Gilles Gauthier's (1995) treatment of ‘The Linear City’ was very incomplete, as he made no attempt to acknowledge even cursorily an obvious debt to earlier architects, especially those professionals who clearly predate Gauthier's thinking on the subject.

Sky & Stone (1976) devoted five text pages to exactly the same idea, namely the 1910 ‘Roadtown’ by Edgar Chambless, who died in 1936, and, more significantly, the 1964–66 ‘Linear City’ by Michael Graves. Like Gauthier, several architects have seemed to crystallize an attitude and an approach which, for better or worse, had been in the air for some time without them actually realizing it until they saw it so crystallized. ‘Roadtown’ was evidently to be a continuous, serpent-shaped building which would be self-extending because of the railroad enclosed within it. Both buildings, along with Gauthier's, are representative of ‘Megastructural Architecture’. The term ‘megastructure’ was first used for this kind of building in the vocabulary of ‘Urbatecture’ in approximately 1964. The latter was the visible Earth-crust superficial architecture, as opposed to LaNier's (1970) invisible subterranean architecture called ‘Geotecture’.

In a critique of my paper on ‘greenhouse’ gas (GHG) emissions from Amazonian reservoirs (Fearnside 1995), Rosa et al. (1996) suggest that I have reached overly pessimistic conclusions because the reservoirs on which my calculations are based are unrepresentative and because methods based on the Intergovernmental Panel on Climate Change's (IPCC) global warming potentials (GWPs) are unfair for comparing hydroelectric and fossil fuel options. I rush to defend my analysis.

Over the past few decades the Common Agricultural Policy (CAP) of the European Union (EU) has resulted in major surpluses of agricultural products. However, it has also resulted in severe environmental pollution and degradation. For these reasons, in the early 1990s, the CAP was reformed by means of the Mac Sharry Plan (MSP) (Commission of the EC 1991). This Plan aims to: 1) reduce agricultural surpluses and expenses, 2) adopt a more market-oriented approach, 3) keep a sufficient number of farmers in the countryside, and 4) render agriculture more benign to nature and the environment. The last of these aims has not yet been adequately elaborated in the MSP and it is uncertain whether the adopted measures will really lead to less agricultural pressure on nature and the environment.

The Republic of Belarus lies in between Russia and Poland, and to the north of Ukraine. It has a population of 10 million and a complicated history; parts of Belarus were in Poland and parts in Russia. When within the USSR, policies were adopted, especially in the 1980s, that were at the expense of member parts of the Union. The Chernobyl power plant was built in the Ukraine, near the southern border of Belarus. When the Chernobyl disaster happened on 26 April 1986 (Mould 1988; Park 1989), for three days running the wind blew in the direction of Belarus and we received about 60% of the total fallout. It was not the fault of the Ukraine, but ultimately that of a bureacratized society of over-confident technocrats. About one-fifth of Belarus, as a region which acquired autonomy in July 1991 upon the collapse of the Soviet Union, has been affected to the extent that we have had to organize large resettlements of people, and we now have 300 km2 of land seriously affected and unfit for human habitation, surrounded by a wider circle of about 10 000 km2 which is taken to be endangered, and this within a country of 220 000 km2. Both before and after independence, Belarus' resources have been enormously drained by this disaster.

In spite of the many laws and regulations regarding the development of property and the protection of open space and wildlife, developers often try to get around compliance with the law using subtle, or not–so–subtle, tactics. In some cases, they violate the law because they know that there is little or no enforcement, or, if caught, they pay the fine and charge it up as a cost of doing business which is of course tax-deductible. Over the last few years I have been involved in a status study on two species of lizards of special concern (the Orange-throated Whiptail, Cnemidophorus hyperythrus and the Coastal Horned Lizard, Phrynosoma coronatum) for the California Department of Fish and Game. During this study, I noticed several of what I call ‘developers' devious digressions’. As a biologist and environmental consultant, I have seen, over the last few decades, developers use these same ways of getting around environmental laws in Arizona, Montana, Mexico, and Australia. I have placed these digressions, detours and non-conformities, with the law in the following several categories.

Indirect sources were used to characterize the nature and magnitude of threats to the native plants and forest ecosystems caused by the cultivation and control of coca, the precursor to cocaine, in the Huallaga valley of Peru, whence the majority of the world's cocaine originates. Deforestation is concentrated between 500 and 2000 m in the tropical premontane forest belt. Recent listing of Peru's seed plants permitted a quantification of plant species known from the department of San Martin between 500–2000 m and thus at risk due to forest degradation. This flora consists of 169 plant families, almost 900 genera, and about 2600 species. Fifteen percent of the species are restricted in distribution to Peru, while 6% are known only from San Martin. An additional 778 species, including 46 narrow endemics, are known from vegetation types found below 500 m. More than 223 000 ha of land were found to be in ‘hill agriculture’, consisting predominantly of coca fields and this suggests that the total impact of coca/cocaine deforestation is greatly under-estimated by using simply the area of coca under cultivation. Degraded tropical pre-montane forest may amount to as much as 1 000 000 ha in all of Peru.

This paper analyzes the justifications for governmental involvement in the development and commercialization of environmental technologies. To do so, a list of ‘generic’ rationales for government R&D involvement is extracted from various literature sources. Each rationale is discussed theoretically, and then analyzed in terms of its possible application to the environmental field. The intended contribution of the paper is to provide a theoretical background concerning the proper role of government in the development of environmental technologies. By determining the circumstances under which government involvement is justified, the groundwork is laid for the development of appropriate governmental policies.

The paper argues that there are several salient features of the environmental field which may justify governmental involvement. The increasingly high degree of environmental regulation has already caused indirect market failures that hinder private R&D efforts. Potential technologies to counter environmental externalities represent public goods which have social benefits for which there are no incentives in the private market. Uncertainty due both to our lack of understanding of the complexities of the natural environment and to shifting environmental regulations and policies may cause a risk aversion in the private sector against developing technologies. Imperfect public knowledge concerning environmental issues leads to less than optimal demand for new environmental technologies. All of these features generate market distortions which cause private R&D to deviate from what is socially optimal. As a result, governmental involvement in environmental technology development may well be warranted.

The production and import of fertilizer have previously been identified as the major source of three separate European environmental problems related to nitrogen compounds. In order to obtain a picture of the changes in the anthropogenic nitrogen flows needed for a solution, the effectiveness of several more radical interventions is estimated using Substance Flow Analysis (SFA). A selection of rigorous technical measures is expected to reduce the atmospheric deposition of N compounds to a level that seems acceptable for the EU as a whole, and will reduce the anthropogenic input of N compounds into the North Sea well below the agreed level of 50% of the present load. The third problem, the pollution of groundwater with nitrates, would remain unsolved. Resolution of this last problem requires radical changes in the agricultural sector, reducing agricultural output substantially. Two directions are explored by assessing the impacts of the extremes: termination of industrial fertilizer use to combat the problems at the source, and abolition of the entire stock-breeding sector to increase agricultural efficiency radically. These changes do contribute to a solution of the groundwater problem, but imply either greater dependence on imported food, or a major change in food consumption patterns, from animal towards vegetable products. The current EU population and diet are incompatible with the absence of environmental problems. The question then arises, how does acceptance of the draconian measures required to solve such an environmental problem weigh up against acceptance of the fact of having to cope with contaminated groundwater?

Many natural and human-induced events create disturbances in seagrasses throughout the world, but quantifying losses of habitat is only beginning. Over the last decade, 90000 ha of seagrass loss have been documented although the actual area lost is certainly greater. Seagrasses, an assemblage of marine flowering plant species, are valuable structural and functional components of coastal ecosystems and are currently experiencing worldwide decline. This group of plants is known to support a complex trophic food web and a detritus-based food chain, as well as to provide sediment and nutrient filtration, sediment stabilization, and breeding and nursery areas for finfish and shellfish.

We define disturbance, natural or human-induced, as any event that measurably alters resources available to seagrasses so that a plant response is induced that results in degradation or loss. Applying this definition, we find a common thread in many seemingly unrelated seagrass investigations. We review reports of seagrass loss from both published and ‘grey’ literature and evaluate the types of disturbances that have caused seagrass decline and disappearance. Almost certainly more seagrass has been lost globally than has been documented or even observed, but the lack of comprehensive monitoring and seagrass. mapping makes an assessment of true loss of this resource impossible to determine.

Natural disturbances that are most commonly responsible for seagrass loss include hurricanes, earthquakes, disease, and grazing by herbivores. Human activities most affecting seagrasses are those which alter water quality or clarity: nutrient and sediment loading from runoff and sewage disposal, dredging and filling, pollution, upland development, and certain fishing practices. Seagrasses depend on an adequate degree of water clarity to sustain productivity in their submerged environment. Although natural events have been responsible for both large-scale and local losses of seagrass habitat, our evaluation suggests that human population expansion is now the most serious cause of seagrass habitat loss, and specifically that increasing anthropogenic inputs to the coastal oceans are primarily responsible for the world-wide decline in seagrasses.

The following corrections are made to the article ‘The effect of reunification of Germany on the water chemistry and ecology of selected rivers’ by M.S. Adams et al., which was published in 1996 in Environmental Conservation23 (1): 35–43.

Attitudes and incentives of people living around protected areas are widely considered to constrain successful management of these areas. Two contrasting protected areas in Honduras, a Biosphere Reserve of high biodiversity rainforest, and a cloud forest providing essential environmental services to the capital city, are analyzed in terms of their management problems and the strategies used for their protection. The response at the national level to the issues raised in these case studies is then assessed, focusing on the impact of government policies, legal changes affecting land tenure and use, and the role of state institutions in protected area management. The case studies indicate that while the non-government organizations (NGOs) have tried to promote a more participatory approach to conservation (with mixed success), the Honduras Government has tried to follow a more regulatory approach but without the resources and political will to implement it effectively. Opportunities have been missed to provide positive incentives for protection, for example in the area of eco-tourism and community-based natural forest management in situations where this would appear to be a viable option. The participatory approach has also been complicated by policies and land legislation which have sent out negative or ambiguous signals to local communities. Above all the case studies show how critical local attitudes are to the achievement of conservation objectives, and demonstrate the need for positive economic incentives that link development with conservation in buffer zones and surrounding areas.

Understanding the effects of forest fragmentation on biodiversity is essential for successful and efficient forest conservation. Four factors may cause loss of biodiversity in forest fragments: the effect of non-random sampling of the original forest, reduced forest size, isolation and edge effects. A review of 58 papers on effects of forest fragmentation reveals that general conclusions from fragmentation research are biased due to a focus on birds, on size-effects rather than isolation, and on species presence rather than population sizes. Perhaps the most important finding is that current knowledge on fragmentation effects is based mainly on studies in small fragments (<10 ha). These are dominated by edge effects, can not contain viable populations for many species and are rarely the focus of conservation programmes. Studies of small fragments can not be extrapolated to larger-sized, protected areas, and do not necessarily support the case for needing extremely large, protected areas. Conservation of medium-sized, strategically-located areas may be a more efficient option for biodiversity conservation, given financial, social and logistic limitations. More research is needed on forest fragments that arc representative of the sizes of real-world protected areas (i.e. >10 000–100 000 ha) and should focus on the biological and human-induced processes which determine species persistence.

The environmental impact of the Nigerian economic Structural Adjustment Programme (SAP) on the livelihood of the rural dwellers has been little studied. A study was conducted amongst 10 villages in the Olokemeji area of Oyo State, Nigeria using standardized interviews of 200 household heads.

The oil boom of the 1970s in Nigeria drove many male heads of households in the study area to the cities, but the collapse of the urban unskilled labour market in the 1980s brought men back to the villages. However, by 1990, renewed dominance of female-headed households in the study area has followed further male emigration. Changing roles of women in managing the forest environment are indicated over the three time periods and I argue that female-headed households attempt to conserve and improve the state of the environment more than their male counterparts. This is achieved through the cultivation of less nutrient-demanding crops such as cassava and yam, and using environmentally-friendly farming systems such as terracing and taungya.

Trade in tropical timber, while a minor cause of deforestation in the tropics, can be a substantial factor in promoting forest degradation and deforestation. International organizations and conferences increasingly recognize that adverse environmental effects of international trade can be reduced through regulations and economic incentives. Three international agreements, the GATT, the CITES, and the ITTA, now affect the tropical timber trade and are here reviewed. Adopted at different times, they illustrate different philosophies, pursue different objectives, and develop contradictory trade policy perspectives. Legal conflicts among these agreements reduce their effectiveness, and mitigate a global objective of making international trade in tropical timber more responsive to environmental issues. Harmonization among the GATT, the CITES, and the ITTA, and collaboration among organizations in charge of managing these agreements, should be reinforced in order to establish a coherent and uniform policy for tropical timber trade.