Theory and estimation of the household production function for wildlife recreation

The household production function is an intuitively appealing way to model man's interaction with nature. This paper models the interaction between the household's behavior and publicly provided inputs into wildlife recreation. The paper shows how to compute benefits, assuming that the household production function is known. The household production function approach collapses to the simple travel cost approach when households are unable to substitute their own inputs for publicly provided inputs. In addition, the paper demonstrates the conditions under which the parameters of cost and preference functions can be identified. The conditions for identification are quite restrictive when several choices are endogenous.     

The Triple Bottom Line for Sustainable Community Development

Rural communities in Australia are confronting a period of unprecedented change. They face declining commodity prices, the withdrawal of both public and private sector services, such as banks and hospitals, and the closure of small businesses. Their populations are in decline, with young people leaving for the larger regional centres. Many also face a declining resource base as soils become saline and water resources are sold to areas with higher unit returns. This paper presents a framework for sustainable community development based on emerging ideas of performance auditing and the development of progress indicators. The triple bottom line community audit approach is recast for the community level, measuring performance on improved community wellbeing, reduced environmental impact and increased economic vitality. Rural communities need to redefine their future. A sustainability focus offers a way forward. Las comunidades rurales en Australia estan afrontando un periodo de cambio sin precedente. Enfrentan disminución en los precios de los productos, retiro de servicios de ambos sectores, publico y privado, como bancos y hospitales y el cierre de pequeños negocios. Su población está disminuyendo, la gente joven emigra hacia centros regionales mas grandes. Muchos tambien enfrentan un deterioro en los recursos base ya que los suelos se tornan salinos, y los recursos de agua son vendidos a áreas con retorno de unidad mas alto. Este documento presenta una estructura para el desarrollo comunitario sostenible basado en el surgimiento de ideas de la revisión del desempeño y del desarrollo de indicadores de progreso. El enfoque de auditoria del triple resultado final esta rehecho para el nivel de la comunidad, midiendo el desempeño en el bienestar de la comunidad mejorada, el impacto ambiental reducido, y la vitalidad económica incrementada. Las comunidades rurales necesitan redefinir su futuro. Un enfoque sostenible ofrece una vía hacia adelante.     

Estimates of cloud water deposition at Mountain Acid Deposition Program sites in the Appalachian Mountains

Cloud water deposition was estimated at three high-elevation sites in the Appalachian Mountains of the eastern United States (Whiteface Mountain, NY; Whitetop Mountain, VA; and Clingman's Dome, TN) from 1994 through 1999 as part of the Mountain Acid Deposition Program (MADPro). This paper provides a summary of cloud water chemistry, cloud liquid water content, cloud frequency, estimates of cloud water deposition of sulfur and nitrogen species, and estimates of total deposition of sulfur and nitrogen at these sites. Other cloud studies in the Appalachians and their comparison to MADPro are also summarized. Whiteface Mountain exhibited the lowest mean and median concentrations of sulfur and nitrogen ions in cloud water, while Clingman's Dome exhibited the highest mean and median concentrations. This geographic gradient is partly an effect of the different meteorological conditions experienced at northern versus southern sites in addition to the difference in pollution content of air masses reaching the sites. All sites measured seasonal cloud water deposition rates of SO4(2-) greater than 50 kg/ha and NO3(-) rates of greater than 25 kg/ha. These high-elevation sites experienced additional deposition loading of SO4(2-) and NO3(-) on the order of 6-20 times greater compared with lower elevation Clean Air Status and Trends Network (CASTNet) sites. Approximately 80-90% of this extra loading is from cloud deposition.     

Microbial influenced degradation of solidified waste binder

Ordinary cement pastes with water/cement (w/c) ratios of 0.2, 0.4 and 0.5 were used to examine the chemical and physical effects of microbial influenced degradation (MID). Samples were exposed to an active culture of Thiobacillus thiooxidans or to sterile media containing sulphuric acid using an intermittent immersion technique. Acid consumption and Ca, Al and Fe releases are presented for an exposure period of 90 days. Exposed samples were also sectioned and analysed by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). All cement paste samples were subject to significant degradation in either sterile acid media or the T. thiooxidans lixiviant. Corrosion depths observed from SEM examination of exposed samples were affected by the w/c ratio of the cement. The extent and rate of degradation were not apparent from the calculated rate of hydrogen ion consumption, or the leaching rates of Ca, Al and Fe. It was not possible to distinguish differences in corrosion due to the chemical and microbial influenced degradation from the results obtained to date and further work is focusing on modified procedures to address this.     

The effects of Orimulsion and Fuel Oil #6 on the hatching success of copepod resting eggs in the seabed of Tampa Bay,Florida

A 3-month microcosm study was conducted to observe the potential effects of two fuels, Orimulsion and Fuel Oil #6, on the hatching success of copepod resting eggs in the seabed of Tampa Bay, Florida. Microcosms were dosed with one of five hydrocarbon treatments via hydrocarbon-coated sand and compared with controls. Acartia tonsa eggs were nonviable in all treatments after only a few weeks of incubation, as evidenced by a marked decline in the abundance of nauplii. However, there was no evidence that exposure to simulated spills of 700 or 7000 ppm of either fuel led to significant increases in resting egg mortality as compared with controls. The results further indicate that, regardless of environmental conditions, resting eggs of A. tonsa do not remain viable in the sediment for extended periods of time.     

A landscape ecological approach to address scaling problems in conservation management and monitoring

Management of many African game reserves is today often still an art based on experience and intuition, rather than a science. Decision-making is based on an informal integration of accumulated individual knowledge and keen field observations. Data are generally poorly captured and curated. Until fairly recently, denominators of biological parameters (such as the unit of land or unit of plant production used as measurement) have generally been treated as being homogenous. The patchiness of landscapes and the issue of ecological scaling were ignored, often because of a lack of appropriate technical tools. The ecological data available on the 49,000-ha Songimvelo Game Reserve (SGR) result from a number of discrete survey and monitoring projects undertaken by different researchers, with different objectives, at different spatial and temporal scales. A landscape ecological approach towards research and monitoring is appropriate for an area of the size and diversity of the SGR. A combination of a database approach and spatial representation was used to consolidate and integrate data across temporal and spatial scales. Herbivore spatial and temporal distribution patterns were explored across three spatial scales. An understanding was achieved of the importance of landscape patchiness in controlling resource availability for herbivores. This insight is important in guiding management and monitoring of the SGR by placing perceived patch overutilization in its proper landscape context. The landscape ecological approach bridges the traditional scale-independent view to a more contemporary scale-related understanding of ecosystem diversity and functioning.     

Heavy metals in an urban watershed in southeastern Michigan

The occurrence of heavy metals in the soil was measured over a period of several years to determine background concentrations in a heavily urbanized watershed in southeastern Michigan. A spatially dispersed sample was collected to capture the inherent variability of the soils and historic land use. The analysis focused on 14 metals (antimony, arsenic, barium, beryllium, cadmium, chromium, copper, lead, mercury, nickel, selenium, silver, thallium, and zinc) that are part of the USEPA's list of the 129 most common pollutants. Metal concentrations were measured at three depths: near-surface (<0.5 m), shallow subsurface (0.5-10 m), and depths greater than 10 m across six soil units in glacial terrain. Additional analyses assessed the metal concentrations in each depth profile across three general land use categories: residential, commercial, and industrial. Metal concentrations were the highest in the near-surface with Pb present at concentrations averaging 15.5 times that of background in industrial areas and approximately 16 times background in residential areas. Cadmium, Hg, and Zn were also present in surface soils at levels of several times that of background. The highest concentrations of each of these metals were present in the clay-rich soils located in the eastern, more urbanized and industrialized part of the watershed. Metals detected at elevated concentrations decreased in concentration with increasing depth and distance from the urbanized and industrialized center of the watershed. Statistically significant differences in the concentrations of heavy metals were also noted between the land use categories, with Cd, Cr, Cu, Pb, Ni, and Zn observed within industrial areas at mean concentrations several times greater than background levels.     

Measuring the Net Economic Value of Recreational Boating as Water Levels Fluctuate1

Abstract: The purpose of this article was to show how the value of recreational boating can be assessed and how that value can be linked to water levels. Data were gathered via a survey of recreational boaters to determine days boated and willingness‐to‐pay (net economic value) for boating on Lake Ontario and on the St. Lawrence River in 2002. Depth measurements were taken at marinas and yacht clubs, boat launch ramps, and private docks. Stage‐damage curves were used to pinpoint at what water levels and to what extent boaters would be impacted. Boaters recreated an estimated 1.3 million days in 2002 and spent an estimated US$178 million in New York counties bordering Lake Ontario and the St. Lawrence River. The mean net economic value per day per boat (above current expenditures) was $69.36, with an estimated total net economic value of US$90 million. Using Lake Ontario as an example, the stage‐damage curves show that the overall negative impact would be small, between 245 and 248 ft. Maintaining water levels within that range for the entire boating season would be ideal for Lake Ontario boaters and associated businesses.