scholarly journals Root Foraging Precision: Do Experimental Conditions Matter?

2021 ◽  
Author(s):  
Pavlína Stiblíková ◽  
Martin Weiser
Keyword(s):  
Plant Nutrient ◽  
Experimental Conditions ◽  
Root Foraging ◽  
As Species ◽  
Pot Size ◽  
Heterogeneous Soil ◽  
Specific Trait ◽  
Species Specific ◽  
Meta Analyses ◽  
Experiment Duration

Abstract Purpose: Root foraging precision, i.e., preferential root proliferation in nutrient-rich patches in heterogeneous soil, contributes significantly to plant nutrient acquisition. The ability to forage is usually studied experimentally, although often under different conditions. It remains unclear whether different experimental conditions affect root foraging precision. We studied the effect of experiment duration, pot size and root separation on root foraging precision and the appropriateness of using root foraging as species-specific values in databases and meta-analyses.Methods: We cultivated three perennial species in pots with spatially heterogeneous nutrient supplies and manipulated the experiment duration (4 – 10 weeks). We partly replicated the experiment in two consecutive years. In two of the three species we compared outcomes when root types were separated and unseparated, and for one species we also manipulated pot size. We assessed the effects of the manipulated factors on foraging precision expressed as the ratio of root biomass in nutrient-rich and poor patches.Results: Root foraging precision was not affected by experiment duration or pot size. Separating roots to use only the fine ones for root foraging assessment amplified foraging precision values and reduced their intraspecific variation.Conclusions: Our study investigated various methods of the root foraging research and their impact on the root foraging precision. Root foraging precision is invariable to the studied factors, therefore it is suitable as a species-specific trait, if the effect of other factors (such as nutrient patch characteristics) is taken into account.

scholarly journals Flight-call as species-specific signal in South American parrots and the effect of species relatedness in call similarity

2017 ◽  
Vol 25 (3) ◽  
pp. 143-151 ◽  
Author(s):  
Carlos B. de Araújo ◽  
Paulo A. M. Marques ◽  
Jacques M. E. Vielliard
Keyword(s):  
South American ◽  
Specific Signal ◽  
As Species ◽  
Species Specific

scholarly journals Trichothecene Genotypes of Fusarium graminearum Populations Isolated from Winter Wheat Crops in Serbia

Toxins ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 460 ◽  
Author(s):  
Vesna Krnjaja ◽  
Slavica Stanković ◽  
Ana Obradović ◽  
Tanja Petrović ◽  
Violeta Mandić ◽  
...  
Keyword(s):  
Fusarium Graminearum ◽  
Gene Clusters ◽  
Sensu Stricto ◽  
Molecular Techniques ◽  
Weather Data ◽  
Morphological Observation ◽  
Specific Primer ◽  
Head Blight ◽  
As Species ◽  
Species Specific

Fusarium graminearum as the main causal agent of Fusarium head blight (FHB) and its ability to produce trichothecenes was investigated by molecular techniques. A total of 37 strains isolated from the wheat, harvested in Serbia in 2005, 2008 and 2015, and previously designated by morphological observation as F. graminearum, were used for trichothecene genotypes characterization. The strains were identified using the species-specific primer set FG16R/FG16F while genotypic characterization was done using specific TRI13 and TRI3 sequences of the trichothecene gene clusters. The PCR assays identified all strains as species of F. graminearum sensu stricto with the DON/15-ADON genotype. The quantification of the mycotoxin (DON) was performed using the biochemical assay. The high levels of DON (>20,000 µg kg−1) were recorded in all of the strains from 2005, four strains from 2008 and two strains from 2015. Weather data of the investigated seasons, showed that the optimal temperature, frequent rains and high relative humidity (RH) was very favourable for the development of F. graminearum, affecting the DON biosynthesis.

scholarly journals Computational Design of Sensitized Combustion Chemistry Experiments

2021 ◽  
Vol 7 ◽  
Author(s):  
Cody Ising ◽  
Pedro Rodriguez ◽  
Daniel Lopez ◽  
Jeffrey Santner
Keyword(s):  
Shock Tube ◽  
Initial Conditions ◽  
Computational Design ◽  
Reaction Rates ◽  
Oxidation Reactions ◽  
Combustion Chemistry ◽  
Experimental Conditions ◽  
As Species ◽  
User Friendly

In combustion chemistry experiments, reaction rates are often extracted from complex experiments using detailed models. To aid in this process, experiments are performed such that measurable quantities, such as species concentrations, flame speed, and ignition delay, are sensitive to reaction rates of interest. In this work, a systematic method for determining such sensitized experimental conditions is demonstrated. An open-source python script was created using the Cantera module to simulate thousands of 0D and hundreds of 1D combustion chemistry experiments in parallel across a broad, user-defined range of mixture conditions. The results of the simulation are post-processed to normalize and compare sensitivity values among reactions and across initial conditions for time-varying and steady-state simulations, in order to determine the “most useful” experimental conditions. This software can be utilized by researchers as a fast, user-friendly screening tool to determine the thermodynamic and mixture parameters for an experimental campaign. We demonstrate this software through two case studies comparing results of the 0D script against a shock tube experiment and results of the 1D script against a spherical flame experiment. In the shock tube case study we present mixture conditions compared to those used in the literature to study H + O2 (+M)→HO2(+M). In the flame case study, we present mixture conditions compared to those in the literature to study formyl radical (HCO) decomposition and oxidation reactions. The systematically determined experimental conditions identified in the present work are similar to the conditions chosen in the literature.

Phenotypic plasticity in leaves of four species of arctic Festuca (Poaceae)

1995 ◽  
Vol 73 (11) ◽  
pp. 1810-1823 ◽  
Author(s):  
Nicole S. Ramesar-Fortner ◽  
Nancy G. Dengler ◽  
Susan G. Aiken
Keyword(s):  
Phenotypic Plasticity ◽  
Cross Sections ◽  
Leaf Blade ◽  
Growth Traits ◽  
Continuous Light ◽  
Taxonomic Status ◽  
Trichome Density ◽  
Experimental Conditions ◽  
University Of Toronto ◽  
Species Specific

Leaf phenotypic plasticity of 12 morphological, anatomical, and growth traits was investigated using four species of arctic Festuca (F. baffinensis, F. brachyphylla, F. edlundiae, and F. hyperborea). Plants collected around 78°N in the Canadian Arctic Archipelago were grown for 10 weeks at the University of Toronto in growth chambers in continuous light, under four regimes of temperature and moisture. Significant differences were found between leaves at the time of field collection and leaves of the same plant at the end of the experiment in (i) leaf blade length, (ii) surface vestiture, both in trichome density and angle of the trichomes to the blade surface, and (iii) characters seen in leaf cross sections: blade width, rib thickness, and inter-rib thickness. The four species responded similarly to the experimental conditions, indicating that most of these changes represent part of the developmentally inevitable component of plasticity rather than species-specific adaptations. Trichome density was the only characteristic for which species showed different patterns of response, with a unique pattern of response in F. edlundiae. This and certain growth traits support the taxonomic status of this newly recognized species. The significant effects of temperature and to a lesser degree, water treatments on these leaf anatomical traits indicate that they should be used with caution for the purposes of taxonomy and identification. Key words: Festuca, leaf blade anatomy, phenotypic plasticity.

scholarly journals Uneven distribution of cryptic diversity among higher taxa of parasitic worms

2010 ◽  
Vol 7 (2) ◽  
pp. 241-244 ◽  
Author(s):  
Robert Poulin
Keyword(s):  
Cryptic Species ◽  
Zoonotic Diseases ◽  
Helminth Parasites ◽  
Morphological Markers ◽  
Molecular Tools ◽  
Invasive Pathogens ◽  
Higher Taxa ◽  
As Species ◽  
Species Specific ◽  
Parasitic Worms

Cryptic species cause problems for estimates of biodiversity. In the case of parasites, cryptic species also plague efforts to detect potential zoonotic diseases or invasive pathogens. It is crucial to determine whether the likelihood of finding cryptic species differs among higher parasite taxa, to better calibrate estimates of diversity and monitor diseases. Using published reports of cryptic species of helminth parasites identified using molecular tools, I show that the number of species found is strongly related to the number of parasite individuals sequenced, weakly influenced by the number of host species from which parasites were obtained, and unaffected by the genetic markers used. After correction for these factors, more cryptic species of trematodes are found than in other helminth taxa. Although several features distinguish trematodes from other helminths, it is probable that our inability to discriminate among sibling species of trematodes results from their lack of structures serving as species-specific morphological markers. The available data suggest that current estimates of helminth diversity may need to be doubled (tripled for trematodes) to better reflect extant diversity.

scholarly journals Sex aggregation and species segregation cues in swarming mosquitoes: role of ground visual markers

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Serge B. Poda ◽  
Charles Nignan ◽  
Olivier Gnankiné ◽  
Roch K. Dabiré ◽  
Abdoulaye Diabaté ◽  
...  
Keyword(s):  
Experimental Conditions ◽  
Closely Related Species ◽  
Laboratory Setup ◽  
Visual Markers ◽  
Constant Distance ◽  
Species Specific ◽  
Marker Size ◽  
Swarm Size ◽  
Species Segregation

Abstract Background Mating swarm segregation in closely related insect species may contribute to reproductive isolation. Visual markers are used for swarm formation; however, it is unknown whether they play a key role in swarm location, species segregation and sex aggregation. Methods Using two sympatric closely related species of the Anopheles gambiae complex, An. coluzzii and An. gambiae (s.s.), we investigated in both laboratory and semi-field conditions (i) whether males of the two species use visual markers (black cloths) to locate their swarm; and (ii) whether the presence/absence and size of the marker may differentially affect swarm characteristics. We also investigated whether conspecific virgin females use these markers to join male swarm sites. Results We showed that males of the two species used visual markers but in different ways: An. coluzzii swarm right above the marker whereas An. gambiae (s.s.) locate their swarm at a constant distance of 76.4 ± 0.6 cm from a 20 × 20 cm marker in the laboratory setup and at 206 ± 6 cm from a 60 × 60 cm marker in the semi-field setup. Although increased marker size recruited more mosquitoes and consequently increased the swarm size in the two species, An. coluzzii swarms flew higher and were stretched both vertically and horizontally, while An. gambiae (s.s.) swarms were only stretched horizontally. Virgin females displayed a swarm-like behavior with similar characteristics to their conspecific males. Conclusions Our results provided experimental evidence that both An. coluzzii and An. gambiae (s.s.) males use ground visual markers to form and locate their swarm at species-specific locations. Moreover, the marker size differentially affected swarm characteristics in the two species. Our results also showed that virgin females displayed a swarm-like behavior. However, these “swarms” could be due to the absence of males in our experimental conditions. Nevertheless, the fact that females displayed these “swarms” with the same characteristics as their respective males provided evidence that visual markers are used by the two sexes to join mating spots. Altogether, this suggests that visual markers and the way species and sexes use them could be key cues in species segregation, swarm location and recognition.

Inferring prior distributions of recruitment compensation metrics from life-history parameters and allometries

2020 ◽  
Vol 77 (2) ◽  
pp. 295-313 ◽  
Author(s):  
Joseph Munyandorero
Keyword(s):  
Life Histories ◽  
Growth Parameters ◽  
Meta Analysis ◽  
The United States ◽  
Prior Distributions ◽  
Compensation Ratio ◽  
Species Specific ◽  
Meta Analyses ◽  
The Relationship ◽  
Spawning Biomass

The recruitment compensation metrics, the stock–recruit steepness (h) and compensation ratio (κ), are difficult to estimate, yet they are integral components of contemporary fishery models. To aid in the estimation of κ and h, a hybrid method to construct their prior distributions for a species is developed. The method is hybrid because it integrates (i) a meta-analysis of the relationship between maximum rates of recruit production (α) and asymptotic lengths obtained across fish species of different life histories and (ii) species-specific unfished spawning biomass per recruit (Φ0). This method is applied to five finfish species found off the East Coast of the United States. Uncertainty is introduced by sampling growth parameters, α, and natural mortality and — through Monte Carlo simulations — propagated into Φ0, κ, and h for the Beverton–Holt and Ricker stock–recruit relationships. Descriptive statistics and parameters from probability density functions of the simulated distributions of κ and h are generated. The method developed requires fewer inputs than the reproductive ecology method while likewise allowing the development of species-specific statistics for κ and h. These statistics, rather than their counterparts generated from classical meta-analyses, are better suited for use in fishery models.

scholarly journals Restoration Scaling Approaches to Addressing Ecological Injury: The Habitat-Based Resource Equivalency Method

2020 ◽  
Vol 65 (2) ◽  
pp. 161-177 ◽  
Author(s):  
Mary Baker ◽  
Adam Domanski ◽  
Terill Hollweg ◽  
Jason Murray ◽  
Diana Lane ◽  
...  
Keyword(s):  
Natural Resource ◽  
Oil Spills ◽  
Error Rates ◽  
Hazardous Substances ◽  
Habitat Equivalency Analysis ◽  
Natural Resource Damage Assessment ◽  
As Species ◽  
Ecological Habitat ◽  
Multiple Species ◽  
Species Specific

AbstractNatural resource trustee agencies must determine how much, and what type of environmental restoration will compensate for injuries to natural resources that result from releases of hazardous substances or oil spills. To fulfill this need, trustees, and other natural resource damage assessment (NRDA) practitioners have relied on a variety of approaches, including habitat equivalency analysis (HEA) and resource equivalency analysis (REA). The purpose of this paper is to introduce the Habitat-Based Resource Equivalency Method (HaBREM), which integrates REA’s reproducible injury metrics and population modeling with HEA’s comprehensive habitat approach to restoration. HaBREM is intended to evaluate injury and restoration using organisms that use the habitat to represent ecological habitat functions. This paper seeks to expand and refine the use of organism-based metrics (biomass-based REA), providing an opportunity to integrate sublethal injuries to multiple species, as well as the potential to include error rates for injury and restoration parameters. Applied by NRDA practitioners in the appropriate context, this methodology can establish the relationship between benefits of compensatory restoration projects and injuries to plant or animal species within an affected habitat. HaBREM may be most effective where there are appropriate data supporting the linkage between habitat and species gains (particularly regionally specific habitat information), as well as species-specific monitoring data and predictions on the growth, density, productivity (i.e., rate of generation of biomass or individuals), and age distributions of indicator species.

A routine test for the relative susceptibility of potato genotypes with resistance to Meloidogyne chitwoodi

Nematology ◽  
2016 ◽  
Vol 18 (9) ◽  
pp. 1079-1094 ◽  
Author(s):  
Misghina G. Teklu ◽  
Corrie H. Schomaker ◽  
Thomas H. Been ◽  
Leendert P.G. Molendijk
Keyword(s):  
Logistic Model ◽  
Multiplication Rate ◽  
Experimental Conditions ◽  
Meloidogyne Chitwoodi ◽  
Second Stage ◽  
Final Population ◽  
Pot Size ◽  
Optimal Protocol ◽  
Dry Soil ◽  
Resistant Genotypes

The population dynamics of Meloidogyne chitwoodi on eight potato genotypes was compared to the susceptible cv. Desiree in four glasshouse experiments. The initial nematode densities consisted of log series 2x, with . Seinhorst’s logistic model was fitted to the final population densities to estimate the parameters maximum multiplication rate (a), maximum population density (M) and the ratios RSa, RSM and . Average RSa and RSM of the seven resistant genotypes were smaller than 0.29%. The ratios on six resistant genotypes and cv. Desiree were the same, 1.3, indicating independence of RS. One genotype stood out with , whereby RSa < RSM. Both RS and were unaffected by pot size or experimental conditions. Screening protocols at second-stage juveniles (g dry soil)−1 in 2 or 3 kg pots were evaluated for distinctiveness between the two genotype groups. Based on the results, an optimal protocol for a routine resistance test is proposed.

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