Roles or expressions of attitude which scientists should play or display in achieving a better environment for Man and Nature need to include (1) a positive and optimistic viewpoint, (2) a proper perspective in time-dimensions, (3) identification of major developments that have profoundly influenced our view of ourselves as humans, (4) development of a rational conceptual framework within which to arrange the activities required to influence the human environment (involving the four basic processes of energy provision, materials-cycling, life-cycling, and information leading to decision-making), (5) relating of these four basic processes to linking Man far more propitiously than latterly to his environment, (6) effective interaction among disciplines and concomitant advising of decision-makers, (7) developing sophisticated insight into the array of societal issues that confront mankind, and (8) tackling the set of environmental hazards that are particularly critical in developing countries.

The paper ends with an appeal to all ‘to reaffirm a robust faith in the destiny of Man.’

The exclusion of fire from the low-elevation foothills of the southern Sierra Nevada of California over the past century has resulted in large expanses of over-mature, senescent chaparral. The fuel buildup associated with this situation poses a threat, in that any fire which gets started has the potential of becoming a major holocaust.

A detailed analysis is made of the vegetational succession following fire in four different-aged stands of Chamise chaparral in the southern Sierra Nevada. Progression from a diverse multi-species herb and shrub community towards a dense, structurally uniform, low-diversity stand dominated by a single woody species, Adenostoma fasciculatum (Chamise), is demonstrated. An increase in shrub cover and height along with the amount of dead material found laddered through the canopy, create optimal conditions for combustion within some 35 years following the last fire. The herbaceous vegetation shows a high diversity and cover in the first few years after burning, but rapidly decreases thereafter. Evidence is presented that frequent fires are required to maintain the chaparral community in a vigorous and healthy state. The need to institute progressive fuel-management programmes which recognize the natural role of fire in the evolution of the chaparral type wherever it is found, is discussed and advocated. Attempts are also made to relate these findings to the preservation of other fire-adapted vegetation types of the world.

Certain areas of the Piceance Creek Basin are important, not only for their beauty and other amenities but also for their unusual ecosystems. Stoecker (1974) has suggested maintaining one of the larger boxcanyons in the southern portion as a nature reserve. Knutson & Boardman (1973) have suggested preserving a ‘green belt’ to involve the magnificient bluffs adjacent to the Colorado River. Preservation of the Cathedral Bluffs running north and south in the western portion has also been suggested. It is clear that a movement is growing to provide a system of natural areas throughout the Basin. Such a system would maintain important examples of representative vegetation types, wildlife habitat, geological and archaeological features, and other areas of particular ecological interest. This preserve system would maintain natural (or semi-natural) areas both as ecological baselines and as nuclei for obtaining biological ‘seed’ for rehabilitation of disturbed areas. A study to delineate suitable areas that could be included in such a system is surely needed.

Man is viewing vast resources in the Piceance Creek Basin, which probably has the world's largest known hydrocarbon deposit, and his use thereof seems inevitable. The magnitude of the deposit certainly demands a major planning effort. One can even speculate into the future, as Knutson & Boardman (1973) have done, to visualize a concerted or systems approach to obtaining and processing this resource.

Nevertheless, until commercial activity begins and monitoring procures actual data, predictions will remain speculative. Operation of a few commercial plants, mines, and rehabilitation activities, is needed in order that precise predictions can be made for better delineation and quantification of the environmental impacts of a major shale-oil industry.

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.

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.

After repotting the present situation of marine parks and reserves in the Mediterranean Sea and along the Italian coasts, the author lists and comments on the proposals for the establishment of further marine parks and reserves in Italy. The major bureaucratic and other obstacles to the establishment of these areas are discussed.

Scientists, conservationists, and some formerly indifferent people, are pressing hard for the institution of such marine parks and reserves, and even though the areas may cover only a tiny fraction of the Mediterranean Sea, their establishment in the face of steadily increasing human populations may set a good example for others; the adoption of anti-pollution measures by a few factories in the areas concerned suggests that this campaign may be having some effect already.