Thomas V. Armentano

Fog chemistry at an urban midwestern site

The Holcomb Research Institute is monitoring fog chemistry in Indianapolis, Indiana and at sites in and near the heavily industrialized Ohio River Valley. Results reported here indicate that fogs in this area can be strongly acidic, and that further studies are warranted. We report 1) the ionic composition of three fog events, samples collected in Indianapolis between December 1985 and February 1986, and 2) the pH of three additional events, samples collected between November 1985 and February 1986. (The volume of fog collected during the latter three events was insufficient for chemical analysis other than pH.) The pH of the fog samples ranged from 2.85 to 4.06; some of this fell within the range known to damage foliage and yield of some plant species. It has been demonstrated that even one exposure to highly acidic mists (pH par. delta 2.5) can damage certain crop species; hence, it is important to document the occurrence of any events having acidity near this level.

Air Pollution Threats to US National Parks of the Great Lakes Region

The Great Lakes region of the interior of North America supports a large human population, a major industrial base, and recreational and scenic amenities of unusual contrast and quality. To protect portions of this landscape and meet national recreational needs, the US Federal Government has established 10 National Parks, Monuments, and Lakeshores, in the region, extending from northern Minnesota to the southern shore of Lake Erie. However, air pollutant sources from the industrial Midwest, and large-scale coal combustion for electricity along the Ohio Valley, show evidence of significantly threatening the resource qualities protected in these parks. A review of the natural resources and amenities in each of the National Parks, Monuments, and Lakeshores, in the region shows that scenic vistas are of primary significance, with unique biota (largely northern coniferous species and associated bird-life) and clear water also prominent. Pollutant concentrations in the southern sites, however, are above the thresholds that are known to produce stress, foliage damage, and altered growth-rates on many sensitive species, including the coniferous trees. These pollutants include gases such as sulphur dioxide and nitrogen oxides (NO X ) that are primary emissions of relatively local origin, as well as pollutants such as sulphate particulates, ozone, and acidic deposition, produced by chemical transformations during long-distance atmospheric transport. The particulates, in combination with the high average summer humidity, produce a reduction of visibility at the southern sites, and hence the partial loss of an important amenity.

Air-pollution-induced foliar injury to natural populations of jack and white pine in a chronically polluted environment

Air-pollution-induced foliar injury was determined for natural populations of jack pine (Pinus banksiana) and white pine (P. strobus) on Lake Michigan sand dunes in Indiana. Chlorotic mottle and tip necrosis were found in all populations and one or both symptoms appeared in most trees. However, considering the proximity of the populations to pollution sources, foliar injury levels were notably low. Despite a limited range of individual tree injury for mottle, necrosis, needle retention, and needle length, populations within each species differed significantly (P < 0.05). Juvenile trees showed greatest injury. Symptom expression in both species was related to qualitative site rankings for 03 and S02 exposure in nested analysis of variance, even when tree-to-tree variation was controlled. In both species, mottle increased with 03 ranking and tip necrosis with SO2 rank, but relationships were not always monotonic and showed interactions with site factors. For most trees, tip necrosis affected less than 1 % of the needle length of one-year needles, and mottle covered under 2% of needle surface. The low visible injury range is hypothesized to result from genetic selection favoring genotypes tolerant of the lowered air quality that has characterized the region for the past 70 yr.

The Effects of Land Use Alteration on Tropical Carbon Exchange

Abstract The net annual release of carbon from tropical forests of the world is estimated to range from 0.6 to 1.1 × 10 9 tons (Gt), based on computer model simulations. The simulations incorporate the most recent data on tropical land use change, regional differences in biomass and soil carbon density, and the conversion of forest to both shifting cultivation and to permanent agriculture. Carbon accumulation in fallow and immature forests and in organic soil wetlands also is included. The study represents the first attempt to integrate all these factors into an estimate of the tropical forest carbon balance. Model simulations indicate that releases of 0.30 to 0.48 Gt/yr occur in South America, the region with the largest forest area, although its deforestation rates are lower than the global average. In Southeast Asia, where mean regional forest biomass is high, carbon release rates range from 0.17 to 0.34 Gt/yr. Our simulated releases are significantly lower than those resulting from some earlier analyses which evaluated less detailed data on land-use change and carbon densities. The results, which agree with other recent papers, suggest that tropical forests, when compared to fossil-fuel sources, are presently a relatively small carbon source. However, an understanding of the biospheres role in the global carbon cycle requires further refinement in analysis of the many asynchronous regional, carbon pools.

Estimating Crop Yield Effects from Ambient Air Pollutants in the Ohio River Valley

Results from an analysis of the probable effects of air pollutants upon crop yield are given. The contents of ozone and carbon dioxide in the air were monitored and crop production losses were recorded. 27 refs.

Effects of increased wood energy consumption on carbon storage in forests of the United States

Large but feasible increases that have been projected for the production of wood energy in the United States can be expected to significantly alter the current carbon storage patterns in US forest vegetation. The 1976 net wood increment left after forest cutting equals about 136 × 106 tons of carbon/year, with about 60% of the increment found in merchantable trees, and the remainder in nonmerchantable components.Achieving 5–10 quads of wood energy beyond 1976 levels by the year 2010 can significantly change current carbon storage patterns with the magnitude of change dependent on the extent of residue harvest to meet energy goals, and the rate of future forest growth. Complete loss of the apparent net wood increment is a possible outcome.Although the future growth and harvest situation cannot be known now, a range of possible scenarios suggests that US forests in the year 2010 will store much less carbon than today, thus significantly changing their role in the global carbon cycle.

State-of-the-art science and environmental assessments: the case of acid deposition

Scientific quality in a technical policy document is defined in terms of the proportion of contemporary scientific principles on a subject that the document competently discusses. As a case study of the scientific quality of such documents, this articles examines the treatment of acid deposition effects in 126 environmental impact statements on fossil-fuel power plants. On average, the relevant environmental statements cover only a quarter of the eligible scientific principles. Bureaucratic and political factors influence the quality of discussion of acid deposition more than do strictly objective or scientific factors. In particular, public participation and interagency review processes foster relatively thorough consideration of scientific information in environmental impact statements.