The present global economic order is one which fails to recognize the finiteness of global resources and the finiteness of the global ecosystem to absorb wastes. Indeed, there may be a great deal of lip-service paid to these truths; but nevertheless the global economic system, as it is functioning today, exhibits little or no awareness that they are at all important to a stable world economy. Superimposed upon this condition is the ‘Autophage Effect’, which points to a continuing acceleration in depletion of raw resources even though the net resource-demands of the world's populations may stabilize.

This is a human predicament which cannot and will not continue indefinitely. The key question is, ‘Will Earth's societies acknowledge the situation early enough to choose alternatives?’ There appear to be only two fundamental alternatives: either the present level of population and material abundance (imperfect as it may be) will crash, or it will be replaced by a world economic order which attends to the finiteness of this planet. Should we be fortunate enough or quick enough to realize the second alternative, I suggest that the basic structure of the new economic order may rather closely resemble the ecologists' ‘trophic’ divisions in natural ecosystems (e.g. Lindeman, 1942). If this comes to pass, conservation of energy and order (negentropy) will very likely emerge as the prime forcing functions in the resulting world socio-economic order.

This exploration has progressed from logical derivation into imagination, but still leaves a plethora of unanswered questions. If one does admit that industrial civilizations must eventually face resource limitations and thereby be driven towards the patterns exposed by the hypothetical society that has been sketched here, how do we get there from our present predicament? Can such a society be capitalistic, with grossly or moderately unequal distribution of resources among its citizens? Or must it be a form of socialistic idealism; and, if so, should it be democratic or autocratic? Can the present momentum of the highconsumption Keynesian theology be redirected? And if so, how—and will there be time? If the seeds offered here have any credibility, they should be nurtured further.

Disposal of municipal solid wastes may result in needless environmental damage and loss or degradation of land. In addition, the material and fuel resources contained in the wastes remain unused. The extents of these latter in the entire United States are estimated in this paper.

New terms are introduced to aid more precise estimation than hitherto of the amount of energy which can be conserved through processing and recovering the resources in municipal solid waste. Further, the likely rate of implementation of resource recovery in the U.S. is predicted on the basis of a simple model which relies on the assumption that the rate of implementation is proportional to the number of plants that are or will be actually on-line.

There is a great temptation to combine the rate of implementation with the sum of the energy potentially recoverable from the various sources of wastes, and to convert the answer to, for example, so many barrels of oil per day. As is indicated in the discussion, this exercise in not technically justified. Nonetheless, the energy that is potentially recoverable from solid wastes has an arithmetic equivalence of the order of magnitude of 1 million barrels of oil per day (1.6 × 106 m3, or 158 × 106 litres) in the United States alone, and even more if a generous fraction of agricultural and crop residues could be garnered for processing. This order of magnitude, perhaps as much as substitution equivalence, should be compared with the stated U.S. goal of conservation of 2 million barrels of oil per day (presumably also an arithmetic equivalence) from all sources by the end of 1977—not just from solid wastes (Ford, 1975).

The analogy of solid waste as an ‘urban ore’ has been used to the point of almost becoming trite. Nevertheless it may well be timely to extend the analogy to waste as an urban oil-well or coal-mine.

The Author reports some information regarding three recent accidents in Italy: the sinking of a freighter transporting lead tetraethyl and tetramethyl, an explosion in a tower of a chemical plant which resulted in a considerable outflow of arsenic dioxide, and the Seveso explosion with the consequent contamination by highly poisonous Dioxin of a large inhabited area adjacent to the factory.

Difficulties due to lack of knowledge, conflicting opinions, and contradictory ‘remedies’, are reported and discussed. It is concluded that the local populace and authorities should be informed of the nature of cargoes that are being carried across sea basins or through smaller channels, of the types of wastes that are eliminated regularly into the air or water by a factory, and what a factory is producing during its various working processes that could cause risks to employees or others around—also, what possible measures could remove or alleviate these risks.

Exclusion of human interference from national parks and nature reserves commonly results in undesirable successional changes in the vegetation. First of all the semi-natural plant communities, which have been formed and maintained by traditional methods of extensive land-use—mowing, grazing, burning, etc.—are affected. In Poland this has happened, for example, to the halophytic meadows on the Baltic coast, the secondary xerothermic (‘steppe’) grassland in the southern highlands, and the mesic hay-meadows of the forest zones in the Carpathian Mountains. When neither mown nor grazed, they all lose more and more of their typical components, and finally disappear. Many such communities originated hundreds or thousands of years ago and include a number of native plant species which cannot be found in any of the natural vegetation types.

The problems of conservation of semi-natural plant communities have been studied by the Author in three representative areas of Southern Poland: in the Gorce Mountains (Western Carpathians), the Niepolomice Forest, and the Ojców National Park near Cracow. In the Gorce Mountains about half the existing major plant communities belong to the semi-natural category and exhibit a much higher species-diversity than the natural forest vegetation (Table I). Similarly, in the northern part of the Niepolomice Forest, many more species are concentrated in the semi-natural, non-forest communities than in natural ones (Table II). For the Ojców area two maps, one of the actual vegetation and another of the expected or ‘potential natural’ vegetation, were compared and the topographic arrangement and successional trends of plant communities established (Table III). It became evident that, if all human impact were to be excluded from the Park, the rich semi-natural plant communities would completely disappear and many of their interesting components would become extinct at least locally.

These data, as well as similar observations reported by other authors, explicitly demonstrate that very often the existing vegetation diversity in national parks and nature reserves may be maintained only when the ecological situation has been rightly understood and the proper management adopted.

The tropical American shrub Clidemia hirta (Koster's Curse) has become a pest in pastures, cropland, and forests, where it has become naturalized in many parts of the humid tropics. It has spread through the island of Oahu, Hawaii, since 1941, despite attempts at biological control by the introduction of the parasitic thrips, Liothrips urichi, which had proven effective in supressing growth of this noxious weed in Fiji.

The pest has colonized habitats similar to those occupied over its natural range—such as forest clearings, trail-sides, and burn-sites. In addition, in Hawaii it has intruded into the understorey of forests which were formerly free from exotic weeds. Fears are held that the resulting ecological disruptions may place further stress on the frail island ecosystems and cause plant and animal extinctions while producing other management and aesthetic problems.

Immediate action is necessary to eradicate small colonies of Koster's Curse that have become established on near-by islands, and recommendations are made regarding efforts needed to devise means to control heavy infestations in the highly inaccessible mountains of Oahu.

Bushmeat is meat, of whatever nature, that is obtained from wild animals, and historically people everywhere in the inhabited world have, at some stage in the evolution of their culture, been dependent on it to some extent. Wildlife conservation is essential for varied bushmeat production, and the two are particularly closely interconnected in the countries of Africa lying to the south of the Sahara; this brings in environmental conservation as a third factor of basic importance.

The economic incentive being often considerable, the record of protection and management of wildlife in some countries in Africa south of the Sahara is impressive, though in others it is lagging, while even in the famous National Parks the failure to cull large mammals may lead to drastic habitat deterioration due to over-population: wider, regularized use of bushmeat could provide a beneficial answer to this problem. Meanwhile there is a great demand for bushmeat in Ghana and many other African countries, and it is expected that this demand—and hopefully the supply—will increase with changing patterns of land-use.

There is thus strong economic and other justification for environmental management with the objective inter alia of maintaining and increasing bushmeat production in most countries of Africa south of the Sahara.

Mangroves play an important role in estuarine ecological systems as well as in shoreline protection. Such large areas of mangroves have been lost by dredging, land-filling, and other means, that it has become important to develop techniques for restoring or replacing them. Such techniques are needed both for the sake of restoring the mangroves as a valuable shoreline habitat and to estimate their monetary value, which must at least equal the restoration cost.

It is accordingly suggested that future destruction of mangroves be permitted only if they are subsequently replaced at the same site or at some appropriately developed alternative site.

Mangroves have been planted at several sites in Florida, and planting success has been evaluated. Mangroves of several sizes have been planted at a variety of sites that differed in shoreline energy, tidal depth, root-parasite prevalence, substrate type, salinity, and public access. Counts and measurements made after periods of up to 4 years indicated that shoreline energy, tidal depth, and vandalism, were the most important factors limiting mangrove establishment and survival.

Planting costs were estimated from collecting and planting by research assistants and from estimates of the price of larger (3-years-old) nursery-grown trees. Planting cost estimates were $462/acre ($1,140/ha) for unrooted Red Mangrove propagules spaced 3 feet (91 cm) apart, $1,017/acre ($2,500/ha) for established Red, Black, or White, Mangrove seedlings spaced 3 feet (91cm) apart; and $87,500/acre ($216,130/ha) for 3-years-old trees of Red, Black, or White, Mangroves spaced 4 feet (123 cm) apart.

An industrial energy-budget for a Rainbow Trout farm shows that 93% of the energy costs of production are incurred in feeding the fish, seven-tenths of which is due to fishnieal incorporated in the food pellets. Only one-tenth of the input energy is converted into fish, but the energy subsidy of the farming operation compares favourably with conventional fishing and is 423 input megajoules per kg of output fish protein (55 MJ per kg wet-weight of fish landed). However, if the Trout could be fed on a diet composed of suitable vegetable protein, this performance would be improved to an overall conversion efficiency of one-third, and a subsidy of about 160 MJ per kg. A smaller but similar improvement could result if the Peruvian anchovy fishery regained its former production level.

As these improved energy-costs are comparable with those of crops of potatoes, and with those of bread and milk production, a 2-men Rainbow Trout farm yielding 25 tonnes per year on one hectare would become an attractive protein-producing enterprise in localities where the necessary water-supply is available.

The term ‘ecodisaster’ may be defined as ‘a global catastrophe of the human species’. Any ecodisasters occurring in the near future will, almost certainly, be caused, directly or indirectly, by the present overpopulation of the world, accompanied by unwise and irresponsible disregard of environmental deterioration.

The suggestion is made here that Man's first and, it is to be hoped, last, ecodisaster may already have begun. Although not dramatic, it is taking the form of a steady decline in the standard of living nearly everywhere, coupled with massive pollution, and widespread malnutrition in the under-developed countries of the world. It will persist until world population eventually becomes adjusted to environmental resources.

It is ironical that control of the pests and diseases which have inflicted so much misery on mankind in the past, should have helped to engender the present population explosion with all the hunger and privation that accompany it in the under-developed regions of the world.