In the United States, the numbers of humans living on floodplains seem recently to have increased, and so probably have the annual costs of flood damage. This is despite expenditures of many millions of dollars on flood-control devices in the United States alone.

The means which we use to control or contain excessive water-energy are the dam, channel, levee, sea-wall, and floodplain management. Logic and evidence, although incomplete, seem to argue against employing only structures; indeed there now seems good reason to think that structures should rarely be employed for flood-control. The case against relying solely on a structural strategy to abate floods rests on four main arguments: it is often counter-productive in that it encourages human occupation of the floodplain, thus introducing the elements of future disaster that may be more serious than if nothing had been done; it causes severe and unnecessary losses of resources; it discourages the economic use of land; and it is not cost-effective.

Floodplain management, keeping the floodplain generally free from flood-control structures, is the only method which is effective in the long run. If it is planned adequately, its life is not as dependent on maintenance and upstream activity as are the structural alternatives. Moreover floodplains, when left undeveloped, are ideal and highly productive for a wide range of conservation and allied uses—including farming, parklands, open spaces, and habitats for wildlife.

The general situation concerning the contribution that industrial development has made to the conservation of wildlife in Britain is reviewed. Two major types of site have been identified, namely discrete and linear, each being divided into a number of categories, with further subdivisions depending upon the nature of the site: for example, used or disused (canals, railways, etc.) or wet or dry (gravel pits, clay pits, etc.).

The wildlife value of a representative sample of sites of each type is described qualitatively. It is argued that industrial development produces areas which are often richer in wildlife than much of the remaining rural or urban environment. This results from the existence of ‘wilderness areas’ within industrial complexes, from the creation of new habitats, from the passage of time, and from the protection given against public access and against intensive agricultural, forestry, and landscape, management. The linear systems are seen as forming a network of ‘wildlife corridors’ linking together discrete sites, thus providing reservoirs for the colonization of new habitats and enabling wildlife to survive in close proximity to intensively used urban and rural land. Many ‘industrial sites’ provide facilities for field studies, environmental trails, and environmental education, as well as forming the basis of country or linear parks. They also enable many rare species to survive, and probably prevent many of the common species from becoming less frequent.

Although they were widely distributed during Cainozoic times, both the Sierra Redwood (Sequoiadendron giganteum) and the Coast Redwood (Sequoia sempervirens) became restricted to greatly reduced ranges in California (and, in the latter instance, southernmost Oregon) during the late Tertiary and Quaternary periods. Today, the Sierra Redwood occurs in about 70 scattered groves, occupying an aggregate of 144 km2 on the west slope of the Sierra Nevada; about 66% of the areas of these groves remain unlogged, and most of these virgin stands are protected within national parks.

Fire suppression policies of the National Park Service and other government land agencies have created conditions that are both unsuited for Sierra Redwood reproduction and hazardous to existing trees. Successful seed germination requires a mineral seed-bed, such as is usually exposed through fire. Burned sites also enhance seedling survival through increased sunlight penetration, reduced competition, and improved soil-moisture content. Fire suppression has, however, allowed the accumulation of large volumes of combustible fuels, increasing the probability of destructive crown-fires. In order to rectify these problems, the National Park Service has begun a programme of prescribed burning in Sequoia–Kings Canyon National Parks; to date, about 3.4 km2 have been treated. Thus, the environmental issues facing the Sierra Redwood involve perpetuating the tree within parks that are secure from commercial utilization.

Black-fly (Simulium spp.) occurs practically through out the world. It poses biting problems wherever it is found. In Africa, black-fly carries a human disease called Onchocerciasis or river blindness. The World Health Organization has decided on a £50 million project, spreading over 20 years, to control this disease. They propose to apply, very extensively and protractedly, larvicides which are non-selective, reasonably persistent, and only mildly toxic to Man and other higher animals but fatally toxic to Simulium larvae (the target) and some other forms of aquatic life (non-target). This will result in the reduction of the already small quantities of fish available to the people. It will also put at risk the lives of the animals that constitute the major source of the scanty protein supply of the local populace, and hence conceivably jeopardize their own lives.

The decision to go ahead with the project was based on the grounds that chemical control of Simulium breeding is the only sure method of dealing with Onchocerciasis, and that the areas of West Africa to be affected are among the least developed. But foreseeable consequences of the project alone are considered serious enough to justify its reconsideration, while quite likely consequences are powerful enough in themselves to make such as review seem necessary.

Until such a time as the world is able to devise a universally acceptable method of controlling black-fly, the current method of treatment preventing Onchocerciasis from causing blindness should be extended to all areas where the disease is present.

The suggestion is made that Man evolved orthograde posture and bipedal locomotion at the fringe of tropical forest rather than in open savanna. The primary adaptive function of bipedal locomotion was for walking and stalking game from the cover of trees, in the absence of undergrowth. Hairlessness was thermally advantageous when Man emerged from the trees, yet would have imposed no great hardship on our hominid ancestors while they were inside the forest, where the climate was constantly warm. Man's primitive skin-colour was probably pale-brown. It is thought that dark skins were later acquired primarily as a protection against ultraviolet radiation in tropical regions, whereas depigmentation occurred as an adaptation that enhanced the synthesis of calciferol in regions of low light-intensity.

Man's so-called ‘racial’ adaptations occurred when his scavenging and hunter-gathering technology was unable to counter natural selection. Recently, however, he has ceased to respond to environmental feed-back. Unless he begins to do so again soon, degradation of the environment may accelerate beyond the point of no return and our species be doomed.

Australian rain-forests range from tropical to temperate types and offer a great variety of habitats for diverse life-forms. Early colonial descriptions of the rain-forests saw them as a source of timber and an indicator of fertile land. In the nineteenth century, rain-forests were cleared rapidly, without the true nature of their ecosystems being understood. However, at the peak of the period of rain-forest logging and clearance, the National Parks concept began to influence Australia, and National Parks were established in New South Wales and Queensland, starting in 1879. Much of the land cleared from rain-forest is now of little agricultural value, but the exploitation of the rain-forest continues. Forestry policies are directed primarily at increased timber production, and many local communities depend on continued access to rain-forest logging areas for their survival.

The debate on the future of Australia's rain-forests has been heightened by the April 1974 Forwood Conference on the development of forestry and wood-based industries. The Conference wisely recommended multiple-use of rain-forests, and the presservation of representative rain-forest sites, as standard forestry policy; but conservation groups are not satisfied that values other than timber production will be given sufficient weight. More thorough consideration of all the factors involved in environmental management is needed for the successful planning of the use of Australia's rain-forest lands.

Recent research has shown that many industrial projects are not being designed with the environment in mind. The intellectual exercise of thinking ‘what impact does this project have on the environment?’ has not yet been made an integral part of industrial project-planning. More thoughtful and informed planning is needed, for reasons of both sound environmental management and, increasingly, sound project economics. An environmentally-oriented mode of planning, in which inputs and means related to environmental concerns are carefully taken into account during the planning, is discussed. This mode represents a tentative summary statement of an emerging consensus. Its objective is to facilitate informed and socially desirable choice among alternative actions in such a manner that adverse environmental consequences will be avoided or at least minimized.

Environmentally-oriented planning requires that a new methodology, that of impact assessment, be fully integrated into the very fabric of planning. Impact assessment consists of three analytical functions: description, prediction, and evaluation. These functions can be translated into a series of tasks, which in their entirety constitute the full process of impact assessment. The process can be achieved operationally by incorporating environmental considerations into planning via five dimensions: multidisciplinary professional involvement, broad public participation, holistic thinking, systematic analysis, and continuous integration. Adoption and application of the process can be encouraged and/or facilitated by a number of internal organizational adjustments, or by external public-policy adjustments.

The genus Sequoia has existed since Mesozoic times, and early Tertiary Redwoods occurred practically throughout the northern hemisphere. Today, the Coast Redwood (Sequoia sempervirens) is the only living species of the genus, and it is restricted to the coastal environments of California and the southern extremity of Oregon. Climatic factors determine the outer limits of Redwood distribution, while edaphic, biotic, and hydrologic, variables influence the occurrence of Redwood within the climatic range.

Human use of Redwood forests has altered the environmental conditions under which the Sequoia now grows. Logging has exposed the forest floor to increased light and higher temperatures, while in some places it has exposed the soil to accelerated erosion. Recent floods in the major watersheds of north-western California have been particularly disastrous in undercutting large trees along the river banks. Increased degradation rates on upper slopes have resulted in delivery of coarse sediments to floodplains, with possibly deleterious effects on living old-growth Redwoods.

Although nature conservation may appear to be ‘wasteful’ to many people, it can only be truly described as such if one's sole purpose is mere survival for a short period of years. Longer time-horizons or other purposes require at least some level of nature conservation. The exact amount, in terms of land set aside mainly for this purpose, is difficult to determine precisely, but some general indications are given. Taking the world as a whole, it is concluded that something in the order of 20 per cent of each country should be devoted mainly to nature conservation (with countries having less than this amount contributing to the maintenance of reserves in countries with more than 20 per cent), if nature conservation is to be placed on an equal footing with alternative intensive forms of land-use.