The nature of the present (pseudo) and coming (real) energy crises have been indicated. Recent evidence suggests that pollutive dangers from nuclear fission plants are far greater than had been thought. The resuscitation on a large scale of coal as an energy source would give pollutive dangers, including climatic changes due to excess carbon dioxide.

Solar energy systems, earlier impossibly expensive, are now predicted to have the same capital cost-range as have nuclear reactors. Cheap, high-purity silicon coatings which adsorb at <10–4 cm but do not emit at >10–4 cm, thin-film photovoltaics, thermoelectrics, and photosynthesis, are areas of immediate solar energy research interest.

Roof-top energy collection may be a permanent part of the future, but will not avoid the necessity of large ‘solar farms’ to collect energy for industry and transportation. Storage should be in the form of hydrogen: there are advantages in developing cheap hydrogen as a general and clean fuel, for transportation and other purposes.

The physics problems remaining to be solved to achieve practical fusion power by magnetic confinement techniques are believed to be well posed and soluble. A programme plan recently developed in the United States calls for progressively larger plasma confinement experiments to address these physics questions in line with a serious programme in fusion power engineering. Implementation of the plan is expected to lead to the first production of power from a deuterium–tritium-fuelled system in 1980. Thereafter, three progressively larger experimental electrical power reactors are planned, leading to fusion power commercialization in the later 1990s.

The environmental characteristics of fusion reactors have been estimated by analyzing conceptual reactor designs. It is projected that the only volatile radioactive material in a fusion power-plant will be the tritium fuel. Analyses indicate that tritium leakage can be held to very low levels and accordingly should not pose a significant environmental hazard.

Careful selection of the materials of construction of a fusion reactor core will minimize radioactivity induced by neutron activation. This activity will be nonvolatile, and it can be isolated from the environment by the use of existing techniques. Because this induced activity is short-lived, it does not represent a long-term storage problem.

Anticipated thermal efficiencies of fusion powerplants range from present-day levels (30–40%) using standard conversion systems to about 50% when more exotic techniques (such as liquid-metal topping cycles) are utilized.

Northern Africa is rather poor in national parks and nature reserves in comparison with equatorial and southern Africa. The remaining populations of nomadic ungulates in the Saharan region are difficult to protect within the boundaries of national parks, if only because they are nomadic and move over great areas in an irregular pattern owing basically to the erratic rainfall. It ought, however, to be a conservation priority for many countries of northern Africa to make an effort to conserve desert and subdesert antelopes of various species before it is too late, because these animals are so productive and thrive in areas with meagre vegetation and no surface water for long periods. They are an excellent renewable resource of the deserts!

In northern Africa only a fraction of the former herds of wild ungulates still survive in declining numbers, whereas in southern Africa a semi-desert country such as Botswana still harbours important herds of many herbivorous species. But also in Botswana their numbers are declining drastically in comparison with the situation only about fifteen years ago, though, fortunately, several large reserves have been established in that country during recent years. This is also the case in most other countries of southern Africa.

Madagascar and the Mascarene Islands also share similar conservation problems with continental Africa, but in these areas with a high proportion of endemic plants and animals the human overexploitation tends to have more serious and immediate effects on the biota than is the case on the African mainland.

The present conservation needs of Africa include more national parks and other protected areas. These are of fundamental importance for environmental conservation, being in effect in many regions the only major areas where the environment of today and even of the past may be preserved.

The deterioration of the physical environment in many metropolitan areas is a fact of modern life. In the United States the traditional alignment of power and institutions have proved to be ineffective in coping with environmental problems. Obvious as is this disparity between the nature of regional environmental management problems and the administrative machinery established to remedy it, too little serious effort has been made so far to do better.

The six experiments described here represent an effort to expand the environmental data-base, to improve the capacity of elected officials and their civil servants to anticipate better the consequences of a variety of environmental decisions, and to provide the broadest possible range of contributing citizens—so that environmental decision-making can become truly participatory. All of the regions involved have so far enjoyed more success technically than in the matters of transfer of information and improving citizen participation.

Since the passing of the Mineral Workings Act 1951 there have been (1) changing pursuits in agriculture and improved methods of restoration, (2) continually rising costs of machinery and labour, and (3) nationalization of the steel industry.

Recently, a new Act was passed, namely the Mineral Workings Act 1971, to make further provision in relation to contributions to and payments out of the Ironstone Restoration Fund, and to abolish the Advisory Committee on Ironstone Restoration. This Act necessited new regulations as follows:

Statutory Instrument 1972 No. 210:

‘This Order prescribes the full and reduced rates of contributions to be paid by ironstone operators towards the Ironstone Restoration Fund under section 1 of the Mineral Workings Act 1971, in respect of ironstone extracted on or after 1 April 1971 and the sum which may be deducted from payments made under mining leases and mineral rights orders (in accordance with section 3 of that Act) in respect of full-rate contributions.’

Statutory Instrument 1972 No. 211:

‘Section 9 of the Mineral Workings Act 1951 provides that the rate of payments out of the Ironstone Restoration Fund to be made to ironstone operators in respect of the restoration of worked ironstone land in compliance with conditions of a planning permission shall represent the amount by which the estimated cost per acre of the work of restoration exceeds such sum per acre as the Minister may determine to be the standard rate. The Ironstone Restoration Fund (Standard Rate) Order 1955 determined that rate to be £110 per acre.

This Order made under section 3 of the Mineral Workings Act 1971 prescribes a new rate of £260 per acre in respect of all work completed after 31 March 1972.’

Seed germination and dry-weight production in Lolium perenne were examined in relation to growth on 12-years-old colliery waste separated into seven size-fractions. The size-range was from more than 4,000 μ to less than 125 μ, and the growth period was up to 30 days. Germination percentages after 6 days generally increased with decreasing particle-size, as did dry-weight. Shoot : root ratios also showed an inverse relationship with particle size.

After 30 days there was no distinction between dryweights on different particle sizes, except that on the largest fractions it had been found impossible to keep the plants alive. Problems of water-holding capacity are discussed, and the significance of soil particle-size in revegetation work is examined, it being concluded that an admixture of small particles is important for water retention and plant growth.

Covering broad areas of tropical shorelines are unique plants known as mangroves, which exhibit several structural and physiological modifications to the saline environment—especially in their root systems. Prop-roots and pneumatophores, two obvious modifications, allow mangroves to play a role in coastal geomorphology, either as land-builders or as stabilizers of substrates derived from classical sedimentation processes.

Current data show that: (1) Provided with proper substrates, mangrove seedlings can be raised in the laboratory for later planting in the field, although on exposed beaches success ratios may be low. (2) Larger mangrove plants (1.0–5.0 m in height) may be transplanted with relative ease and appear to succeed with few or no mortalities resulting from the techniques used. (3) Pruning of mangroves appears to be a successful method of mangrove control, allowing their utilization for stabilization around housing developments. (4) Fossil evidence for mangroves as shoreline developers is suggested by the discovery of a fossil mangrove reef off the Miami, Florida, coast. However, submergence of near-by mangrove areas has occurred, as evidenced by sea-grass beds growing above buried peat in the bay bottom. (5) Black Mangroves may be more useful than Red Mangroves as shoreline stabilizers due to their cold-hardiness, ability to tolerate disturbed substrates, and rapid production of pneumatophores. (6) Insect and isopod damage to mangroves has been documented, and it has been suggested by several research workers that such damage may lead to increased erosion of coastlines in many areas of southern and central Florida. In addition, boring activities in Red Mangrove seedlings may result in decreased numbers of seedlings being available for new mangrove growth and colonization. (7) Mangroves have been suggested for use as stabilizers of substrates in conjunction with planned filling and sea wall construction.

The movement of surface currents and the availability of coral prey are probably not responsible for the discontinuities in the distribution of Acanthaster (the Crown-of-thorns Starfish or Sea-star) in American waters. Temperature and salinity conditions are critical in development, and it is possible that these parameters are effective locally, for example in the Gulf of Panamá. There is a strong possibility that continuing field work will show that Acanthaster has a significantly more widespread distribution in the eastern Pacific than is currently known.

Adult Acanthaster and several species of coral prey exhibited an unusually high tolerance to varying conditions of temperature and salinity. The possibility of step-wise colonization to new areas, mediated by resistant adult populations that can become established during favourable seasons, should be considered in any plans to alter the existing freshwater canal in Panamá. For introductions can be environmentally dangerous.

The highest population densities of Acanthaster so far observed in the eastern Pacific, 1 individual/40 m2 to approximately 1 individual/100 m2, are comparable to population sizes in the Indo-Pacific region that are not considered to have a serious impact on coral communities. Coral destruction by Acanthaster can be significant in certain limited areas, but is usually less than that caused by other corallivores.

An analysis of coral community structure in relation to Acanthaster density failed to show a significant correlation with (a) number of species, (b) number of live coral colonies, (c) species diversity (H'), or (d) species evenness (J').

Prey preference data indicate that Acanthaster selectively destroys rare corals. Replacement of rare, predated corals by fast-growing species (Pocillopora spp.) has been observed in the field, showing that Acanthaster could have a negative effect on species diversity.

Much of the published research on the effects of air pollutants on plants suffers from a lack of understanding of the relationship between the conditions employed and naturally occurring concentrations of pollutant. Frequently lacking is information as to the effective dosages of pollutants used in laboratory studies. The importance of dosage is discussed, as is its relation to concentration and flux. It is suggested that a greater interrelationship between observations from different research workers would be achieved by the simple expedient of measuring pollutant uptake by the plants under study, rather than merely describing concentrations in the surrounding air.