scholarly journals Low Temperature Decreases the Phylogenetic Diversity of Ammonia-Oxidizing Archaea and Bacteria in Aquarium Biofiltration Systems

2007 ◽  
Vol 74 (3) ◽  
pp. 894-900 ◽  
Author(s):  
Hidetoshi Urakawa ◽  
Yoshiyuki Tajima ◽  
Yoshiyuki Numata ◽  
Satoshi Tsuneda
Keyword(s):  
Population Structure ◽  
Species Richness ◽  
Low Temperature ◽  
Phylogenetic Diversity ◽  
Cold Water ◽  
Diversity Indices ◽  
Rarefaction Analysis ◽  
Ammonia Oxidizing Archaea ◽  
Key Factor

ABSTRACT The phylogenetic diversity and species richness of ammonia-oxidizing archaea (AOA) and bacteria (AOB) were examined with aquarium biofiltration systems. Species richness, deduced from rarefaction analysis, and diversity indices indicated that the phylogenetic diversity and species richness of AOA are greater than those of AOB; the diversity of AOA and of AOB is minimized in cold-water aquaria. This finding implies that temperature is a key factor influencing the population structure and diversity of AOA and AOB in aquarium biofiltration systems.

scholarly journals Phylogenetic diversity as a window into the evolutionary and biogeographic histories of present-day richness gradients for mammals

2011 ◽  
Vol 366 (1576) ◽  
pp. 2414-2425 ◽  
Author(s):  
T. Jonathan Davies ◽  
Lauren B. Buckley
Keyword(s):  
Species Richness ◽  
Phylogenetic Diversity ◽  
Diversity Indices ◽  
Environmental Predictors ◽  
Terrestrial Mammals ◽  
Extinction Rates ◽  
Biogeographic History ◽  
Shared Ancestry ◽  
History Of ◽  
Dispersal Events

Phylogenetic diversity (PD) captures the shared ancestry of species, and is increasingly being recognized as a valuable conservation currency. Regionally, PD frequently covaries closely with species richness; however, variation in speciation and extinction rates and/or the biogeographic history of lineages can result in significant deviation. Locally, these differences may be pronounced. Rapid recent speciation or high temporal turnover of lineages can result in low PD but high richness. In contrast, rare dispersal events, for example, between biomes, can elevate PD but have only small impact on richness. To date, environmental predictors of species richness have been well studied but global models explaining variation in PD are lacking. Here, we contrast the global distribution of PD versus species richness for terrestrial mammals. We show that an environmental model of lineage diversification can predict well the discrepancy in the distribution of these two variables in some places, for example, South America and Africa but not others, such as Southeast Asia. When we have information on multiple diversity indices, conservation efforts directed towards maximizing one currency or another (e.g. species richness versus PD) should also consider the underlying processes that have shaped their distributions.

scholarly journals Bryozoan epifauna on brachiopods from the Faroe Islands (NE Atlantic)

2015 ◽  
Vol 60 ◽  
pp. 96 ◽  
Author(s):  
Nina V. Denisenko ◽  
Elsebeth Thomsen ◽  
Ole S. Tendal
Keyword(s):  
Species Richness ◽  
Low Temperature ◽  
Significant Relationship ◽  
Cold Water ◽  
Common Species ◽  
Water Area ◽  
Frequency Of Occurrence ◽  
Faroe Islands ◽  
Ne Atlantic ◽  
Bryozoan Species

Fifteen bryozoan species were found on three species of brachiopods in the Faroe area, but only two of the brachiopod species can be regarded as common biogenic substrates for bryozoans. Incrusting bryozoan species were the most diverse compared to other growth­ forms. A maximum of five species were found on one valve, but usually from one to three species. Most species were found in restricted depth zones and they can be regarded as accidental epibionts due to the absence of any relationship between the bryozoan species richness and brachiopod abundance in total. <em>Diplosolen obelia </em>and <em>Disporella hispida </em>are the most common species, their frequency of occurrence exceeding 50% and their abundance correlating significantly with the brachiopod abundance. The preference of some brachiopod species as substrate for bryozoans is related to the morphology of the brachiopod valves. Boreal and boreoarctic species predominate in the study area. Occurrence of arctic forms of bryozoans corresponds to the waters with low temperature, where significant relationship is found between them and brachiopod abundance, although the last one is low in the cold water area.

scholarly journals Decomposing phylogenetic entropy into α , β and γ components

2010 ◽  
Vol 7 (2) ◽  
pp. 205-209 ◽  
Author(s):  
Maud A. Mouchet ◽  
David Mouillot
Keyword(s):  
Species Richness ◽  
Phylogenetic Trees ◽  
Phylogenetic Diversity ◽  
Biological Diversity ◽  
Diversity Indices ◽  
Species Loss ◽  
Full Understanding ◽  
Abundance Distribution ◽  
Additive Decomposition ◽  
Weak Monotonicity

Measuring the phylogenetic diversity of communities has become a key issue for biogeography and conservation. However, most diversity indices that rely on interspecies phylogenetic distances may increase with species loss and thus violate the principle of weak monotonicity. Moreover, most published phylogenetic diversity indices ignore the abundance distribution along phylogenetic trees, even though lineage abundances are crucial components of biodiversity. The recently introduced concept of phylogenetic entropy overcomes these limitations, but has not been decomposed across scales, i.e. into α , β and γ components. A full understanding of mechanisms sustaining biological diversity within and between communities needs such decomposition. Here, we propose an additive decomposition framework for estimating α , β and γ components of phylogenetic entropy. Based on simulated trees, we demonstrate its robustness to phylogenetic tree shape and species richness. Our decomposition fulfils the requirements of both independence between components and weak monotonicity. Finally, our decomposition can also be adapted to the partitioning of functional diversity across different scales with the same desirable properties.

Aquatic and semi aquatic Hemiptera community of Sonebeel, the largest wetland of Assam, northeastern India

2018 ◽  
Vol 10 (13) ◽  
pp. 12792-12799
Author(s):  
Anupama Saha ◽  
Susmita Gupta
Keyword(s):  
Species Richness ◽  
Pest Control ◽  
Relative Abundance ◽  
Species Distribution ◽  
Diversity Indices ◽  
Environmental Data ◽  
Northeastern India ◽  
Ecological Roles

Aquatic and semiaquatic Hemiptera bugs play significant ecological roles, and they are important indicators and pest control agents.  Little information is currently available concerning its populations in southern Assam.  This study assessed hemipterans in four sites of Sonebeel, the largest wetland in Assam (3458.12 ha at full storage level), situated in Karimganj District.  The major inflow and outflow of the wetland are the rivers Singla and Kachua, respectively (the Kachua drains into the Kushiyara River).  Samples were trapped with pond nets and were seasonally recorded.  This study recorded a total of 28 species of aquatic and semiaquatic hemipterans belonging to 20 genera under nine families.  Population, geographical and environmental data (e.g., rainfall) were used to assess the relative abundance of species, species richness and different diversity indices, and species distribution. 

scholarly journals Influence of Co-Precipitation Agent on the Structure, Texture and Catalytic Activity of Au-CeO2 Catalysts in Low-Temperature Oxidation of Benzyl Alcohol

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 641
Author(s):  
Lukasz Wolski ◽  
Grzegorz Nowaczyk ◽  
Stefan Jurga ◽  
Maria Ziolek
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Low Temperature ◽  
Benzyl Alcohol ◽  
Low Temperature Oxidation ◽  
Temperature Oxidation ◽  
Oxidation Of Benzyl Alcohol ◽  
Key Factor ◽  
Au Particle Size ◽  
Co Precipitation

The aim of the study was to establish the influence of a co-precipitation agent (i.e., NaOH–immediate precipitation; hexamethylenetetramine/urea–gradual precipitation and growth of nanostructures) on the properties and catalytic activity of as-synthesized Au-CeO2 nanocomposites. All catalysts were fully characterized with the use of XRD, nitrogen physisorption, ICP-OES, SEM, HR-TEM, UV-vis, XPS, and tested in low-temperature oxidation of benzyl alcohol as a model oxidation reaction. The results obtained in this study indicated that the type of co-precipitation agent has a significant impact on the growth of gold species. Immediate co-precipitation of Au-CeO2 nanostructures with the use of NaOH allowed obtainment of considerably smaller and more homogeneous in size gold nanoparticles than those formed by gradual co-precipitation and growth of Au-CeO2 nanostructures in the presence of hexamethylenetetramine or urea. In the catalytic tests, it was established that the key factor promoting high activity in low-temperature oxidation of benzyl alcohol was size of gold nanoparticles. The highest conversion of the alcohol was observed for the catalyst containing the smallest Au particle size (i.e., Au-CeO2 nanocomposite prepared with the use of NaOH as a co-precipitation agent).

Field Margin Weed-Species Diversity in Relation to Landscape Attributes and Adjacent Land Use

Weed Science ◽  
2007 ◽  
Vol 55 (2) ◽  
pp. 129-136 ◽  
Author(s):  
Lynn M. Sosnoskie ◽  
Edward C. Luschei ◽  
Mark A. Fanning
Keyword(s):  
Land Use ◽  
Species Richness ◽  
Agricultural Landscape ◽  
Elevation Gradient ◽  
Shape Index ◽  
Diversity Indices ◽  
Weed Species ◽  
Field Margin ◽  
Local Climate ◽  
Modeling Strategy

The importance of managing weeds in seminatural habitats that are adjacent to farm fields is unclear. Weedy-margin vegetation may harbor pests or pathogens and may ALSo serve as source populations for ongoing immigration of weeds into the field. It is ALSo possible, however, that margin vegetation provides habitat for organisms that consume weed seeds or suppress the likelihood of pest or pathogen outbreak. We examined the nature of margin habitat using spatial-scaling of Weed-Species richness as an ecological assay. In 2003, we recorded the occurrence of weedy species along the perimeters of 63 fields in Wisconsin. The fields were distributed within six counties that differed in topography, geological history, local climate, and soil type and which spanned the range of variability in the agricultural landscape. We identified seven habitats that differed in geology and land use. The relationship between species richness and margin class was estimated using an analog of the power law. Additionally, we investigated broadscale correlates of habitat heterogeneity at the field level, using a modeling strategy that included additional explanatory factors logically connected to plant diversity. Using a model-confrontation approach, the survey supported the inclusion of two topographical diversity indices, elevation gradient and a field-shape index, into our model. Our broadscale survey provides information on one of a suite of important considerations needed to make decisions about the importance of managing weeds in field margins.

scholarly journals Flower‐visitor communities of an arcto‐alpine plant—Global patterns in species richness, phylogenetic diversity and ecological functioning

2018 ◽  
Vol 28 (2) ◽  
pp. 318-335 ◽  
Author(s):  
Mikko Tiusanen ◽  
Tea Huotari ◽  
Paul D. N. Hebert ◽  
Tommi Andersson ◽  
Ashley Asmus ◽  
...  
Keyword(s):  
Species Richness ◽  
Phylogenetic Diversity ◽  
Alpine Plant ◽  
Flower Visitor ◽  
Global Patterns ◽  
Ecological Functioning

scholarly journals Temperate carbonate cycling and water mass properties from intertidal to bathyal depths (Azores, N-Atlantic)

2010 ◽  
Vol 7 (3) ◽  
pp. 3297-3333 ◽  
Author(s):  
M. Wisshak ◽  
A. Form ◽  
J. Jakobsen ◽  
A. Freiwald
Keyword(s):  
Cold Water ◽  
Light Availability ◽  
Euphotic Zone ◽  
Carbonate Production ◽  
Carbonate Budget ◽  
Mass Properties ◽  
Accretion Rates ◽  
Key Factor ◽  
Temperate Carbonate ◽  
Factor Governing

Abstract. The rugged submarine topography of the Azores supports a diverse heterozoan association resulting in intense biotically-controlled carbonate production and accumulation. In order to characterise this cold-water (C) factory a 2-year experiment was carried out to study the biodiversity of hardground communities and for budgeting carbonate production and degradation along a bathymetrical transect from the intertidal to bathyal 500 m depth. Seasonal temperatures peak in September (above a thermocline) and bottom in March (stratification diminishes) with a decrease in amplitude and absolute values with depth, and with tidal-driven short-term fluctuations. Measured seawater stable isotope ratios and levels of dissolved nutrients decrease with depth, as do the calcium carbonate saturation states. The photosynthetic active radiation shows a base of the euphotic zone in ~70 m and a dysphotic limit in ~150 m depth. Bioerosion, being primarily a function of light availability for phototrophic endoliths and grazers feeding upon them, is ~10 times stronger on the illuminated upside versus the shaded underside of substrates in the photic zone, with maximum rates in the intertidal (−631 g/m2/yr). Rates rapidly decline towards deeper waters where bioerosion and carbonate accretion are slow and epibenthic/endolithic communities take years to mature. Accretion rates are highest in the lower euphotic zone (955 g/m2/yr), where the substrate is less prone to hydrodynamic force. Highest rates are found – inversely to bioerosion – on downward facing substrates, suggesting that bioerosion may be a key factor governing the preferential settlement and growth of calcareous epilithobionts on downward facing substrates. In context of a latitudinal gradient, the Azores carbonate cycling rates plot between known values from the cold-temperate Swedish Kosterfjord and the tropical Bahamas, with a total range of two orders in magnitude. Carbonate budget calculations for the bathymetrical transect yield a mean 266.9 kg of epilithic carbonate production, −54.6 kg of bioerosion, and 212.3 kg of annual net carbonate production per metre of coastline in the Azores C factory.

scholarly journals COMPARISON ON VEGETATION COMPOSITION AND STRUCTURE OF EXCLOSURES VS. OPEN GRAZING LANDS IN NORTHERN ETHIOPIA

2021 ◽  
Vol 9 (8) ◽  
pp. 70-99
Author(s):  
Samson Shimelse Jemaneh
Keyword(s):  
Population Structure ◽  
Species Richness ◽  
Plant Species ◽  
Woody Species ◽  
Soil Parameters ◽  
Northern Ethiopia ◽  
Indigenous Species ◽  
Regeneration Status ◽  
Composition And Structure ◽  
Grazing Lands

This study was conducted with the objectives of study investigates, compare, and try to describe the floristic composition and structure of the vegetation of exclosures and open grazing lands. A stratified preferential sampling design technique with flexible systematic model was used for data collection. Data on vegetation and environmental parameters were gathered from 120 quadrants (90 from restorations or exclosures of different ages and 30 from adjacent open grazing lands), of 20 m x 20 m (400 m2) size. Species richness and the presence or absence of herbaceous plants were recorded like soil samples in a 2 m x 2 m (4 m2) subplot inside each main quadrant from five points, one at each corner and one at the center.  A total of 142 plant species belonging to 118 genera and 52 families were identified. All exclosures displayed higher plant species richness, diversity, and aboveground standing biomass compared to the adjacent open grazing lands. Consideration of edaphic (e.g. soil total nitrogen, available phosphorus, CEC, exchangeable bases, soil pH and soil texture) and site (e.g. Stoniness, Grazing) variables will help to optimize the selection of areas for the establishment of future exclosures. Moreover, our study suggests that with time exclosures may increasingly obtain an important role as refugees and species pool similar to church forests and should be protected and managed in a sustainable manner. However, economic and social impacts of exclosures should be included in feasibility studies before establishing exclosures in the future.  Altitude, Grazing and some soil parameters like Mg were the major environmental factors in the division of the vegetation into plant community types. The result of the frequency distribution of woody species showed a high proportion of small-sized individuals in the lower diameter classes indicating good recruitment potential of the forest patches and the rare occurrence of large individuals. Such trend was probably caused by past disturbance of the original vegetation resulting in a succession of secondary vegetation. In addition, the analysis of species population structure indicated that some tree species had abnormal population structure with no or few individuals at lower size classes. Moreover, assessment of regeneration status on the basis of age classes indicated that significant proportion of woody species were represented by few or no seedlings, entailing that they were under threat. Substantial numbers of forest species were found to have irregular population structure and are in reduced regeneration status. To prevent local extinction of these species, present efforts of nursery establishment and plantation of indigenous species in the exclosures should be strengthened and extended.

Forty years of dietary studies on barn owl (Tyto alba) reveal long term trends in diversity metrics of small mammal prey

2018 ◽  
Vol 68 (2) ◽  
pp. 129-146 ◽  
Author(s):  
Giuliano Milana ◽  
Luca Luiselli ◽  
Giovanni Amori
Keyword(s):  
Species Richness ◽  
Relative Abundance ◽  
Negative Correlation ◽  
Linear Models ◽  
Prey Availability ◽  
Diversity Indices ◽  
Barn Owl ◽  
Tyto Alba ◽  
Local Conditions ◽  
Over Time

AbstractThe diet of predators is influenced by local conditions (e.g., characteristics of habitat and microhabitat, seasonality, prey availability) and therefore tends to change across time. In this paper, the diet composition of the barn owl (Tyto alba) in Italy was studied using a meta-analysis of 47 articles (covering 212 independent sites, with multiple surveys for some sites, thus giving a total of 290 datasets) between 1972 and 2012. General Linear Models were used to assess the effects of year and study site on four distinct diversity indices (species richness, dominance, Shannon-Weaver diversity and equitability). The year of data collection was a factor used in all analyses. Year had a greater effect than study site on all diversity indices, but the effect was not significant for the evenness and the species richness. However, dietary dominance increased significantly over the years, the Shannon-Weaver index of diversity decreased significantly over time, and equitability also decreased significantly over time. The relative abundance of various species of rodents did not increase/decrease progressively over the years, although there were inter-annual fluctuations. On the other hand, the relative abundance of insectivores tended to decrease with time, and there was a significantly negative correlation between year and the frequency of consumption of Sorex spp. and a marginally significant negative correlation for Crocidura leucodon.

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