scholarly journals Seed Removal Rates in Forest Remnants Respond to Forest Loss at the Landscape Scale

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1144
Author(s):  
Alain Hambuckers ◽  
Franck Trolliet ◽  
Astrid Simon ◽  
Eliana Cazetta ◽  
Larissa Rocha-Santos
Keyword(s):  
Forest Cover ◽  
Removal Rate ◽  
Supply And Demand ◽  
Landscape Scale ◽  
Fast Method ◽  
Seed Removal ◽  
Removal Rates ◽  
Forest Remnants ◽  
Forested Landscapes ◽  
Plant Animal Interactions

Seed removal is a key component of seed dispersal and may be influenced by both landscape-scale and local attributes, and it has been used as an indicator of the intensity of interactions between ecosystem components. We examined how the seed removal rates, which integrate the activity of seed dispersers and seed predators, vary with landscape-scale forest cover. We collected data under 34 trees belonging to two zoochoric species (Helicostylis tomentosa (Poepp. and Endl.) J. F. Macbr. and Inga vera Willd.) in 17 remnants in the Brazilian Atlantic forest, with different percentages of forest cover. The seed removal rate was estimated using a fast method based on the abundance of intact fruits and fruit scraps on the ground. The amount of forest cover affected the rate of seed removal in a humpbacked shape, with a maximum seed removal rate at intermediate forest cover. Seed removal rates must be related to the amount of food resources offered and diversity of dispersers and predators in the region. In landscapes with intermediate forest amount, there is a better balance between supply and demand for fruits, leading to a higher seed removal rate than more deforested or forested landscape. Our results also show that local factors, such as crop size and canopy surface, together with forest cover amount, are also important to the removal rate, depending on the species. In addition, our results showed that plant–animal interactions are occurring in all fragments, but the health status of these forests is similar to disturbed forests, even in sites immersed in forested landscapes.

scholarly journals Post-Dispersal Seed Removal in a Large-Seeded Palm by Frugivore Mammals in Western Ecuador

2020 ◽  
Vol 13 ◽  
pp. 194008292094704
Author(s):  
Sebastián Escobar ◽  
Onja H. Razafindratsima ◽  
Rommel Montúfar ◽  
Henrik Balslev
Keyword(s):  
Forest Cover ◽  
Camera Trap ◽  
Agroforestry System ◽  
Seed Removal ◽  
Mammal Species ◽  
Removal Rates ◽  
Removal Experiments ◽  
Phytelephas Aequatorialis ◽  
Disturbed Forest ◽  
Dispersal Events

Post-dispersal seed removal by ground-foraging frugivores promotes secondary dispersal of large seeds, reducing seed predation and increasing recruitment and regeneration. We studied how habitat disturbance influences seed removal patterns in the large-seeded palm Phytelephas aequatorialis within three habitats forming a continuum of disturbance (agroforestry system, disturbed forest, and less-disturbed forest) using seed removal experiments and camera trapping. We tested whether seed removal rates, and both richness and composition of seed remover communities varied between the habitats. On average, 15 seeds were removed under each tree in the agroforestry system over seven days, which was significantly lower compared to the disturbed forest (18) and the less-disturbed forest (19). Eight mammal species were identified removing seeds in the three habitats. On average, one mammal species removed seeds at each station in the agroforestry system, which was significantly lower than the two species observed in the two forests. The composition of seed remover communities was significantly different between the three habitats. Our results suggest that the loss of forest cover in the agroforestry system has reduced the richness of seed removers, which subsequently caused decreased removal rates. Nevertheless, this habitat could still maintain effective seed dispersal events because spiny rats were important seed removers. Our camera trap data should be taken as preliminary because we could only identify less than half of the animals responsible for seed removal. This study highlights the importance of medium- and large-sized rodents for the removal and effective dispersal of large seeds in disturbed tropical habitats.

Analysis of organic removal rates in the aerated submerged fixed film process

1998 ◽  
Vol 38 (8-9) ◽  
pp. 213-221 ◽  
Author(s):  
Mohamed F. Hamoda ◽  
Ibrahim A. Al-Ghusain
Keyword(s):  
Pilot Plant ◽  
Removal Rate ◽  
Domestic Wastewater ◽  
Removal Rates ◽  
Hydraulic Loading ◽  
Organic Removal ◽  
Wide Range ◽  
Fixed Film ◽  
Cod Removal Rate ◽  
And Performance

Performance data from a pilot-plant employing the four-stage aerated submerged fixed film (ASFF) process treating domestic wastewater were analyzed to examine the organic removal rates. The process has shown high BOD removal efficiencies (> 90%) over a wide range of hydraulic loading rates (0.04 to 0.68 m3/m2·d). It could also cope with high hydraulic and organic loadings with minimal loss in efficiency due to the large amount of immobilized biomass attained. The organic (BOD and COD) removal rate was influenced by the hydraulic loadings applied, but organic removal rates of up to 104 kg BOD/ m2·d were obtained at a hydraulic loading rate of 0.68 m3/m2·d. A Semi-empirical model for the bio-oxidation of organics in the ASFF process has been formulated and rate constants were calculated based on statistical analysis of pilot-plant data. The relationships obtained are very useful for analyzing the design and performance of the ASFF process and a variety of attached growth processes.

The comparison of trichloroethylene removal rates by methane- and aromatic-utilizing microorganisms

1998 ◽  
Vol 38 (7) ◽  
pp. 19-24 ◽  
Author(s):  
C.-J. Lu ◽  
C. M. Lee ◽  
M.-S. Chung
Keyword(s):  
Cell Concentration ◽  
Removal Rate ◽  
Carbon Sources ◽  
Batch Reactors ◽  
Initial Cell Concentration ◽  
Removal Rates ◽  
Initial Cell ◽  
Toluene Concentration ◽  
Cell Source ◽  
Removal Efficiencies

The comparison of TCE cometabolic removal by methane, toluene, and phenol utilizers was conducted with a series of batch reactors. Methane, toluene, or phenol enriched microorganisms were used as cell source. The initial cell concentration was about 107 cfu/mL. Methane, toluene, and phenol could be readily biodegraded resulting in the cometabolic removal of TCE. Among the three primary carbon sources studied, the presence of phenol provided the best cometabolic removal of TCE. When the concentration of carbon source was 3 mg-C/L, the initial TCE removal rates initiated by methane, toluene, and phenol utilizers were 1.5, 30, and 100 μg/L-hr, respectively. During the incubation period of 80 hours, TCE removal efficiencies were 26% and 96% with the presence of methane and toluene, respectively. However, it was 100% within 20 hours with the presence of phenol. For phenol utilizers, the initial TCE removal rates were about the same, when the phenol concentrations were 1.35, 2.7, and 4.5 mg/L. However, TCE removal was not proportional to the concentrations of phenol. TCE removal was hindered when the phenol concentration was higher than 4.5 mg/L because of the rapid depletion of dissolved oxygen. The presence of toluene also initiated cometabolic removal of TCE. The presence of toluene at 3 and 5 mg/L resulted in similar TCE removal. The initial TCE removal rate was about 95 μg/L-hr at toluene concentrations of 3 and 5 mg/L compared to 20 μg/L-hr at toluene concentration of 1 mg/L.

Relations between carbon removal rates, biofilm size and density of a novel anaerobic reactor: the inverse turbulent bed

2000 ◽  
Vol 41 (4-5) ◽  
pp. 253-260 ◽  
Author(s):  
P. Buffière ◽  
R. Moletta
Keyword(s):  
Removal Rate ◽  
Removal Rates ◽  
Carbon Removal ◽  
Biofilm Growth ◽  
Loading Rates ◽  
Biomass Activity ◽  
High Turbulence ◽  
The One ◽  
High Level ◽  
Very High

An anaerobic inverse turbulent bed, in which the biogas only ensures fluidisation of floating carrier particles, was investigated for carbon removal kinetics and for biofilm growth and detachment. The range of operation of the reactor was kept within 5 and 30 kgCOD· m−3· d−1, with Hydraulic Retention Times between 0.28 and 1 day. The carbon removal efficiency remained between 70 and 85%. Biofilm size were rather low (between 5 and 30 μm) while biofilm density reached very high values (over 80 kgVS· m−3). The biofilm size and density varied with increasing carbon removal rates with opposite trends; as biofilm size increases, its density decreases. On the one hand, biomass activity within the reactor was kept at a high level, (between 0.23 and 0.75 kgTOC· kgVS· d−1, i.e. between 0.6 and 1.85 kgCOD·kgVS · d−1).This result indicates that high turbulence and shear may favour growth of thin, dense and active biofilms. It is thus an interesting tool for biomass control. On the other hand, volatile solid detachment increases quasi linearly with carbon removal rate and the total amount of solid in the reactor levels off at high OLR. This means that detachment could be a limit of the process at higher organic loading rates.

scholarly journals Enhanced Wastewater Treatment by Immobilized Enzymes

2021 ◽  
Author(s):  
Jakub Zdarta ◽  
Katarzyna Jankowska ◽  
Karolina Bachosz ◽  
Oliwia Degórska ◽  
Karolina Kaźmierczak ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Process Optimization ◽  
Organic Pollutants ◽  
Large Scale ◽  
Removal Rate ◽  
Immobilized Enzymes ◽  
Future Research ◽  
Process Conditions ◽  
Removal Rates ◽  
Catalytic Cycles

Abstract Purpose of Review In the presented review, we have summarized recent achievements on the use of immobilized oxidoreductases for biodegradation of hazardous organic pollutants including mainly dyes, pharmaceuticals, phenols, and bisphenols. In order to facilitate process optimization and achievement of high removal rates, effect of various process conditions on biodegradation has been highlighted and discussed. Recent Findings Current reports clearly show that immobilized oxidoreductases are capable of efficient conversion of organic pollutants, usually reaching over 90% of removal rate. Further, immobilized enzymes showed great recyclability potential, allowing their reuse in numerous of catalytic cycles. Summary Collected data clearly indicates immobilized oxidoreductases as an efficient biocatalytic tools for removal of hazardous phenolic compounds, making them a promising option for future water purification. Data shows, however, that both immobilization and biodegradation conditions affect conversion efficiency; therefore, process optimization is required to achieve high removal rates. Nevertheless, we have demonstrated future trends and highlighted several issues that have to be solved in the near-future research, to facilitate large-scale application of the immobilized oxidoreductases in wastewater treatment.

Lubricant Removal, Degradation, and Recovery on Particulate Magnetic Recording Media

1992 ◽  
Vol 114 (1) ◽  
pp. 61-67 ◽  
Author(s):  
V. J. Novotny ◽  
T. E. Karis ◽  
N. W. Johnson
Keyword(s):  
Bulk Viscosity ◽  
Magnetic Recording ◽  
Photoelectron Spectroscopy ◽  
Removal Rate ◽  
Lateral Diffusion ◽  
Recording Media ◽  
Magnetic Recording Media ◽  
Removal Rates ◽  
Linear Chains ◽  
Mechanical Durability

Lubrication of particulate magnetic recording media improves their mechanical durability in sliding and flying by several orders of magnitude compared with unlubricated media. Lubricant removal, degradation, and recovery were studied using microslit scanning Fourier transform infrared spectroscopy and microspot scanning X-ray photoelectron spectroscopy. These techniques measure the total and surface lubricant amounts in the porous film, respectively. Lubricant dynamics were compared for two physisorbed polyperfluoroalkylether lubricants of similar molecular weight but different molecular structure—Y with a CF3 side group and Z with linear chains. The bulk viscosity of Y was about ten times higher than the viscosity of Z. In sliding, the lubricant removal rate of Y was significantly higher than that of Z while in flying the removal rates were reversed. Removal rates in sliding were orders of magnitude higher than those in flying. Effective lateral diffusion coefficients estimated from the rate of lubricant reflow back to the depleted tracks were close to inversely proportional to the bulk viscosity. During sliding and flying both lubricants degraded as evidenced by chemically altered lubricant detected on the surfaces after dissolution of undegraded lubricant.

Mechanisms of High Efficiency and Stabilization of Baffled Constructed Wetland in Treatment of Domestic Sewage

2013 ◽  
Vol 295-298 ◽  
pp. 1057-1061 ◽  
Author(s):  
Chang Bing Ye ◽  
Zhi Ming Zhou ◽  
Ke Zhao ◽  
Qin Liu
Keyword(s):  
Constructed Wetland ◽  
Removal Rate ◽  
Short Circuit ◽  
Domestic Sewage ◽  
Wetland Plants ◽  
Stable Operation ◽  
Removal Rates ◽  
Operational Life ◽  
High Efficient ◽  
Hydraulic Load

To solve the problem of short-circuit of individual current constructed wetland, a baffled constructed wetland was designed and applied to treat domestic sewage by our research group. The wetland plants were composed of Eichhormia crassipes, Oenanthe javanica, Cyperusalternifolius, Phragmites communis and Aquatic. The results of 18 month indicated that the optimal hydraulic load of baffled constructed wetland was 2.0~2.2 m3/(m2•d). At the hydraulic load of 2.0m3/(m2•d), the COD, TN and TP removal rates of baffled constructed wetland could be over 76.40%, 76.12%, 65.37%, respectively, at 24°C. When the temperature decreased to 12°C, the COD, TN, TP removal rates of system decreased to 67.56%、62.75% and 61.33%, respectively; The SS removal rate of the first 6 compartments was about 79.5% and that of system could maintain 87.18% during the operation of system. Based on the results of trial, the mechanisms of extending the baffled constructed wetland's operational life was owed to high efficient SS removal rate of the first 6 compartments which was used as constructed wetland and anaerobic baffled reactor (ABR). As a result, the long-term stable operation of system in treatment of domestic sewage was explained with extending about 5 times service life than that of individual current constructed wetland. The mechanisms of higher efficiency of baffled constructed wetland in treatment of domestic sewage were owed to the longer flow line of system and the up-down flow of domestic sewage makes pollutant more intimate contact with roots of wetland plants.

Bird research in the ACWERN lab at the Faculty of Forestry and Environmental Management, University of New Brunswick

2008 ◽  
Vol 84 (4) ◽  
pp. 548-552 ◽  
Author(s):  
Antony W Diamond
Keyword(s):  
New Brunswick ◽  
Forest Cover ◽  
Spatial Scales ◽  
Breeding Habitat ◽  
Research Network ◽  
Spatial Effects ◽  
Winter Habitat ◽  
Forested Landscapes ◽  
Carry Over ◽  
Species Specific

Research on forest bird ecology in the ACWERN (Atlantic Cooperative Wildlife Ecology Research Network) lab at the University of New Brunswick, Fredericton, since 1995 has focused on assessing the relative contributions of habitat quality at large (“landscape”) and small (“local” or “stand”) spatial scales. To do so we had to develop methods for assessing key demographic components of fitness (productivity and survival) at large spatial scales. The large extent of forest cover in the Maritimes contrasts with regions where such work has traditionally been carried out, in which forest is clearly fragmented by agriculture or residential development. Our main findings are that spatial effects in highly forested landscapes can often be detected only by using species-specific habitat models, rather than broader categories such as “mature” or “softwood”, that Blackburnian Warblers (Dendroica fusca) are effective indicators of mixedwood forest but define it differently than forest managers do, and that cavity nesters (e.g., woodpeckers) may require different habitat components for nesting and feeding and so cannot be managed for solely on the basis of providing snags for nesting. Our focus has shifted recently to intensive studies on a species at risk, Bicknell's Thrush (Catharus bicknelli), which in New Brunswick breeds in man-made regenerating softwood forest stands, and assessing its response both to precommercial thinning of the breeding habitat and to effects carrying over from the winter habitat in the Caribbean. Key words: landscape effects, thresholds, survival, productivity, fitness, carry-over, habitat, fragmentation

scholarly journals Effects of microhabitat on rodent-mediated seed removal of endangered Kmeria septentrionalis in the karst habitat

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10378
Author(s):  
Guohai Wang ◽  
Yang Pan ◽  
Guole Qin ◽  
Weining Tan ◽  
Changhu Lu
Keyword(s):  
Predation Risk ◽  
Rattus Norvegicus ◽  
Removal Rate ◽  
Soil Surface ◽  
Predation Rate ◽  
Seed Removal ◽  
Seed Type ◽  
Stone Surface ◽  
Broad Variety ◽  
High Removal Rate

Seed removal behaviors of rodents are largely influenced by microhabitat. Although the karst ecosystem is composed of a broad variety of microhabitats, we have no information on how they affect such behaviors. We investigated rodents’ seed removal behaviors in four karst microhabitats (stone cavern, stone groove, stone surface, and soil surface) using three types of Kmeria septentrionalis seeds: fresh, black (intact seeds with black aril that dehydrates and darkens), and exposed (clean seeds without the aril). We show that Rattus norvegicus, Leopoldamys edwardsi and Rattus flavipectus were the predominant seed predators. Even though all seed types experienced a high removal rate in all four microhabitats, but rodents preferentially removed seeds from the three stone microhabitats (stone caves: 69.71 ± 2.74%; stone surface: 60.53 ± 2.90%; stone groove: 56.94 ± 2.91%) compared to the soil surface (53.90 ± 2.92%). Seeds that had been altered by being exposed to the environment were more attractive to rodents than fresh seeds (76.25 ± 2.20% versus 36.18 ± 2.29%). The seed removal behavior of rodents was significantly affected by the microhabitat and seed type. Finally, seeds that had fallen on the soil surface microhabitat incurred a lower predation risk than seeds fallen on other microhabitats, which increased their probability to germinate. Our results indicate that the lower predation rate of seeds from the endangered K. septentrionalis dropped on the soil surface increases trees’ likelihood of survival.

scholarly journals Effect of Cell Density on the Removal of Microcystis by Coagulation

2020 ◽  
Vol 42 (6) ◽  
pp. 319-326
Author(s):  
Joo Eun Han ◽  
Wontae Lee
Keyword(s):  
Surface Water ◽  
Chlorophyll A ◽  
Cell Density ◽  
Target Cell ◽  
Removal Rate ◽  
Nakdong River ◽  
Removal Rates ◽  
Cell Densities

Objectives:This study evaluated the removal of <i>Microcystis</i> by coagulation in raw waters with three different cell densities.Methods:Raw waters were prepared at three different cell densities (target cell densities of 10,000, 100,000, and 1,000,000 cell/mL; actual cell densities of 9,950, 102,000, and 991,000 cell/mL) by adding <i>Microcystis</i> into surface water from Nakdong river. Jar-tests were conducted with PACL, alum, illite, and loess at dosages of 0-150 mg/L.Results and Discussion:Regardless of coagulant types, the removal rates of <i>Microcystis</i> increased as the coagulant dosages increased. PACl and alum exhibited higher removal rates than illite and loess; PACl was the best coagulant to remove <i>Microcystis</i>. Removal of chlorophyll-a was highest when PACl added at 20.4 mg/L, and no significant increase in removal rate was observed with higher dosages of PACl. However, removal rates of chlorophyll-a by illite and loess gradually increased as the dosages increased.Conclusions:With the coagulants tested in this study, removal rates of <i>Microcystis</i> increased as the coagulant dosages increased. Removal rates of <i>Microcystis</i> increased as the cell densities increased probably because <i>Microcystis</i> acted as particles which could enhance the coagulation efficiency.

Sign in / Sign up

Export Citation Format

Share Document