Periodic Migration and Lowland Forest Refugia in a "Sedentary" Neotropical Bird, Wetmore's Bush-Tanager

Although the concept of tropical birds as sedentary is pervasive, evidence suggests many are not. Our grasp of movement status in tropical birds is decidedly poor, but the successful long-term conservation of these birds depends on such information. Sedentariness will likely doom much tropical avian diversity, but increased vagility is a two-edged sword: beneficial in promoting immigration, but detrimental in that more than one habitat may be required. Birds requiring more than one habitat may be unable to locate a particular type as landscape modifications increase. Our long-term data set from the Sierra de Los Tuxtlas in southern Veracruz, México, reveals infrequent, large-scale movements in a local highland endemic. Wetmore's Bush-Tanager ( Chlorospingus ophthalmicus wetmorei) seems occasionally dependent upon lowland forests (now greatly diminished) as a refugium from temporarily unsuitable highlands. Our data and observations lead us to three conclusions: 1) assumptions of sedentariness in tropical birds should be made with extreme caution; 2) normal, but periodic phenomena may be easily overlooked, even in relatively long-term studies; and 3) missing such phenomena jeopardizes the success of any conservation plan because over the long term a population may be dependent upon refugia only occasionally occupied.     

Total Factor Productivity Change in the New England Groundfish Fishery: 1964–1993

We develop estimates of total factor productivity (TFP) change in the New England groundfish fishery from 1964 to 1993, using a procedure similar to Squires' (1992, Rand J. Econom.23(2), 221–236) method, which extends standard TFP measurement by including the effect of fluctuations in stock abundance. The results indicate that TFP increased on average by 4.4% per year from 1964 to 1993. A higher average rate of increase occurred between 1964 and 1982, possibly due to new technologies (e.g., fishfinders). TFP declined at 0.33% annually from 1983 to 1993 due to stringent output and effort control measures.     

The Crumbling Infrastructure of Biodiversity: The Avian Example

The successful conservation of biodiversity depends in part upon an accurate assessment of the diversity to be preserved. This assessment is in the domain of systematics, taxonomy, and general comparative biology. Specimens play a central role in this science, and research collections thus represent the touchstone of biodiversity. The massive job of describing and understanding avian diversity is far from complete, yet the specimen basis for much-needed work is not being added to our collections; current holdings are inadequate. The dwindling influx of specimens is due primarily to opposition to collecting, which is fueled by (1) focusing conservation at the level of the individual; (2) unfamiliarity with population biology; (3) misunderstanding of scientific research; (4) typological thinking; and (5) misplaced morality. Specimen-based avian research has a long and scientifically strong history, and the benefits of this research have been extensive. Our research collections must serve as functional biological libraries. The majority of avian populations can easily withstand the relatively tiny levels of collecting required to keep this science vigorous. Insofar as avian conservation necessarily includes the preservation of a myriad of species comprising the ecosystems upon which birds rely, this problem has broad implications for the conservation of biodiversity.     

Microcosm studies on the air-soil exchange of hexachlorobenzene and polychlorinated biphenyls

Soils have an important role to play in supplying and receiving contaminants from the atmosphere, and in the global cycling of certain persistent organic pollutants (POPs). A microcosm study was conducted, in which some aspects of air-soil exchange likely to be important for the global cycling of POPs were simulated. HCB and PCBs were introduced into a sealed chamber, which contained soils of varying organic matter content, and in which soil mixing was a variable. Uptake of these compounds on to the soils was monitored over time. Subsequently, the primary chemical source was removed and further changes in the residues retained on the soils were monitored. The rates of uptake onto the different soil treatments are compared and the influence of the soil organic matter content and mixing evaluated. The implications for the global cycling of POPs are discussed.     

How do long-term development and periodical changes of river-floodplain systems affect the fate of contaminants? Results from European rivers

In many densely populated areas, riverine floodplains have been strongly impacted and degraded by river channelization and flood protection dikes. Floodplains act as buffers for flood water and as filters for nutrients and pollutants carried with river water and sediment from upstream source areas. Based on results of the EU-funded “AquaTerra” project (2004-2009), we analyze changes in the dynamics of European river-floodplain systems over different temporal scales and assess their effects on contaminant behaviour and ecosystem functioning. We find that human-induced changes in the hydrologic regime of rivers have direct and severe consequences on nutrient cycling and contaminant retention in adjacent floodplains. We point out the complex interactions of contaminants with nutrient availability and other physico-chemical characteristics (pH, organic matter) in determining ecotoxicity and habitat quality, and draw conclusions for improved floodplain management.     

From Spatial to Local: The Impact of the European Union on Local Authority Planning in the UK

In 1998 the Minister for the Regions, Regeneration and Planning issued a statement which argued that the European context for planning had been largely missing from the planning system in England. This paper explores the impact of European Union (EU) membership on the practice of local authority planning in the UK. The research was based on nine local planning authorities in England, Scotland and Wales. The results indicate that EU membership has exerted a direct and indirect influence on planning at the local level. A classification of EU influences on local planning activities is developed. The research also indicates that the scope and structure of the UK planning system are being influenced by EU membership. There is considerable emphasis on the role of planning as a tool for sustainable development, and the development of environmental quality standards, coupled with existing policies in the sphere of nature conservation, present a challenge to the traditional approach of the UK planning system of balancing all material considerations.     

Aerial lift fall injuries: a surveillance and evaluation approach for targeting prevention activities

PROBLEM: Work on aerial lift platforms exposes workers to fall hazards. The objective of this study was to identify the most common injury scenarios and determine current research gaps for addressing fall incidents associated with aerial lifts. METHODS: Three databases were searched: Census of Fatal Occupational Injuries (CFOI), NIOSH Fatality Assessment and Control Evaluation (FACE) reports, and OSHA Incident Investigation Records. RESULTS: The majority of falls/collapses/tipovers were within the height-category of 10-29 feet. Tipovers comprised 44-46% of boom-lift falls and 56-59% of scissor-lift falls. Constructing and repairing activities were most commonly associated with fall/collapse/tipover incidents. DISCUSSION: CFOI and OSHA/FACE show convergent data, suggesting similar scenarios for aerial lift tipovers. IMPACT ON INDUSTRY: The analysis provides the aerial lift industry information to prioritize their efforts on aerial lift design.