Relative Frequency Of Species Research Articles

Trees Diversity and Species with High Ecological Importance for a Resilient Urban Area: Evidence from Cotonou City (West Africa)

Rapid urbanization and climate change effects may cause dramatic changes in ecosystem functions in cities, thereby inevitably affecting the growth performance of old trees. Few studies have explored species diversity and spatial differentiation in Benin urban areas. This study aims to explore this dimension of urban ecology in order to build resilience to climate change in the city of Cotonou. Its objective was to determine the predominant level of tree diversity in the city’s land use units. The urban green frame was subdivided into six land use units, namely, establishments, residences, green spaces, commercial areas, administrative areas, and roads. The forest inventories were carried out in 149 plots with surfaces evaluated at 2500 m2 each. The IVI, an index that highlights the relative density, relative dominance, and relative frequency of species, has been used to characterize the place occupied by each species in relation to all species in urban ecosystems. This shows ecological importance through the diversity and quality of ecosystems, communities, and species. A total of 62 tree species in 55 genera and 27 families were recorded. The results show that the flora of the city of Cotonou is characterized by a strong preponderance of exotic species with some differences in species presence. The most abundant species with high ecological importance (IVI) in the different types of land use of the city are Terminalia catappa (IVI = 121.47%), Terminalia mantaly (IVI = 90.50%), Mangifera indica (IVI = 64.06%), and Khaya senegalensis (IVI = 151.16%). As the use of ecosystem services is recommended to tackle urban climate hazards, this study shows that direct development of this urban vegetation could improve the resilience of urban life to climate hazards through the provision of urban ecosystem services, potential ecological infrastructure foundations, and urban nature-based solutions.

Evidence of Successful Mangrove Conservation Avicennia marina viewing from Bivalvian Diversity in Central Lombok

Administratively, the coastal area of Central Lombok Regency is included in the mangrove conservation program which is currently in the process of rehabilitation. Shellfish as one of the associated biota that live in the mangrove ecosystem. This study aims to analyze the diversity (H'), uniformity (E), dominance (D), and abundance (R) of associated biota in the mangrove ecosystem conservation area on the south coast of Central Lombok Regency. Data analysis consisted of determining sampling stations, processing mangrove vegetation data, processing bivalve data, and environmental parameters. The results showed that there were nine types of mangroves, 15 types of bivalves were found. The highest density of mangroves in Dondon was Avicennia marina (84.16%) and the highest relative frequency of mangrove species (66.67%). The lowest mangrove density in Gili Perigi was Rhizophora stylosa (3.1%) and the lowest relative species frequency (6.67%). Furthermore, the highest relative frequency in Tanjung Batutiang is Avicennia marina (30.00%) and the lowest is Avicennia lanata (3.33). While the highest relative frequency in Gili Perigi was Avicennia marina (50.00%) and the lowest was Rhizopora stylosa (6.67%). The highest value of the dominance index on the Dondon Coast was 0.84 and was classified as low, meaning that no species dominated. In conclusion, the Indonesian government has initiated many mangrove Rehabilitation programs through replanting, especially on Lombok Island. This study shows that members of the genus Avicennia marina have the potential to increase the growth and stability of mangrove ecosystems on the south coast of Central Lombok.

Cacti in the Mazapil Region, Chihuahuan Desert, Mexico: Diversity, Geographical Patterns and Conservation

The Chihuahuan Desert Region (CDR) is the largest desert area in North America, and the southeastern portions contain the richest areas in Cactaceae in the continent. This research was advocated to understand the diversity of cacti in northern Zacatecas and southern Coahuila, as well as to explore species rarity, environmental relations and conservation alternatives. A geographical square measuring a quarter degree was intensively surveyed through 50, 3-km long transects, distributed in 25, 6-minute sub-squares. The geographical square was selected because of its altitudinal and environmental heterogeneity. Cacti were identified and local rareness observed, 764 specimens were deposited at the National Herbarium of Mexico (MEXU). Specimen and locality information were captured in the Database for Cacti of Central and North America. A general evaluation of the cactus diversity (species richness), levels of endemism and rarity were performed. A total of 45 species were found, just below El Huizache, Tolimán and Mier y Noriega, with 7 new records for Zacatecas, 2 for Coahuila and 3 for both Mexican states. We found 26 endemic species from the CDR, five endemic to the Main and Meridional subregions and 21 endemic to the Main subregion, sensu Hernández. Two species are endemic to the state of Zacatecas and three species are endemic to both states. A new index for rarity (Average rarity, Ar) is presented, obtained as the mean of five variables: level of endemism, species relative frequencies, local rareness, and climatic and edaphic (soil) specialization. Rabinowitz rarity (1981) was calculated for all species and transformed into numerical values to compare it with the obtained Ar values. There are 26 rare species following Rabinowitz and 16 rare species following Ar (≥0.5). Ar values resulted smooth and with a higher explanation power (r2). Just five species resulted with a Rabinowitz rarity of 7 (transformed R of 1) and Ar (≥0.82). A general complementarity analysis was used to address conservation in the studied area, which was enhanced with other four complementarity analyses, including our Ar. Nine sub-squares were found relevant for cacti protection. Soil types and a complete climatic analysis from original data were used to search for environmental relations through Principal Component Analyses. The main preferences for climatic variables and anomalies are highlighted. The Ar index is an adequate tool for measuring species rarity and presents it in a balanced and smooth way, not just fixed Rabinowitz categories, allowing the understanding that some species might be rare in different ways in different areas and environmental conditions, something that seems to occur in cacti. Further research is encouraged on Ar for comparisons and even mapping, as well as for Natural Protected Areas (NPA) design.

Strolling through a Century: Replicating Historical Bird Surveys to Explore 100 Years of Change in an Urban Bird Community.

AbstractIn 1898, Herbert and Alice Walter started a 5-year survey of birds in Lincoln Park-the largest park in Chicago, Illinois-and summarized their data in an urban birding field guide, Wild Birds in City Parks. Twenty-nine years later, William Dreuth compared the relative frequency of species in the Walters' study to that in his own 5-year Lincoln Park survey. Between 2012 and 2015, we replicated these surveys to investigate a century of bird diversity and community composition change in urban Chicago. While species richness did not change, community composition did. We found that (1) species with a greater diet breadth and (2) species that increased in statewide occupancy were more likely to increase in frequency over time. We conclude that factors at multiple scales brought temporal changes to Chicago's bird community. Overall, this survey highlights the slow and subtle ways in which species may respond to a century of urban intensification.

STRUKTUR KOMUNITAS MANGROVE DI PESISIR DESA TATENGESAN, KECAMATAN POSOMAEN, KABUPATEN MINAHASA TENGGARA

The purpose of this study was to examine the structure of the mangrove community on the coast of Tatengesan, Posomaen District, Southeast Minahasa Regency, North Sulawesi. The data collection of the mangrove community structure used the line transect quadratic method measuring 10 m x 10 m 5 times. The research implementation period is 6 (six) months in 2021, starting from the preparation of proposals, data analysis, examination of research results, and the implementation of thesis examinations. Based on the results of the study, found 3 types of mangroves, namely: Rhizophora apiculata, Rhizophora mucronata, and Bruguiera gymnorrhiza. The value of the highest species relative density was found on transect 2 with a value of 88.33% by R. mucronata. For the value of the highest relative frequency of species on transects 1,2 and 3 by R. mucronata, namely 8.3 cm/m. The highest relative species cover was R. mucronata with a value of 76.99% on transect 2. The highest important value index was found in R. mucronata, which was 220.88 on transect 2. The highest diversity index was found on transect 3 with a value of 0.85. The highest evenness index was found on transect 1 with a value of 0.99. For further research, it is necessary to conduct an inventory of mangrove species using the roaming method to find out all the species in the research location.Keywords: Mangrove, Tatengesan, Community, Diversity and Evenness

The dual nature of metacommunity variability

There is increasing interest in measuring ecological stability to understand how communities and ecosystems respond to broad‐scale global changes. One of the most common approaches is to quantify the variation through time in community or ecosystem aggregate attributes (e.g. total biomass), referred to as aggregate variability. It is now widely recognized that aggregate variability represents only one aspect of communities and ecosystems, and compositional variability, the changes in the relative frequency of species in an assemblage, is equally important. Recent contributions have also begun to explore ecological stability at regional spatial scales, where interconnected local communities form metacommunities, a key concept in managing complex landscapes. However, the conceptual frameworks and measures of ecological stability in space have only focused on aggregate variability, leaving a conceptual gap. Here, we address this gap with a novel framework for quantifying the aggregate and compositional variability of communities and ecosystems through space and time. We demonstrate that the compositional variability of a metacommunity depends on the degree of spatial synchrony in compositional trajectories among local communities. We then provide a conceptual framework in which compositional variability of 1) the metacommunity through time and 2) among local communities combine into four archetype scenarios: spatial stasis (low/low), spatial synchrony (high/low), spatial asynchrony (high/high) and spatial compensation (low/high). We illustrate this framework based on numerical examples and a case study of a macroalgal metacommunity in which low spatial synchrony reduced variability in aggregate biomass at the metacommunity scale, while masking high spatial synchrony in compositional trajectories among local communities. Finally, we discuss the role of dispersal, environmental heterogeneity, species interactions and suggest future avenues. We believe this framework will be helpful for considering both aspects of variability simultaneously, which is important to better understand ecological stability in natural and complex landscapes in response to environmental changes.

KEANEKARAGAMAN DAN KEPADATAN ECHINOIDEA DAN ASTEROIDEA DI RATAAN TERUMBU KARANG PERAIRAN TONGKAINA DAN BAHOWO KOTA MANADO (

The waters of Tongkaina, which are part of northern Manado's waters, are known to have mangrove, seagrass, and seaweed ecosystems. Therefore efforts are needed to manage the population and diversity of echinoderms in these waters. Echinoderms' ecology has an essential role in maintaining the marine ecosystem's balance, which plays a role in recycling nutrients. This study aimed to determine diversity, species density, species relative density, species frequency, species relative frequency, dominance, and the index of importance of Echinoidea and Asteroidea's species in the waters of the Tongkaina Village and their density. The method used in this research is the quadratic line transect method. First of all, the survey was conducted to the sampling site's location in the coral reef flats of Tongkaina Village's waters, including Tongkaina beach and Bahowo beach, before operating the sampling. Then the observation stations were determined, namely Tongkaina waters (near Batu Meja) and Bahowo waters. The quadratic line transect method is used in this research. Species of class Echinoidea and Asteroidea in the quadrat were recorded among the total of individuals, and the species is documented. This study's results indicate that six species were found, including the survey, and five species were found based on the line transect method with 182 individuals. Including Asteroidea 85 Individuals and Echinoidea 99 Individuals. Value of Diversity at station 1 has a value of H '= 1.170 with a dominance of C = 0.364, while at Station 2 has a value of H' = 1.232 and dominance value of C = 0.316. the highest density in Station 1 is Diadema savigny 1.967 ind/m2 relative 50.86%, and Linckia laevigata with the highest frequency Fi = 0.533. The highest important value index is Diadema savigny, with a value of 81.09%, while at station 2, the Protoreaster nodosus has the highest value of important value index with a value of 87.51%. These species also have the highest density of 0.933 ind/m2 and a relative number of 41.79%.Keywords: Tongkaina, Echinoderm, Line Transect Quadrat Method, Asteroidea, Echinoidea, Coral Reef Flat

Vegetation Structure and Damage Level Mangrove Forest in Manomadehe Island, Subdistrict South Jailolo, North Maluku Province

Mangrove forest is a natural resource typical of tropical coasts, which has multiple benefits with a very broad impact when viewed from social, economic and ecological aspects. Management of natural resources must be very prudent because it takes a long time to be able to recover when damage / extinction has occurred. The purpose of this study was to determine the composition of mangrove species, the structure of mangrove forest vegetation (species density, relative density of species, frequency of species, relative frequency of species, species cover, relative cover of species and important values) and to determine the level of damage. Extraction of mangrove vegetation using the "spot check" method. The transects are drawn perpendicular to the coastline along the mangrove vegetation. The composition of mangrove species were 7 species, namely Rhizophora apiculata, R. stylosa, Bruguirea gymnorrhiza, Ceriops tagal, Sonneratia alba, Xylocarpus granatum and Aegiceras floridum. In the vegetation structure, the highest density and relative density were found in Rhizophora stylosa and the lowest was Xylocarpus granatum. The highest species and relative frequencies were Rhizophora stylosa, R. apiculata and the lowest were Bruguiera gymnorrhiza. The highest type and closure were Sonneratia alba and the lowest was Ceriops tagal. Meanwhile, the highest importance was in Sonneratia alba and the lowest was Xylocarpus granatum. Overall, the density value of mangrove species on Manomadehe Island is 2796 trees / ha so that the condition of the mangrove forests on Manomadehe Island is still in the good category (very dense).

Species Interactions and Nitrogen Use during Early Intercropping of Intermediate Wheatgrass with a White Clover Service Crop

Perennial grain crops intercropped with legumes are expected to use nitrogen (N) resources efficiently. A pot experiment using the 15N isotope dilution method demonstrated interspecific competition and use of N from the soil and N2 fixation in intermediate wheatgrass (Thinopyrum intermedium (Host) Barkworth & D.R. Dewey, IWG) and white clover (Trifolium repens L., WC) intercrops at five species-relative frequencies and four levels of inorganic N fertilizer in a replacement series design. The proportion of N in WC derived from the atmosphere increased from 39.7% in a sole crop to 70.9% when intercropped with IWG, and 10.1% N in IWG transferred from WC. Intermediate wheatgrass showed high fitness with maintained high total dry matter production at low relative frequencies. Decreasing IWG-relative frequency only increased dry matter and N accumulation of WC, resulting in increased amounts of N2 fixed. Increased levels of N fertilization increased the proportion of N acquired from the fertilizer in IWG and WC but decreased the N fixed by WC and N absorbed by IWG from the soil. Our study indicates that WC supply sufficient fixed N2 for IWG intercrop biomass yields under appropriate levels of soil N fertility and species-relative frequencies.

Survey of the Culicide community (Diptera: Culicidae) in the Caatinga Biome, Bom Jesus City, Piauí, Brazil

Mosquitoes are insects of great medical importance, acting as vectors of arboviruses and other pathogens that could be transmitted to humans. With the climate change many species of mosquitoes have adapted to survive in these altered conditions. The goal of this study was to describe the community of Culicidae in three gradients of environment within the Caatinga biome in the Bom Jesus municipality, Brazil. The environmental gradients included ​​native forest, rural and urban areas. Mosquitoes were collected and the following variables were analyzed: total and relative species abundance, total and relative species frequency, diversity, domain, the correlation among meteorological data, genus and the similarity between areas. The captures were made monthly for three consecutive days for a one-year period. Passive capture was performed using CDC traps placed a minimum distance of 50 meters apart in each sampling site. The mosquitoes collected were identified as: Aedeomyia spp., Aedes spp., Anopheles spp., Culex spp., Coquillettidia spp., Psorophora spp. and Uranotaenia spp. The genres Aedes, Anopheles, Culex, Coquillettidia and Psorophora were present year-round in at least one of the areas. The most abundant genres were the Anopheles and Culex, respectively. The native forest contained the highest diversity. However, the highest abundance of individuals was found in the rural areas, suggesting species adaptation to anthropized environments. Overall, the high abundance of the genus Anopheles and Culex is a public health concern as these genres are known to be involved in the transmission of malaria, human filariasis, and arboviruses.

Three eco‐physiological strategies of response to drought maintain the form and function of a tropical montane grassland

Abstract Ecologists seek a general scheme to classify the diversity of plant responses to environmental factors into a few strategies (e.g. competitor—C, stress tolerant—S, ruderal—R), while plant physiologists seek a mechanistic scheme to explain such different responses (e.g. tolerance, escape, avoidance). So far, few attempts have been made to combine both perspectives into plant eco‐physiological strategies. Moreover, the relative contribution of different strategies to maintain both community structure and ecosystem functioning during drought has rarely been assessed. Thus, limiting our capacity to predict how extreme events caused by climate change will affect plant communities. Here, we present an integrated framework to identify plant eco‐physiological strategies and to estimate their contribution to community originality (diversity of trait combinations), dominance (species relative frequency) and ecosystem functioning (productivity and evapotranspiration). We applied this framework in a tropical montane grassland in Brazil (Campos de Altitude) and found three eco‐physiological strategies co‐occurring in this community (S‐tolerance/avoidance, CS‐escape/tolerance and CR‐escape/avoidance). While CS‐species contributed more to dominance and functionality, CR‐ and S‐species contributed more to originality. Therefore, all three strategies were important to support the grassland form and function. Synthesis. Plants exhibit different strategies, as well as different contributions to community and ecosystem attributes. We developed an integrated approach to both identify strategies and estimate their relative contribution. Thereby, as droughts intensify, we can better predict which plants are more likely to be lost and how their loss will impact the communities and ecosystem where they occur. This knowledge is necessary for specifying conservation priorities and for developing more efficient conservation practices.

Articles of Significant Interest in This Issue

Pseudomonas aeruginosa and Staphyloccocus aureus are among the most important pathogens in polymicrobial infections, and their co-occurrence is linked to outcomes that are more severe than those of the respective monospecies infections. There is great interest in understanding how these two species interact and the consequences of those interactions for the host. Work by Niggli and Kümmerli (e00962-20) showed that ecological factors such as strain genetic background, relative species frequency, and environmental conditions are important elements governing population dynamics and species coexistence patterns. An improved understanding of what influences these interspecies interactions may provide a basis for better treatment of polymicrobial infections.

Improved normalization of species count data in ecology by scaling with ranked subsampling (SRS): application to microbial communities.

BackgroundAnalysis of species count data in ecology often requires normalization to an identical sample size. Rarefying (random subsampling without replacement), which is the current standard method for normalization, has been widely criticized for its poor reproducibility and potential distortion of the community structure. In the context of microbiome count data, researchers explicitly advised against the use of rarefying. Here we introduce a normalization method for species count data called scaling with ranked subsampling (SRS) and demonstrate its suitability for the analysis of microbial communities.MethodsSRS consists of two steps. In the scaling step, the counts for all species or operational taxonomic units (OTUs) are divided by a scaling factor chosen in such a way that the sum of scaled counts equals the selected total number of counts Cmin. The relative frequencies of all OTUs remain unchanged. In the subsequent ranked subsampling step, non-integer count values are converted into integers by an algorithm that minimizes subsampling error with regard to the population structure (relative frequencies of species or OTUs) while keeping the total number of counts equal Cmin. SRS and rarefying were compared by normalizing a test library representing a soil bacterial community. Common parameters of biodiversity and population structure (Shannon index H’, species richness, species composition, and relative abundances of OTUs) were determined for libraries normalized to different size by rarefying as well as SRS with 10,000 replications each. An implementation of SRS in R is available for download (https://doi.org/10.20387/BONARES-2657-1NP3).ResultsSRS showed greater reproducibility and preserved OTU frequencies and alpha diversity better than rarefying. The variance in Shannon diversity increased with the reduction of the library size after rarefying but remained zero for SRS. Relative abundances of OTUs strongly varied among libraries generated by rarefying, whereas libraries normalized by SRS showed only negligible variation. Bray–Curtis index of dissimilarity among replicates of the same library normalized by rarefying revealed a large variation in species composition, which reached complete dissimilarity (not a single OTU shared) among some libraries rarefied to a small size. The dissimilarity among replicated libraries normalized by SRS remained negligibly low at each library size. The variance in dissimilarity increased with the decreasing library size after rarefying, whereas it remained either zero or negligibly low after SRS.ConclusionsNormalization of OTU or species counts by scaling with ranked subsampling preserves the original community structure by minimizing subsampling errors. We therefore propose SRS for the normalization of biological count data.

Knowledge status of predators of the freshwater prawn Cryphiops caementarius (Decapoda: Palaemonidae) in river systems along the North Western Andean region from Perú and Chile

Introduction: Cryphiops caementarius, is an endemic prawn from river ecosystems in Southern Perú and Northern Chile. In these watersheds, natural populations are threatened by multiple anthropic interventions such as mining activities and fishing pressure, but also, by increasing impacts of invasive exotic predators. Information related with predation on C. caementarius is scarce representing a major knowledge gap to ensure suitable management and conservation practices. Accordingly, the further deepening in relevant aspects such as the estimation of populations losses due to predators has been indicated as critical by relevant agencies as FAO. Objective: To conduct a complete registry and classification of C. caementarius predators, updating the knowledge for the Andean region. Methods: A thorough bibliographic review on existing information on C. caementarius' predators from Perú and Chile was carried out calculating percentage of occurrence, relative frequency of species, zoogeographic origin, trophic structure, phenotypic attributes, river zone that inhabits and life stage of incidence. The registry was complemented using semi-structured interviews from prawn´s fishers in central-Northern Chile. Results: C. caementarius is predated along the entire fluvial network (estuary, potamon and rhithron) by 21 species of opportunists, carnivores, omnivores and herbivores, mostly aquatic vertebrates. In turn, these belong to 15 families and six guilds of native, exotic and cosmopolitan species. Approximately 86 % predate on adult prawns, whilst, 71 % on juveniles and 24 % on larvae. More than 40 % of the predation pressure seems to be exerted by native waterfowls and 24 % by exotic fish. Conclusions: The results emphasize the relevance for conservation of native species of predators in the Andean region and the need of control measures on exotic species in a latitudinal basis. Accordingly, this review may serve as an initial decision-making tool for future conservation efforts both on prawns and native biota, but also supporting restocking actions, fisheries management plans and risk assessment for C. caementariuspopulations across the Andean region.

Early interspecific dynamics, dry matter production and nitrogen use in Kernza (Thinopyrum intermedium) – alfalfa (Medicago sativa L.) mixed intercropping

ABSTRACTThe global interest in growing perennial grain crops such as intermediate wheatgrass (Thinopyrum intermedium) (Kernza) for production of food and feed is increasing. Intercropping Kernza with legumes may be a sustainable way of supplying nitrogen to soil and associated intercrop. We determined the competitive interactions between intercropped Kernza (K) and alfalfa (Medicago sativa L.) (A) under three inorganic nitrogen (N) rates N0, N1, N2 (0, 200, 400 kg ha−1) and five species relative frequencies (SRF) (100%K:0%A, 75%K:25%A, 50%K:50%A, 25%K:75%A and 0% K:100%A) in mixed intercrops (MI) in a greenhouse pot experiment. After 11 weeks of growth. Kernza dry matter yield (DM) and N accumulated (NACC) were low, but alfalfa DM and NACC high at 0 kg N ha−1. 200 and 400 kg N ha−1 fertiliser application increased the competitive ability (CA) of Kernza and reduced the CA of alfalfa. SRF had large impacts on alfalfa DM, NACC and NFIX only at 0 kg N ha−1 fertiliser, and insignificant impacts on Kernza at all N fertiliser levels, indicating that adjustment of SRF may not be an effective way to modulate the interspecific competition of Kernza. Further research on the other factors that influence the interspecific competition are warranted.

Human gut microbiome changes during a 10 week Randomised Control Trial for micronutrient supplementation in children with attention deficit hyperactivity disorder

It has been widely hypothesized that both diet and the microbiome play a role in the regulation of attention-deficit/hyperactivity disorder (ADHD) behaviour. However, there has been very limited scientific investigation into the potential biological connection. We performed a 10-week pilot study investigating the effects of a broad spectrum micronutrient administration on faecal microbiome content, using 16S rRNA gene sequencing. The study consisted of 17 children (seven in the placebo and ten in the treatment group) between the ages of seven and 12 years, who were diagnosed with ADHD. We found that micronutrient treatment did not drive large-scale changes in composition or structure of the microbiome. However, observed OTUs significantly increased in the treatment group, and showed no mean change in the placebo group. The differential abundance and relative frequency of Actinobacteria significantly decreased post- micronutrient treatment, and this was largely attributed to species from the genus Bifidobacterium. This was compensated by an increase in the relative frequency of species from the genus Collinsella. Further research is required to establish the role that Bifidobacterium contribute towards neuropsychiatric disorders; however, these findings suggest that micronutrient administration could be used as a safe, therapeutic method to modulate Bifidobacterium abundance, which could have potential implications for modulating and regulating ADHD behaviour. Our pilot study provides an initial observation into this area of research, and highlights an interesting avenue for further investigation in a larger cohort. Furthermore, these novel results provide a basis for future research on the biological connection between ADHD, diet and the microbiome.

Metabarcoding by capture using a single COI probe (MCSP) to identify and quantify fish species in ichthyoplankton swarms.

The ability to determine the composition and relative frequencies of fish species in large ichthyoplankton swarms could have extremely important ecological applications However, this task is currently hampered by methodological limitations. We proposed a new method for Amazonian species based on hybridization capture of the COI gene DNA from a distant species (Danio rerio), absent from our study area (the Amazon basin). The COI sequence of this species is approximately equidistant from all COI of Amazonian species available. By using this sequence as probe we successfully facilitated the simultaneous identification of fish larvae belonging to the order Siluriformes and to the Characiformes represented in our ichthyoplankton samples. Species relative frequencies, estimated by the number of reads, showed almost perfect correlations with true frequencies estimated by a Sanger approach, allowing the development of a quantitative approach. We also proposed a further improvement to a previous protocol, which enables lowering the sequencing effort by 40 times. This new Metabarcoding by Capture using a Single Probe (MCSP) methodology could have important implications for ecology, fisheries management and conservation in fish biodiversity hotspots worldwide. Our approach could easily be extended to other plant and animal taxa.

Occurrence and Pathogenicity of Root-Knot Nematodes (Meloidogyne species) in South African Vineyards

The occurrence of root-knot nematodes (Meloidogyne species) in viticultural regions of South Africa was determined. Meloidogyne javanica constituted 73,2% of all species identified while M. arenaria (17 ,0% ), M. incognito (7 ,1 % ) and M. hap/a (2,7%) were also found. The relative frequency of species in the various regions differed widely, with M. incognito more prominent in the warm inland regions. Experiments on different rootstock cultivars showed that all four species were able to infest susceptible rootstocks while none of them could infest cultivars known to be resistant to root-knot nematodes. Meloidogyne incognito and M. javanica, however, were found to be more pathogenic than the other two species. Meloidogyne incognito also showed a higher pathogenicity at 33°C than M. javanica, while results demonstrated a breakdown ofrootstock resistance at this temperature. It could not be verified by short-term pot trials that a sandy soil type enhance the degree of root-knot nematode infestation.

Medium- and large-sized mammals in a steppic savanna area of the Brazilian Pampa: survey and conservation issues of a poorly known fauna.

The wildlife of the Brazilian Pampa is threatened by large-scale habitat loss, due in particular to the expansion of soybean cultivation and the conversion of grasslands areas into extensive areas of silviculture. It is essential to study how the mammal fauna copes with the highly fragmented, human-influenced, non-protected landscape. Our study presents the results of a survey of the large- and medium-sized mammals of a typical human-influenced steppic savanna area of the Pampa biome. The survey was conducted exclusively with the use of camera traps over a period of 16 months. The relative frequencies of species in the area were evaluated. We recorded 18 species, some of them locally threatened (Tamandua tetradactyla, Alouatta caraya, Leopardus colocolo, Leopardus geoffroyi, Leopardus wiedii, Puma yagouaroundi, Mazama gouazoubira and Cuniculus paca). Several species were found to thrive in the area; however, many species were considered rare, and undoubtedly new species could be recorded if we continued the sampling. Our results contribute to the knowledge of faunal diversity in the Pampa biome and associated habitats, warn about threats and provide support for conservation measures.

Assessment of endophytic yeast diversity in rice leaves by a culture-independent approach.

Endophytic microorganisms inhabit internal plant tissues in the host plant without causing any symptoms or negative effects. Although the diversity of endophytes has been evaluated by both culture-dependent and culture-independent methods, less information is available on yeast communities. Therefore, in this study a culture-independent method was used to examine endophytic yeasts associated with rice leaves based on the large subunit of ribosomal DNA using a semi-nested PCR technique. Sequence analysis indicated that the colonization frequency and the relative species frequency (RF) of endophytic yeast phylotypes were 0.41 and 0.06, respectively, and the majority of the yeast phylotypes were basidiomycetous yeasts. The phylotypes were designated as five known species (Cryptococcus victoriae, Debaryomyces hansenii, Debaryomyces vindobonensis, Meyerozyma guilliermondii and Pseudozyma antarctica), together with seventeen phylotypes closest to Candida metapsilosis, Cryp. foliicola, Cryp. laurentii, Pseudozyma abaconensis, Pseudozyma aphidis and Trichosporon asahii, among which some could be novel species. The most prevalent phylotypes were those closest to Cryp. foliicola (47.5 % RF) followed by D. hansenii (22.8 % RF) and P. antarctica (16.8 % RF). The presence of the phylotypes related to species known for their potential applications as biocontrol agents and plant growth promoting hormone producers suggests that they may have valuable applications. In addition, our findings revealed the occurrence of novel phylotypes at high frequency, which should encourage extensive studies to discover novel yeast species and to understand their roles in the rice leaves.