Positive long-term effect of mulching on species and functional trait diversity in a nutrient-poor mountain meadow in Central Europe

Oligotrophic mountain meadows are threatened biodiversity hotspots throughout Europe. The traditional summer hay-making followed by autumn grazing is no longer economic and question is whether alternative managements can maintain both plant species and functional diversity typical of these habitats. In the Bohemian Forest Mts., we applied three treatments (mowing once a year - i.e., cutting and removing the biomass, mulching once a year - cutting and leaving the crushed biomass to decompose in situ, fallowing - no cutting) in order to assess temporal changes in meadow vegetation, plant trait composition and biomass production in a 13-year experiment. We recorded for each species twenty-five traits as to be most informative of plant strategies related to growth, resource acquisition and carbon-water economy. We compared different components of trait composition (community averages that mostly reflect traits of dominant species vs. the Rao index of functional diversity that reflects trait dissimilarity among species) and their impact on biomass production. We show that mulching promotes species and functional diversity by facilitating heliophilous forbs and legumes with more acquisitive strategies in resource use and release, e.g., higher foliar N and P content. This occurs at the expense of tall grasses (with resource-retentive strategies, e.g., high leaf dry matter content) which dominate the mown and fallow plots. The divergence in most quantitative traits indicates that niche complementarity is the dominant assembly process in mulched plots, which can prevent competitive exclusion and enable species coexistence. The divergent development was detected only after 5-6 years. This slow floristic and functional response is caused by acidity of soil and severe mountain climate that preclude rapid responses of vegetation to land-use changes. We conclude that mulching represents a good compromise maintaining both plant species and functional diversity as well as a relatively high biomass production. Mowing without grazing leads to gradual nutrient loss and thus reduces the productivity and diversity in these oligotrophic ecosystems. Fallowing causes gradual loss in diversity by increased grass competition and litter accumulation.     

Ackee apple (Blighia sapida) seeds: a novel adsorbent for the removal of Congo Red dye from aqueous solutions

The ability of ackee apple (AA) seeds to remove Congo Red (CR) dye from aqueous solution was investigated. AA was characterised using thermo gravimetric analyser, scanning electron microscopy, Braunauer Emmett Teller, pH_pzc, elemental analysis and Boehm titration. The effects of operational parameters such as adsorbent dosage, contact time, initial dye concentration and solution pH were studied in a batch system. pH has a profound influence on the adsorption process. Maximum dye adsorption was observed at pH 3.0. The reaction was fast, reaching equilibrium in 90 min. Adsorption data were best described by Langmuir isotherm and the pseudo-second-order kinetic model with a maximum monolayer coverage of 161.89 mg·g^?1. Both boundary layer and intraparticle diffusion mechanisms were found to govern the adsorption process. Thermodynamic parameters such as standard free energy change (Δ G ⁰), standard enthalpy change (Δ H ⁰), and standard entropy change (Δ S ⁰) were studied. Values of Δ G ⁰ varied between?30.94 and?36.56 kJ·mol^?1, Δ H ⁰ was 25.61 kJ·mol^?1, and Δ S ⁰ was 74.84 kJ·mol^?1·K^?1, indicating that the removal of CR from aqueous solution by AA was spontaneous and endothermic in nature. Regeneration and reusability studies were carried out using different eluents. AA gave the highest adsorption efficiency up to four cycles when treated with 0.3 M HCl. AA was found to be an effective adsorbent for the removal of CR dye from aqueous solution.     

Adsorptive removal of a synthetic textile dye using cocoa pod husks

The adsorption of a synthetic textile dye (Remazol Brilliant Black Reactive) on cocoa pod husk-based activated carbon was investigated in batch process. The adsorbent prepared was characterized by gas adsorption surface analysis (Brunauer Emmett Teller, BET), scanning electron microscopy, and Fourier transform infrared spectroscopy. The effects of initial dye concentration, contact time, solution temperature, and solution pH were evaluated. Equilibrium data were fitted to Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherm models, the first being the best with maximum monolayer coverage of 111?mg?g^?1. Kinetic data were fitted into pseudo-first-order, pseudo-second-order, intraparticle diffusion, and Elovich models; the pseudo second-order model provided the best correlation. Maximum adsorption was observed at pH 7. Standard free energy, standard enthalpy, and standard entropy were also calculated. The adsorption interaction was found to be endothermic and spontaneous. Both the mean free energy of adsorption and the activation energy show that the mechanism is by physisorption.     

Adsorption of methylene blue onto activated carbon derived from periwinkle shells: kinetics and equilibrium studies

Periwinkle shell, an abundant and inexpensive natural resource, was used to prepare activated carbon by physicochemical activation with potassium hydroxide (KOH) and carbon dioxide (CO₂) as the activating agents at 850 °C for 2 h. The adsorption equilibrium and kinetics of methylene blue dye on such carbon were then examined at 25 °C. Adsorption isotherm of the methylene blue (MB) on the activated carbon was determined and correlated with common isotherm equations. The equilibrium data for methylene blue adsorption well fitted to the Langmuir equation, with maximum monolayer adsorption capacity of 500.00 mg/g. Two simplified kinetic models including pseudo-first-order and pseudo-second-order equation were selected to follow the adsorption processes. The adsorption of methylene blue on activated carbon derived from periwinkle shell could best be described by the pseudo-second-order equation. The kinetic parameters of this best-fit model were calculated and discussed.     

Clustering of the abundance of West Nile virus vector mosquitoes in Peel Region,Ontario, Canada

Understanding the spatial–temporal distribution of vector mosquitoes is essential in designing an efficient mosquito control strategy to reduce the risk of the mosquito-borne disease. In this paper, we apply a non-parametric clustering method, CLUES, to the surveillance data of West Nile virus vector mosquitoes collected by light traps in Peel Region, Ontario, during the mosquito seasons in 2004–2010. In order to obtain robust and reliable results, a statistical smoothing procedure LOWESS is applied to the original time series data. It was found that the mosquito trap sites can be clustered into three groups. The weather impact on the mosquito abundance of each clustered group are similar, while the interannual variability and the highest abundance and peak time in each mosquito season are different. The impact of weather factors on this clustering is investigated.     

Dynamic heterogeneous analysis of pollution reduction in SANEM countries: lessons from the energy-investment interaction

Environmental Science and Pollution Research - This scientific enquiry examines the role of capital investment in the energy-pollution model in SANEM countries. The methodology is based on the...     

Output and substitution elasticity estimates between renewable and non-renewable energy: implications for economic growth and sustainability in India

Environmental Science and Pollution Research - The energy profile of India is dominated by fossil fuels, which create concerns over resource and environmental sustainability as fossil fuels are...     

Pervaporation of ethanol produced from banana waste

Banana waste has the potential to produce ethanol with a low-cost and sustainable production method. The present work seeks to evaluate the separation of ethanol produced from banana waste (rejected fruit) using pervaporation with different operating conditions. Tests were carried out with model solutions and broth with commercial hollow hydrophobic polydimethylsiloxane membranes. It was observed that pervaporation performance for ethanol/water binary mixtures was strongly dependent on the feed concentration and operating temperature with ethanol concentrations of 1–10%; that an increase of feed flow rate can enhance the permeation rate of ethanol with the water remaining at almost the same value; that water and ethanol fluxes was increased with the temperature increase; and that the higher effect in flux increase was observed when the vapor pressure in the permeate stream was close to the ethanol vapor pressure. Better results were obtained with fermentation broth than with model solutions, indicated by the permeance and membrane selectivity. This could be attributed to by-products present in the multicomponent mixtures, facilitating the ethanol permeability. By-products analyses show that the presence of lactic acid increased the hydrophilicity of the membrane. Based on this, we believe that pervaporation with hollow membrane of ethanol produced from banana waste is indeed a technology with the potential to be applied.     

The co-occurrence network patterns and keystone species of microbial communities in cattle manure-corn straw composting

Environmental Science and Pollution Research - Microbes often form complex ecological networks in various habitats. Co-occurrence network analysis allows exploring the complex community...