The ability of conditioned Microplitis croceipes (Hymenoptera: Braconidae) to distinguish between odors of aflatoxigenic and non-aflatoxigenic fungal strains

Summary. The parasitic wasp Microplitis croceipes (Cresson) (Hymenoptera: Braconidae) learns to associate odors with food resources and subsequently exhibits a characteristic food-seeking behavior when encountering the learned odor. Wasps so conditioned, learned and subsequently demonstrated an ability to distinguish among aflatoxigenic and non-aflatoxigenic Aspergillus flavus and A. parasiticus strains. The effects of fungal species, strain, age (5, 10-12, 20, and 30 d) and growth media (potato dextrose agar, peanut agar and corn agar) on the learning and recognition responses of the conditioned wasps were examined. The level of differentiation between fungal strains by conditioned wasps was lowest when working with 5-d-old fungal cultures but increased with age and generally peaked with 20-d-old fungi. Wasps responded generally stronger to the fungal strain conditioned to independent of growth media. This ability of parasitic wasps to learn and distinguish fungal odors can open new avenues in insect learning.     

Carbon monoxide and carbon dioxide concentrations in Santiago de Chile associated with traffic emissions

CO/CO₂ ratios have been measured in different locations of Santiago de Chile city. Measurements were carried out in a tunnel (prevailing emissions from cars with catalytic converter) and close to heavy traffic streets. Concentrations measured along the city traffic tunnel or temporal profiles of concentrations measured near heavy traffic streets allow an estimation of CO/CO₂ ratios emitted from mobile sources. Values obtained range from 0.0045 ± 0.0006 to 0.0100 ± 0.0004 and depend on the prevailing type of mobile sources. In particular, lowest values were found close to a street with heavy traffic dominated by diesel-powered public transportation, while the highest values were found at the city tunnel. Places located near streets of mixed mobile sources (public buses and cars) showed intermediate values. Average CO/CO₂ ratios are compatible with emission factors proposed for Santiago’s main mobile sources.     

Environmental education in Sweden

Summary Schools and higher education institutions in Sweden have developed a wide range of innovative and demanding curricula to meet the objectives of Sweden's environmental policy. Environmental education in compulsory schools is taught principally through biological sciences, although social studies are beginning to occupy a substantial component of the environmental curriculum. Upper secondary schools offer more opportunities to develop environmental awareness, understanding and practical skills than comparable sixth form and post-secondary colleges in England. In Sweden there is a strong emphasis on practical work developed through projects based on contemporary environmental issues and their resolution. The development of environmental education has been well supported by a substantial input of new resources, especially materials developed by the Swedish Environmental Protection Agency and Industry. Universities have also begun to adopt new organisational structures to help develop inter-disciplinary teaching and research teams. Several universities are experimenting with common core courses, parts of which comprise environmental elements.Dr P. Brown is currently Visiting Professor of Environmental Education, in the School of Natural Sciences at the University of Hertfordshire. All five authors were until recetly members of Her Majesty's Education Service Inspectorate.     

Using markets for land preservation: Results of a TDR program

This paper reviews different approaches to using transferable development rights (TDRs) as a way to preserve rural lands in the face of development pressure. One TDR program is examined in detail, that of Calvert County, Maryland, which has had an active TDR market since the mid-1980s. This program uses TDRs as a key policy tool for achieving a total amount of preserved acreage in the county, and for providing incentives for preservation in some areas and development in others. The paper examines both the early difficulties in developing participation in the program, and the events that lead eventually to an active TDR market. It assesses the workings of the market including factors that influence the demand and supply of TDRs, the movement of prices over time, and the location of preserved areas and of additional developed areas. The study found that the program is achieving many of the county's land preservation goals because of the high level of activity in the TDR market. However, most of the additional density is being channeled into rural areas with underlying low-density zoning.     

DETECTING CUMULATIVE EFFECTS ON HEADWATER STREAMS IN THE ROUTT NATIONAL FOREST,COLORADO1

ABSTRACT: This study evaluated the use of a modified pebble count procedure (Bevenger and King, 1995) to detect cumulative watershed effects on headwater streams in the Routt National Forest in northcentral Colorado. The 42 sample reaches were stratified by disturbance (reference or disturbed) and geologic terrene (granitic or mixed sedimentary-volcanic). Water surface slope was a significant control on the number of fine particles in the reference reaches in both terranes, and the data from the disturbed reaches were adjusted accordingly. The disturbed reaches in the granitic terrene generally had a higher percentage of fine particles, and the adjusted number of fine particles was significantly correlated with the number of road crossings. Disturbed reaches in the sedimentary-volcanic (s-v) terrane generally did not have significantly more fine particles, nor were the adjusted numbers of fine particles significantly correlated with any management index. The lack of significant trends in the s-v streams is probably due to differences in weathering between the two rock types, and the location of the sample reach relative to sedimentary outcrops. Two other procedures were also used to assess cumulative watershed effects, with the Pfankuch channel stability rating yielding stronger and more consistent differences between the reference and the disturbed streams than the Tarzwell substrate ratio. We conclude that it may be difficult to define a standard reference condition, and that the number of road crossings is more strongly correlated with the number of fine particles than equivalent clearcut area.     

Climate Change, Coral Reef Ecosystems, and Management Options for Marine Protected Areas

Marine protected areas (MPAs) provide place-based management of marine ecosystems through various degrees and types of protective actions. Habitats such as coral reefs are especially susceptible to degradation resulting from climate change, as evidenced by mass bleaching events over the past two decades. Marine ecosystems are being altered by direct effects of climate change including ocean warming, ocean acidification, rising sea level, changing circulation patterns, increasing severity of storms, and changing freshwater influxes. As impacts of climate change strengthen they may exacerbate effects of existing stressors and require new or modified management approaches; MPA networks are generally accepted as an improvement over individual MPAs to address multiple threats to the marine environment. While MPA networks are considered a potentially effective management approach for conserving marine biodiversity, they should be established in conjunction with other management strategies, such as fisheries regulations and reductions of nutrients and other forms of land-based pollution. Information about interactions between climate change and more “traditional” stressors is limited. MPA managers are faced with high levels of uncertainty about likely outcomes of management actions because climate change impacts have strong interactions with existing stressors, such as land-based sources of pollution, overfishing and destructive fishing practices, invasive species, and diseases. Management options include ameliorating existing stressors, protecting potentially resilient areas, developing networks of MPAs, and integrating climate change into MPA planning, management, and evaluation.     

A bioeconomic model of afforestation in Southern Ontario: Integration of fiber,carbon and municipal biosolids values

This study explores the economic attractiveness of afforestation as a strategy for the joint production of fibre, carbon storage and biosolids (treated municipal sewage sludge) disposal for municipalities in Southern and Central Ontario, Canada. We use a spatial, stochastic model, the Canadian Forest Service Afforestation Feasibility Model (CFS-AFM), to simulate a range of spatial biosolids application scenarios in hybrid poplar afforestation projects. Results suggest that such joint afforestation strategies could be financially attractive. Significant cost savings can be expected through decreases in transportation distances and avoided waste disposal fees. Sensitivity analysis is used to examine the effects of variations in critical model parameters on net present values. Our findings indicate that waste disposal savings from application of biosolids on hybrid poplar plantations combined with incentives for landowners to sequester carbon can easily compete with agricultural land rental values in some regions of Ontario. Social acceptance of this kind of activity, however, may be an impediment to adoption.     

Herd no More: Livestock Husbandry Policies and the Environment in Israel

Livestock production in both industrial systems, where livestock are packed tightly together, and in highly traditional systems, where a shepherd follows her herd in dispersed rangelands, are cited as key contributors in some of the most acute environmental problems around the globe. Israel is one of the few countries where both of these systems exist, with surprisingly little contact between them. The environmental impact of the sectors were examined along with Israel’s public policies in the field. While historically, much attention has been placed on the contribution of the Bedouin pastoralists to desertification and erosion, this may be linked to historic misapprehension about actual impacts of goats on local rangelands as well as political motivations and concerns about losing national sovereignty over large areas of rangelands. The true environmental effects appear to be minor. A far more critical concern is water pollution caused by the industrial sector of livestock production—an issue that recently has attracted considerable government attention and investment in a successful dairy infrastructure initiative. The divisions between governmental supports for the Jewish and Arab sectors of livestock management are inconsistent with efficient environmental management. Policies should be designed to encourage Bedouin to find ways to sustainably continue their traditional livestock husbandry practises, which today are largely associated with ecological benefits and constitute a unique cultural asset for Israel and the world.     

Local and interregional economic analysis of large US Department of Energy waste management projects

An economic simulation model was used to understand the local and interregional economic impacts of four alternative waste management technologies proposed for the US Department of Energy's Savannah River nuclear weapons site. The simulations of the four technologies, each of which will cost at least a billion dollars, were done for the period 2000-2015. The analyses show that differences in project costs are not directly reflected in local economic impacts because of differences among the technologies during the design, testing and construction phases; differences in locations where the design and pilot-testing would occur; and choices about how any of the technologies would be funded.