Efficiency of a herbivore–plant interaction: conversion of biomass from flax (Linaceae) to aphid, Macrosiphum euphorbiae (Hemiptera: Aphididae)

2008 ◽  
Vol 140 (5) ◽  
pp. 600-602 ◽  
Author(s):  
Robert J. Lamb ◽  
Larry Grenkow
Keyword(s):  
Plant Tissue ◽  
Linum Usitatissimum ◽  
Biomass Conversion ◽  
Dry Mass ◽  
Trophic Levels ◽  
Macrosiphum Euphorbiae ◽  
Dicotyledonous Plant ◽  
Plant Interaction ◽  
Specific Impact

AbstractThe specific impact of the aphid Macrosiphum euphorbiae (Thomas) on seedlings of common flax, Linum usitatissimum L., is 3.317 mg/mg, quantified as the dry mass of plant tissue required to produce a unit of herbivore tissue. This measure of the efficiency of biomass conversion between trophic levels for the aphid–flax interaction is similar to that previously reported for seven species of aphid on monocotyledonous cereals (Poaceae), but lower than that for two species of aphid on a species of Brassicaceae, a dicotyledonous plant. Therefore, the interaction between M. euphorbiae and the dicot, flax, does not support the hypothesis that aphids have less impact on monocots than on dicots.

Insect–Plant Interactions: A Multilayered Relationship

2020 ◽  
Author(s):  
Garima Sharma ◽  
Praful Ashokrao Malthankar ◽  
Vartika Mathur
Keyword(s):  
Plant Resistance ◽  
Crucial Role ◽  
Chemical Cues ◽  
Defense Responses ◽  
Trophic Levels ◽  
Plant Interactions ◽  
Plant Metabolites ◽  
Specific Chemical ◽  
Plant Interaction ◽  
Morphological Defense

Abstract During herbivory, insects recognize their host plant based on specific chemical cues, whereas the plants induce various chemical and morphological defense responses to resist this attack. However, the seemingly bidirectional insect–plant interaction involves various confounding aspects that influence the performance and fitness of the two participants. These interactions are often mediated by associated microbiota, competitors, predators, and parasitoids that interact in either obligate or facultative manner. Insect endosymbionts play a crucial role in the perception, nutrition, metabolism as well as reproduction of their host, which together determine its survival and fitness on the plant. Endosymbionts also help their host to overcome plant defenses by detoxifying plant metabolites. On the contrary, plant-associated microbes contribute in induced systemic plant resistance by enhancing chemical and morphological defense. These interactions determine the association of insect and plant, not only with the high trophic levels but also with the ecosystem as a whole. Thus, insect–plant interaction is a multilayered relationship extending to various micro- and macro-organisms associated either temporally or spatially. All these relationships may be considered to obtain a wholesome perspective of the natural environment.

scholarly journals Response of nutrients, biofilm, and benthic insects to salmon carcass addition

2006 ◽  
Vol 63 (6) ◽  
pp. 1230-1241 ◽  
Author(s):  
Shannon M Claeson ◽  
Judith L Li ◽  
Jana E Compton ◽  
Peter A Bisson
Keyword(s):  
Leaf Litter ◽  
Litter Decomposition ◽  
Headwater Streams ◽  
Dry Mass ◽  
Trophic Levels ◽  
Leaf Litter Decomposition ◽  
Ammonium Concentration ◽  
Benthic Insects ◽  
Salmon Carcass ◽  
Density And Biomass

Salmon carcass addition to streams is expected to increase stream productivity at multiple trophic levels. This study examined stream nutrient (nitrogen, phosphorus, and carbon), epilithic biofilm (ash-free dry mass and chlorophyll a), leaf-litter decomposition, and macroinvertebrate (density and biomass) responses to carcass addition in three headwater streams of southwestern Washington State, USA. We used stable isotopes (δ13C and δ15N) to trace incorporation of salmon-derived (SD) nutrients into stream food webs. SD nutrients were assimilated by biofilm, benthic insects (Perlidae and Limnephilidae spp.), and age-1 steelhead (Oncorhynchus mykiss gairdneri). SD nutrients peaked ~2 weeks after carcass addition for insects and fish feeding on carcasses, but indirect uptake of SD nutrients by biofilm and insects was delayed by ~2 months. A strong stable isotope signal did not always correspond with measurable biological change. At reaches 10–50 m downstream from carcasses, ammonium concentration, leaf-litter decomposition, and benthic insect density all increased relative to upstream control sites. The strongest responses and greatest SD-nutrient uptake were observed 10 m from decomposing carcasses, with effects generally decreasing to undetectable levels 250 m downstream. Carcass addition to headwater streams can have a transient effect on primary and secondary trophic levels, but responses may be limited to specific taxa near carcass locations.

Assessing food-web structure, matter fluxes, and system attributes of a Central European mountain stream by performing mass-balanced network analysis

2004 ◽  
Vol 61 (9) ◽  
pp. 1565-1581 ◽  
Author(s):  
Elisabeth I Meyer ◽  
Rainer Poepperl
Keyword(s):  
Food Web ◽  
Salmo Trutta ◽  
Dry Mass ◽  
Trophic Levels ◽  
Mountain Stream ◽  
Food Web Structure ◽  
Total Consumption ◽  
Cottus Gobio ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Brown Trout Salmo Trutta

Trophic interactions and cycling of matter within the community in a soft-water mountain stream were analyzed on the basis of a compartment food-web model. The model describes (i) the structure of the food web, quantifying biomass, production, and consumption of individual elements as well as of the entire system, and (ii) the flow of matter between compartments as well as trophic levels. Detritus and primary producers sustain a broad variety of invertebrate consumers. Fishes are the top predators; sculpin (Cottus gobio) and a compartment consisting of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) are at the highest trophic level. Heterotrophic microorganisms (227.1 g dry mass (DW)·m–2·year–1) and aufwuchs algae (150.1 g DW·m–2·year–1) have the highest production. Secondary production of fishes and macroinvertebrates amounts to 2.56 and 19.9 g DW·m–2·year–1, respectively. Total consumption amounts to 1136.41 g DW·m–2·year–1. Main flows occur between the lower trophic levels. Food intake is greatest for microorganisms and Ephemeroptera. A relatively high fraction of invertebrate production is consumed by predators. For 10 of 19 compartments, over 95% of production is used as food by other organisms. Transfer efficiencies are generally low (<10%). A large proportion of matter transfer occurs at the lower discrete trophic levels of the stream.

scholarly journals Conversion of Mixtures of Soybean Curd Residue and Kitchen Waste by Black Soldier Fly Larvae (Hermetia illucens L.)

Insects ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 23
Author(s):  
Xinfu Li ◽  
Zhihao Zhou ◽  
Jing Zhang ◽  
Shen Zhou ◽  
Qiang Xiong
Keyword(s):  
Animal Feed ◽  
Biomass Conversion ◽  
Dry Mass ◽  
Biodiesel Production ◽  
Least Squares Regression ◽  
Kitchen Waste ◽  
Black Soldier Fly ◽  
Hermetia Illucens ◽  
Soybean Curd ◽  
Soybean Curd Residue

The production of insect biomass from organic waste is a major challenge in terms of reducing the environmental impacts of waste and maintaining feed and food security. The feasibility of the co-conversion of soybean curd residue (SCR) and kitchen waste (KW) to breed black soldier fly (BSF, Hermetia illucens) larvae was evaluated so as to enhance biomass conversion efficiency and supply animal feed and allow it to be used in biodiesel production. Co-digestion was found to significantly increase larval yield, bioconversion rate, and bioaccumulation of lipid. Partial least squares regression showed that the conversion of 30% SCR with 70% KW is an appropriate proportion. The appropriate performance parameters of BSF were: survival rate (98.75%), prepupal rate (88.61%), larval biomass (30.32 g fresh and 11.38 g dry mass), bioconversion rate (18.45%), efficiency conversion of ingested food (ECI) (28.30%), and FCR (2.51). Our results show that conversion of mixtures (e.g., SCR with KW) by BSF larvae (BSFL) could play an important role in various organic materials management.

scholarly journals Identifying conversion efficiency as a key mechanism underlying food webs evolution: A step forward, or backward?

2019 ◽  
Author(s):  
Coralie Fritsch ◽  
Sylvain Billiard ◽  
Nicolas Champagnat
Keyword(s):  
Body Size ◽  
Food Webs ◽  
Conversion Efficiency ◽  
Biomass Conversion ◽  
Adaptive Dynamics ◽  
Trophic Levels ◽  
Evolutionary Models ◽  
Key Factors ◽  
Main Factors ◽  
Dynamics Models

AbstractBody size or mass is generally seen as one of the main factors which structure food webs. A large number of evolutionary models have shown that indeed, the evolution of body size (or mass) can give rise to hierarchically organized trophic levels with complex between and within trophic interactions. However, because these models have often very different assumptions, sometimes arbitrary, it is difficult to evaluate what are the real key factors that determine food webs evolution, and whether these models’ results are robust or not. In this paper, we first review the different adaptive dynamics models, especially highlighting when their assumptions strongly differ. Second, we propose a general model which encompasses all previous models. We show that our model recovers all previous models’ results under identical assumptions. However, most importantly, we also show that, when relaxing some of their hypotheses, previous models give rise to degenerate food webs. Third, we show that the assumptions made regarding the form of biomass conversion efficiency are key for food webs evolution, a parameter which was neglected in previous models. We conclude by discussing the implication of biomass conversion efficiency, and by questioning the relevance of such models to study the evolution of food webs.

Influence of salmon spawner densities on stream productivity in Southeast Alaska

1999 ◽  
Vol 56 (9) ◽  
pp. 1600-1611 ◽  
Author(s):  
Mark S Wipfli ◽  
John P Hudson ◽  
Dominic T Chaloner ◽  
John P Caouette
Keyword(s):  
Chlorophyll A ◽  
Pink Salmon ◽  
Dry Mass ◽  
Trophic Levels ◽  
Oncorhynchus Gorbuscha ◽  
Southeast Alaska ◽  
Natural Stream ◽  
Forest Stream ◽  
Natural Streams ◽  
Freshwater Salmon

We conducted this study to determine the relationship between salmon spawner abundance and stream biofilm and benthic macroinvertebrate abundance in Southeast Alaska. Experiments took place in outdoor artificial and natural streams. Six pink salmon (Oncorhynchus gorbuscha) carcass treatments (0.00, 1.45, 2.90, 4.35, 5.80, and 7.25 kg wet mass) placed in artificial channels were subsampled repeatedly for biofilm ash-free dry mass (AFDM), chlorophyll a, and macroinvertebrates. In a small (nonanadromous) forest stream, we sampled benthos throughout a 66-m reach 17 days after distributing 60 carcasses along the lower half of that reach. All response variables significantly increased in response to carcass additions in both artificial and natural streams. Chlorophyll a continued to increase across all loading rates, while AFDM and total macroinvertebrate densities showed no further response to loading beyond the first treatment (1.45 kg) in artificial streams. In the natural stream, AFDM and chironomid densities continued increasing across loading levels. These results indicated that increased spawner densities increased lower trophic level abundance until a trophic capacity was reached. Salmon escapement goals should consider food web effects, especially on trophic levels that support juvenile salmonids, that ultimately affect freshwater salmon production.

Latent infections and residues of the bioherbicide agentColletotrichum gloeosporioidesf.sp.malvae

Weed Science ◽  
1999 ◽  
Vol 47 (5) ◽  
pp. 589-595 ◽  
Author(s):  
Roberte M. D. Makowski ◽  
Knud Mortensen
Keyword(s):  
Brassica Napus ◽  
Plant Tissue ◽  
Linum Usitatissimum ◽  
Lens Culinaris ◽  
Colletotrichum Gloeosporioides ◽  
Growing Season ◽  
Carthamus Tinctorius ◽  
Wash Water ◽  
Latent Infections ◽  
Growing Seasons

Latent infections ofColletotrichum gloeosporioidesf.sp.malvae(C. g. malvae) in plants and seed were determined in several crops under field conditions after application ofC. g. malvaeconidia at 12 times the recommended rate.Colletotrichum g. malvaewas isolated in trace amounts fromBrassica napus/campestris, Linum usitatissimum, Lens culinaris, Brassica juncea/hirta, Helianthus annuus, andTriticumspp. only at the 2-wk isolation.Colletotrichum g. malvaewas never isolated fromBeta vulgaris.After 5 wk,C. g. malvaewas not detected in any of the crops, except forCarthamus tinctoriusat harvest, and was not detected from wash water of plant tissue or seed after 72 h.Colletotrichum g. malvaerecovery in the field, as in controlled environmental conditions, decreased with time, which indicates that buildup of inoculum did not occur. Fungi other thanC. g. malvaeand bacteria isolated from seed and from wash water of plant tissue increased with time throughout the growing season.Colletotrichum g. malvaewas not recovered from seed or crowns of any of the crop cultivars at either location in either growing season, except forC. tinctorius.Only one seed of theC. tinctoriuscultivar ‘S-208’ out of 17,280C. tinctoriusseed analyzed over three growing seasons tested positive forC. g. malvae. Colletotrichum g. malvaewas found only on the seed coat; the germinated seedling was not infected.Colletotrichum g. malvaewas not recovered from any of the wash water from seed. These results should alleviate any of the concerns regarding the fate of the millions of conidia applied during a normal spray operation on nontarget plants, the potential infectivity of nontarget plants, the potential buildup ofC. g. malvaein the field, and the utilization of any of theC. g. malvae-treated crops for food or feed.

scholarly journals Germination and vigor of linseed seeds under different conditions of light, temperature and water stress

2017 ◽  
Vol 38 (3) ◽  
pp. 1161 ◽  
Author(s):  
Raquel Stefanello ◽  
Bruna Boucinha Viana ◽  
Luiz Augusto Salles das Neves
Keyword(s):  
Water Stress ◽  
Linum Usitatissimum ◽  
Dry Mass ◽  
Seedling Development ◽  
Raw Material ◽  
Economic Potential ◽  
Linum Usitatissimum L ◽  
Normal Seedling ◽  
Presence And Absence ◽  
Osmotic Potentials

Linseed (Linum usitatissimum L.), cultivated from seeds, is one of the oldest plants domesticated by humans and is popularly used as a medicine. It can be used as the raw material to produce oil and bran because it has high lipids content, fiber and proteins. Based on the economic potential of this species and the need for more information about its physiology, the goal of this study was to analyze the effects of light, temperature and water stress on the germination and vigor of linseed seeds. In experiment I the seeds were sown on paper at constant temperatures of 15, 20, 25 and 30 ºC in the presence and absence of light. In experiment II, the seeds were placed on paper germitest soaked in solutions of polyethylene glycol (PEG 6000) at osmotic potentials corresponding to zero, -0.10, -0.20, -0.30, -0.40, -0.50 and -0.60 MPa. To evaluate the physiological potential, the following tests were made: germination, first germination count, length and dry mass of seedlings, and water stress. It was found that the highest percentages of germination and vigor occurred at a constant temperature of 20 °C, both in the presence and absence of light. The reduction of the osmotic potential of the substrate promoted a significant decrease in the germination and vigor of the linseed seeds. Osmotic potentials equal or less than -0.30 MPa were harmful to germination and there was no normal seedling development starting at -0.50 MPa.

scholarly journals Trade-off in plant-ant interactions: seasonal variations

2020 ◽  
Vol 80 (4) ◽  
pp. 921-933
Author(s):  
J. Martins ◽  
A. Moreira ◽  
M. Assunção ◽  
A. Oliveira ◽  
J. Almeida
Keyword(s):  
Ecological Model ◽  
Dry Season ◽  
Trophic Levels ◽  
Plant Fitness ◽  
Biotic Factors ◽  
Seasonally Dry ◽  
Plant Interaction ◽  
Dry Tropical Forests ◽  
Systematic Collection ◽  
Dry And Rainy Seasons

Abstract This work evaluated the effect of seasonality on ant-plant interaction in a Seasonally Dry Tropical Forests, using as an ecological model the species Ipomoea carnea subs. fistulosa (Convolvulaceae). We performed systematic collection of ants, herbivores and leaves in marked plants, evaluated the efficiency of herbivorous capture by ants, and the effects of ant presence over the pollinator behavior and plant fitness in dry and rainy seasons. The presence of ants in the plants reduced the number of herbivores (dry season: F2.27=4.7617, p=0.0166; rainy season: F2.27=5.8655, p=0.0078). However, the capture efficiency was negatively affected by the presence of myrmecophilous larvae, so that the average of ants recruited on termite leaves was 2.06 ants per termite, the average recruitment of ants on larval leaves was 22.4 larva ants. In addition, the presence of ants reduced pollinator visits and promoted fruit reduction during the dry season (ANOVA: F = 3.44; p = 0.0653). In conclusion, the association with ants can result in a balance not always favorable to the host plant, and this result actually depends on abiotic (e.g. precipitation) and biotic factors (e.g. ant species composition and abundance, influence of other trophic levels and identity of associated herbivores).

Demonstration of a Pilot-Scale Plant for Biomass Torrefaction and Briquetting

2018 ◽  
Vol 34 (1) ◽  
pp. 85-98 ◽  
Author(s):  
Mark A. Severy ◽  
Charles E. Chamberlin ◽  
Anthony J. Eggink ◽  
Arne E. Jacobson
Keyword(s):  
Energy Density ◽  
Moisture Content ◽  
Pilot Plant ◽  
Biomass Conversion ◽  
Dry Mass ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Scale Production ◽  
Long Distance ◽  
Throughput Rate

Abstract. A semi-mobile torrefaction and densification pilot plant was constructed in order to determine ideal operating conditions and evaluate briquette quality and throughput rate using forest residuals as the input feedstock. Experiments were conducted at various conditions with feedstock moisture content ranging from 4% to 25% (wet basis), reactor residence times of 10 and 20 min, and final product temperatures between 214°C and 324°C. Optimal operating conditions, evaluated based on throughput rate, specific electricity demand, torrefied briquette grindability, briquette volumetric energy density, and briquette durability, were identified to occur with a short residence time (10 min), low feedstock moisture content (&lt;11% wet basis), and high final product temperature between 267°C and 275°C. These conditions were able to process 510 to 680 kg h-1 (wet basis) feedstock with a dry mass yield of 79% to 84% to produce torrefied biomass with a higher heating value of 21.2 to 23.0 MJ kg-1 (dry basis) compared to 19.6 MJ kg-1 for the original biomass. Torrefied briquettes produced at these conditions had a neatly stacked packing density of 990 kg m-3 and a volumetric energy density of 21,800 MJ m-3. Their specific grinding energy was an average 37% of the energy required to grind a raw biomass briquette. These torrefied briquettes were more durable (94% DU) than raw briquettes (85% DU) directly following production, but were less durable after undergoing temperature and humidity fluctuations associated with long distance transportation (74% DU for torrefied and 84% DU for raw biomass briquettes). Results from this pilot plant are promising for commercial scale production of high quality torrefied briquettes and should lead to additional research and development of a torrefaction system optimized for a higher throughput rate at these conditions. Keywords: Biomass, Biomass conversion technology, Bioenergy, Briquetting, Densification, Forest residuals, Pyrolysis, Torrefaction.

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