Positive perceptions of green and open space as predictors of neighbourhood quality of life: implications for urban planning across the city region

The provision of green and open space in the face of wider development pressure is a key urban challenge. Despite this, few studies have critically investigated the quality of life implications of such provision. This paper focuses on perceptions of built environment factors and their influence on neighbourhood quality of life. Data are drawn from a household survey questionnaire completed by 483 residents living in three neighbourhoods in Dublin, Ireland – an inner city neighbourhood, a suburb and a peri-urban settlement. Positive perceptions of green and open space were identified as important predictors of high levels of neighbourhood satisfaction, surpassed only by dwelling characteristics. This suggests that development strategies which fail to provide for properly planned green and open spaces may be detrimental to neighbourhood quality of life. Furthermore, the results suggest a need for design solutions which consider neighbourhood typology in achieving improved neighbourhood quality of life.     

Planetary Stewardship in an Urbanizing World: Beyond City Limits

Cities are rapidly increasing in importance as a major factor shaping the Earth system, and therefore, must take corresponding responsibility. With currently over half the world’s population, cities are supported by resources originating from primarily rural regions often located around the world far distant from the urban loci of use. The sustainability of a city can no longer be considered in isolation from the sustainability of human and natural resources it uses from proximal or distant regions, or the combined resource use and impacts of cities globally. The world’s multiple and complex environmental and social challenges require interconnected solutions and coordinated governance approaches to planetary stewardship. We suggest that a key component of planetary stewardship is a global system of cities that develop sustainable processes and policies in concert with its non-urban areas. The potential for cities to cooperate as a system and with rural connectivity could increase their capacity to effect change and foster stewardship at the planetary scale and also increase their resource security.     

Aviation and global climate change in the 21st century

Aviation emissions contribute to the radiative forcing (RF) of climate. Of importance are emissions of carbon dioxide (CO₂), nitrogen oxides (NO_x), aerosols and their precursors (soot and sulphate), and increased cloudiness in the form of persistent linear contrails and induced-cirrus cloudiness. The recent Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC) quantified aviation's RF contribution for 2005 based upon 2000 operations data. Aviation has grown strongly over the past years, despite world-changing events in the early 2000s; the average annual passenger traffic growth rate was 5.3% yr^?1 between 2000 and 2007, resulting in an increase of passenger traffic of 38%. Presented here are updated values of aviation RF for 2005 based upon new operations data that show an increase in traffic of 22.5%, fuel use of 8.4% and total aviation RF of 14% (excluding induced-cirrus enhancement) over the period 2000–2005. The lack of physical process models and adequate observational data for aviation-induced cirrus effects limit confidence in quantifying their RF contribution. Total aviation RF (excluding induced cirrus) in 2005 was ～55 mW m^?2 (23–87 mW m^?2, 90% likelihood range), which was 3.5% (range 1.3–10%, 90% likelihood range) of total anthropogenic forcing. Including estimates for aviation-induced cirrus RF increases the total aviation RF in 2005–78 mW m^?2 (38–139 mW m^?2, 90% likelihood range), which represents 4.9% of total anthropogenic forcing (2–14%, 90% likelihood range). Future scenarios of aviation emissions for 2050 that are consistent with IPCC SRES A1 and B2 scenario assumptions have been presented that show an increase of fuel usage by factors of 2.7–3.9 over 2000. Simplified calculations of total aviation RF in 2050 indicate increases by factors of 3.0–4.0 over the 2000 value, representing 4–4.7% of total RF (excluding induced cirrus). An examination of a range of future technological options shows that substantive reductions in aviation fuel usage are possible only with the introduction of radical technologies. Incorporation of aviation into an emissions trading system offers the potential for overall (i.e., beyond the aviation sector) CO₂ emissions reductions. Proposals exist for introduction of such a system at a European level, but no agreement has been reached at a global level.     

Elevated testosterone advances onset of migratory restlessness in a nearctic-neotropical landbird

The primary cue for initiation of spring migratory restlessness (Zugunruhe) in landbird migrants is photoperiod. Gonadal hormones are known to have a role in the regulation of migratory disposition; however, the extent of their effect is not well understood. We examined the impact of exogenous testosterone on the onset of migratory restlessness in gray catbirds (Dumetella carolinensis). Catbirds were stratified by sex and randomly assigned to two rooms; individuals in one room were photoadvanced to initiate migratory restlessness and the other room was maintained on a 12:12 light/dark photoperiod. Each room had three groups (n?=?10/group); males with testosterone implants, males with empty implants, and females. We predicted that in the photoadvanced room males with testosterone implants would initiate migratory activity earlier than empty-implanted males. We found that in the photoadvanced group, testosterone-implanted males initiated migration 2 weeks prior to empty-implanted males, and 3 weeks prior to females. In the non-photoadvanced males, the testosterone-implanted males initiated migration at the same time as the corresponding group in the photoadvanced room, while the empty-implanted males and females did not exhibit Zugunruhe. Our results illustrate that elevated testosterone can advance the onset of Zugunruhe, even in the absence of an extended photoperiod. Additionally, the onset of migratory restlessness observed in the photoadvanced, non-testosterone-implanted males and females further supports the importance of photoperiod as a cue for migratory restlessness. An interesting observation was the intersexual differences in the onset of migratory activity in gray catbirds, a species not previously known to exhibit protandry.     

The reproductive cycle of the sea urchin Arbacia lixula in northwest Mediterranean: potential influence of temperature and photoperiod

We studied the reproductive cycle of the sea urchin Arbacia lixula in a subtidal population from northeast Spain over four years using a gonadosomatic index (GSI) and gonad histology. Our results show that the GSI of A. lixula follows a seasonal cycle which peaks in May–July and attains its lowest values in October–November every year. The time course of the GSI matched closely the photoperiod cycle. We also found a remarkable inter-annual variability in the maximum value of GSI, which correlated with mean water temperature during the gonad growth period (winter and spring). Gonad histology was also in agreement with a single gametogenic cycle per year in this species. We explored the application of circular statistics to present and analyse gonadal development data, which allowed us to adequately handle the high intra-individual variability detected, with several developmental stages commonly found within the same gonad. The picture that emerged is one of a gametogenic timing driven by photoperiod, while the amount of reproductive output is determined by temperature. This is coherent with the tropical origin of the species and lends support to recent warnings about an increase in the abundance of this species in the Mediterranean as a result of global warming, with associated increased impact potential in sublittoral communities.     

Air quality and micro-meterological monitoring of gaseous pollutants/flame emissions from burning crude petroleum in poultry house

Air quality of gaseous emissions from crude petroleum flames and fumes were monitored in a poultry house at 10 min intervals; from 10.10am–11.10am daily for 14 days. The crude petroleum burning was simulated in a metal burner, 22.86 cm high with a diameter of 17.80 cm and a thickness of 1.27 cm designed for the purpose. The micro-climate (ambient temperature, relative humidity and light intensity) of the experimental environment (poultry houses) was recorded. Results showed that the mean gaseous pollutants emitted before and during the experiments varied within the poultry house. Gases such as sulphur dioxide (SO₂), hydrogen sulphide (H₂S), methane(CH₄) and carbon monoxide (CO) were higher in the brooding than finishing phase, while volatile organic carbon (VOC) and suspended particulate matter (SPM) levels were lower at the brooding than finishing phase. The values obtained in this study for 60 min (at 10 min intervals) are far higher than the values elucidated by the Federal Environmental Protection Agency, which are outdoor air quality measurements as compared to those in this study measured indoors.     

Phytoremediation of landfill leachate

Leachate emissions from landfill sites are of concern, primarily due to their toxic impact when released unchecked into the environment, and the potential for landfill sites to generate leachate for many hundreds of years following closure. Consequently, economically and environmentally sustainable disposal options are a priority in waste management. One potential option is the use of soil-plant based remediation schemes. In many cases, using either trees (including short rotation coppice) or grassland, phytoremediation of leachate has been successful. However, there are a significant number of examples where phytoremediation has failed. Typically, this failure can be ascribed to excessive leachate application and poor management due to a fundamental lack of understanding of the plant-soil system. On balance, with careful management, phytoremediation can be viewed as a sustainable, cost effective and environmentally sound option which is capable of treating 250m(3)ha(-1)yr(-1). However, these schemes have a requirement for large land areas and must be capable of responding to changes in leachate quality and quantity, problems of scheme establishment and maintenance, continual environmental monitoring and seasonal patterns of plant growth. Although the fundamental underpinning science is well understood, further work is required to create long-term predictive remediation models, full environmental impact assessments, a complete life-cycle analysis and economic analyses for a wide range of landfill scenarios.     

Effect of Experimental Selective Logging on Tropical Butterflies

Abstract: I investigated the effects of an experimental selective logging regime on the assemblage of fruit-feeding butterflies in replicated experimental plots in the Chiquibul Forest, Belize. Over a 12-month period, I caught 1187 individuals of 49 species using fruit-baited traps. Selective logging at densities of six stems per ha 3 years before the study had little effect on butterfly species richness, the abundance of individual species, or the shape of species-abundance distributions. There was no tendency for taxa with restricted geographical ranges to be particularly sensitive to selective logging. Mark-release-recapture results suggest that most butterflies move relatively short distances, but that some dispersal occurs between plots separated by distances of ≥1 km. The apparent similarity of the fruit-feeding butterfly assemblage in selectively logged and unlogged forest contrasts with previous studies of butterfly assemblages but mirrors results for birds in the same plots. A possible explanation is the high frequency of natural disturbance—hurricanes and associated fires—in the Chiquibul Forest. The species present appear to be adapted to naturally disturbed habitats and may therefore be relatively unaffected by selective logging. Local studies of the effects of selective logging must take into account the history of natural and human disturbance in the study area. The results support the case for "ecological forestry," in which sustainable management regimes work within the limits imposed by natural disturbance.