii for shrimp, this approach identified additional, albeit yet unidentified, copepod species as being important in the diet of S. watermeyeri. We conclude that the lower number of species identified using metabarcoding was most likely a result of amplification bias, resulting in key copepod species missing from the dietary analysis. These findings suggest that metagenomics is not only a useful complementary method for molecular dietary analysis, but may in some cases outperform metabarcoding. However, metagenomics is even more strongly affected by the lack of reference sequences than is metabarcoding, as the majority of sequences originate from genomic regions that have not yet been sequenced for the putative prey species in question.

Biological Assessment of Anthropogenic Impacts in Buguma Creek, Rivers State, Nigeria

The objective of this research was to assess the anthropogenic impact on plankton and macrobenthic fauna composition, abundance, distribution, and diversity of four communities in Buguma creek. The Phytoplankton, zooplankton, and benthic fauna samples were collected quantitatively monthly from each of the four sampling stations between January and June 2020 using standard sampling methods. Margalef (D), Shannon Wienner (H), and Evenness indices were used to determine species richness and diversity respectively using the PAST statistical package. This study revealed that artisanal refinery activities, sand mining/dredging, and discharge of industrial, domestic, human, and animal wastes have adversely affected the aquatic biota (plankton and macrobenthic fauna) in Buguma creek. The effects of these activities have remarkable spatial manifestations; with the more perturbed especially station 2, having a lower number of species and abundance. The preponderance of indicator species is a confirmation while the community structure gave an insight into the negative impact of these activities individually and cumulatively. The brunt of these activities rests more on the macrobenthic fauna; probably due to their unique characteristics and position in the aquatic environment. The result indicated that Buguma creek had been polluted seriously to a large extent. Keywords: Aquatic biota, Bioindicator, Anthropogenic, Artisanal refinery, Diversity

Significant roles of core prokaryotic microbiota across soil profiles in an organic contaminated site: Insight into microbial assemblage, co-occurrence patterns, and potentially key ecological functions

Extreme environmental disturbances induced by organic contaminated sites impose serious impacts on soil microbiomes. However, our understanding of the responses of the core microbiota and its ecological roles in organic contaminated sites is limited. In this study, we took a typical organic contaminated site as an example and investigated the composition and structure, assembly mechanisms of core taxa and their roles in key ecological functions across soil profiles. Results presented that core microbiota with a considerably lower number of species (7.93%) than occasional taxa presented comparatively high relative abundances (38.04%) yet, which was mainly comprised of phyla Proteobacteria (49.21%), Actinobacteria (12.36%), Chloroflexi (10.63%), and Firmicutes (8.21%). Furthermore, core microbiota was more influenced by geographical differentiation than environmental filtering, which possessed broader niche widths and stronger phylogenetic signals for ecological preferences than occasional taxa. Null modelling suggested that stochastic processes dominated the assembly of the core taxa and maintained a stable proportion along soil depths. Core microbiota had a greater impact on microbial community stability and possessed higher functional redundancy than occasional taxa. Additionally, the structural equation model illustrated that core taxa played pivotal roles in degrading organic contaminants and maintaining key biogeochemical cycles potentially. Overall, this study deepens our knowledge of the ecology of core microbiota under complicated environmental conditions in organic contaminated sites, and provides a fundamental basis for preserving and potentially utilizing core microbiota to maintain soil health.

Theoretical Study of Intramolecular H-Migration Reactions of Peroxyl Radicals of JP-10 (Exo-Tetrahydrodicyclopentadiene)

ABSTRACT Intramolecular H-migration reactions of peroxyl radicals of JP-10 (C10H15OO•) play an important role in developing the oxidation mechanism of JP-10 at low temperature. However, accurate rate coefficients for these reactions are lacking in the literature. Therefore, 33 H-migration reactions of C10H15OO•, which belong to six series of reactions, were investigated. Quantum chemical computations at the CBS-QB3 level reveal that C10H15OO• do not obey the rule that the energy barrier of 1,4-H migration reaction is higher than that of 1,5-H migration reaction because of the special steric cyclic structure of C10H15OO• and the ring strain in the transition state. The transition state theory and Rice-Ramsberger-Kassel-Marcus/Master-Equation theory were used to obtain high-pressure limit rate coefficients and pressure-dependent rate coefficients, respectively. The results show that H-migration reactions of C10H15OO• have obvious pressure-dependent effect. The most competitive reaction was obtained among 33 reactions. Moreover, branching ratios of each series of reactions were used as weight ratios to lump this series of reactions. Six series of reactions were lumped as six lumped reactions by the isomer lumping method. This will provide accurate rate coefficients for constructing a mechanism with the low number of species and suitability for computational fluid dynamics simulation.

Nuclear DNA Amounts in Chinese Bryophytes Estimated by Flow Cytometry: Variation Patterns and Biological Significances

There exists an obvious gap in our knowledge of the nuclear DNA amount of bryophytes, not only in terms of the low number of species represented, but also in systematic and geographic representation. In order to increase our knowledge of nuclear DNA amounts and variation patterns in bryophytes, and their potential phylogenetic significances and influences on phenotypes, we used flow cytometry to determine the DNA 1C values of 209 bryophyte accessions, which belong to 145 mosses and 18 liverworts collected from China, by using Physcomitrella patens as a standard. We quantified the differences in DNA 1C values among different orders and families and constructed a phylogenetic tree of 112 mosses with four gene sequences (nad5, rbcL, trnL-F, and 18S-ITS1-5.8S-ITS2-26S). DNA 1C values were mapped onto the phylogenetic tree to test a potential phylogenetic signal. We also evaluated the correlations of the DNA 1C value with the sizes of individuals, leaves, cells, and spores by using a phylogenetically controlled analysis. New estimates of nuclear DNA amounts were reported for 145 species. The DNA 1C values of 209 bryophyte accessions ranged from 0.422 pg to 0.860 pg, with an average value of 0.561 pg, and a 2.04-fold variation covered the extremes of all the accessions. Although the values are not significantly different (p = 0.355) between mosses (0.528 pg) and liverworts (0.542 pg), there are variations to varying extents between some families and orders. The DNA 1C value size exerts a positive effect on the sizes of plants, leaves, and cells, but a negative effect on spore size. A weak phylogenetic signal is detected across most moss species. Phylogenetic signals are comparatively strong for some lineages. Our findings show that bryophytes have very small and highly constrained nuclear DNA amounts. There are nucleotype effects of nuclear DNA amounts for bryophytes at the individual, organ, and cell levels. We speculate that smaller nuclear DNA amounts are advantageous for bryophytes in dry environments. Significant differences in the DNA 1C values among some moss families and orders, as well as phylogenetic signals for some lineages, imply that nuclear DNA amount evolution in mosses seems to be unidirectional.

New species of Pavlovophyceae (Haptophyta) and revision of the genera Exanthemachrysis, Rebecca and Pavlova

The justification of the 4 genera that currently compose the class Pavlovophyceae is based on a low number of species and a relative paucity of available, traceable and referenced cultures. Previous integrative phylogeny work revealed strains that can refine and strengthen our knowledge of the genera in the class. The application of multiple light and electron microscopy techniques allowed us to prioritize the cytomorphological characters (pyrenoid, thylakoid, stigma, knob-scales, life stage / life cycle) used for the taxonomy of these algae and to describe two new species: Exanthemachrysis fresneliae Véron sp. nov. and Rebecca billardiae Véron sp. nov. Consequently, revisions of the two genera Exanthemachrysis Lepailleur emend. Véron and Rebecca Green emend. Véron were made. In addition, the genus Pavlova Butcher emend Véron is revised in the light of these characters. Particular emphasis is placed on the life stages and habitat of the species.

Inside a sediment‐stressed Middle Devonian carpet reef: Cave exposes details of three‐dimensional facies architecture and palaeoecology

ABSTRACTDuring the Middle Devonian, reef growth reached an acme, and corals and stromatoporoids colonized depositional niches commonly considered unfavourable for reefal organisms. This paper documents the detailed facies architecture and palaeoecology of a stratigraphically thin (ca12 m, ‘carpet reef’), lower Givetian reefal body exposed along the walls and ceilings of the labyrinthine passages in the Klutert Cave in western Germany. The cave exposures (ca26 000 m2of rock surface) and data from short cores, neighbouring caves and outcrops document the growth and demise of an autoparabiostrome. The reef forms part of a parasequence with a lower carbonate and an upper clastic unit, bounded by flooding surfaces. Despite the comparatively small study area (ca1 km2), the exceptional exposure quality reveals facies changes over relatively short distances both vertical and lateral. The sedimentary matrix of the reefal build‐up contains between 20 to 95 wt.‐% of clay and quartz of silt to sand fraction. Based on this observation, the corals and stromatoporoids thrived in murky waters and under sediment‐stressed conditions. Stromatoporoids, for example, display irregular ragged flanks, a feature that is in agreement with a sediment‐stressed environment. No evidence of reduced growth rates, decreased calcification rates, or lower numbers of species is found. In fact, coral diversity and density are highest within one of the two biostromal units that show peak clastic matrix values, indicating a remarkable adaptation of reef builders to sediment‐stressed conditions. The initial settlement of rugose phaceloid corals took place on a mixed clastic–carbonate substrate (the basal flooding surface). Up‐section, a succession of coral–stromatoporoids is present that is here described in great detail. Reef collapse occurred when much of the accommodation space was filled, and argillaceous sediments suffocated stromatoporoids and corals in a protected, low‐energy environment.

Drivers of Insect Community Change along the Margins of Mountain Streams in Serra da Estrela Natural Park (Portugal).

Mountain ecosystems are important biodiversity hotspots and valuable natural laboratories to study community assembly processes. Here, we analyze the diversity patterns of butterflies and odonates in a mountainous area of high conservation value-Serra da Estrela Natural Park (Portugal)-and we assess the drivers of community change for each of the two insect groups. The butterflies and odonates were sampled along 150 m transects near the margins of three mountain streams, at three elevation levels (500, 1000, and 1500 m). We found no significant differences in odonate species richness between elevations, but marginal differences (p = 0.058) were found for butterflies due to the lower number of species at high altitudes. Both insect groups showed significant differences in beta diversity (βtotal) between elevations, with species richness differences being the most important component for odonates (βrich = 55.2%), while species replacement drove the changes between butterfly assemblages (βrepl = 60.3%). Climatic factors, particularly those depicting harsher conditions of temperature and precipitation, were the best predictors of total beta diversity (βtotal) and its components (βrich, βrepl) for the two study groups. The study of insect biodiversity patterns in mountain ecosystems and of the role played by different predictors contribute to further our understanding on the community assembly processes and may help to better predict environmental change impacts on mountain biodiversity.

Effectiveness of the Natura 2000 network for freshwater fish conservation in a Mediterranean region

Protected areas (PAs) are the cornerstones of global biodiversity conservation efforts, but to fulfil this role they must be effective at conserving both habitat and species. Among protected taxa, freshwater fish are exposed to multiple disturbances and are considered one of the most endangered. The Natura 2000 reserves network was established with the aim of preserving biodiversity across Europe, but few assessments have been made on its effectiveness on the conservation of freshwater fish species. We tested the hypothesis that fish community is exposed to less anthropogenic pressures within the Natura 2000 sites than outside, hosting a higher number of native species and maintain lower number of non-native species. We tested these hypotheses considering 3,777 sampling sites, found across the entire Italian territory. Results showed that PAs did not guarantee less anthropogenic impacts and higher fish species richness than outside PAs, suggesting that PAs are not a panacea for anthropogenic pressures and safeguarding fish diversity. Nevertheless, more caution should be applied to the management measures and the design of new PAs due to the limitations of the protection of a single stretch within a whole river ecosystem. Moreover, the impossibility to operate any management of invasive fish species on the broad scale of a whole river basin is likely the most limiting factor to fish biodiversity conservation in Italy. Finally, it is also necessary to extend the analysis to other basins and Natura 2000 sites in Europe.