Vertebrate diversity revealed by metabarcoding of bulk arthropod samples from tropical forests

Julkaisu on kaksikielinen: suomi ja ruotsi

Effects of landscape configuration and composition on phylogenetic diversity of trees in a highly fragmented tropical forest

© 2016 British Ecological Society. Fragmentation of tropical forests is a major driver of the global extinction crisis. A key question is understanding how fragmentation impacts phylogenetic diversity, which summarizes the total evolutionary history shared across species within a community. Conserving phylogenetic diversity decreases the potential of losing unique ecological and phenotypic traits and plays important roles in maintaining ecosystem function and stability. Our study was conducted in landscapes within the highly fragmented Brazilian Atlantic forest. We sampled living trees with d.b.h. ≥ 4.8 cm in 0.1 ha plots within 28 fragment interiors and 12 fragment edges to evaluate the impacts of landscape configuration, composition and patch size, as well as edge effects, on phylogenetic diversity indices (PD, a measure of phylogenetic richness; MPD, phylogenetic distance between individuals in a community in deep evolutionary time; and MNTD, phylogenetic distance between each individual and its nearest phylogenetic neighbour). We found that PD and MPD were correlated with species richness, while MNTD was not. Best models suggest that MPD was positively related to edge density and negatively related to the number of forest patches, but that there was no effect of landscape configuration and composition metrics on PD or MNTD, or on standardized values of phylogenetic structure (sesPD, sesMPD and sesMNTD), which control for species richness. Considering all selected models for phylogenetic diversity and structure, edge density and number of forest patches were most frequently selected. With increasing patch size, we found lower PD in interiors but no change at edges and lower sesMNTD regardless of habitat type. Additionally, PD and sesMNTD were higher in interiors than at edges. Synthesis. Changes in MPD and sesMNTD suggest that extirpation of species at edges or in highly fragmented landscapes increases the dominance of species within a subset of clades (phylogenetic clustering), likely those adapted to disturbance. Smaller patch sizes are phylogenetically diverse and overdispersed, probably due to an invasion of edge-adapted species. Conservation must enhance patch area and connectivity via forest restoration; pivotally, even small forest patches are important reservoirs of phylogenetic diversity in the highly threatened Brazilian Atlantic forest

Krill biomass estimation : sampling and measurement variability

FB is funded by an EPSRC studentship (grant code: EP/R513337/1).Krill are the subject of growing commercial fisheries and therefore fisheries management is necessary to ensure long-term sustainability. Krill catch limits, set by Commission for the Conservation of Antarctic Marine Living Resources, are based on absolute krill biomass, estimated from acoustic-trawl surveys. In this work, we develop a method for determining an error budget for acoustic-trawl surveys of krill which includes sampling and measurement variability. We use our error budget method to examine the sensitivity of biomass estimates to parameters in acoustic target strength (TS) models, length frequency distribution and length to wetmass relationships derived from net data. We determined that the average coefficient of variation (CV) of estimated biomass was 17.7% and the average CV due from scaling acoustic observations to biomass density was 5.3%. We found that a large proportion of the variability of biomass estimates is due to the krill orientation distribution, a parameter in the TS model. Orientation distributions with narrow standard deviations were found to emphasise the results of nulls in the TS to length relationship, which has to potential to lead to biologically implausible results.Publisher PDFPeer reviewe

Quantas espécies de plantas vasculares existem em um hotspot local de biodiversidade no sudeste do Brasil?

Scientific information about the distribution of species richness and diversity is necessary for full comprehension of our evolutionary heritage forming a powerful tool for the development of nature conservation strategies. The aim of this article was to estimate the vascular plant species richness of the campos rupestres from the Itacolomi State Park (ISP) in order to verify the park´s classification as a local hotspot of biodiversity and to outline the status quo of knowledge about biodiversity in the region. For that, the species richness of two phytosociological surveys of 0.15 ha each were extrapolated using (a) the species-area relationship fitted by the power and the logarithmic model as well as (b) the taxon ratio model. The taxon ratio model estimates total vascular plant species richness to 1109 species using seven different taxa. Extrapolations of different fittings of the species-area relationships calculate the complete park’s richness to values between 241 and 386 (logarithmic model), and 3346 to 10421 (power model). These extrapolations are far beyond realistic: the logarithmic model underestimates the park´s species richness, because more than 520 vascular plant species have already been registered in the park. On the other hand, it is not plausible that one-fourth or more of all species registered so far in the Atlantic Tropical Forest Biome occur in the ISP as indicated by the extrapolation with the power model. The most realistic estimation was achieved by the taxon ratio model. Although confidence intervals are large, the species richness estimated by this method legitimates the classification of the ISP as a local hotspot of biodiversity, but this value also outlines the lack of knowledge about biodiversity in this region and the urgent need for more taxonomical and ecological research.Key words: campos rupestres, species-area relationship, taxon ratios, Espinhaço Mountain Range.Informação científica sobre a distribuição de riqueza e diversidade de espécies é necessária para a compreensão plena da nossa herança evolutiva formando uma ferramenta poderosa para o desenvolvimento de estratégias de conservação de natureza. O objetivo deste trabalho constituiu-se em estimar a riqueza de plantas vasculares nos campos rupestres do Parque Estadual do Itacolomi (PEI) para justificar a sua classificação como um hotspot local de biodiversidade e para delinear o status quo do conhecimento sobre a biodiversidade na região. Para isso, o número de espécies encontradas em dois levantamentos fitossociológicos de 0,15 ha cada foi extrapolado usando (a) a relação espécie-área ajustada pelo modelo de potência e pelo modelo logarítmico bem como (b) o modelo de relação de táxons. O modelo de relação de táxons estimou a riqueza total para 1.109 espécies usando sete diferentes táxons. Extrapolações de diferentes modelos da relação espécie-área estimaram a riqueza total dos campos rupestres do parque para valores entre 241 e 386 (modelo logarítmico) e 3346 e 10421 (modelo de potência). As extrapolações da relação espécie-área foram muito além do real: o modelo logarítmico subestimou a riqueza de espécies do parque, porque há mais de 520 espécies de plantas vasculares registradas para o parque. Por outro lado, não é plausível que um quarto ou mais das espécies registradas no Bioma Mata Atlântica ocorra no PEI como a extrapolação do modelo de potência indicou. A estimativa mais realista foi alcançada pelo modelo de relação dos táxons. Embora os intervalos de confiança sejam grandes, a riqueza de espécies estimada por esse método justificou a classificação do PEI como um hotspot local de biodiversidade. A riqueza estimada de espécies também destacou a falta de conhecimento sobre a biodiversidade da região e a necessidade urgente de mais pesquisas taxonômicas e ecológicas.Palavras-chave: campos rupestres, relação espécie-área, relações táxon, Serra do Espinhaço

Using acoustic data from pelagic fishing vessels to monitor fish stocks

Pelagic trawlers make intensive use of echosounders and therefore could potentially be used as acoustic data collection platforms. The present project has investigated the possibility of collecting acoustic data during normal fishing trips and the potential of this data to estimate fish stock biomass. Within this project, two real-scale data collection trials were realised, one in spring 2012 during the blue whiting fishing season, and one in summer 2012 during the North Sea herring and sprat fishing season

A review of the small pelagics fishery resources of the Dutch Caribbean and adjacent areas

This deskstudy gives a review of small pelagic fish species and fisheries in the Dutch Caribbean, specifically species which distributions exceed the national boundaries and where international cooperation in research and management is required

Bottom and Suspended Sediment Backscatter Measurements in a Flume—Towards Quantitative Bed and Water Column Properties

For health and impact studies of water systems, monitoring underwater environments is essential, for which multi-frequency single- and multibeam echosounders are commonly used state-of-the-art technologies. However, the current scarcity of sediment reference datasets of both bottom backscatter angular response and water column scattering hampers empirical data interpretation. Comprehensive reference data derived from measurements in a controlled environment should optimize the use of empirical backscatter data. To prepare for such innovative experiments, we conducted a feasibility experiment in the Delta Flume (Deltares, The Netherlands). Several configurations of sonar data were recorded of the flume floor and suspended sediment plumes. The results revealed that flume reverberation was sufficiently low and that the differential settling of fine-sand plumes in the water column was clearly detected. Following this successful feasibility test, future comprehensive experiments will feature multi-frequency multi-angle measurements on a variety of sediment types, additional scatterers and sediment plumes, resulting in reference datasets for an improved interpretation of underwater backscatter measurements for scientific observation and sustainable management