THE IMPORTANCE OF INSTITUTIONAL STRUCTURE IN CONTROLLING AGRICULTURAL RUNOFF1

Abstract: Agricultural runoff, such as dissolved mineral salts and selenium, creates pronounced downstream impacts to agricultural producers and to wildlife. The ability to manage these problems efficiently depends critically on the institutional pricing structure of irrigation water delivery agencies. An important characteristic of irrigation water delivery is whether irrigators pay per unit of water received or make one payment regardless of the quantity of water received. In this study we compare the effectiveness of agricultural runoff reduction policies in two regions that employ these different water pricing structures. We find that reduction policy is more effective and can be achieved at a lower cost when water is priced on a per unit basis and that growers have greater incentive to act on their own to reduce runoff problems. Operating under a per unit pricing system encourages water conservation and runoff reduction, which creates public benefits that are not achieved under the single-payment, fixed allotment method of irrigation water delivery.     

What's wrong with virtual trees? Restoring from stress in a mediated environment

Restorative environments are environments that can help restore depleted attention resources or reduce emotional and psychophysiological stress. These effects have been demonstrated not only in real environments, but also in mediated (projected, broadcasted, etc.) environments. However, the importance of simulation qualities to restoration outcomes has not been systematically studied. The present experiment investigates the importance of immersion in a mediated environment in relation to restoration. Is a projected natural environment more restorative when one is more immersed in it, and hence feels more present in it? The hypothesis was that a more immersive projection would show stronger stress-reducing effects of a mediated restorative environment. After performing a stress-inducing task, participants watched a nature film on either a high or low immersive screen. Physiological measurements (heart period and skin conductance level) were taken throughout the experiment. In addition, we measured self-reported affect and presence using the ITC-Sense of Presence Questionnaire. Significant effects of the screen size manipulation appeared on physiological measures, but not on self-reported affect. The data showed an interaction between screen size and restorative phase on heart period and skin conductance level, indicating stronger restoration for the immersive screen condition over time. We therefore conclude that immersion enhances restorative potential of a mediated natural environment. Self-reported affect did correlate significantly with experienced presence, illustrating the relevance of this experiential counterpart of immersion, although a mediating effect of presence has not yet been established.     

Innovation in the minerals industry: Australia in a global context

The pattern of innovation in the global minerals industry is changing as the industry becomes increasingly globalised. In this paper, we look at the structure of innovation in the industry and the drivers of change. We first consider the broad international trends and then examine these more closely with special reference to the Australian industry. Issues addressed include the apparent decline in corporate research and development spending, changing patterns in research collaboration and outsourcing, and the uptake of information and communication technologies in the industry. We also look at the potential implications of these trends for step-change technological developments and at the role of technological innovation in the future development of the industry.     

EVAPOTRANSPIRATION DYNAMICS AT AN ECOHYDROLOGICAL RESTORATION SITE: AN ENERGY BALANCE AND REMOTE SENSING APPROACH1

ABSTRACT: Little work is reported where spatial methods are employed to monitor evapotranspiration (ET) changes as a result of vegetation and wetland restoration. A remote sensing approach with the Surface Energy Balance Algorithm for Land (SEBAL) for estimating ET at The Nature Conservancy's Glacial Ridge prairie‐wetland restoration site in northwestern Minnesota is presented. The calibrated 24‐hour ET from SEBAL was estimated with an average error of prediction of ?4.3 percent. Monthly, interseasonal, and seasonal ET for the period of June to September (2000 to 2003) from three adjacent land‐uses: a hydrologic control preserved wetland; a treated or restored site; and a nontreated or impacted wetland, were used in the study. Results from comparing ET behavior to the preserve suggest restoration efforts have affected monthly and seasonal ET within the treated site. Spatial average standard deviations of the seasonal ET within the preserve, treated, and nontreated sites give 47.3, 75.7, and 109.9 mm, respectively, suggesting hydrologic stabilization within the treated site. Monthly and interseasonal comparisons show similar behavior to that of the seasonal data, where monthly correlations suggest increasing agreement within the treated site, approaching those within the preserve.     

CHARACTERIZATION OF HYDROLOGIC CONDITIONS TO SUPPORT PLATTE RIVER SPECIES RECOVERY EFFORTS1

ABSTRACT: Efforts are under way to recover habitat for several threatened and endangered species in and along the Platte River in central Nebraska. A proposed recovery program for these species requires a means of characterizing “wet” versus “normal” versus “dry” hydrologic conditions in order to set corresponding Platte River instream flow targets. Methods of characterizing hydrologic conditions in real time were investigated for this purpose. Initially, 10 watershed variables were identified as potentially valuable indicators of hydrologic conditions. Ultimately, six multiple linear regression equations were developed for six periods of the year using a subset of these variables expressed as frequencies of nonexceedence. The adequacy of these equations for characterizing conditions was assessed by evaluating their historic correlation to subsequent flow in the central Platte River (1947–1994). These equations explained 54 to 82 percent of variability in the observed flow exceedences in the validation datasets, depending upon the period of year evaluated. These equations will provide initial criteria for setting applicable flow targets to determine, in real time, whether water regulation projects associated with the species recovery effort can divert or store flows without conflicting with recovery objectives.     

Not seeing eye to eye: differences in supervisor and subordinate perceptions of and attributions for psychological contract breach

This study examines supervisor and subordinate perceptions of and attributions for psychological contract breach. The data suggest that supervisor and subordinate perceptions are most likely to differ on the extent to which the organization violated its obligations to provide fair pay, advancement opportunities, and a good employment relationship. In addition, the results indicate that the greater the degree of psychological contract breach reported by subordinates, the less committed they are to the organization and the lower their job performance (as rated by their supervisor). Moreover, when psychological contract breach is perceived, supervisors' and subordinates' attributions regarding the reasons for the breach are likely to differ. Specifically, the findings suggest that subordinates are more likely to attribute breach to the organization's intentional disregard for the commitments that it had made to the employee, while supervisors are more inclined to attribute breach to situations beyond the organization's direct control. Copyright © 2001 John Wiley & Sons, Ltd.     

Designating Air Quality Management Areas (AQMAs) in the UK Implications for Securing UK Air Quality Objectives

Across the United Kingdom, the majority of local authoritieshave now completed their first phase of local air qualityreview and assessment work, as required under the AirQuality Strategy for England, Scotland, Wales and NorthernIreland (DETR, 2000a). Emerging from this first phasework is an anticipated suite of over 110 Air QualityManagement Areas (AQMAs). These areas are identifiedlocations where one or more of the national air qualityobjectives are predicted to exceed by specific target dates,and their spatial extent and shape is emerging as highlyvariable. Local authorities are guided to use a variety ofscientific tools to underpin the scientific assessments, anda consideration of uncertainty in both the tools used andsubsequent delineation of AQMAs is likely to affect theemerging management areas significantly. With subsidiarity underpinning the process of local air qualitymanagement (LAQM), local decision-making is anticipated toinfluence the outcome of the LAQM process in its entirety,with the declaration of AQMAs necessitating the preparationand implementation of air quality action plans. UKexperience of the effective management of local air quality,through the designation of AQMAs, demonstrates a valuableframework for other European countries developing mechanismsto manage air quality locally.     

Chemical Changes in Sediment Pore-Waters of an Acidic Mining Lake After Addition of Organic Substrate and Lime for Stimulating Lake Remediation

In the past five years, enclosures have beeninstalled in an acidic mining lake in Lusatia to investigate insitu remediation processes. They were treated with straw, withstraw and Carbokalk, or with Carbokalk alone, where Carbokalkis a by-product of the sugar industry (solid precipitate ofnon-sugars after lime clarification of extracted sugar beetjuice). Sediment samples were taken as cores to get informationabout the behaviour of organic and inorganic components insediment pore-water with depth. Vertical distributions of pH,soluble reactive phosphate, nitrate, ammonium, silica,aluminium, iron, manganese, calcium, magnesium, sodium,potassium, sulphate, and DOC were measured. The resultingprofiles, each consisting of 15 data points at differentdepths, were compared by cluster analysis. The similarities ofsediment cores from different treated enclosures relating toprofiles of chemical components were discussed. Increasedconcentrations of potassium and sulphate were found in pore-water after substrate treatment. The data imply dissolution ofpotassium iron sulphate hydroxide minerals (jarosite) after anincrease of pH caused by dissolution of lime and by sulphatereducing processes which were stimulated by organic substrateaddition.     

Biological Pollutants: Alien Fishes in Mountain Lakes

Many lakes in the national parks of the Canadian Rockies were stocked with alien fish species in the early to mid 20th century. Changes to Parks Canada's mandate require the original communities of these lakes to be restored. We document the changes to invertebrate communities caused by the stocking of alien fishes into three fishless alpine lakes, and describe the results of two restoration experiments, one the reintroduction of Hesperodiaptomus arcticus, a planktonic predator that had been eliminated from Snowflake Lake by stocked fish, and the other the removal of brook trout (Salvelinus fontinalis) from Bighorn Lake. In both cases, there were great changes to the zooplankton communities, which required several years to complete, probably because of the cold water and unproductive nature of the lakes. Many of the invertebrate species extirpated by stocked alien fishes co-exist with native fish species in nearby lakes. Possible reasons are discussed.