Deforestation control in Mato Grosso: a new model for slowing the loss of Brazil's Amazon forest

Controlling deforestation in Brazil's Amazon region has long been illusive despite repeated efforts of government authorities to slow the process. From 1997 to 2000, deforestation rates in Brazil's 9-state "Legal Amazon" region continually crept upward. Now, a licensing and enforcement program for clearing by large farmers and ranchers in the state of Mato Grosso appears to be having an effect. The deforestation rate in Mato Grosso was already beginning to slacken before initiation of the program in 1999, but examination of county-level data suggests that deforestation in already heavily cleared areas was falling due to lack of suitable uncleared land, while little-cleared areas were experiencing rapid deforestation. Following initiation of the program, the clearing rates declined in the recent frontiers. Areas with greater enforcement effort also appear to have experienced greater declines. Demonstration of government ability to enforce regulations and influence trends is important to domestic and international debates regarding use of avoided deforestation to mitigate global warming.     

Flooding patterns of the Okavango Wetland in Botswana between 1972 and 2000

The inundated area of the Okavango Delta changes annually and interannually. The variability relates to regional precipitation over the catchment area in the Angolan highlands, and to local rainfall. The patterns of the wetland were captured using more than 3000 satellite images for the period 1972 to 2000, near daily NOAA AVHRR data for 1985-2000, and less frequent images of the Landsat sensors from 1972 onwards. One AVHRR image for every 10-day period was classified into land and water using an unsupervised classification method. Evaluation against Landsat TM and ERS2-ATSR data indicate an agreement of 89% for the size of estimated inundation area. Results show that the wetland area has varied between approximately 2450 km2 and 11400 km2 during the last 30 years.     

Risk perception and trust in the context of urban brownfields

Data are reported from a postal questionnaire completed by 747 residents of two urban local authority areas within which there were sites of brownfield land with significant levels of contamination. Respondents rated their perceptions of the extent to which their neighbourhood and own home were relatively vulnerable to contamination, their concern about possible effects of contamination, their satisfaction with their council in terms of consultation with residents on housing and development issues, and their trust in their council with respect to contaminated land risks. Satisfaction with, and trust in, the council was generally low in both areas, and especially so among those who perceived themselves to be more vulnerable to contamination. Nonetheless, dissatisfaction was less marked in the area where the local authority, according to background information, had pursued a more open and proactive style of risk communication and consultation with residents. The main predictors of trust, across both areas, were perceptions that the council was openly prepared to tell residents what they knew, and that the council had residents’ interests at heart. Implications are discussed for the impact of different modes of risk communication on trust.     

Strategies for controlling hazards at work

This paper presents an heuristic framework for analyzing hazards (potential for loss or harm) and strategies that may be developed to control their realization. Two basic forms of intervention for hazard control (anticipation and reaction) are identified. Three broad anticipative strategies are discussed: (1) elimination of the source of the hazard, (2) containment of the risk of its realization, and (3) mitigation of likely consequences. The communication and judgmental processes involved in decisions about strategies are shown to be embedded in the organizational “political” context, in which a variety of interests backed by varying sources of power and influence are represented. The development, implementation, and monitoring of any strategies that are decided upon are then discussed, including the fact that such actions and events may not produce the intended results. Comments are also made on the need for data provided by monitoring to be evaluated and appropriate adaptations made. Finally, a brief section of the paper discusses reactive strategies.     

Source-pathway-receptor investigation of the fate of trace elements derived from shotgun pellets discharged in terrestrial ecosystems managed for game shooting

Spent shotgun pellets may contaminate terrestrial ecosystems. We examined the fate of elements originating from shotgun pellets in pasture and woodland ecosystems. Two source-receptor pathways: i) soil-soil pore water-plant and ii) whole earthworm/worm gut contents - washed and unwashed small mammal hair were investigated. Concentrations of Pb and associated contaminants were higher in soils from shot areas than controls. Arsenic and lead concentrations were positively correlated in soils, soil pore water and associated biota. Element concentrations in biota were below statutory levels in all locations. Bioavailability of lead to small mammals, based on concentrations in washed body hair was low. Lead movement from soil water to higher trophic levels was minor compared to lead adsorbed onto body surfaces. Lead was concentrated in earthworm gut and some plants. Results indicate that managed game shooting presents minimal risk in terms of element transfer to soils and their associated biota.     

Exemplifying whole-plant ozone uptake in adult forest trees of contrasting species and site conditions

Whole-tree O3 uptake was exemplified for Picea abies, Fagus sylvatica and Larix decidua in stands at high and low altitude and contrasting water availability through sap flow measurement in tree trunks, intrinsically accounting for drought and boundary layer effects on O3 flux. O3 uptake of evergreen spruce per unit foliage area was enhanced by 100% at high relative to low elevation, whereas deciduous beech and larch showed similar uptake regardless of altitude. The responsiveness of the canopy conductance to water vapor and, as a consequence, O3 uptake to soil moisture and air humidity did not differ between species. Unifying findings at the whole-tree level will promote cause-effect based O3 risk assessment and modeling.     

A MANGANESE OXIDATION MODEL FOR RIVERS1

ABSTRACT: The presence of manganese in natural waters (>0.05 mg/L) degrades water-supply quality. A model was devised to predict the variation of manganese concentrations in river water released from an impoundment with the distance downstream. The model is one-dimensional and was calibrated using dissolved oxygen, biochemical oxygen demand, pH, manganese, and hydraulic data collected in the Duck River, Tennessee. The results indicated that the model can predict manganese levels under various conditions. The model was then applied to the Chattahoochee River, Georgia. Discrepancies between observed and predicted may be due to inadequate pH data, precipitation of sediment particles, unsteady flow conditions in the Chattahoochee River, inaccurate rate expressions for the low pH conditions, or their combinations.     

Financial assurance and mine closure: Stakeholder expectations and effects on operating decisions

Financial assurance is increasingly seen as a means to ensure orderly, clean and lasting closure of mines. Broadly interpreted, “closure” requires leaving viable ecosystems on mining lands that are compatible with a healthy environment and with human activities, that have low hazard, and that encompass measures to prevent ongoing pollution from the site in the long-term. Financial assurance encompasses environmental surety instruments that protect the government and public in the event a mining company cannot meet its reclamation or rehabilitation obligations. As such, financial assurance is in essence the money available for closure of the mine in the case when the mine owner is not available to perform the work. A general trend towards greater environmental concern among social stakeholders in mining further serves to focus attention on policies and practices that can actually “assure” financial assurance.Financial assurance is also perceived as a means to address closure-related challenges that are increasing in number as well as diversity. Notably, current trends involve a shift towards a greater focus to the societal aspects of mine closure rather than just the ecological. The use of financial assurance, however, also raises some fundamental questions about how assurance mechanisms influence mining operations and the relationship between mining operations and their surroundings. This paper examines both the internal effect of a variety of financial assurance approaches on mining operations—in particular the manner in which environmental and social concerns are addressed by mining firms, and the almost inevitable tension between some form of financial provision for closure on the one hand, and governmental expectations of tax revenue on the other. As a major argument for supporting the conduct of mining is that state revenues from the extractive industries supply monies for the building of human and infrastructural capital, this second area of tension also has strong social and developmental overtones.     

Anaerobic treatment of atrazine bearing wastewater.

Performance of mixed microbial anaerobic culture in treating synthetic waste-water with high Chemical Oxygen Demand (COD) and varying atrazine concentration was studied. Performance of hybrid reactors with wood charcoal as adsorbent, with a dose of 10 g/l and 40 g/l, along with the microbial mass was also studied. All the reactors were operated in sequential mode with Hydraulic Retention Time (HRT) of 5 days. In all the cases, COD removal after 5 days was found to be above 81%. Initial COD was above 1,000 mg/l. From a hybrid reactor COD removal after 2 days was observed to be 90%. Atrazine reduction after 5 days by microbial mass alone was 43.8%, 40% and 33.2% with an initial concentration of 0.5, 1.0 and 2.0 mg/l respectively. MLSS on all the cases were almost same. Increasing MLSS concentration by about 2 fold did not increase the atrazine removal efficiency significantly. Maximum atrazine removal was observed to be 64% from the hybrid reactor with 10 g/l of wood charcoal and 69.4% from the reactor with 40 g/l of wood charcoal. Atrazine removal from the hybrid reactors after 15 days were observed to be 35.7% and 38.7%, which showed that the higher dose of wood charcoal in hybrid reactor did not improve the atrazine removal efficiency significantly. Specific methanogenic activity test showed no inhibitory effect of atrazine on methane producing bacteria. The performance of anaerobic microorganisms in removing atrazine with no external carbon source and inorganic nitrogen source was studied in batch mode. With an initial concentration of 1.0 mg/l, reduction of atrazine by the anaerobic microorganisms in absence of external carbon source after 35 days was observed to be 61.8% where as in absence of external carbon and inorganic nitrogen source the reduction was only 44.2% after 150 days. Volatilization loss of atrazine was observed to be insignificant.