Using integrated food‐web and population‐based models for environmental monitoring,remediation decisions,and long‐term planning

While ecologists have used food‐web models to understand how ecosystems function, the potential role of integrated food‐web and population‐based models in environmental monitoring and decision making has been ignored. Sound ecological principles should be integrated with state‐of‐the‐art monitoring and management practices. This article presents the ways in which population‐based models can answer basic ecological questions necessary for decision making about remediation and restoration, and for monitoring to ensure long‐term stewardship. Discussed are the uses of food‐web and population‐based models for understanding the movement of chemicals through different trophic levels. Three examples, including global warming, tributyltin, and monomethylmercury scenarios, are presented to illustrate how such models are useful. The responses of the component parts varies, depending on parameters such as birth, death, and respiration, as well as feeding rates, predator‐prey rates, and uptake and elimination rates. There are several different models available for decision making, with different levels of complexity, based on the specific hypothesis or question being asked and the amount of current information available. Therefore, it is recommended to use deterministic‐based, population‐based food‐web models for ecological risk assessment. © 2001 John Wiley & Sons, Inc.     

Meta‐Analysis of the Effects of Human Disturbance on Seed Dispersal by Animals

Animal‐mediated seed dispersal is important for sustaining biological diversity in forest ecosystems, particularly in the tropics. Forest fragmentation, hunting, and selective logging modify forests in myriad ways and their effects on animal‐mediated seed dispersal have been examined in many case studies. However, the overall effects of different types of human disturbance on animal‐mediated seed dispersal are still unknown. We identified 35 articles that provided 83 comparisons of animal‐mediated seed dispersal between disturbed and undisturbed forests; all comparisons except one were conducted in tropical or subtropical ecosystems. We assessed the effects of forest fragmentation, hunting, and selective logging on seed dispersal of fleshy‐fruited tree species. We carried out a meta‐analysis to test whether forest fragmentation, hunting, and selective logging affected 3 components of animal‐mediated seed dispersal: frugivore visitation rate, number of seeds removed, and distance of seed dispersal. Forest fragmentation, hunting, and selective logging did not affect visitation rate and were marginally associated with a reduction in seed‐dispersal distance. Hunting and selective logging, but not fragmentation, were associated with a large reduction in the number of seeds removed. Fewer seeds of large‐seeded than of small‐seeded tree species were removed in hunted or selectively logged forests. A plausible explanation for the consistently negative effects of hunting and selective logging on large‐seeded plant species is that large frugivores, as the predominant seed dispersers for large‐seeded plant species, are the first animals to be extirpated from hunted or logged forests. The reduction in forest area after fragmentation appeared to have weaker effects on frugivore communities and animal‐mediated seed dispersal than hunting and selective logging. The differential effects of hunting and selective logging on large‐ and small‐seeded tree species underpinned case studies that showed disrupted plant‐frugivore interactions could trigger a homogenization of seed traits in tree communities in hunted or logged tropical forests. Meta Análisis de los Efectos de la Perturbación Humana sobre la Dispersión de Semillas por Animales     

Differential autumn migration of the aquatic warbler Acrocephalus paludicola

Relatively little attention has been paid to sex differences in the migration of birds in autumn. We studied the autumn migration strategy of molecularly sexed males and females in the globally threatened aquatic warbler Acrocephalus paludicola. We captured 176 birds at a stopover site in the Loire estuary at Donges, France. The median date for the passage of adults was 8 days earlier in males than females, although the timing of migration in first-year males and females was similar. This indicates that males, who are without parental duties, can start their migration earlier than females and first-year birds. Adults were significantly heavier than immature birds but did not have higher fat scores. In both age categories, more males (two to three times more) were captured. However, various factors (including tape-luring) can affect observed sex ratio.     

Scottish peat bog records of atmospheric vanadium deposition over the past 150 years: comparison with other records and emission trends

Cores from four Scottish ombrotrophic peat bogs were used to reconstruct the historical record of atmospheric vanadium (V) deposition in Scotland over the last 150 years. The general similarity of V and Pb concentration profile trends in (210)Pb-dated cores from each of the sites strongly suggested that V, like Pb, is essentially immobile in ombrotrophic peat. After allowance via use of the conservative element Ti for the contribution of soil dust V, the deposition of anthropogenic V was found to be greatest (～ 1.3 to 2.0 mg m(-2) y(-1)) in the mid-20(th) century before decreasing to 0.1-0.3 mg m(-2) y(-1) in the early years of the 21(st) century. The latter values were in good agreement with directly measured atmospheric V fluxes at nearby sites, a finding also observed in the case of Pb. The decline in peat-core-derived fluxes for both V and Pb from 1970 to 2004, however, was not as large as the decline in official UK emission estimates for the two metals during this period. This, along with an order of magnitude discrepancy between the anthropogenic V/Pb ratios at the peat core surface and the higher values of the ratio for UK emissions in the early 2000s, suggests that the recently revised UK emissions data for V may perhaps still be overestimated and/or that some previously deposited Pb is being resuspended in the atmosphere.     

Support for First Nations' Land Claims amongst Members of the Wilderness Preservation Movement: The Potential for an Environmental Justice Movement in British Columbia

Abstract

In this paper we examine the relationship between identification with the environmental movement and support for First Nations' land claims in order to determine the potential for an environmental justice movement in British Columbia. The findings are based on survey data collected from members of a wilderness preservation movement organization based on Vancouver Island. The findings demonstrate that the stronger an individual identifies with the environmental movement, the more s/he supports linking First Nations' land claims to conservation campaigns. We conclude by proposing that the wilderness preservation movement could increase its mobilization potential and widen the scope of the movement by including First Nations' issues in their campaigns. It could do this by expanding its frame to include issues of environmental justice, thereby connecting environmental protection and fair access to resources.     

Characteristics of Muscular Load in Computer Data Entry Workers Assessed by EMG and Postural Angles

The goal of this study was to characterize the muscular load in computer data entry workers. Electromyography (EMG) parameters of trapezius muscle and postural angles of head, arm, and back were chosen as indicators of musculoskeletal load. The examination was done according to the methods and protocol of international MEPS studies (the “Musculoskeletal, Visual, and Psychosocial Load in VDT [Video Display Terminal] Operators in Optimized Environment” international program). The musculoskeletal load during routine VDT data entry work performed by a group of 36 women was assessed on the basis of 1-hr physiometer recordings. Results show that the musculoskeletal load associated with data entry is relatively high compared to other VDT operators’ tasks described in the literature. An analysis of the measured parameters shows that most of the time women worked with a muscular load higher than optimal. It is postulated that the main reason for the heavy musculoskeletal load was improper posture compelled by unergonomic spatial configuration of work stands.