A brief description is given of the physiography, climate, and natural vegetation, of Iran. Subsequently an analysis is made of the environmental problems which are building up to crisis proportions. Of particular concern is the alteration and destruction of natural ecosystems through the impact of Man over a period of many centuries. As a result of H. I. M. the Shahanshah's personal attention to this problem, forests were nationalized, range improvement measures have been instigated, and the Department of the Environment has undertaken a comprehensive programme of conservation and management of areas of national importance.

A programme of scientific investigation and management of wildlife resources has been initiated. Intensive studies of Wild Sheep, gazelles, and Persian Ibex, are now under way. In all reserves the condition of the vegetation is closely monitored. Due to these measures, wildlife populations have increased in most reserves. Iran has some of the finest wetlands in south-west Asia, and has made much progress towards their preservation, over one million hectares of the most important wetlands being now fully protected.

The Department of the Environment has had considerable success in its programme of protection of endangered species—including the Onager, the Persian Fallow Deer, the Asiatic Black Bear, the Asiatic Cheetah, the Marsh Crocodile, the Great Bustard, and the Caucasian Black Grouse. The future of these species is now almost certainly ensured in national reserves.

Iran now has four categories of reserves: National Parks, Protected Areas, Wildlife Refuges, and National Nature Monuments. Thirteen National Parks have recently been approved. Currently there are 27 Wildlife Refuges. An extension of this network of national reserves is planned within an international framework.

The Pacific Northwest is economically dependent upon its forest resources, which at present represent about 30% of the nation's softwood supply. Predicted decreases in the available supply have encouraged more intensive forest management, and new methods of planting, harvesting, and transport, have been developed.

Even with these improvements, problems exist in reducing erosion and accommodating other uses of forest lands and streams. With adequate planning and effort, however, most of these problems can be solved. But costs are high, and State laws controlling all forest practices are forcing Federal, State, and private, landowners to cooperate in planning for the future. Decisions that must soon be made should reflect an ecological understanding that could ensure the economic future of the Pacific Northwest.

In spite of a relatively pollution-free ground- and surface-water system in the Ljubljana region of Yugoslavia, large public investments are planned for waste-water treatment systems. This is due to a high level of public awareness of pollution dangers and to particular characteristics of the decentralized economic and political institutional framework of the Yugoslav self-management system. The decentralized framework leads to a trend towards parsimonious decisionmaking—that is, adoption of the simplest solutions to otherwise complex policy-problems.

The new ‘water self-management communities’ in Slovenia may potentially become the instruments for regional basin-wide planning, but face four major existing problems: (1) the proliferation of local wastewater facilities throughout the region; (2) without consideration of their cost-effectiveness, the major policy goal is simply to provide sewers for 90% of the population, and not optimization of water-quality or investments; (3) the fragmentation of water management institutions hinders a comprehensive basinwide approach; and finally (4) the system of waterquality monitoring is not related to the planning process, while discharge standards and stream classifications are not based on utilization of in-stream assimilative capacity.

Three alternative systems of waste-water treatment and disposal are considered: decentralization, regionalization, and the present trend towards local communal treatment facilities but with a centralized system. Even taking into account scale economies, regionalization is probably the most costly because of the low-density urban pattern in the region, and the last-mentioned trend should be the least costly in terms of short-run capital outlays. The study could have wide implications as an example.

Malaysia is one of the world's most successful ‘developing’ countries. As such it provides some excellent examples of rapidly changing man–environment relationships of a type that are soon to be expected in many other Third World nations.

The examples selected for this paper have been chosen to show both the degree of Man's impact on the natural environment of Peninsular Malaysia and also the changing relationships between Man and his environment. These two themes are inextricably related. The case-studies used illustrate these themes on different areal scales.

The impact of oil spillage from grounded supertankers using the Straits of Malacca and Singapore illustrates the international implications of a potentially widespread ecological disaster. The need for international control is stressed. In Malaysia, effluent from palm-oil processing mills is becoming an increasingly serious water-pollution problem in many of the Peninsula's rivers. Although the effects may be confined to individual drainage-basins, the results can be catastrophic to both aquatic and marine ecosystems and to the people who obtain their livelihood from them.

Land development and forest clearance have resulted in the opening up of vast areas to new rural settlements, a process paralleled by rapid urbanization. The third case-study considers Man's changing relationship to his disease environment in both rural and urban areas from the point of view of man–mosquito relationships. Finally, as a local problem, the Batu Caves situation is taken to illustrate conflicting resource demands for a unique limestone habitat. The impact of industrial pollution on the local population is emphasized.

These problems are finally considered from the point of view of the quality of life and human welfare in developing countries. It is argued that raising levels of human welfare through development without giving due consideration to environmental impact may be a self-defeating process. Local issues probably make the individual aware of this paradox. Perhaps only when the cumulative environmental and individual impact of human activities is appreciated at local, regional, and national, scales will effective legislative controls be introduced.

The present bacteriological pollution of chlorinated drinking-water supplies in many regions of Jordan gives cause for considerable alarm, especially as it has been ascertained in the work described in this paper that faecal coliform Bacteria have already polluted 37% of the underground wells in the Amman–Zarqa area. Intensive efforts should be launched in order to prevent further pollution of ground-water in Jordan.

It is conventionally argued that a stable ecosystem, namely one with high species-diversity and high constancy in physical parameters, is less sensitive to additional stress than a system with varying physical parameters and low species-diversity. By this logic, the Baltic would be more susceptible to additional stress, such as that of pollution, than the North Sea.

Examples of irreparable damage to some of the most stable ecosystems in the world, such as coral reefs and tropical rain-forests, suggest, on the contrary, that these systems are more vulnerable than low-diversity ecosystems, such as a brackish-water zone in the mouth of a river or a coniferous forest in a temperate region.

Studies of stress tolerance in estuaries showed that the species already living under stress, such as that of reduced and changing salinities, were more tolerant to pollution than species in a less fluctuating environment. This adaptability to environmental changes seems to be characteristic of ecosystems with a low degree of individual specialization and high genetic diversity (i.e. a large number of alleles). Following this conclusion, we question the underlying assumptions in the statement that for example the Baltic Sea, which can be regarded as a large estuary, is an area particularly susceptible to stress; purely marine ecosystems are probably more sensitive.

Ecosystem stress-tolerance should be made a top priority in ecological research; this is a necessity inter alia for future localization of industries, in order to minimize their effects on the environment.

The effects of cement dust emissions from a cement factory on the growth and yield of trees in the adjacent Olive plantation were investigated. Some characteristics of the soils in the polluted and non-polluted areas of the plantation were studied.

In the polluted area the cement dust had formed a crust ca 1 cm thick on the soil surface, and the leaves of Olive trees in this area were also covered with a cement crust. The amount of dust deposited on the leaves of the polluted trees was around 2.55 mg/sq. cm of leaf surface, but they did not show any visible symptoms of injury. However, as compared with a non-polluted tree, the polluted trees showed up to 50 and 55.6 per cent reduction in growth and fruit yield, respectively. Moreover, the length and width of the fruits of the polluted trees were, respectively, some 15 and 20 per cent shorter.

As regards herbaceous plants, there were only 6 species growing in the polluted area and these were practically confined to the soil under the trees whereas there were 26 species growing virtually at random in the non-polluted area. The soil of the polluted area had a lower moisture-content, less organic matter, a lower water-holding capacity, and a markedly reduced content of calcium carbonate, than that of the non-polluted area, which, however, had a somewhat lower content of other salts.

The marked reduction in the growth and yield of Olive trees in the polluted area may be explained in terms of the shading effect of the foliar cement crust as well as through the changes in soil characteristics that had been brought about by the cement factory effluents. Thus the uncontrolled emissions of a cement kiln can affect the growth of the adjacent vegetation through both the air and the soil.

Current trends in the utilization of wildlife in China continue a tradition of satisfying material needs for meat, apparel, and medicinal and other products. Wild animals have been hunted to bolster income from agriculture and to supply the industrial sector of the economy with material goods. Decisions about conserving or protecting animals are therefore based largely upon utilitarian premises. If they decrease agricultural productivity or are harmful to humans, predatory animals are heavily persecuted.

Chinese biologists have followed initiatives, begun in the Soviet Union, of introducing alien animals to areas where they can multiply and be cropped for commercial purposes. Research also continues to be focused on the possible relocation of faunal elements within China, to develop the market for meat and skins.

However, there appears to be a growing concern for preserving certain rare, unusual, and threatened, species because they are unique to China or have beneficial or symbolic value. This concern is likely to increase as studies in animal behaviour, migration, and ecology, demonstrate that significant declines have occurred in the populations of many ‘useful’ birds and mammals.

Investigations conducted along the west coast of Florida from Tampa to Cape Sable have shown that mangroves are confined to the upper portion of the intertidal zone by the wood-boring isopod, Sphaeroma terebrans Bate. As a result of this activity, mangroves are unable to become established throughout the intertidal zone and to extend shorelines in their usual manner.

The attack on mangroves is most severe from Marco to Cape Sable, and is probably the single most important factor responsible for the erosion that is currently occurring along this section of coastline. Throughout its length, tides, temperature, and salinity, appear to influence the severity of the attack on mangroves by S. terebrans.

Mangrove-dominated estuaries from Tampa to Cape Sable serve as nursery areas and feeding grounds for several commercially important marine fishes and Crustacea. The continual loss of mangroves as a result of S. terebrans activity, erosion, and human interference, may well decrease the extent to which these vital estuaries can be used as nurseries by commercially important species.

Sixteen species of butterflies occur in a small suburban garden in Leicester, England. During a five-years' survey, 9,000 individuals were caught, marked, and released, and it is suggested that this astonishing total is evidence that English gardens support a vast and highly mobile community of butterflies.

The contrived vegetational diversity of gardens provides an excellent environment for adult butterflies, but apart from Pieris rapae and Pieris brassicae, rather few seem to breed in gardens. One attractive species, Anthocharis cardamines, may have recently become adapted to breeding on Arabis albida, a common plant in rock-gardens. Suggestions are offered as to how gardens can be made attractive for butterflies.

Dredging operations are often needed for the improvement of a channel and/or harbour area. Unavoidably the water resources close to the dredging site will be contaminated to some degree. This paper initially presents the main feature and operation methods of new-work dredging and of maintenance dredging. The former comprises the improvement (i.e. deepening or widening) of a channel and/or harbour area mainly by removing stones and compacted sediments which were deposited through geologic ages. The latter is employed mainly to remove the loose sediments which tend to fill up previously excavated channels and harbours. The clamshell dredge, the dipper dredge, the pipeline dredge, and the hopper dredge, are four common types of dredges that are used for river and harbour excavation by the U.S. Army Corps of Engineers. Their functions, operations, and cost data, are indicated.

In general only the sediments excavated from maintenance dredging operations are polluted with obnoxious or toxic contaminants that are detrimental to the land, air, and water, environment. The sources of pollution that are associated with the channel and harbour sediments may be categorized as being from municipal and industrial discharge, storm-runoff, agricultural runoff, soil erosion, and accidental spills.

Typical dredged materials from Ashtabula and Fairport Harbors in Ohio were collected and analyzed for investigation. It was found that the sediments varied widely, in their physical and chemical characteristics, between harbours and even at different locations within each harbour. Nevertheless, the pollutants in the dredged materials of a specific harbour (or channel) can be generally characterized. Settleability of the dredging samples was investigated in detail. It was observed that oil and grease and heavy-metals were intimately associated with sediments and could be removed with settlement of solids.

The current dredging practices in the U.S.A. includes the disposal of dredged materials in open sea, open lake, along-shore diked areas, off-shore diked areas, abandoned strip-mine areas, and other disposal sites. Due to the excellent settleability of the dredged materials, it is desirable that the polluted dredgings be stored on a disposal site for some time prior to any treatment. A disposal area can be used to create new land if satisfactory fill is produced. The satisfactory fill can be the non-polluted dredged materials from the new-work dredging operations, or well-treated sediments from maintenance dredging operations. The treated sediments or particles should be free from oil and grease, from toxic heavy-metals, and from any substances which are putrescent, deleterious, or odorous. They should not cause any organic decomposition or ground-water contamination.

The dredged materials can be separated into the sediment and the supernatant water (i.e., spoil) by settling. From the dredging-settling data presented in this paper, it appears that sufficient settling of dredging in a diked disposal area, followed by discharge of supernatant to Great Lakes water, will not contravene the proposed Great Lakes Water Standards, and so the goal of water resources conservation could be achieved.