Competition and cooperation: bumblebee spatial organization and division of labor may affect worker reproduction late in life

Within-group conflict may influence the degree to which individuals within a group cooperate. For example, the most dominant individuals within a group often gain access to the best resources and may be less inclined to perform risky tasks. We monitored space use and division of labor among all workers in three colonies of bumblebees, Bombus impatiens, during the ergonomic and queenless phases of their colony cycle. We then measured the two largest oocytes in each worker to estimate each individual's reproductive potential at the end of the colony cycle. We show that workers that remained farther from the queen while inside the nest and avoided risky or more energy-expensive tasks during the ergonomic phase developed larger oocytes by the end of the colony cycle. These individuals also tended to be the largest, oldest workers. After the queen died, these workers were more likely than their nestmates to increase brood incubation. Our results suggest that inactive bumblebees may be storing fat reserves to later develop reproductive organs and that the spatial organization of workers inside the nest, particularly the distance workers maintain from the queen, may predict which individuals will later have the greatest reproductive potential in the colony.     

Nitrate production and availability in residential soils

The rapid increase in residential land area in the United States has raised concern about water pollution associated with nitrogen fertilizers. Nitrate (NO3-) is the form of reactive N that is most susceptible to leaching and runoff; thus, a more thorough understanding of nitrification and NO3(-) availability is needed if we are to accurately predict the consequences of residential expansion for water quality. In particular, there have been few assessments of how the land use history, housing density, and age of residential soils influence NO3(-) pools and fluxes, especially at depth. In this study, we used 1 m deep soil cores to evaluate potential net nitrification and mineralization, microbial respiration and biomass, and soil NO3(-) and NH4+ pools in 32 residential home lawns that differed by previous land use and age, but had similar soil types. These were compared to eight forested reference sites with similar soils. Our results suggest that a change to residential land use has increased pools and production of reactive N, which has clear implications for water quality in the region. However, the results contradict the common assumption that NO3(-) production and availability is dramatically higher in residential soils than in forests in general. While net nitrification (128.6 +/- 15.5 mg m(-2) d(-1) vs. 4.7 +/- 2.3 mg m(-2) d(-1); mean +/- SE) and exchangeable NO3(-) (3.8 +/- 0.5 g/m2 vs. 0.7 +/- 0.3 g/m2) were significantly higher in residential soils than in forest soils in this study, these measures of NO3(-) production and availability were still notably low, comparable to deciduous forest stands in other studies. A second unexpected result was that current homeowner management practices were not predictive of NO3(-) availability or production. This may reflect the transient availability of inorganic N after fertilizer application. Higher housing density and a history of agricultural land use were predictors of greater NO3(-) availability in residential soils. If these factors are good predictors across a wider range of sites, they may be useful indicators of NO3(-) availability and leaching and runoff potential at the landscape scale.     

Revisiting Sphere: new standards of service delivery for new trends in protracted displacement

The proportion of people living in protracted displacement, as well as the duration of this displacement, is increasing. International humanitarian standards for services provided in protracted displacement are based on the Sphere Standards, which were formulated using evidence and experience from acute phase emergencies. However, the majority of protracted emergencies are in the post‐emergency phase. This paper discusses trends in displacement, outlines reasons why using the Sphere Standards as minimum standards of service provision in protracted displacement does not adequately meet the needs of these populations, and analyses areas where greater standards of service provision are necessary. An expansion of the evidence base regarding determinants of morbidity and mortality in protracted emergencies is needed. This, followed by a joint approach to designing new, effective standards focused on proactive policies, will allow the humanitarian community more appropriately to serve and enable the millions of people currently living in protracted displacement.     

From Experiential Knowledge to Public Participation: Social Learning at the Community Fisheries Action Roundtable

Extensive research demonstrates that public participation in environmental decision making can increase understanding of diverse worldviews and knowledge bases, public faith in governance institutions, and compliance with resulting rules. Concerns linger around costs, possibilities of polarization and decreased legitimacy in cases of poorly executed processes, and the ability of newly empowered groups to gain political leverage over others. If participants in public processes can bracket their personal experience to better assess other viewpoints, establishing mutual respect and understanding through deliberative exchange, they increase the likelihood of maximizing participatory benefits and minimizing risks. Such reflexivity indicates double-loop social learning, change undertaken through collective discussion and interaction. A capacity-building workshop program aims to foster such learning within the Maine fishing industry. Case material draws primarily on participant observation and interview data, using a grounded theory approach to qualitative analysis. Evidence indicates that in social contexts removed from the norms of daily life and the frustrations of past fishery management confrontations, harvesters acquire knowledge and skills that facilitate more strategic and productive behavior in formal and informal marine resource decision venues. Suspensions of longstanding spatio-temporal assumptions around the prosecution and management of fisheries comprise key learning moments, and yield corresponding changes in industry attitudes and actions. With heightened appreciation for a diversity of experiences and management priorities, harvesters can better mobilize a broad spectrum of local knowledge to develop viable regulatory proposals and collaborative decision processes.     

Quest for communicating sustainability: Gb-Quest as a learning tool for effecting conceptual change

Abstract

The overall purpose of this study was to assess whether interaction with a regionally based computer simulation software tool, Gb-Quest, was an effective tool for learning about sustainability. A questionnaire was administered to 189 participants, before and after attending a workshop on Gb-Quest. Factor analysis was used to determine the factor structure of the three scales used in this study. Seven variables were identified and were examined for group differences (gender, age, and whether or not they were Canadian born). In particular, younger individuals and males were more likely to endorse the view that the earth is being destroyed by humans. In addition, Canadian-born individuals were more likely to endorse the consumption of environmentally friendly products, but less likely to be supportive of development and using public transportation. We also examined change for each of the variables and found that Gb-Quest had an effect on all of them. Findings are discussed in terms of implications for future research.     

A case for urban liveability from below: exploring the politics of water and land access for greater liveability in Kampala,Uganda

ABSTRACT

Improving urban liveability and prosperity is commonly set as a priority in urban development plans and policy around the world. Several annual reports produced by international consulting firms, media, and global agencies rank the liveability of cities based on a set of indicators, to represent the quality of life in these cities. The higher is the ranking, the more liveable is the city. In this paper, we argue that such quantitative approaches to framing and addressing urban liveability challenges leave little room to reflect on people's experiences of this liveability, which cannot be expressed through numbers. To illustrate our argument, we draw on empirical evidence of urban liveability challenges in access to water and land in Kampala, the capital city of Uganda, ranked recently as the most liveable East African city by various global agencies and media outlets. By showing that increasing the number of water connections does not guarantee improved access to water and sanitation in the long run, first, we demonstrate how urban liveability challenges are tightly linked with land-title issues in the city. Second, we highlight the political game-playing between the central government, the opposition, the traditional leadership, and the slum dwellers in governance processes of service delivery. Finally, by arguing that urban liveability can be enhanced by broadening political participation in city development planning, we discuss some of the strategies that can be used by communities to make collective claims towards improving their quality of life and the environment.     

Use of 210Pb and 137Cs to simultaneously constrain ages and sources of post-dam sediments in the Cordeaux reservoir, Sydney, Australia

Environmental radionuclides can be employed as tracers of sediment movement and delivery to water bodies such as lakes and reservoirs. The chronologies of sediments that have accumulated in the Cordeaux reservoir in Sydney, Australia, were determined by the rate of change of (210)Pb(ex) with depth and indicate slow accretion in the reservoir. The ratio of enrichment of radionuclides in sediment cores to (210)Pb(ex) and (137)Cs concentrations in a reference soil sample within the Cordeaux catchment indicates that the dominant source of sediment in the Cordeaux reservoir is surface erosion (detachment and removal of sediment at depths less than 30 cm). However, in the Kembla Creek arm of the reservoir a mixture of sources was detected and includes sheet and rill erosion together with sub-soil contributions. Implications for the utility of these radionuclide sedimentation assessments, especially where samples are limited, are that well-constrained chronologies and sources of soil erosion are facilitated.     

Albatross populations in peril: a population trajectory for black-browed albatrosses at south Georgia.

Simulation modeling was used to reconstruct Black-browed Albatross (Diomedea melanophris) population trends. Close approximations to observed data were accomplished by annually varying survival rates, reproductive success, and probabilities of returning to breed given success in previous years. The temporal shift in annual values coincided with the start of longline fishing at South Georgia and potential changes in krill abundance. We used 23 years of demographic data from long-term studies of a breeding colony of this species at Bird Island, South Georgia, to validate our model. When we used annual parameter estimates for survival, reproductive success, and probabilities of returning to breed given success in previous years, our model trajectory closely followed the observed changes in breeding population size over time. Population growth rate was below replacement (lambda < 1) in most years and was most sensitive to changes in adult survival. This supports the recent IUCN uplisting of this species from "Vulnerable" to "Endangered." Comparison of pre-1988 and post-1988 demography (before and after the inception of a longline fishery in the breeding area) reveals a decrease in lambda from 0.963 to 0.910. A life table response experiment (LTRE) showed that this decline in lambda was caused mostly by declines in survival of adults. If 1988-1998 demographic rates are maintained, the model predicts a 98% chance of a population of fewer than 25 pairs within 78 years. For this population to recover to a status under which it could be "delisted," a 10% increase in survival of all age classes would be needed.     

Transport and fate of nitrate in headwater agricultural streams in Illinois

Nitrogen inputs to the Gulf of Mexico have increased during recent decades and agricultural regions in the upper Midwest, such as those in Illinois, are a major source of N to the Mississippi River. How strongly denitrification affects the transport of nitrate (NO(3)-N) in Illinois streams has not been directly assessed. We used the nutrient spiraling model to assess the role of in-stream denitrification in affecting the concentration and downstream transport of NO(3)-N in five headwater streams in agricultural areas of east-central Illinois. Denitrification in stream sediments was measured approximately monthly from April 2001 through January 2002. Denitrification rates tended to be high (up to 15 mg N m(-2) h(-1)), but the concentration of NO(3)-N in the streams was also high (>7 mg N L(-1)). Uptake velocities for NO(3)-N (uptake rate/concentration) were lower than reported for undisturbed streams, indicating that denitrification was not an efficient N sink relative to the concentration of NO(3)-N in the water column. Denitrification uptake lengths (the average distance NO(3)-N travels before being denitrified) were long and indicated that denitrification in the streambed did not affect the transport of NO(3)-N. Loss rates for NO(3)-N in the streams were <5% d(-1) except during periods of low discharge and low NO(3)-N concentration, which occurred only in late summer and early autumn. Annually, most NO(3)-N in these headwater sites appeared to be exported to downstream water bodies rather than denitrified, suggesting previous estimates of N losses through in-stream denitrification may have been overestimated.