印度洋-太平洋海洋生态系统的占有:活礁鱼食品贸易的实例研究

我们对珊瑚礁渔业,特别是活礁鱼食品贸易(FT)的生态足迹的分析表明,许多国家目前的消费量超过了估计的可持续的人均全球、地区及地方珊瑚礁生产水平.香港通过其FT需求占有了东南亚年礁鱼生产量135 260～286 560t的25%,超过地区生物生产力8.3倍;礁鱼渔业需求超过印度洋-太平洋和东南亚地区可持续产量2.5～6倍.相比之下,大多数太平洋岛屿靠本身的礁渔业手段维持生计,当地的需求小于大洋洲整个能力的20%.FT每年需要多达40%东南亚的估计礁鱼产量以及几乎所有其估计的(鱼旨)科鱼产量.我们的研究分析结果强调了FT的不可持续性以及对印度洋-太平洋珊瑚礁渔业加以区域管理和保护的迫切必要性.     

Altered ecohydrologic response drives native shrub loss under conditions of elevated nitrogen deposition

Many regions of southern California's coastal sage scrub (CSS) are rapidly declining as exotic annual plants replace native shrubs. During this conversion, the subsurface hydrology of the semiarid hillslopes that support CSS may be altered. This could chronically suppress the ability of native shrubland to revegetate the landscape since ecosystem processes of nutrient availability and of seedling establishment rely on spatial patterns of available soil water. In this work, soil water and nutrient N regimes were compared over a 2-yr period between a southern California site where CSS has declined (approximately 5% shrub cover) with high additions of anthropogenic N, and one where CSS remains dominant (over 50% shrub cover) with predominantly background atmospheric additions of N. These two sites have similar climate, bedrock lithology, soils, and topography, and had the same vegetation type (Riversidean CSS) 30 years ago. We found that the depth and rate of rainwater percolation into wildland hillslope soils in response to early-season storm events has been greatly reduced after loss of CSS shrubs and vegetation type conversion to invasive grassland. With decreased rainwater redistribution to soil depths of 100 to 150 cm, the predominant zone of soil water has become the upper 25 cm. This shift exacerbates vegetation type conversion by (i) concentrating smog-produced nitrogenous (N) chemicals in the uppermost soil, where they become readily available, along with high soil water, to shallow-rooted exotic grasses early in the growing season and (ii) depriving adult and juvenile shrubs of deeper regolith water.     

Development of the German version of the Hospital Survey on Patient Safety Culture: Dimensionality and psychometric properties

Despite the importance of safety climate assessment in healthcare, the psychometric properties of existing safety climate surveys have seldom been tested. We developed a German version of the HSOPSC and investigated its dimensionality and predictive validity. In adapting the survey we differentiated between the two management levels (hospital, unit) by duplicating dimensions of the HSOPSC. Based on a sample of n = 568, confirmatory and exploratory factor analyses (CFA, EFA) were applied. Relationships between safety climate and outcome variables were investigated by regression analyses. CFA did not replicate the proposed factor structure, supporting evidence from other European countries. EFAs revealed eight factors (instead of twelve proposed for the original instrument) and allowed for differentiating between management levels (hospital, unit). For physicians and nurses, different predictors were identified for overall safety climate perception. Further cross-cultural investigations of dimensionality are necessary for international comparisons of safety climate in healthcare. Our results highlight the importance of capturing the impact of different management levels, especially in large hospitals, and differences between professional groups in order to design interventions accordingly.     

Competitive mobilization of phosphate and arsenate associated with goethite by root activity

Arsenate (As V) is the predominant form of arsenic in soils under aerobic conditions and competes with the major plant nutrient phosphorus (P) in the form of phosphate (PV) not only for sorption sites on mineral surfaces in soil but also for root membrane transporters. Plants have evolved several mechanisms for the mobilization of PV in soils in response to P deficiency, such as the release of organic anions and protons. The aim of the present study was to test whether these mechanisms result in a simultaneous mobilization of arsenate and what would be the consequences for As transfer from soil to plant. The compartment system approach with Zea mays as model crop was chosen as an experimental setup. The system is equipped with micro suction cups and allowed us to investigate processes occurring in the vicinity of roots. As a case study, an artificial quartz substrate with well defined soil physical properties was fertilized, spiked with As V, and amended with increasing amounts of goethite (0, 1, and 4 g kg(-1) in treatments G-0, G-1, and G-4, respectively). The addition of goethite alleviated the As V-induced growth reduction and reduced As V transfer from the substrate to the plant but induced P deficiency at the same time. When low amounts of goethite (1 g kg(-1)) were added, plants mobilized PV but not As V, which might be related to differences in surface complexation reported for PV and As V. No mobilization of PV or As V was observed with the addition of higher amounts of goethite, probably because of decreasing competition between organic anions, PV, and As V for binding sites.     

Public Participation and Local Environmental Planning: the collective action problem and the potential of social capital

Expanding the opportunities for public participation in environmental planning is not always the best option. Starting from an institutional public choice analysis of public participation in terms of the collective action problem, this paper emphasises the roots of participatory activities in the incentive structures facing potential participants. It then goes on to consider the strategies that may be adopted for encouraging greater public involvement and looks particularly to the social capital literature for suggestions of how institutional redesign may alter these incentive structures. The paper concludes by distinguishing three different modes of environmental planning, in terms of the rationale for participation, the severity of the collective action problem and the associated participatory strategy that can be adopted.