Urban Poverty:

Summaries The article describes how and why the scale of urban poverty in much of Africa, Asia and Latin America seems to have been underestimated, its nature misunderstood (or for political reasons, misrepresented) and the best means for reducing it rarely acted upon. It suggests that the income level needed to avoid poverty in most urban areas has been underestimated, largely because too little consideration is given to the cost of essential non?food items. It also suggests that most low?income groups in urban areas face a health burden from their housing whose physical, social and economic costs have been underestimated. This is because the only housing they can afford is of poor quality, usually too small in relation to household size, lacking in basic services and often built on a dangerous site. The article also outlines different measures through which urban poverty can be reduced. These measures include not only increasing incomes and enhancing assets for low?income households, but also upholding their right to justice and legal protection and responding to their needs and priorities for adequate housing and basic services. The final section discusses the relative balance between action at national, city and community level, and the most appropriate form of intervention for any agency that seeks to support poverty reduction at a community level

Three pillars of sustainability: in search of conceptual origins

The three-pillar conception of (social, economic and environmental) sustainability, commonly represented by three intersecting circles with overall sustainability at the centre, has become ubiquitous. With a view of identifying the genesis and theoretical foundations of this conception, this paper reviews and discusses relevant historical sustainability literature. From this we find that there is no single point of origin of this three-pillar conception, but rather a gradual emergence from various critiques in the early academic literature of the economic status quo from both social and ecological perspectives on the one hand, and the quest to reconcile economic growth as a solution to social and ecological problems on the part of the United Nations on the other. The popular three circles diagram appears to have been first presented by Barbier (Environ Conserv 14:101, doi: 10.1017/s0376892900011449, 1987), albeit purposed towards developing nations with foci which differ from modern interpretations. The conceptualisation of three pillars seems to predate this, however. Nowhere have we found a theoretically rigorous description of the three pillars. This is thought to be in part due to the nature of the sustainability discourse arising from broadly different schools of thought historically. The absence of such a theoretically solid conception frustrates approaches towards a theoretically rigorous operationalisation of ‘sustainability’

Advisory Committee:

Nitrogen is commonly thought of as the most limiting nutrient to plant growth, yet elevated N deposition can result in N accumulating in excess of biotic demand, a condition known as 'TI Saturation. " Excess N can perturb soil microbial N transformations and may cause initial increases in net N mineralization rates followed by decreases in net N mineralization with concomitant increases in net nitrification. Along with increases in net nitrification and N loss, N saturation is often associated with a loss of forest productivity. Understanding nitrogen dynamics in soil under enhanced N deposition is key to predicting future forest health. We studied forest floor and mineral soils at the Bear Brook Watershed in Maine (BBWM), a paired watershed experiment with one watershed serving as a reference and another treated with (NH&SO4. We used both lab incubations and in situ measurements to evaluate net N mineralization and netnitrification in both watershed soils. Significantly higher net N mineralization and net nitrification rates were observed in the treated watershed by both methods. For example in situ net N mineralization was 4.25 mg kg " day " in the treated watershed compared to 3.00 mg kg- ' day- ' in the reference watershed. Soil under differing dominant forest types present in these watersheds resulted in different N cycling rates and different response t

Sustainable development: an evolutionary economic approach

In this paper, it is argued that the view of the economic sphere as a closed system cannot appropriately deal with the issue of sustainable development. Evolutionary economics is then presented as a fruitful alternative to apprehend the interactions between the economic, the human and the natural spheres. This emerging field offers both a firm theoretical basis (based upon recent developments in physics, biology, dynamic systems theory and the sciences of complexity) and practical, pragmatic answers to the implementation of a sustainable path of development. This is further illustrated with the presentation of the evolutionary logic of a multi-level common regime. Such a regime could be an institutional counterpart of social and environmental dynamics. Copyright © 2002 John Wiley & Sons, Ltd. and ERP Environment.