EVALUATION OF THE ROSGEN STREAM CLASSIFICATION SYSTEM IN CHEQUAMEGON‐NICOLET NATIONAL FOREST,WISCONSIN1

ABSTRACT: Data collected from 121 stream reaches during 1991 to 1993 were evaluated to determine the applicability of the Rosgen Stream Classification System (RSCS) to the low relief terrain within the Chequamegon‐Nicolet National Forest (CNNF) in Wisconsin, USA. All reaches were classified to RSCS Level I and II except that 10.7 percent had sinuosities below the continuum limits and one reach had a predominantly organic substrate. Five of eight possible RSCS Level I types were observed including B, C, D, A, E, and F; 86 percent were C and E types. Seventeen of 94 possible RSCS Level II types were observed. Most reaches were slightly entrenched, had low to moderate width/depth ratios, relatively low sinuosity, low slope, and sand or gravel as the dominant channel material. Discriminant analyses were used to verify the applicability of RSCS for streams within the CNNF; discriminant functions correctly classified 92.5 and 94.7 percent of the Level I and II RSCS types, respectively. When limits for E and F types were modified slightly at Level II by adding an additional category for slopes less than 0.1 percent (a modification we recommend for low relief terrain), discriminant functions correctly classified 99.1 percent of the types. Adding another slope break at 0.3 percent produced similar results. Based on our analyses, RSCS works well within the CNNF and is probably applicable to other areas with low‐relief terrain.     

The war in Kosovo

During the operation “Allied Force” in the spring of 1999, the burning or damaging of industrial and military targets in the Former Republic of Yugoslavia resulted in the release of a large number of chemicals into the atmosphere. The releases contained not only conventional air pollutants, but also Semi-Volatile Organic compounds (SVOs) which are known to be hazardous to health. Under suitable meteorological conditions, these chemicals can be transported across borders over large distances. In this paper, an analysis of measurements and dispersion calculations is presented which provides evidence of pollutant transport from the conflict area to Greece. The measuring program was carried out in Xanthi, Greece and included aerosol sampling and subsequent analysis for the determination of the concentration of SVOs including dioxins, furans, PCBs (PolyChlorinated Biphenyls), PAHs (Polycyclic Aromatic Hydrocarbons) and organic phthalates. This paper focuses on two episodes of organic phthalates that were observed during the conflict period. Pollution measurements are interpreted by means of air trajectories and dispersion calculations. For this purpose, the HYSPLIT_4 (HYbrid Single-Particle Langrangian Integrated Trajectory) modeling system is used to calculate the dispersion of toxic substances.     

The anti-predator function of ‘eyespots’ on camouflaged and conspicuous prey

Animals utilise various strategies to reduce the risk of predation, including camouflage, warning colours and mimicry, and many of these protective signals promote avoidance behaviour in predators. For example, various species possess paired circular ‘eyespots’, which startle or intimidate predators, preventing or halting an attack. However, little is known of how the efficacy of such signals relates to the context in which they are found, and no studies have tested the relative effectiveness of anti-predator signals when on otherwise camouflaged and conspicuous prey. We find that the protective value of conspicuous wing spots, placed on artificial moth-like targets presented to wild birds in the field, is strongly affected by the attributes of the prey ‘animal’ on which they are found. Wing spots reduced predation when on conspicuous prey but were rendered ineffective when on otherwise camouflaged targets, indeed they increased the risk of predation compared to non-marked camouflaged controls. These results demonstrate how different anti-predator strategies may interact, and that protective signals can switch from being beneficial to costly under different contexts.     

A Mathematical Model for the Effects of Fertilization on Nitrogen Concentrations in Unsaturated Soil on Blueberry Farms in Southern New Jersey

Nitrogen is commonly known as a food source for crops. However, the nitrogen compounds used in crop fertilizers, most commonly nitrate (NO₃) and ammonium (NH₄), are not widely understood. Blueberry plants do not take up these compounds as efficiently as organic nitrogen so varying amounts of leaching into the soil and groundwater will occur. A biogeochemical model consisting of ordinary and partial differential equations is implemented to computationally predict the concentrations of nitrate and ammonium in unsaturated soil of blueberry plants, specifically in the southern region of New Jersey. The model takes into account the type of soil of the region, the nitrate uptake of the plant, the water content in the roots region, the pressure heads in the soil pores, and the application rates of fertilizers containing nitrate, ammonium, and organic nitrogen. Computational simulations demonstrate that the model accounts for natural processes and, in addition, show that commonly used fertilizer application rates cause unnecessarily high concentrations of both nitrate and ammonium in the unsaturated soil level. Further, simulations show that decreasing nitrate fertilizer applications by 85.7% in annual and 91.8% in bi-annual schedules provides an optimal system for safe reapplication.     

Effect of water treatment residuals on soil phosphorus, copper and aluminium availability and toxicity

Water treatment residuals (WTRs) are produced by the treatment of potable water with coagulating agents. Beneficial recycling in agriculture is hampered by the fact that WTRs contain potentially toxic contaminants (e.g. copper and aluminium) and they bind phosphorus strongly. These issues were investigated using a plant bioassay (Lactuca sativa), chemical extractions and an isotopic dilution technique. Two WTRs were applied to an acidic and a neutral pH soil at six rates. Reductions in plant growth in amended soils were due to WTR-induced P deficiency, rather than Al or Cu toxicity. The release of potentially toxic Al from WTRs was found to be mitigated by their alkaline nature and pH buffering capacity. However, acidification of WTRs was shown to release more soluble Al than soil naturally high in Al. Copper availability was relatively low in all treatments. However, the lability of WTR-Cu increased when the WTR was applied to the soil.     

Simulating the fine and coarse inorganic particulate matter concentrations in a polluted megacity

A three dimensional chemical transport model (PMCAMx) is applied to the Mexico City Metropolitan Area (MCMA) in order to simulate the chemical composition and mass of the major PM₁ (fine) and PM_1–10 (coarse) inorganic components and determine the effect of mineral dust on their formation. The aerosol thermodynamic model ISORROPIA-II is used to explicitly simulate the effect of Ca, Mg, and K from dust on semi-volatile partitioning and water uptake. The hybrid approach is applied to simulate the inorganic components, assuming that the smallest particles are in thermodynamic equilibrium, while describing the mass transfer to and from the larger ones. The official MCMA 2004 emissions inventory with improved dust and NaCl emissions is used. The comparison between the model predictions and measurements during a week of April of 2003 at Centro Nacional de Investigacion y Capacitacion Ambiental (CENICA) “Supersite” shows that the model reproduces reasonably well the fine mode composition and its diurnal variation. Sulfate predicted levels are relatively uniform in the area (approximately 3 μg m^?3), while ammonium nitrate peaks in Mexico City (approximately 7 μg m^?3) and its concentration rapidly decreases due to dilution and evaporation away from the urban area. In areas of high dust concentrations, the associated alkalinity is predicted to increase the concentration of nitrate, chloride and ammonium in the coarse mode by up to 2 μg m^?3 (a factor of 10), 0.4 μg m^?3, and 0.6 μg m^?3 (75%), respectively. The predicted ammonium nitrate levels inside Mexico City for this period are sensitive to the physical state (solid versus liquid) of the particles during periods with RH less than 50%.     

R&D Activities,Operating Experience Discussed at Fabric Alternatives Forum

ABSTRACT

Previously reported volatile organic compounds (VOC) radiocarbon (¹⁴C) measurements for 1992 summertime Atlanta, GA, have been compared with chromatographic data and emissions inventory predictions. The chromatographic approach that was used provided a more comprehensive VOC characterization than typically achieved, and the emissions inventory was research-grade level (date-, site-, and time-specific). The comparisons are in general agreement that biogenic emissions contribute only modestly (<10%) to the VOC content of the particular ambient samples that were collected and measured. The choices of sampling site (near city-center) and times (early morning and late evening) are major influences on the results, which consequently should not be regarded as representing the average VOC biogenic impact for the Atlanta area.     

Photochemical processing of aldrin and dieldrin in frozen aqueous solutions under arctic field conditions

Organochlorine (OC) contaminants are transported to the Polar Regions, where they have the potential to bioaccumulate, presenting a threat to the health of wildlife and indigenous communities. They deposit onto snowpack during winter, and accumulate until spring, when they experience prolonged solar irradiation until snowmelt occurs. Photochemical degradation rates for aldrin and dieldrin, in frozen aqueous solution made from MilliQ water, 500 μM hydrogen peroxide solution or locally-collected melted snow were measured in a field campaign near Barrow, AK, during spring-summer 2008. Significant photoprocessing of both pesticides occurs; the reactions depend on temperature, depth within the snowpack and whether the predominant phase is ice or liquid water. The effect of species present in natural snowpack is comparable to 500 μM hydrogen peroxide, pointing to the potential significance of snowpack-mediated reactions. Aldrin samples frozen at near 0 °C were more reactive than comparable liquid samples, implying that the microenvironments experienced on frozen ice surfaces are an important consideration.     

Impacts of atmospheric pollution on the plant communities of British acid grasslands

Air pollutants are recognised as important agents of ecosystem change but few studies consider the effects of multiple pollutants and their interactions. Here we use ordination, constrained cluster analysis and indicator value analyses to identify potential environmental controls on species composition, ecological groupings and indicator species in a gradient study of UK acid grasslands. The community composition of these grasslands is related to climate, grazing, ozone exposure and nitrogen deposition, with evidence for an interaction between the ecological impacts of base cation and nitrogen deposition. Ozone is a key agent in species compositional change but is not associated with a reduction in species richness or diversity indices, showing the subtly different drivers on these two aspects of ecosystem degradation. Our results demonstrate the effects of multiple interacting pollutants, which may collectively have a greater impact than any individual agent.     

Developmental toxicity of two common corn pesticides to the endangered southern bell frog (Litoria raniformis)

To examine the link between corn agriculture and the observed decline of the endangered southern bell frog (SBF), the effects of two corn crop pesticides on larval growth and development were investigated. Tadpoles were exposed to terbufos sulfone (10 μg/L), a major breakdown product of the insecticide terbufos, and the herbicide atrazine (25 μg/L) individually and as a mixture until the completion of metamorphosis. Atrazine did not interact synergistically with terbufos sulfone or result in significant effects on growth and development alone, although there was some indication of accelerated metamorphosis in the pilot study. Terbufos sulfone alone and as a mixture (terbufos/atrazine) significantly slowed larval development and ultimately delayed metamorphosis. The observed developmental effects from an environmentally relevant concentration of terbufos sulfone indicates a risk posed by this persistent degradation product to the endangered SBF, which breeds and develops in the rice bays adjacent to corn fields treated with pesticides.