Comparative analysis of small mammal communities in Chisinau and Yaroslavl, two European cities located in different biomes

Comparative analysis of the structure of small mammal communities has been performed in two European cities located in different biomes: Chisinau (2008?C2009) and Yaroslavl (1994?C2002). The parameters studied included abundance, species composition, similarity and difference of faunas, species diversity, and proportions of groups differing in predisposition to synanthropy. It has been found that the structure of small mammal communities in these cities depends on specific physiographic conditions of the surrounding areas and on the distinctive features of the cities themselves (their structure, age, etc.). The similarity between the faunas is accounted for by the common ecological patterns of fauna formation in the biota of urban cenoses.     

The role of topography in forming the thermal regime and biological diversity of relict ecosystems on limestones in the northeast of European Russia

Integrated studies on the temperature regime in a limestone outcrop area have been performed, including analysis of the latitudinal trends and dynamics of direct solar radiation input onto slopes of different exposures and the redistribution of temperatures depending on mesotopographic features of the slopes. Assessment of the diversity of ecological conditions in this model landscape has shown that about 3.3% of its area is potentially suitable for the formation of a relict lithophytic floristic assemblage.     

Some Effects of Atmospheric Fluoride on Plant Metabolism

Leaves of Tendergreen bean plants exposed to atmospheric fluoride concentrations in the range 1.7 to 7.6 μg/m³ showed increased levels of enolase and catalase activity and decreased levels of pyruvate and α-ketoglutarate. Phosphoenolpyruvate carboxylase activity and oxalacetate were not affected. The leaves of Milo maize plants exposed to 5.0 μg F/m³ showed increased levels of enolase and pyruvate kinase activity and a decreased level of pyruvate. Oxalacetate and α-ketoglutarate levels were not affected. Catalase activity was increased, then decreased by IIF fumigation. The changes induced by HF were greatest six to 10 days after the start of fumigation and disappeared or decreased in magnitude during the post-fumigation period.     

Report on International Affairs Committee

This is a report on Meetings of Representatives of National Air Pollution Preventions Associations to Consider the Establishment of an International Union, held in Washington, D. C, June 18–19, 1964 and Houston, Texas, June 21–22, 1964.     

The Effect of Nucleating Particulates on Photochemical Aerosol Formation

The role of nucleating particulates in the formation of photochemical aerosols has been studied in a steady, laminar flow of ultrafiltered air containing NO₂ and octene-1 in the concentration range of (30 to 170 ppm) when subjected to intense irradiation under isothermal conditions. The particulates consisted of monodisperse polystyrene latex (d = 0.36 μ.) in concentrations similar to those in the atmosphere (6 × 10¹ to 3 × 10³ cm^–3); the irradiation intensity varied between (6 to 40 × 10³ lumen/liter) and the mean exposure duration between 30 and 180 sec. Samples of the flow prior to and after its photoactivation were withdrawn either by an Aerosol Spectrometer (AS) or by a Royco Aerosol Photometer (PH). While these indications refer thus to the same system, they differ, because the photometric data include all colloidal components in the airborne state, whereas the counts obtained from the AS deposits refer only to the nucleated latex particles. The following pattern becomes evident: The photochemical reaction yields fractional products (less than three percent) which have the tendency to agglomerate (or polymerize) due to their relatively low volatility—independent of the presence or absence of nucleating particulates. In their presence, this reaction becomes kinetically more probable and thus faster, hence the accumulant formation occurs preferably on the nuclei and causes their growth such that, e.g., a 10-fold higher nuclei concentration will produce under the same conditions 10 times the accumulant mass while autonucleation is suppressed. The growth process appears thus principally different from that of fog formation by H₂O-condensation, whereas for identical super saturation it is inversely proportional to the nuclear concentration. In the absence of nuclei autonucleation, i.e., self-agglomeration, occurs at a much lesser reaction rate and higher photon demand. The growth rate of the nuclei, when present, depends on the concentration of the oxidation catalyst (NO₂), its interaction with the nuclei surface is indicated. Under identical conditions the mass of nuclear accumulant is directly proportional to the concentration of the reactive hydrocarbon, while the growth rate depends on the light intensity and the exposure duration. The findings indicate that density and nature of particulate matter present in an air mass prior or during photo-activation are—aside from the chemical reactant levels—of major significance in aerosol formation.     

Fuel Oil Additives for Controlling Air Contaminant Emissions

An addition of additives to fuel oils prior to combustion is one way of reducing combustible contaminant emissions to the outer air. Reported test results show that some additives improve, moderately, the combustive properties of fuel oils. Combustion is also improved but to a lesser degree, in boiler systems that are deficient in operation and design. Being combustible, polynuclear hydrocarbons emissions would be reduced by use of additives. Other types of additives to reduce slagging and inhibit corrosion from combustion of fuel oils are also available. The cost of using additives is low. Improved additives are required, especially ones to better combustion in the deficient boiler systems. These can be found by research and literature surveys. Their effectiveness and nontoxicity would be confirmed by laboratory and field testing.     

An Atmospheric Diffusion Model for Metropolitan Areas

An urban diffusion model, which does not require the use of an electronic computer, is presented. The main simplifying assumptions are that continuous pollutant sources are uniformly distributed over the urban area and vertical diffusion occurs until the effluent from each line source reaches the top of the mixing layer, after which the effluent is uniformly distributed through the mixing layer. After the appropriate vertical diffusion coefficient is specified, the calculated concentration is a function of source strength, linear dimension of the metropolis, mixing depth, and wind speed. The calculated concentration is interpreted either as a representative maximum concentration or, through integration, as the average concentration over the metropolitan area. When a representative pollutant concentration is known, the model may be used to determine the apparent “uniform” source strength.     

A Note on Comparison of Statistical and Analytical Results for Calculating Oxides of Nitrogen Concentrations

A question often asked about analytical diffusion models is “How do the analytical results for calculating pollution concentrations compare with those obtained by statistical techniques?” Miller and Holzworth (1967) have developed a simple analytical diffusion model that yields relative pollution concentrations, x/Q, as a function of afternoon mixing depth, mean transport wind speed, and city size. This analytical model may also be used in reverse to determine apparent afternoon source strengths from observed afternoon pollution concentrations. The apparent source strengths may then be used with the model on independent data to estimate pollution concentrations. It is the purpose of this note to compare results of calculating average afternoon concentrations of oxides of nitrogen (NO_x) by use of the Miller-Holzworth model with those obtained from statistical regression equations.     

Apparent Photosynthesis as a Measure of Air Pollution Damage

A system has been developed to automatically measure the effects of air pollutants in the ambient air on the rate of CO₂ exchange by intact leaves of citrus trees growing in the field. A miniaturized system utilizing the same nondispersive infrared CO₂ analyzer has been designed to study individually the effects of different concentrations of air pollutants on photosynthesis and respiration by plants.