Critical appraisal of available thermodynamic data for the complexation of antimony(III) and antimony(V) by low molecular mass organic ligands

Antimony is an element of increasing environmental significance but one whose chemical speciation has received little attention and, until recently, one which had not been modelled in any comprehensive way. This paper reports thermodynamic data for computer speciation models of antimony in aqueous, multicomponent solutions of environmental and biological interest involving low molecular mass organic ligands. The available data have been critically evaluated and entered into a thermodynamic database. The JESS suite of computer programs has been used to develop the thermodynamically-consistent mass balance equations used for modelling purposes. No data could be found for Sb(V) complexes and only a few of the existing data for Sb(III) complexes can be considered as being reliably described.     

Assessment of community noise problem in Greater Beirut Area,Lebanon

Over the last two decades, urban noise has been increasingrapidly, primarily in urban areas, due to population growthand the increase of certain noise sources. The main objectiveof this paper is to assess the sources and possible impactsof the community noise problems in Lebanese urban areas,particularly the Greater Beirut Area. The causes and effectsof community noise pollution are briefly presented. Soundpressure levels that were measured to define existing noiseexposure levels in various locations in the Greater BeirutArea are also presented. The attitudes toward noise pollutionand perceived annoyance impact on a sample of 1,038 exposedresidents are described. The association between measurednoise levels and sources, as well as annoyance, is examinedusing correlation analysis and linear and multiple linearregressions. A set of recommendations is presented to reducecommunity noise problem in Greater Beirut Area.     

Quantifying the relative irreplaceability of important bird and biodiversity areas

World governments have committed to increase the global protected areas coverage by 2020, but the effectiveness of this commitment for protecting biodiversity depends on where new protected areas are located. Threshold‐ and complementarity‐based approaches have been independently used to identify important sites for biodiversity. We brought together these approaches by performing a complementarity‐based analysis of irreplaceability in important bird and biodiversity areas (IBAs), which are sites identified using a threshold‐based approach. We determined whether irreplaceability values are higher inside than outside IBAs and whether any observed difference depends on known characteristics of the IBAs. We focused on 3 regions with comprehensive IBA inventories and bird distribution atlases: Australia, southern Africa, and Europe. Irreplaceability values were significantly higher inside than outside IBAs, although differences were much smaller in Europe than elsewhere. Higher irreplaceability values in IBAs were associated with the presence and number of restricted‐range species; number of criteria under which the site was identified; and mean geographic range size of the species for which the site was identified (trigger species). In addition, IBAs were characterized by higher irreplaceability values when using proportional species representation targets, rather than fixed targets. There were broadly comparable results when measuring irreplaceability for trigger species and when considering all bird species, which indicates a good surrogacy effect of the former. Recently, the International Union for Conservation of Nature has convened a consultation to consolidate global standards for the identification of key biodiversity areas (KBAs), building from existing approaches such as IBAs. Our results informed this consultation, and in particular a proposed irreplaceability criterion that will allow the new KBA standard to draw on the strengths of both threshold‐ and complementarity‐based approaches.     

IntergovernmentalEnvironmental Planning: Addressing the Commitment Conundrum

Public policies aimed at environmental problems from improper land use typically work through or with the co-operation of local governments. But local governments sometimes fail to appreciate the importance of the environmental issues or programmes announced by higher level governments. In this paper, we use data on mitigation of natural hazards gathered in Florida in the US and New South Wales in Australia to demonstratethat planning mandates can suffer from gaps in local commitment to the environmental goals of higher level governments. Planning mandates must foster higher quality plans and also build supportivelocal political constituencies if they are to overcome this 'commitment conundrum'. We show that the needed improvements in the quality of plans can be fostered through capacity building. Supportive constituencies can be created through programmesthat enhance public awareness of environmental problems and also through provisions of environmental mandates that require local governments to undertake collaborative planning processes with affected stakeholders.     

Metal exposure and effects in voles and small birds near a mining haul road in Cape Krusenstern National Monument, Alaska

Voles and small passerine birds were live-captured near the Delong Mountain Regional Transportation System (DMTS) haul road in Cape Krusenstern National Monument in northwest Alaska to assess metals exposure and sub-lethal biological effects. Similar numbers of animals were captured from a reference site in southern Cape Krusenstern National Monument for comparison. Histopathological examination of selected organs, and analysis of cadmium, lead, and zinc concentrations in liver and blood samples were performed. Voles and small birds captured from near the haul road had about 20 times greater blood and liver lead concentrations and about three times greater cadmium concentrations when compared to those from the reference site, but there were no differences in zinc tissue concentrations. One vole had moderate metastatic mineralization of kidney tissue, otherwise we observed no abnormalities in internal organs or DNA damage in the blood of any of the animals. The affected vole also had the greatest liver and blood Cd concentration, indicating that the lesion might have been caused by Cd exposure. Blood and liver lead concentrations in animals captured near the haul road were below concentrations that have been associated with adverse biological effects in other studies; however, subtle effects resulting from lead exposure, such as the suppression of the activity of certain enzymes, cannot be ruled out for some individual animals. Results from our 2006 reconnaissance-level study indicate that overall, voles and small birds obtained from near the DMTS road in Cape Krusenstern National Monument were not adversely affected by metals exposure; however, because of the small sample size and other uncertainties, continued monitoring of lead and cadmium in terrestrial habitats near the DMTS road is advised.     

Parsnip webworms and host plants at home and abroad: trophic complexity in a geographic mosaic

Due to differences in the structure of communities in which interactions are embedded, the intensity of interactions between species may vary with location; thus, what results from differences in outcomes and in degree of specialization is a geographic mosaic, which provides the raw material for divergent coevolutionary trajectories. Where selection intensity is great, reciprocal responses are likely in so-called "hotspots"; in contrast, where selection pressures are relaxed, reciprocal responses in "coldspots" are far less likely to occur. There are few if any studies examining how a gradient of increasing trophic complexity might influence the probability of phenotype matching and, correspondingly, the "temperature" of the coevolutionary interaction. This study was conducted to compare outcomes of the interaction between wild parsnip (Pastinaca sativa) and parsnip webworm (Depressaria pastinacella) in its indigenous area, Europe, to its area of introduction, the midwestern United States. Specifically, we tested the hypothesis that increasing trophic complexity, represented by alternate host plants or the presence of natural enemies, reduces the selective impact of parsnip webworms and hence diminishes linkage between host plant chemistry and webworms that would be expected in coevolutionary hotspots. This comparison of a two-species interaction in its area of introduction and its area of indigeneity revealed common patterns that are more reflective of interaction temperature than of continental origin. Where webworms are rare, parsnips produce lower levels of xanthotoxin and bergapten in both the midwestern United States and Netherlands populations. However, the most striking result from this intercontinental comparison is that what is a ubiquitous two-species interaction in North America is in fact exceptional in Europe; webworms could more reliably be found infesting H. sphondylium even where P. sativa was available as well. This preference for H. sphondylium exists despite the comparatively high probability of parasitism associated with this host plant and may reflect the overall lower furanocoumarin content of H. sphondylium. The interaction of parsnip webworms and wild parsnips at home and away demonstrates clearly the potential for rapid contemporary evolution of chemical traits upon re-association with a coevolved enemy, a potential evolutionary outcome that should be considered in the design and implementation of future weed biological control programs.     

Demography of Two Mexican Spotted Owl Populations

Abstract: The Mexican Spotted Owl ( Strix occidentalis lucida ) is a threatened subspecies of the southwestern United States and northern Mexico. Although threatened, little is known about its population status. We studied the demography of the Mexican Spotted Owl in one study area in Arizona and one in New Mexico from 1991 to 1997. We estimated annual survival rates (φ), fecundity rates (   b ), and abundance (   N ) to test the hypothesis that population trends were stationary. Although annual fecundity rates (   b ^ = 0.494 for Arizona and 0.380 for New Mexico) and annual juvenile survival rates ( φ^ = 0.179 for Arizona and 0.109 for New Mexico) differed in magnitude between the study areas, they exhibited similar temporal patterns. Annual survival for territorial owls varied randomly in Arizona but declined linearly in New Mexico. Mean annual survival for territorial owls was 0.814 in Arizona and 0.832 for owls ≥3 years old and 0.644 for owls 1–2 years old in New Mexico. Based on survival and fecundity estimates, the annual rates of change (λ^) indicated that both populations were declining at ≥10% a year. These estimates were corroborated by observed declines in abundance. Some regional factor may have been affecting fecundity, whereas a combination of factors may have been affecting survival. Two possible reasons for the population declines are declines in habitat quality and regional trends in climate.     

Concentrations and bioaccessibility of metals in vegetation and dust near a mining haul road, Cape Krusenstern National Monument, Alaska

Vegetation, sub-surface peat, and road dust were sampled near the Delong Mountain Transportation System (DMTS) haul road in northwest Alaska in 2005-2006 to document aluminum, barium, cadmium, lead, and zinc concentrations, and to evaluate bioaccessibility of these metals. The DMTS haul road is the transport corridor between Red Dog Mine (a large-scale, lead-zinc mine and mill) and the coastal shipping port, and it traverses National Park Service lands. Compared to reference locations, total metal concentrations in four types of vegetation (birch, cranberry, and willow leaves, and cotton grass blades/stalks) collected 25 m from the haul road were enriched on average by factors of 3.5 for zinc, 8.0 for barium, 20 for cadmium, and 150 for lead. Triple rinsing of vegetation with a water/methanol mixture reduced metals concentrations by at most 50%, and cadmium and zinc concentrations were least affected by rinsing. Cadmium and zinc bioaccessibility was greater in vegetation (50% to 100%) than in dust (15% to 20%); whereas the opposite pattern was observed for lead bioaccessibility (<30% in vegetation; 50% in dust). Barium exhibited low-to-intermediate bioaccessibility in dust and vegetation (20% to 40%), whereas aluminum bioaccessibility was relatively low (<6%) in all sample types. Our reconnaissance-level study indicates that clean-up and improvements in lead/zinc concentrate transfer activities have been effective; however, as of 2006, metal dispersion from past and/or present releases of fugitive dusts along the DMTS road still may have been contributing to elevated metals in surface vegetation. Vegetation was most enriched in lead, but because bioaccessibility of cadmium was greater, any potential risks to animals that forage near the haul road might be equally important for both of these metals.     

Effect of variable fishing strategy on fisheries under changing effort and pressure: An agent-based model application

An agent-based model was used to evaluate the response of a two-species fish community to fishing boat exploration strategies, namely: boats following high-yield boats (Cartesian); boats fishing at random sites (stochast-random); and boats fishing at least exploited sites (stochast-pressure). At low fishing pressure, the stochast-random mode yielded a high average catch per boat while sustaining fish biomass. At high fishing pressure, the Cartesian mode was more effective. For the Cartesian strategy, fish biomass exhibited four distinct behaviors with increasing number of boats. In the first phase, the fish biomass dropped with increasing number of boats due to a corresponding rise in biomass extraction. Rapid exploitation occurred in the second phase, when two or more boats occupied the same initial area, that led to the faster abandonment of those sites which then underwent biomass recovery. In the third phase, adding more boats resulted in a fluctuating stock biomass, where the combined effects of initial spatial distribution of boats and rapid localization led to either full stock recovery when boats were eventually confined to a single location due to spillovers, or stock extirpation when the entire area became fully occupied. Beyond the third phase, stock extirpation was assured. In order to break the pattern of localization (bandwagon effect), we introduced stochast-random intruders in a Cartesian-dominated fishery. Adding a single intruder changed the patchy-structured stock biomass pattern of a purely Cartesian fishery to a uniformly explored stock biomass pattern because of the additional spatial information provided by the intruder. Consequently, the average catch per boat increased but at the expense of a disproportionate decline in equilibrium biomass.     

Spatio-temporal ranging behaviour and its relevance to foraging strategies in wide-ranging wolverines

Conservation of carnivores in an increasingly changing environment is greatly helped by understanding the decision-making processes underlying habitat patch choice. Foraging theory may give us insight into spatio-temporal search patterns and consequent foraging decisions that carnivores make in heterogeneous and fluctuating environments. Constraints placed on central-place foragers in particular are likely to influence both foraging decisions and related spatio-temporal movement patterns. We used discrete choice models to investigate the spatio-temporal ranging behaviour of GPS collared female wolverines (Gulo gulo) with dependent cubs in south-central Norway. Activity patterns, home range use and selection for elevation were analyzed in relation to spatial and temporal covariates (daily and seasonal) and related to different foraging behaviours. In spring, wolverines showed restricted movement patterns around rendezvous sites at high elevations by day, whereas during the night animals were active at lower elevations. Over the summer, this daily pattern in intensity of use diminished and their overall selectiveness for elevation decreased as cubs grow more mobile and independent. At the onset of autumn, wolverines showed intensive use of the profitable forest-alpine tundra ecotone. We argue that reproducing wolverines deployed a foraging strategy attuned to altering their movement patterns throughout the summer to address a continuous, but diminishing, trade-off between providing both food and shelter for their offspring. Incorporating spatially and temporally explicit activity patterns and home range use in discrete choice resource selection models thus enhances the understanding of the motives behind wolverine resource utilization in space and time. Such knowledge may provide guidance to managers designing regional-scale zoning, in order to facilitate carnivore recovery and to minimize conflicts with human activities.