Parentage and sex allocation in the facultatively polygynous ant Myrmicatahoensis

Most social groups have the potential for reproductive conflict among group members. Within insect societies, reproduction can be divided among multiple fertile individuals, leading to potential conflicts between these individuals over the parentage of sexual offspring. Colonies of the facultatively polygynous ant Myrmicatahoensis contain from one to several mated queens. In this species, female sexuals were produced almost exclusively by one queen. The parentage of male sexuals was more complex. In accordance with predictions based on worker sex-allocation preferences, male-producing colonies tended to have low levels of genetic relatedness (i.e., high queen numbers). Correspondingly, males were often reared from the eggs of two or more queens in the nest. Further, over half of the males produced appeared to be the progeny of fertile workers, not of queens. Overall investment ratios were substantially more male biased than those predicted by genetic relatedness, suggesting hidden costs associated with the production of female sexuals. These costs are likely to include local resource competition among females, most notably when these individuals are adopted by their maternal nest. Received: 3 March 1998 / Accepted after revision: 20 June 1998     

Improvements to lawn and garden equipment emissions estimates for Baltimore, Maryland

Lawn and garden equipment are a significant source of emissions of volatile organic compounds (VOCs) and other pollutants in suburban and urban areas. Emission estimates for this source category are typically prepared using default equipment populations and activity data contained in emissions models such as the U.S. Environmental Protection Agency's (EPA) NONROAD model or the California Air Resources Board's (CARB) OFFROAD model. Although such default data may represent national or state averages, these data are unlikely to reflect regional or local differences in equipment usage patterns because of variations in climate, lot sizes, and other variables. To assess potential errors in lawn and garden equipment emission estimates produced by the NONROAD model and to demonstrate methods that can be used by local planning agencies to improve those emission estimates, this study used bottom-up data collection techniques in the Baltimore metropolitan area to develop local equipment population, activity, and temporal data for lawn and garden equipment in the area. Results of this study show that emission estimates of VOCs, particulate matter (PM), carbon monoxide (CO), carbon dioxide (CO2), and nitrogen oxides (NO(x)) for the Baltimore area that are based on local data collected through surveys of residential and commercial lawn and garden equipment users are 24-56% lower than estimates produced using NONROAD default data, largely because of a difference in equipment populations for high-usage commercial applications. Survey-derived emission estimates of PM and VOCs are 24 and 26% lower than NONROAD default estimates, respectively, whereas survey-derived emission estimates for CO, CO2, and NO(x) are more than 40% lower than NONROAD default estimates. In addition, study results show that the temporal allocation factors applied to residential lawn and garden equipment in the NONROAD model underestimated weekend activity levels by 30% compared with survey-derived temporal profiles.     

Adapting to changing climate risk by local government in New Zealand: institutional practice barriers and enablers

Adaptation to climate change has been reviewed in several developed nations, but in none where consideration of the effects of climate change is required by statute and devolved to local government. We examine the role of institutional arrangements, the players operating under them, the barriers and enablers for adaptation decision-making in the developed nation of New Zealand. We examine how the roles and responsibilities between national, regional and local governments influence the ability of local government to deliver long-term flexible responses to changing climate risk. We found that the disciplinary practices of law, engineering and planning, within legal frameworks, result in the use of static mechanisms which create inflexible responses to changing risk. Several enablers are identified that could create greater integration between the different scales of government, including better use of national policy instruments, shared professional experience, standardised information collection and risk assessment methods that address uncertainties. The framing of climate risk as dynamic and changing that differentiates activities over their lifetime, development of mechanisms to fund transitions towards transformational change, are identified as necessary conditions for delivering flexible responses over time.     

Efficacy of Vegetated Buffers in Preventing Transport of Fecal Coliform Bacteria from Pasturelands

An experimental study was conducted in Tillamook, Oregon, USA, to quantify the effectiveness of edge-of-field vegetated buffers for reducing transport of fecal coliform bacteria (FCB) from agricultural fields amended with dairy cow manure. Installation of vegetated buffers on loamy soils dramatically reduced the bacterial contamination of runoff water from manure-treated pasturelands, but the size of the vegetated buffer was not an important determinant of bacterial removal efficiency. Only 10% of the runoff samples collected from treatment cells having vegetated buffers exhibited FCB concentrations >200 colony forming units (cfu)/100 mL (a common water quality standard value), and the median concentration for all cells containing vegetated buffers was only 6 cfu/100 mL. The presence of a vegetated buffer of any size, from 1 to 25 m, generally reduced the median FCB concentration in runoff by more than 99%. Results for FCB load calculations were similar. Our results suggest that where substantial FCB contamination of runoff occurs from manure-treated pasturelands, it might be disproportionately associated with specific field or management conditions, such as the presence of soils that exhibit low water infiltration and generate larger volumes of runoff or the absence of a vegetated buffer. Buffer size regulations that do not consider such differences might not be efficient or effective in reducing bacterial contamination of runoff.     

China's grazed temperate grasslands are a net source of atmospheric methane

A budget for the methane (CH₄) cycle in the Xilin River basin of Inner Mongolia is presented. The annual CH₄ budget in this region depends primarily on the sum of atmospheric CH₄ uptake by upland soils, emission from small wetlands, and emission from grazing ruminants (sheep, goats, and cattle). Flux rates for these processes were averaged over multiple years with differing summer rainfall. Although uplands constitute the vast majority of land area, they consume much less CH₄ per unit area than is emitted by wetlands and ruminants. Atmospheric CH₄ uptake by upland soils was ?3.3 and ?4.8 kg CH₄ ha^?1 y^?1 in grazed and ungrazed areas, respectively. Average CH₄ emission was 791.0 kg CH₄ ha^?1 y^?1 from wetlands and 8.6 kg CH₄ ha^?1 y^?1 from ruminants. The basin area-weighted average of all three processes was 6.8 kg CH₄ ha^?1 y^?1, indicating that ruminant production has converted this basin to a net source of atmospheric CH₄. The total CH₄ emission from the Xilin River basin was 7.29 Gg CH₄ y^?1. The current grazing intensity is about eightfold higher than that which would result in a net zero CH₄ flux. Since grazing intensity has increased throughout western China, it is likely that ruminant production has converted China's grazed temperate grasslands to a net source of atmospheric CH₄ overall.     

The NICE-Whyco technologies partnership: saving energy, dollars, and the environment in the metal plating industry

In partnership with the US Department of Energy’s Office of Industrial Technology, Whyco Technologies, Inc., has developed an innovative perforated plating barrel used in the plating of metal parts. This new technology employs a thin-walled construction, differing from the traditional thick-wall design required to provide adequate structural integrity. The thicker walls lowered the efficiency of transferring plating solution into and out of the barrel and diminished the electrical current pushed through the holes and onto the parts being plated. By machining pockets out of the traditional thick-walled perforated structure, Whyco produced a ‘honeycomb’ of staggered cells, allowing for the greatest number of holes per open area while maintaining structural integrity. Hydrodynamic pumping occurs during barrel rotation to create greater solution transfer than in traditional barrels. The Whyco barrel has higher current density plating, which leads to faster plating cycles, reduced bath concentration, and better plating of difficult chemistries such as in alloys. This new technology has helped the company reduce energy use by 16%, eliminate more than 480 tons/year of solid waste, and reduce wastewater by more than 17 000 gallons/day. The resulting cost savings total more than $500 000 annually. The company has manufactured and sold more than 275 of these barrels to other electroplating companies that are reporting up to a 40% increase in plating productivity and similar energy and environmental impacts.     

acid rain and environmental policy

Editor’s note: This paper by Dr. Jacobson was presented at the 74th annual meeting of the Air Pollution Control Association as part of a panel discussion entitled “Acid Rain–1981: An International Issue.” The session was held on June 22, 1981, and was arranged by APCA’s TT-6 Energy-Environmental Interactions Committee.