Objective: a return to a wholesome human habitat

The continued operation of the biosphere as a wholesome human habitat would be expected to emerge as one of several persistent collective purposes in human affairs. Daly (1993) has pointed to the challenge as accommodating the transition from an empty Earth, where resources exceed demand, to a full Earth, where demand routinely exceeds the resource. Forests are so large in every aspect of the biophysics of the human habitat that their functional integrity is intrinsic to that purpose. How can the functional integrity of forests on a full Earth best be assured on a global basis over the next decades as all pressures on the human habitat continue to soar? Such is the challenge before the World Commission on Forests and Sustainable Development, now completing its final hearings and preparing its report. The Commission was established in 1995 as a non-governmental group of distinguished citizens from the forested countries to do what governments had been unable to do in 1992 at the Rio Conference, namely to address the critical global and international issues of forests in the context of the emergent public interests, as opposed to continued destructive commercial exploitation. The Commission's staff and offices are in Geneva. Its report will be released in 1998.

Fisheries, over-capacity and subsidies

A consensus is emerging regarding world fisheries.

Overall, the world's living marine resources are being overexploited; in many major areas a reprieve in the level of fishing would assure larger and more valuable fish supplies in the long term. Less would be more.

The system is uneconomical and unsustainable. We are paying an unnecessarily high price, in capture costs and environmental degradation, for a dwindling catch.

Conventional management measures (including time, space and gear constraints) have not proved themselves capable of stanching excessive fishing effort. Indeed, many of the traditional measures, by prohibiting the most economical means of fishing, amplify inefficiencies, raising unit costs without compensatory benefits in catch reduction.

Increasing blame is being placed on over-capacity. As long as investment in harvest capacity is excessive, in other words beyond the level required for efficient attainment of fisheries objectives, effective regulatory efforts are frustrated at the levels of both rule making and enforcement.

After addressing a conference on ‘Ethics and the Practising Scientist’ some four years back, I remember the conferees struggling to formulate a code of ethics for those engaged in the so-called ‘hard’ sciences. They could not arrive at a satisfactory formulation, and at one point the chairman, in utter exasperation, confessed that, he didn't care for details about principles or quibbles over which slant the statements took, for ‘frankly any code should do!’ During the decade before and after that 1993 meeting, attempts to enunciate moral principles for researchers and manifestos for responsibility in science have come and gone, and the notes of discord have not abated.

In a previous report I tried to show that the widespread use of electric cars, both battery-powered and so-called ‘hybrid’ types (i.e. vehicles utilizing an electric motor powered by a battery in town, and a combustion engine on open highways), would not reduce, but rather increase, air pollution, because the electricity required to run them would have to be generated by a large number of additional fossil-fuel burning power plants, with a lower total energy efficiency (de Sabata 1995).

Mankind is faced with three interconnected problems, those of rising population, the provision of adequate food and the increasing level of waste carbon dioxide in the atmosphere. The ocean plays an important role at present by annually providing c. 90 Mt of high protein food and absorbing about 1000 Mt of carbon dioxide (CO2) from the atmosphere. By the year 2100 it is predicted by the United Nations (1992) that the world population will have more than doubled its 1990 level of 5.2 thousand million people and will approach 11.5 thousand million. Most of this population increase will occur in the developing countries.

Mahogany as a catalytic species. Logging of American (bigleaf ) mahogany (Swietenia spp.) initiates a series of events that leads to degradation and later destruction of tropical forests in the New World. It also is a spear-point for penetration of indigenous areas by loggers, who inflict both social and environmental impacts on the tribes. Mahogany populations are declining and are not being replenished by natural regener-ation; the situation of the species continues to worsen in the field.

In the beautifully-illustrated book of rare and threatened plants of Greece (Phitos et al. 1995), the selection of species is based strictly on the four World Conservation Union (IUCN) categories of ‘extinct’, ‘endangered’, ‘vulnerable’ and ‘rare’ (Lucas & Synge 1978). The Swedish ‘red data’ book of plants (Aronsson et al. 1995) adds ‘care-demanding species’ to the list. Five percent of the total number of vascular plant species in Greece are included in the Greek book, while 23% of the vascular plant species in Sweden are in the Swedish book. This latter percentage may appear to be sufficiently large, but is it?

Many traditions of coastal peoples may be viewed as traditional forms of marine conservation because, like modern fisheries management, they restrict fishing gear, fishing times, and places, but their effects are little studied in practice. A study was undertaken of human culture and fisheries resources in an area of southern Kenya, designated as a national marine reserve, to determine the effect of the existing 'traditional management' on fisheries yields and on the ecological condition of the fished reefs. This area has one of the oldest and most elaborate cultural traditions concerning sacred sites and rituals of sacrifice along the Kenyan coast. The purpose of the customs is, however, to appease spirits rather than to regulate fish stocks which are traditionally seen to fluctuate independently of fishing effort. Many of these traditions have decayed in recent times as Islamization of the culture has occurred, and authority has shifted towards national organizations, weakening the effectiveness of the traditional leaders. Coincidentally, fishers have adopted new or foreign gear, colleagues, and traditions. Two adjacent landing sites (Mvuleni and Mwanyaza) have, however, successfully stopped pull seiners from landing their catch at their sites for over 20 years through passive means. Other landing sites have adopted pull seining. Both landing areas use arguments based on tradition to justify their use of gear. The two landings that restrict pull seining have higher per capita fish catches than those that do not. Nonetheless, there were no obvious differences in the ecological condition of the reefs at these two management areas; both areas were amongst the most degraded reefs reported in East Africa. Biological diversity and coral cover were reduced greatly in all these areas compared to other fished or fully-protected marine park or reserve sites established by the national government. Presently, traditional management is not effective in protecting species diversity or ecological functions, which was probably never the intention of the customs. The conflict between national organizations and local fishers arises because some resource users are concerned that the management proposed by the national organizations will eventually lead to the total loss of access to, and control of the resource by local fishers. There is, therefore, a need to resolve conflicts concerning gear use and regulation, and a need to increase awareness of the expectations and management programmes among the national and local organizations. Many of the traditional forms of management are compatible with the policies of national organizations, but confusion and conflict occur concerning enforcement and its benefits. To solve these conflicts discussions are required between traditional and national fisheries leaders to develop mutually-acceptable policies that augment and share the power of management.

In the era of space travel, ecology has continued to gain relevance as the science of the ‘spaceship Earth’. In this context, it can be said to have a mission, which is to understand the complex network of the life-support systems that keep biospheric processes operating in a way suitable to sustaining living organisms and their environment (Odum & Sarmiento 1997). With the realization that ecology, in the broad sense, provides the means to understand the mechanics of nature, scholars are using ecological understanding at the interfaces of disciplines to: (1) prevent and reverse the demise of biodiversity in marine and terrestrial ecoregions (conservation biology), (2) reduce impacts of population pressure on the resource base of people (ecological anthropology), (3) establish more parsimonious economic activities to ensure optimum yields for the long term (ecological economics), (4) plan for an appropriately-equitable and socially-integrative sustainable development (environmental design), (5) restore degraded ecosystems and landscapes (restoration ecology), and (6) model hypothetical future scenarios where predictions from ecological theory may prove valuable for the future of mankind (environmental planning).

Moral relations with nature, I contend, are connected with our duty before a social environment. Elsewhere I have defined duty as '‘what is recommended by moral or religious law, and what one has to do in order to be in agreement with one's conscience’ (Schreider 1994, p. 27). Our highest duty, I have argued, is social duty, or duty towards humankind as a whole; but this kind of duty, in fact all so-called ‘moral duty’, is not natural, or predetermined by our natural essence (Schreider 1994, p. 99; Schreider 1996). Now, our social duties, not any ‘natural duties’, have implications for our relations with the environment. This is so, significantly, because no natural reasons exist for there to be harmony between humanity and the environment. Indeed, if such natural processes did exist, why should we invoke the need of duty towards nature, because whatever we did, would not we be doing things naturally? To engage duty, in fact, already presupposes the absence of such natural relations, and turns the spotlight on acts of free will, or human decisions and responsibilities. Our experience of history and social relations is such that we humans are more than often found independent of, sometimes even going against, the perceived ‘natural stream of events’, by either creating or solving environmental problems. The claims of duty, then, have to be clarified on any environmental philosophy, because there is a common trap of letting nature dictate morality, a problem apparent in neo-Spencerian ethics (cf. Trompf 1990, pp. 17-20). As I have not long ago maintained (Schreider 1994, p. 107), duty is a basis for our rational actions, designs and relations, and duty, we would thus rightly expect, has moral foundations, even (more controversially) religious ones. Human responsibility for nature loses any sense unless we presuppose it to depend on free will. Otherwise we are left with a predetermined course of events, not duty, and I hold we would even deny self-existence, ascribing our actions not to ourselves but to some ‘objective reasons’ (Schreider 1996).

The Eastern Ghats (EGs) comprise a chain of ancient low hills in the state of Andhra Pradesh adjoining the east coast of India. These hill ranges are well known for a rich array of tropical forests with great conservation significance which support large human populations. A series of protected areas (PAs) have been established by the government along these ranges to conserve the regional biodiversity, but their effectiveness is often questionable. In order to assess the ecological status of the forests both within and outside the PAs and to assess the impacts of ongoing forestry practices a survey was conducted along the EGs. Plant species richness, and density of shrubs and trees, were estimated along disturbance gradients (core, buffer and fringe situations) using random plots of 10-m radius for trees, and 5-m radius (nested) plots for shrubs and saplings. Indirect evidence (spoor) of domestic and wild animals was recorded within the sample plots to compare habitat use by the animals.

Srivenkateshwara National Park in the Seshachalam Hills, Gundlabrahmeshwaram Sanctuary in Nallamalais and some parts of Srisailam-Nagarjunasagar Tiger Reserve, had the least degraded forests due to their PA status. However, collection of non-timber forest products, bamboo harvesting and livestock grazing continues in all areas irrespective of legal status. All bamboo areas have been heavily worked. It is recommended that bamboo working should be stopped in core areas of the PAs and reduced from nine to six months (October to March) in the buffer zones. Summer is a period of potential water shortage for wild animals and bamboo workers' camps near water courses may affect habitat use by these species.

The proposed Gudem Maripakhala Sanctuary, well known for its biogeographical value and diverse flora, is seriously threatened as a result of to extensive 'podu' (slash and burn) cultivation. It is suggested that an integrated approach to biodiversity conservation and better agricultural practices, should be adopted in this area. Some of the primary and old growth forests should be identified, mapped and given immediate protection, until a scientifically-based management plan is developed.

Tourism is regarded by many countries, particularly resource-poor countries, as a potential stimulus to the economy. Yet tourism, by the nature of the activities involved, is constrained by the natural resource base and infrastructure, and by the pollution and other environmental and social impacts of tourist numbers. Tourism development strategies of national governments have been diverse in the face of this complex relationship between the economic costs and benefits of tourism. This paper examines tourist development based on concepts of open access and renewable natural resources. The experiences of two economies highly dependent on tourism, the Maldives and Nepal, are compared and contrasted. Although these countries offer very different attractions to tourists, they are faced with similar problems in terms of adverse environmental impacts of tourism. The dominant impacts in both areas are those associated with solid waste disposal and water resources, compounded by the depletion of natural resources. Both countries are currently employing 'dispersal' techniques to overcome the adverse impacts of tourism, but such strategies do not address the fundamental problem of maintaining tourism revenues whilst minimizing environmental damage. Even if an ecological carrying capacity can be defined, the experiences of these two countries indicate that impacts on local communities may well exceed so-called cultural carrying capacity.

Critical loads studies (critical load is ‘a quantitative estimate of an exposure to one or more pollutants below which no harmful effects may occur’) have been used as the basis for assessing European strategies for reduction of sulphur emissions within the United Nations (UN) Economic Commission for Europe (ECE) Convention on Long-Range Transboundary Air Pollution (LRTAP). It is expected that the critical loads method will be applied to future international agreements under the Convention. Mapping of European critical loads conducted for the LRTAP Convention have progressed notably in recent years.

The concept of designing pollution control measures with the aim of protecting the most sensitive ecosystems, led to the creation of the Task Force on Mapping and Coordination Centre for Effects to implement these concepts on a European scale together with the corresponding National Focal Centres. The Russian National Focal Centre is used to illustrate how critical load data can be applied at the scale of a large country.

The policy implications resulting from the methods described in this review would support the development of an acidification protocol. While this has been suggested in the past, it is only now that scientific knowledge has advanced sufficiently to consider the feasibility of such a policy.

Deforestation is still rapid in some parts of the Caribbean, though it has attracted much less attention than deforestation in mainland Latin America. This paper examines the history and causes of the recent rapid deforestation of a lowland karst region of the Dominican Republic in the light of models derived from studies in Central America and the Amazon. Investigation was limited to the vicinity of a single village (Los Limones). Information was drawn from interviews, questionnaires and ground reconnaissance, in addition to archival information and aerial photographs. Deforestation at Los Limones involved many of the same elements seen in mainland deforestation, including construction of access roads, spontaneous agricultural colonization, and pasture conversion, but it followed no single mainland model. Logging, not normally emphasized as a cause of Latin American deforestation, played an important role in opening up the forest to agricultural settlement. Pasture conversion was not a matter of aggregation of large ranches by wealthy absentee landowners, as in the Amazon, but apparently a local response to the economic and ecological advantages of cattle raising. Government actions strongly influenced deforestation, but not via colonization schemes or economic subsidies for cattle ranching; the rhythm of deforestation at Los Limones was tied to the monopolistic practices of the dictatorship of Rafael Trujillo and the social disorganization following his assassination. The national government in fact bears the primary responsibility for deforestation of Los Haitises, a conclusion that contradicts the government's own suggestion that the destruction was largely carried out by poor farmers. Prospects for rehabilitation of the deforested area are gloomy because of the extent of ecological damage and the continued adversarial relationship between the government and the rural population.

A variety of organic contaminants can potentially have impact on aquatic birds by their affecting surface tension. Avian plumage constitutes a porous barrier to water and the air trapped between the feathers serves as thermal insulation. When the air is displaced, the birds expend extra energy to maintain a normal body temperature, but this response cannot be sustained for long, especially at low environmental temperatures. When energy stores are depleted, hypothermia and death ensue. Surface tension is the force that resists infiltration of water into the plumage. The critical surface tension for feather wetting is conservatively estimated to be in the range 38–50 mN m-1. The hypothesis that surface-active organic contaminants can have significant detrimental effects on aquatic birds was evaluated. New data obtained in a study of water penetration pressures in Lesser Scaup contour feathers show that the 'wettability safety factor' is reduced by about half during moult. That is, the critical surface tension was raised to approximately 49–58 mN m-1 in moulting Lesser Scaup. The energetic and behavioural effects of oil contamination are reviewed, and it is concluded that even small quantities of organic material may confer significant physiological cost. The available data generally support the hypothesis that waterfowl face a potential risk associated with chronic or periodic mild depression of water surface tension due to organic pollutants, including oils and detergents. However, much of the evidence is indirect and further research, especially long-term assessment of surface tension in marine, estuarine and freshwater habitats, is needed to determine whether a real environmental problem exists.

A half century has elapsed since the appointment of an official body, the Nature Conservancy, in 1949, and the beginnings of what might be described as the modern nature conservation movement in the UK. Whilst ecologists perceived the 'heritage of wild nature' to be largely the outcome of past land use, and that the nature reserves would have to be managed consciously if their wildlife interest were to be sustained, there was only the most rudimentary understanding of how this might be achieved. Drawing for the most part on projects affecting wetlands, the paper illustrates the early steps taken to bring greater scientific rigour to reserve management. Whilst the potential for habitat restoration was recognized, there was little opportunity for its practice in the intensively-farmed countryside until grant aid was made available for such purpose from the agricultural budget in the 1980s. Where nature conservation had begun to subsume nature preservation, some fifty years ago, notions of 'creative conservation' have similarly encouraged reassessment of the purpose and practice of wildlife-resource management. This time however the challenge is being met in both the wider countryside and the built environment.

Several authors have suggested that ecotourism can enhance the value of intact wildlands and thereby promote conservation. Two rainforest lodges dating from the 1970s and located in southeastern Amazonian Perú have been held up as early success stories in tourism-driven conservation, but a more recent assessment reveals that both lodges have since lost their rainforest reserves to encroachment. One of the major reasons for failure was that the national land laws in effect at the time did not allow the purchase of land titles. Recently, Perú has instituted a process for the purchase of land titles in the rainforest. One lodge has used the new land tenure laws with some success to create a rainforest reserve. The very attempt to buy land for purposes of conservation can promote encroachment and land-buying speculation, and the lodge's current agreement with its neighbours to provide a school in exchange for non-encroachment is fraught with moral hazards and appears unstable over the long term. Tourism can promote conservation primarily at the national level, and ecotourism projects in the Peruvian Amazon can stabilize land-use patterns at least in the short term. However, the conservation of habitat over the long-term will rest primarily on the ability of the State to enforce a consistent land use policy with regard to land tenure and Park protection.

Arrested succession is conspicuous in the abandoned pastures of the Andean piedmont that have encroached upon the tropical montane forests toward higher limits and steeper slopes. Habitat 'shredding' is analysed to depict the current spatial configuration of tropical Andean landscapes, based on fragmentation patterns prompted by seed dispersal ecology and pasture encroachment.

Seed dispersal was studied to address the hypo-thesis that seed input constrains the recruitment of montane forest seedlings, thus impeding pasture conversion to forest. It turns out that a better competitor, the tussock grass Setaria sphacelata, is limiting dispersal success due to its bioarchitecture and planting patterns. Because of the variegation of fragments, the area is in danger of landscape homogeneity within a matrix of degraded pasture. Currently, protection of fragmented remnants and restoration of original landscape structure and function are urgent needs for land-use planning toward sustainable development in the region.

Restoration ecology is plausible as a means of conservation for degraded Tropandean forests, since human impacts have shredded landscapes entirely. Dispersal ecology may be used to facilitate pasture conversion to forest in equatorial landscapes, but the proactive approach of pasture removal or planting strategy should differ from that for lowland Amazonia, where abandoned pastures are different from those of montane environs. However, the region may be proactively managed only if political decisions include conservation as a goal of development.

Ecological impacts of urbanization are receiving increasing scientific attention, yet few data sets permit long-term effects on terrestrial and aquatic ecosystems to be assessed. Töölönlahti Bay, in the centre of Helsinki, Finland, provided on opportunity to characterize recent human impacts especially by means of chemical and biostratigraphical analyses of a sediment core. Periods of coniferous forest, forest clearance, urbanization and the development of parks, can be distinguished in the pollen record of the core. Palynological diversity was highest before the forest clearance at the turn of the century. The character of the sediment and the water have changed substantially in response to rapid population growth, the construction of sewage systems and building within the catchment of the bay. This is reflected in marked increases in organic matter, phosphorus and heavy metal (Cd, Cu, Ni, Zn and Pb) concentrations between 1890 and 1960, accompanied by a rapid increase in diatom species indicative of eutrophication and a decline in diatom species diversity.

Since the cessation of waste-water disposal in the 1960s, concentrations of a number of pollutants have declined and water quality has gradually improved, but conditions are still affected by internal and atmospheric loadings. As a consequence of land uplift (2 mm per year) and the rapid sedimentation rate (6 mm per year), the volume of the bay is decreasing. Within 200 years, the shallow bay, which is skirted by extensive parks and famous cultural buildings such as the Finlandia and the Opera Houses, will fill with sediment unless it is dredged.